EP0236392B1 - Process for adjusting the width of the gap in a cone-type crusher or similar - Google Patents

Abstract

PCT No. PCT/EP86/00519 Sec. 371 Date May 11, 1987 Sec. 102(e) Date May 11, 1987 PCT Filed Sep. 9, 1986 PCT Pub. No. WO87/01305 PCT Pub. Date Mar. 12, 1987.A method and apparatus for adjusting the gap width between a rotatable crusher cone and a crusher housing includes determining a reference position of the crusher cone relative to the crusher housing, storing a first quantity representative of the reference position, rotating the crusher cone, moving the crusher cone to the reference position, moving the crusher cone from the reference position toward the crusher housing until a limit is reached and measuring the distance of the crusher cone from the reference position, storing a second quantity representative of the distance, repeating the preceding three steps a plurality of times while separately storing each of the second quantities, obtaining a new reference position based on each of the second quantities, and determining an operating position of the cone crusher based on the new reference position. The apparatus includes a control device, a memory, a position detecting device for detecting the position of the crusher cone, and an apparatus for detecting whether the crusher cone is moving.

Description

The invention relates to a method for adjusting the gap width of a cone crusher or the like with a wobbling revolving cone which is height-adjustable with respect to a crushing jacket and which is moved into a reference position by approaching the crushing jacket, from which the path section corresponding to a predetermined gap width is determined, by which the After moving into its working position, the crushing cone is located away from the reference position, the approach to the crushing jacket being detected by means of a movement measurement and the respective position of the crushing cone being determined by means of a distance measurement.

The gap width, i.e. H. The width of the crushing gap between the stationary crushing jacket and the crushing cone, which is located concentrically in the interior of this crushing jacket and is tumbling during operation, is of decisive importance for the crushing effect and performance of a cone crusher or a similar type of crusher: With a smaller crushing gap, the crushing material is crushed more finely than with a larger crushing gap.

As a result of the wear on the crushing cone and crushing jacket occurring during operation, the width of the crushing gap changes, with the result that the crushed product gradually has an increasingly coarse grain. This undesirable development must be taken into account by the gap width being reset to a predetermined value at least from time to time.

The inclination of the axis of the crushing cone has the result that it has a minimum and a large rod spacing with corresponding transition regions from the stationary crushing jacket; the point that forms the small rod distance is the width of the crushing gap.

In a known generic method - described in British Patent 1,080,085 - the gap width when the crushing cone is at a standstill is adjusted via a movement measurement in the form of a pressure measurement and via a path measurement in such a way that the crushing cone is first approximated to and starts at the crushing jacket the reference position thus obtained causes a displacement of the crushing cone corresponding to the predetermined gap width away from the crushing jacket. Reaching the reference position is determined by a pressure sensor, which is installed in the circuit of the hydraulic displacement drive for the crushing cone; the distance covered in the working position during the opening movement is determined by measuring a volume of liquid displaced with the opening movement. The width of the crushing gap and the extent of wear can be determined using an inductive displacement measurement; this is carried out by means of a measuring piston engaging more or less far into a coil. The known method can also be carried out automatically according to a predetermined program, either after each shutdown of the crushing cone or less frequently.

A method for detecting and regulating the gap width of a cone crusher by electrical means is also known, for example, from German Offenlegungsschrift 20 51 398.

The invention is based on the object of specifying a method (and the components required for its implementation) by means of which the accuracy in setting the width of the crushing gap is improved. The method should in particular be such that, if possible, different signs of wear on the crushing cone and / or crushing jacket are also taken into account when setting the gap.

The stated object is achieved by a method which has the features of claim 1. The concept of the solution on which the invention is based consists in executing several approximation cycles (consisting each of the converging cone approaching the crushing jacket and subsequent opening movement away from the crushing jacket) and using the approximate values obtained in each approach cycle to form a reference value defining the reference position , from which the position of the crushing cone is determined, which this should take into consideration the desired gap width in the working position.

The approximation processes taking place within the framework of the approximation cycles can either be carried out in such a way that the revolving crushing cone comes into contact with the crushing jacket for a short time only, or is kept briefly (in particular via a layer of test material; see claim 9) at a small, reproducible distance from the crushing jacket ; The determination of the reference position can therefore be based on the fact that either a brief contact (when the "zero gap width" is reached) or near contact (when the "almost NUL4 gap width" is reached) is brought about between the crushing cone and the crushing jacket. “Motion measurement” in the sense of the method according to the invention (cf. the preamble of claim 1) is to be understood as a measuring or scanning method or the like which reveals whether the crushing cone has completed its approaching process within the specified number of approaching cycles has come to a standstill (if there is no fault) on the crushing jacket or in the vicinity of the crushing jacket. The process-relevant variables are recorded and the associated components (drives, valves) are expediently carried out via a control unit in which a computer equipped with sufficient storage capacity is integrated.

