METHOD AND DEVICE FOR PRODUCING MOULD MATERIAL MOULDS FOR THE CASTING OF METALS

Abstract

Methods for improved molds for the casting of metals and to prevent the complexity of the production from increasing are disclosed. Improved may be defined such that a mold consisting of the molding material has a surface of uniform hardness, even in the event of a change or variation in the quality of at least one of a plurality of properties of the molding material.

Claims

1. A method for producing a molding-material mold for a cast having a strength for casting of metals, wherein: a granular molding material as a molding substance (41) is filled into a molding box (40); the molding material (41) is compacted above a pattern (44) standing on a pattern plate (46) within the molding box (40) in a molding system; wherein: in a first step, the molding box (40) is moved across a first distance by a pressing device (1) to stop against a frame (13) of a press head (10); in a second step, the pattern plate (46) is moved across a second distance (s.sub.1, s.sub.2) to an end position by the pressing device (1) for hardening or compacting (creating) the molding-material mold; and wherein the second distance is changed as a function of a determined force at the end of a previous hardening or compacting process of the molding material of a previous mold (100, 102; 102) as a result of a change in at least one property of the non-compacted molding material (41); or a length of the second distance is changed as a function of the molding material.

2. The method according to claim 1, wherein a force applied to the molding material (41) by the pressing device (1) or the press head (10) is determined or measured by a sensor (30) during compaction of the molding material (41).

3. The method according to claim 1, wherein the applied force is determined or measured by the sensor (30) and transmitted to a controller (100), wherein a nominal value or limit values of a nominal range for the applied force are preset in a memory (101) of the controller (100), and wherein the measured value is compared to the nominal value or limit values.

4. The method according to claim 3, wherein a deviation is detected by a comparator provided in the controller (100), and wherein the second distance (s.sub.1, s.sub.2) is changed (s) as a result thereof.

5. The method according to claim 3, wherein a program calculates a correction value from the determined deviation, the correction value is converted into a signal by the controller (100), and the signal is output to an actuator (20) which changes a length of the second distance.

6. The method according to claim 1, wherein the stored value is a predetermined or pre-determinable value.

7. The method according to claim 1, wherein the determined force value is detected by the sensor (30) during compaction of a preceding molding-material mold, especially the molding-material mold created immediately prior to the current compaction and measured subsequently thereto.

8. The method according to claim 1, wherein the comparative value is detected during creation of the previous molding-material mold (90), especially immediately prior to the current compaction.

9. The method according to claim 1, wherein the change in length of distance is determined as a function of the calculated correction value.

10. The method according to claim 3, wherein a correction value is determined from the detected deviation, which correction value is, in particular, proportional to the deviation, and wherein the correction value is converted into a signal by the controller (100), which signal is output to an actuator (20) which changes a length of the second distance; wherein the deviation is one of: a non-achievement of the nominal range, i.e. is outside of the nominal range; a shortfall of the target value of the force as a nominal value; and an exceedance of a target value of the force as nominal value.

11. The method according to claim 1, wherein a detected deviation of a measured (30) or determined force at the end of the current compaction process from a desired force as a representative of strength causes the following control direction: if the measured force is too high, the second distance (s.sub.1, s.sub.2) is decreased; or if the measured force is too low, the second distance (s.sub.1, s.sub.2) is increased; especially proportionally to the previously detected deviation in each case.

12. The method according to claim 1, wherein a time range is spanned at the end of the hardening or compacting process, which ranges from the time of the end of compaction, when the lower edge (40a) of the molding box (40) is reached, to at most the duration of the molding cycle or sampling cycle of the control (T), since no or no noticeable change in mold hardness occurs within this range.

13. The method according to claim 1, wherein a changed force-distance characteristic of the currently compacted molding material (41) is compensated or balanced by the change in distance of the pattern plate (46) from a lower edge of the molding box (40) as compared to the force-distance characteristic of the molding material (41) that was compacted more than one compaction process earlier, even though it is supposed to be the same molding material.