The completion of the approach of the crushing cone directly to the crushing jacket or indirectly to this via a test material layer can - in particular by induction - via a speed measurement (claim 2) and / or via a pressure measurement (claim 3) for example in the pressure network of a hydraulic displacement drive for the crushing cone - are recorded; the respective position of the crushing cone with respect to the stationary crushing jacket can be determined, for example, using the known displacement measuring methods mentioned at the beginning.

The method is preferably designed in such a way that an average value is formed from the associated approximate values, which represents the reference value (claim 4); the reference value can in particular be calculated from the arithmetic or the quadratic mean of the associated approximate values.

However, the method according to the invention can also be carried out in such a way that a certain approximation value is selected from the related approximation values as a reference value, specifically the one that indicates the greatest displacement of the crushing cone in the direction of the crushing jacket determined within the framework of the approximation cycles ).

In an advantageous embodiment of the method, the crushing cone is moved into a predetermined opening position, which deviates from the reference position (claim 6), at least after the completion of each approach cycle - possibly also before the first approach cycle; The advantage of this approach is that each approximation cycle - i.e. H. the approach of the crushing cone to the crushing jacket and the subsequent return to the specified opening position - takes place under similar conditions.

In addition, if necessary, the distance between the open position and the reference position can be kept constant (claim 7); This can be done, for example, by adapting the position of the open position to the change determined after determining the reference position. If you save the changing values for the position of the opening position or the reference position and make them recognizable in the form of a curve, the development of wear in the associated time period (to which the individual positions can be assigned) can be read off and also a reference point for the win future wear development. In this context, the method can be designed in a favorable manner by comparing the stored opening position values or reference position values with a predetermined limit value; Reaching this limit value serves, for example, as a visual or acoustic indication that the wear parts of the cone crusher (crushing jacket, crushing cone) have to be replaced.

For a number of applications, it is sufficient to manually check and adjust the gap width after the cone crusher has been emptied at an appropriate time. The setting process runs in such a way that the supply of the crushing material to the cone crusher is first interrupted before the approximation cycles for determining the reference position in question run automatically with a sufficient time delay. Preferably, the approach cycles and the subsequent shifting of the crushing cone into the operating position are triggered automatically at preselectable time intervals, the first approach cycle being delayed in order to interrupt the supply of crushing material (claim 8).

The aforementioned storage of the reference positions or of the opening positions respectively adapted to them is also advantageous in that erroneous measurements can be found by comparison with the stored position values (for example caused by foreign bodies) and suppressed as unusable. If the approach processes always start from a constant, known opening position, it can also be checked on the basis of time measurements running in parallel whether the crushing cone has traveled at least a previously known distance to a standstill.

The determination of the reference position can also take place in such a way that the crushing cone is only moved into the vicinity of the crushing jacket in the course of the approximation cycles. The individual approximation processes come to an end as soon as the rotating crushing cone is supported on the crushing jacket by a layer of test material with known grain size - that is, only indirectly. The layer involved in the formation of the reference position can be produced by introducing a sufficient amount of test material into the crushing gap instead of the crushing material, at least during the approach processes (claim 9). The process variant in question is advantageous in that the determination of the reference position takes place without contact between the rotating crushing cone and the stationary crushing jacket.

The invention is explained in detail below with reference to the drawing, in which a cone crusher with process-essential components is shown in a highly schematic manner.

The housing of the cone crusher 1, to which the method according to the invention is used, is composed of an upper housing part 2a with a feed opening 2b and an outlet opening 2c, a subsequent, only partially illustrated middle housing part 2d and a lower housing part 2e with an axial bearing pointing upwards 2f.

A crushing cone 3 is rotatable and height-adjustable within the housing, the exchangeable crushing jacket 3a of which forms a crushing gap 5 with a frustoconical crushing jacket 4 which is exchangeably fastened to the upper housing part 2a. The crushing cone 3 is immovably supported on a shaft 7 by means of a fastening ring 6, which in turn is supported by a self-aligning bearing 8 on the upper housing part 2a, a radial bearing 9 in the form of a rotating drive housing on the central housing part 2d and its downwardly directed end face 7a on the height-adjustable piston 10a of a stationary hydraulic cylinder 1 0. The drive housing 9 equipped with a ring gear rests on the axial bearing 2f and is connected to the pinion 12a of a three-phase motor 12 via a drive element in the form of a toothed belt 11.