14. The method according to claim 1, wherein the force-distance characteristic of the preceding, i.e. immediately preceding compaction process is used in the change in distance of the pattern plate (46) from a lower edge of the molding box (40) for the force-distance characteristic of the currently compacted molding material (41).

15. A molding system for casting molds for the casting of metals, the system comprising: a linearly movable pressing device for exerting pressure on the mold being created which includes a pattern (44) and a pattern plate (46) carrying this pattern, a molding box (40) for the casting mold and a filling frame (42) for receiving an upper portion of a molding material (41) for the mold; a press head (10) including at least one mold stamp (11); an actuator (20) being coupled to the pressing device or the molding box and including a linear drive that is decoupled from a drive of the pressing device; a force sensor (30, 90) for measuring a force applied to or exerted on the molding material (41) by the pressing device or the press head (10); a controller (100, 102), wherein a distance (s.sub.1) between the pressing device and the molding box can be adjusted by the controller (100) via the actuator (20), when the molding box abuts the press head or a frame of the press head.

16. (canceled)

17. The molding system according to claim 15, wherein the press head (10) comprises a plurality of parallel mold stamps (11).

18. The molding system according to claim 15, wherein the adjustment of the distance (s.sub.1) is carried out before the pattern plate (46) can be moved upwards by the pressing device.

19. The molding system according to claim 15, wherein the force sensor (30) is configured such that it detects a force value during compaction of a preceding molding-material mold, especially the molding-material mold created immediately prior to the current compaction.

20. A method for producing a force-controlled molding-material mold suitable for a cast metal, the molding-material mold having a predetermined or pre-determinable minimum strength at, at least, the surface thereof receiving the cast metal, wherein: a compactible molding material (41) is filled into a box stack including a molding box (40); the molding material (41) is compacted within the box stack above a pattern (44) standing on a pattern plate (46) which initially has a distance (s.sub.1) from a lower edge of the molding box (40), wherein: the box stack, together with the pattern plate, is moved across a first distance by a pressing device (1) for initially compacting the molding material (41); a changed second distance (s.sub.2) is adjusted instead of the first distance as a function of a detected or determined force (F.sub.2) at the end of a compaction process of one of the preceding compaction processes; the pattern plate (46) is moved relative to the molding box (40) across the changed second distance (s.sub.2) to an end position by the pressing device (1) for a second compaction and creation of the molding-material mold.

21. The method according to claim 20, wherein the molding-material mold is a mold half.

22. The method according to claim 20, wherein the second distance (s.sub.2) for the subsequent compaction process is changed as a function of the detected or determined force (F.sub.2) at the end of the compaction process preceding in time.

23. (canceled)

24. The method according to claim 20, wherein the press head (10) comprises a plurality of mold stamps (11).

25. The method according to claim 20, wherein the initial adjustment of the distance (s.sub.1) is carried out before the pattern plate (46) can be moved upwards by the pressing device.

26. A method for producing a molding-material mold for a cast having a minimum strength for the casting of metals, wherein: a granular molding material as a molding substance (41) is filled into a molding box (40); the molding material (41) is compacted above a pattern (44) standing on a pattern plate (46) within the molding box (40) in a molding system; wherein: in a first step, the molding box (40) is moved across a first distance by a pressing device (1) to stop against a frame (13) of a press head (10); in a second step, the pattern plate (46) is moved relative to the molding box (40) across a second distance (s.sub.1, s.sub.2) to an end position by the pressing device (1) for hardening or compacting (creating) the molding-material mold; and wherein the second distance (s.sub.1, s.sub.2) is changed as a function of a determined force at the end of a previous hardening or compacting process of the molding material of a previous mold (100, 102; 102) as a result of a change in at least one property of the non-compacted molding material (41).

27. The method according to claim 1, wherein a force applied to the molding material (41) by the pressing device (1) or the press head (10) is determined by a sensor (30) during compaction of the molding material (41).

28. The method according to claim 27, wherein the applied force is determined or measured by the sensor (30) and transmitted to a controller (100), wherein a nominal value or limit values of a nominal range for the applied force are preset in a memory (101) of the controller (100), and wherein the measured value is compared to the nominal value or limit values.

29. The method according to claim 26, wherein a correction value is calculated from the determined deviation, the correction value is converted into a signal by the controller (100), and the signal is output to an actuator (20) which changes a length of the second distance (s.sub.2).

30. The method according to claim 26, wherein a detected deviation of a measured (30) or determined force at the end of a current compaction process from a desired force as a representative of strength causes the following control direction: if the measured force is too high, the second distance (s.sub.1, s.sub.2) is decreased; or if the measured force is too low, the second distance (s.sub.1, s.sub.2) 15 increased;

31. The method according to claim 30, wherein the second distance is changed proportionally to the previously detected deviation in each case.

32. The method of claim 27, wherein the determination is done at the end of the compaction process.

33. The method of claim 9, wherein the distance is reduced when the detected force is too high.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Embodiments of the invention are illustrated by means of examples and not in a way that transfers or incorporates limitations from the Figures into the patent claims. Same reference numerals in the Figures indicate same or similar elements.

[0062] FIG. 1 shows, in a graphic representation, results of a plurality of samples of one material batch which have been compacted using a predetermined force.

[0063] FIG. 2 shows, in a graphic representation, the achieved compaction as a function of a firmly adjusted stroke.

[0064] FIG. 3 shows, in a graphic representation, a relationship between structural strength and the applied pressing force.

[0065] FIG. 4 shows an enlarged cutout of a graphic representation of a target area for structural strength.

[0066] FIG. 5 shows a cutout of a molding system 1 including force sensors 30, 30.

[0067] FIG. 6 shows a cutout of another molding system V in which the force is measured in a different way at the end of the preceding (e.g. immediately preceding) compaction process.

[0068] FIG. 7 shows a control unit 102 or 102 with the sampling cycle T. A force (of compaction) is determined at the end of the previous compaction process. The control unit 102 then changes the distance from s.sub.0 to s.sub.1 (or from s.sub.1 to s.sub.2) for the subsequent compaction process until the pattern plate 46 reaches the lower edge of the molding box 40. Thus, the stroke of the second portion of the pressing process is changed (indirectly) as well. This is due to the (determined, i.e. measured or calculated from other values, e.g. pressure) differential stability between nominal value and actual value which is fed to the control unit 102 or 102. This is the system deviation of the differentiator 99.

[0069] FIG. 8 shows a control process in which the control unit 102 in the controller 100 reduces the distance s for the next molding, in this case because the force F (applied by the lifting cylinder as a press) was too high at the end of the previous molding.

[0070] FIG. 8a shows an end of the molding including the traveled distance s with a force F.sub.50. The initial position is shown on the left and the end position, when the lower edge 40a of the molding box 40 is reached, is shown on the right. The (changed) force-distance characteristic of a changed molding material results in a different force F with an identical distance s.

[0071] FIG. 8b shows the start of the molding including the not yet traveled distance s without force. The initial position is shown on the left and the same position is shown (enlarged) on the right. The (precise) force-distance characteristic of the molding material 41 to be compacted is still unknown.

[0072] FIG. 9 shows isolated force-distance characteristics of two molding materials A and B or one molding material 41, the immanent property of which has changed during use. Apart from compactability, the fines content and the grain-size distribution have a considerable effect on the force-distance characteristic of one or two molding materials to be compared. An identical distance s is illustrated for both sands A, B. However, a difference of almost a factor of 2 of achieved force (or strength) can be seen on the ordinate what a difference. If an increase in distance is achieved for sand B, a mold hardness may result therefrom which is equal to that achieved for sand A.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0073] FIG. 1 shows the already mentioned standard container which can be filled with a sample of the molding material. The molding material is provided to be compacted to form a molding-material mold for the casting of metals in a molding system. After being filled into the standard container, the molding material can be compacted by use of a stamp. The stamp is connected to, for example, a hydraulic cylinder which presses the stamp into the standard container with an adjustable force. When the stamp is pressed into the standard container with the predetermined force at the maximum, the penetration depth of the stamp into the standard container can be measured.