Due to the eccentric support of the shaft 7 in the drive housing 9, the crushing cone 3 performs a wobble movement within the crushing jacket 4 when the three-phase motor 12 is in operation, the narrowest point between the parts 3a and 4-the crushing gap 5-with respect to the crushing jacket 4.

A feed unit 13, which consists of a hopper 13a, a screw conveyor 13c driven by a feed motor 13b and a feed trough 13d opening into the feed opening 2b, is arranged in front of the feed opening 2b. The conveyor motor 13b is connected via a control line 14 to a control unit 15, in which a computer 15a with sufficient storage capacity is integrated and which has a time control unit 15b for monitoring and controlling procedural steps in terms of time.

The energy network for the hydraulic cylinder 10 consists of a motor-driven hydraulic pump 16, two remote-controlled valves 17 and 18, which are installed in the pressure line 19 and return line 20 of the hydraulic cylinder 10, and an oil tank 21, in which the lines 19 and 20 and the Open return line 17a of valve 17. A pressure sensor 22 is connected upstream of the valve 17 in the direction of the hydraulic cylinder 10 and is connected to the control unit 15 via a measuring line 23. Components 16 to 18 are also connected to control unit 15 via control lines 24, 25 and 26, respectively.

The respective position of the crushing cone 3 with respect to the stationary environment is recorded by means of a displacement measuring unit, which consists of a measuring part 27a attached to the shaft 7 and a stationary displacement measuring sensor 27b which is connected to the control unit 15 via a measuring line 28.

In order to be able to draw conclusions on the operating state of the cone crusher 1 from the power consumption of the three-phase motor 12, a current measuring device 29 is assigned to the drive mentioned, the measured values of which can be entered into the control device 15 via a measuring line 30 and processed there.

Certain data stored in the computer 15a can, if necessary, be made visible by means of a screen 31 connected to the control unit 15. In order to be able to initiate the checking and setting of the width of the crushing gap by hand, the control device has a manual switch 32.

The method according to the invention proceeds as follows:

By pressing the hand switch 32, the conveyor motor 13b is first stopped via the control unit 15 and the control line 14 and the supply of crushing material into the area of the feed opening 2b of the cone crusher 1 is interrupted, while the crushing cone 3 continues to wobble and crushes the crushing material still present. The measured value corresponding to the working position of the crushing cone 3 and detected by the displacement sensor 27b has already been stored in the memory 15a during the previous setting of the crushing cone in the current working position.

About a delay element, not shown, which forms part of the control device 15, the crushing cone 3 is lowered into a predetermined opening position predetermined by the memory 15a with a predetermined, adjustable time delay for actuating the manual switch 32 by closing the valve 17 and opening the valve 18; the time delay is chosen so that the cone crusher 1 with sufficient certainty in the area of the components 3 and 4 no longer contains any crushing material, that is to say it is empty.

After reaching the open position, the crushing cone is briefly brought into contact with the crushing jacket 4 by suitable switching of the hydraulic pump 16 and the valves 17 and 18 in several successive approximation cycles and then returned to the predetermined open position. The approximation values corresponding to the system on the crushing cone 4 are each detected by the displacement sensor 27b and stored in the computer 15a. After the last approximation cycle, which ends with the return of the crushing cone to the above-mentioned opening position, the arithmetic mean value is formed from the determined approximation values, which represents the reference value defining the reference position of the crushing cone and which is also stored. By comparing the reference value and a value entered into the computer and corresponding to the operating position, the distance corresponding to a certain gap width is determined by which the crushing cone must be located from the reference position; the required adjustment movement is in turn - monitored by the displacement sensor 27b - effected by a suitable adjustment of the piston 10a, which is locked in the position assumed after reaching the working position.

The distance measurement corresponding to the working position is also saved.

The approach of the crushing cone to the crushing jacket 4 is determined with the valve 18 closed by the pressure sensor 22, which inputs the pressure increase occurring in the energy network of the hydraulic cylinder 10 via the measuring line 23 into the control unit 15; this then causes the crushing cone to return to the already mentioned opening position by suitable actuation of the valves 17 and 18.

The time control unit 15b can be used to assign the stored values for the reference position and / or the working position to the associated time intervals. In this way it is possible, for example, the stored values for the working position of the crushing cone, plotted over time, on the screen 31 to make it visible and to obtain a statement about the wear that has previously occurred on components 3a and 4.