[0074] This measurable value is representative of the compaction behavior of the material in the standard container and is considered to be representative of the compaction behavior of an entire batch in the prior art. The value of the measurement is used for adjusting a distance or stroke for the post-compaction in a pressing device for producing a molding-material mold. According to the prior art, an entire batch of the molding material is then processed in a molding system using this post-compaction adjustment.

[0075] The graphic representation next to the standard container exemplarily shows the result of pressing processes of a plurality of material samples of a single batch of corresponding molding material with an identical force. In the table, the force acting on the stamp is plotted against the penetration depth of the stamp into the standard container.

[0076] The measuring results show that the molding material of a batch is not nearly homogeneous, but that the penetration depth of the stamp S into the standard container B is between approx. 12 mm and approx. 50 mm when the samples are compacted with an identical force.

[0077] FIG. 2 also shows a graphic representation, as already conveyed with FIG. 1. It is graphically shown by means of arrows that, when a firmly adjusted stroke (distance) is used, the granular molding material is compacted with a force of a minimum of approx. 1700 N and a maximum of 2400 N depending on the composition or property of the molding material. In other words, the molding-material molds produced from these materials with an identical pressure have highly variable strengths which is unfavorable for a smooth production and may result, for example, in increased waste.

[0078] FIG. 3 shows in a further graphic representation that, in the molding-material molds, the achievable strength of the mold is directly (substantially linearly) dependent on the application of force to the molding-material mold at the end of the compaction process, or the force with which the molding material is compacted at the end of the compaction process.

[0079] For showing the relationship between structural strength and the force applied to the molding material at the end of the stroke or distance illustrated in the graph, numerous samples of a molding material were compacted with three different final forces in each case. Thus, it could be shown that a relationship between structural strength and the force applied to the molding material can be described by a linear function with sufficient precision.

[0080] FIG. 4 shows an enlarged cutout of a graphic representation including a target area for an intended structural strength of a molding-material mold. The target area is delimited by a lower limit value F.sub.min and an upper limit value F.sub.max. In other words, a force at the end of the stroke has to be reached in such a manner that a curve in a diagram showing the strength across a distance (of FIG. 2) is within the target area at the end of the stroke. This area can be a hysteresis, or may only have a value as a switching value which is to be achieved or exceeded at least a little bit.

[0081] In the diagram cutout of FIG. 4 a curve I can be seen which rises to a maximum value I.sub.max and then falls again. When a predetermined force is applied, the highest strength is achieved at the point I.sub.max. The maximum value I.sub.max is clearly not within the target area. For compacting the same material to such an extent that the force reaches the target area, only the control variable force can be changed.

[0082] This requires that the application of force must be increased. The result of the increase in force is curve II, the maximum value II.sub.max of which is now within the target area.

[0083] In addition, it can be taken from FIG. 4 that an increase in force or application of force can be achieved via a change of the stroke or distance which is predetermined by the not shown actuator of the molding system. The distance (the stroke travels) is reduced as compared to the previously adjusted stroke.

[0084] The stamp (the pressing device) thus travels a different distance, even though the end of this changed distance is still the lower edge of the molding box. However, the force at the end of the changed distance is a different one, namely a force corresponding to the target value which is representative of the mold hardness at the surface (in most cases at the surface of the pattern).

[0085] FIG. 5 shows an exemplary structure of a pressing device 1 of a molding system in which a molding material 41 can be compacted to form a molding-material mold.

[0086] A pressing device 1 of a molding system for the production of molding-material molds or casting molds for the casting of metals is shown in a vertical longitudinal section. The pressing device comprises a lifting cylinder 2 which can be moved with an adjustable pressure in the direction of the arrow. For lowering the lifting cylinder 2, the cylinder can simply be switched powerless whereby it preferably returns to an initial position by its own weight only. The lifting cylinder 2 may be a cylinder which can be charged with oil or air. Instead of the lifting cylinder 2, a linear drive can be used, for example, a gear rack which can be moved linearly by a gear drive.

[0087] The lifting cylinder 2 is connected to the lower side of a molding box 40 via a connector 3. The molding box 40 comprises a filling frame 42. In the following, the molding box 40 and the filling frame 42 will be subsumed under the term elevated molding box 40. The molding box 40 is filled with a molding material 41. A press head 10 including a multi-stamp 11 is arranged above the molding box 40. A stop 13 protrudes from the press head 10 towards the molding box 40, which stop delimits a movement of the molding box 40 in the direction of the arrow.

[0088] The connector 3 comprises an actuator 20 including a drive 21 and a support cylinder 22 into which the actuator 20 can be retracted at least in part when the lifting cylinder 2 moves to its end position. The drive 21 is decoupled from the drive of the lifting cylinder 2. A distance between the upper side of the lifting cylinder 2 (or the pattern carrier 46) and the lower side or lower edge 40a of the molding box 40 (the pattern plate with the pattern standing on top of it for predetermining the cavity of the molding-material mold) can be increased or decreased by means of the actuator 20.

[0089] In the embodiment, the adjusted distance is s.sub.1. The distance can be a minimum of zero. A maximum value is determined by the structural design of the actuator 20.

[0090] In this embodiment, two sensors 30 are arranged within the molding box 40 which measure a force acting from the lifting cylinder 2 and/or the press head 10 on the molding material 41. The force measured by the sensors 30 is transmitted to a controller 100. The controller 100 comprises a storage medium 101 which stores a predetermined strength value for the molding-material mold to be produced, or limit values within which a desired strength value lies (control variable or target variable).

[0091] A microprocessor 102, as a controller (also referred to as control unit 102), functions as a control (a functionally adapted technical program or a plurality of such modules as a control unit) by means of which a strength value measured by the sensor 30 can be compared to the strength value held in the memory 101 or specified separately.

[0092] When a deviation (as a system deviation) is determined here, a correction value can be calculated which is output to the actuator 20 in the form of a signal. The signal causes activation of the drive 21 which can move the actuator 20 from its position to another position. From the point of view of control, position s.sub.1 is changed to a second position (or a second distance) s.sub.2.

[0093] An operating cycle of the pressing device 1 of the molding system may be as follows . . . [0094] The molding box 40 being filled with molding material 41 is inserted into the pressing device 1. [0095] The support cylinders 22 of the actuator 20 are extended to the calculated position and arrested in the extended position. [0096] The lifting cylinder 2, together with the molding box 40, moves towards the press head 10 until the molding box 40 abuts the stop 13, thereby pressing the multiple stamps 11 into the molding material 41. [0097] The lifting cylinder 2 moves further upwards and overcomes the distance s.sub.1 adjusted by the actuator 20. [0098] The multiple stamps 11 are pressed further into the molding material 41 thereby. [0099] The multiple stamps 11 re-squeeze at a defined pressure. [0100] The lifting cylinder 2 and the multiple stamps 11 return to their respective initial positions. [0101] The molding box 40 is removed.

[0102] FIG. 6 shows an exemplary structure of a pressing device 1 of a comparable molding system in which a molding material 41 is compacted to form a molding-material mold, but in which the controller and its measured values operate in a different manner.

[0103] The force is not measured at the pattern here, but is calculated (determined) via the pressure P of the lower press stamp resulting from the control 90 thereof. The determination is carried out via a proportional factor (force per surface area is pressure). The adjustment of the changed distance s.sub.2 after measuring the force F.sub.2 (in the preceding compaction process) is carried out as the distance of the pattern plate to the lower edge 40a of the molding box 40. It may be an s to the previous adjustment. Thus, s.sub.2=s.sub.1+s, wherein s may also be negative.