However, the timing control unit 15b can also be used in cooperation with the displacement measuring parts 27a, 27b to monitor the approaching processes during the approaching cycles. If there is no incorrect measurement, the crushing cone can only touch the crushing jacket 4 when the approximation process has ended, that is to say the distance measurement value detected by the displacement sensor 27b no longer changes with the time specified by the time unit 15b. By means of the interaction of the components 27a, b and 15b, incorrect measurements can thus be excluded if, at the same time, it is checked by comparison with already stored approximate values whether the crushing cone has covered a minimum distance in the direction of the crushing jacket 4.

In a departure from the method just described, the checking and setting of the gap width can also be triggered and carried out automatically under the action of the time unit 15b. For example, the time unit can be set so that it triggers the method according to the invention automatically once a day.

The method according to the invention can in particular also be designed in such a way that, in addition to or instead of the pressure measurement by means of the pressure sensor 23, an inductive measurement method is used, as is known, for example, from the aforementioned German published application. By using a measuring piston, which engages more or less far into a stationary coil depending on a movement of the crushing cone, not only a change in path but also a change in movement can be detected; For example, it can be determined whether the crushing cone has come to a standstill when the crushing jacket has come into contact with it.

The displacement of the crushing cone into a predetermined working position can, however, also be carried out on the basis of a reference position in which the tumbling revolving crushing cone 3 only almost touches the crushing jacket 4.

In order to be able to obtain reproducible approximate values for determining such a reference position with sufficient accuracy, after the cone crusher 1 has been emptied, test material with known grain size is introduced into the feed opening 2b at least during the approach cycles via the conveyor unit 13. The test material forms a layer in the gap area, over which the crushing cone is only supported indirectly on the crushing jacket after the approximation processes have been completed.

This procedure is associated with additional effort; however, it has the advantage that a reference position of the crushing cone 3 can be determined via reference values without the latter having to touch the crushing jacket 4 during the successive approximation cycles.

If the position of the opening position is adapted to the changing reference position and the associated values are saved, a comparison can be made of the stored values with a limit value for the opening position to determine which wear level is present or whether the interacting wear parts 3a and 4 are replaced is required.

The main advantage of the method according to the invention lies in the fact that the reference value, from which a predetermined working position of the crushing cone is controlled, over several. Approach cycles representing tactile processes is determined, specifically with a rotating cone. Since several reference values are determined in chronological succession, non-uniform wear of the two interacting wear parts is also included in the reference value and thus influences the setting of the width of the crushing gap.

Claims (9)

1. A method of adjusting the gap width (5) of a conical crusher or the like, having a crushing cone (3) which rotates with a swashing movement, can be vertically adjusted in relation to a crusher shell (4), and by approach to the crusher shell (4) is moved into a reference position, starting from which that portion of travel corresponding to a given gap width is determined by which the crushing cone (3) is distant from the reference position after being moved into its operating position, the approach to the crusher shell (4) being detected by movement measurement and the particular position of the crushing cone (3) being determined by travel measurement, characterized in that the rotating crushing cone (3) performs a number of approach cycles in a time sequence; the approach vaiues describing the position of the crushing cone on completion of the individual approach operations are stored; and a reference value determining the reference position is formed from the approach values.

2. A method according to claim 1, characterized in that the approach to the crusher shell (4) is detected via speed measurement.

3. A method according to claim 1 or 2, characterized in that the approach to the crusher shell (4) is detected via pressure measurement.

4. A method according to any of claims 1 to 3, characterized in that a mean value representing the reference value is formed from the associated approach values.

5. A method according to any of claims 1 to 3, characterized in that from the associated approach values that value is selected as the reference value which indicates the furthest determined displacement of the crushing cone (3) in the direction of the crusher shell (4).

6. A method according to any of claims 1 to 5, characterized in that at least on completion of each approach cycle the crushing cone (3) is moved into a given opening position which differs from the reference position.

7. A method according to claim 6, characterized in that the distance between the opening position and the reference position is kept constant.

8. A method according to any of claims 1 to 7, characterized in that the approach cycles and the following displacement of the crushing cone (3) into the operational position are automatically triggered at selectable intervals of time, the first approach cycle commencing delayed in time to interrupt the supply (13) of material for crushing.

9. A method according to any of claims 1 to 8, characterized in that the location of the reference position is determined by testing material of known grain size which is introduced into the crushing gap (5) at least during the approach operations.

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