[0104] At the end of the compaction of this process, the pattern plate is also at the height of the lower edge of the molding box. However, the force has a different value at this time due to the readjustment of the distance to s.sub.2, in which the stamp traveled a changed stroke.

[0105] The determined force F.sub.2 is transmitted to a controller 100. This controller 100 comprises a memory 101 which stores a predetermined strength value for the molding-material mold to be produced, or limit values within which a desired strength value lies (control variable or target variable). A microprocessor or an ASIC 102, as a controller (also referred to as control unit 102), functions as a control (also here, a functionally adapted technical program or a plurality of such modules as a control unit) by means of which the determined strength value can be compared to the strength value held in the memory 101 or specified separately in order to obtain a system deviation from which the control unit calculates a change in control value s.

[0106] In this case, the control unit reduces the distance for next molding process by s, because the force was too high. In another case, the distance is increased by s if the determined force was too low (and thus also the intended strength was too low).

[0107] At the end of the preceding or pre-preceding compaction process, the force is determined which presses the pattern into the molding sand at the end of the stroke s.sub.i. The work cycle of compaction is T. For each T, there is a strength value in the form of the (measured or determined) force at the end of a molding process (as a compaction process). This value is subtracted from nominal value w in order to obtain a system deviation at the differentiator 99, cf. FIG. 7. The new s.sub.2 or (generally) s.sub.i, with i=1 to n, is adjusted by the control unit 102 or 102, which may be a proportional controller, using the system deviation w.

[0108] The control unit changes the distance s.sub.0, s.sub.1, s.sub.2 until the pattern plate 46 reaches the lower edge 40a of the molding box 40. Thus, the stroke of the second phase of a twin-press compaction is changed (indirectly) as well. This is due to the differential stability between nominal value and actual value which is fed to the control unit 102.

[0109] FIGS. 8a and 8b are per se self-explanatory with respect to sequence. They show the beginning of the second compaction, i.e. the approach of the pattern carrier 46 towards the lower edge of the molding box 40 and, in FIG. 8a, the end thereof, at which this lower edge is reached, wherein the resulting force is apparent from the diagram at F.sub.s0. Here, another molding material would have reached only the force (and strength) shown as achieved by the underlying curve.

[0110] FIG. 9 illustrates the force-distance characteristic of two sands (molding materials). Two curves with non-identical force-distance characteristics illustrate the highly variable force (structural strength) obtained with an identical distance s. The identical distance is indicated by arrows of equal length which results in a clearly variable force (shown on the ordinate on the left) of approx. 1.5 kN and approx. 2.8 kN (sand A).

[0111] If the force is to remain constant despite a change in force-distance characteristic, even if gradual, at the end of a respective compaction process, the distance can be adapted. This is precisely the route the solution takes when using the force control and change in distance in the second compaction process (the second stroke), and since the end of the second stroke is compulsory, namely the lower edge 40a of the molding box 40, the stroke to be traveled has to be changed by the above described s.

[0112] Thus, the result can be scientifically explained, wherein an interposition of a distance changed in a controlled manner achieves both, the constant force describing the structural strength as being constant, and a target point of the upward movement which is procedurally defined for the continued use of the mold half 41 (then compacted).

TABLE-US-00001 Legend of Figures FIG. 1 (Figur 1): Kraft [N] =Force [N] Weg [mm] =Distance [mm] FIG. 2 (Figur 2): Hub fest =Constant stroke Kraft =Force Verdichtungsweg =Compaction distance FIG. 3 (Figur 3): Formfestigkeit [N/cm.sup.2] =Structural strength [N/cm.sup.2] Kraft bei Hubende =Force at end of stroke FIG. 7 (Figur 7): Sollwert w FESTIGEKEIT =Nominal value w STRENGTH Regler 102 oder 102 =Control unit 102 or 102 S.sub.0 Nachstellen, als S.sub.1(T) =readjust s.sub.0 to s.sub.1(T) Verdichtungsvorgang =Compaction process Strgr e z (t)-vernderte =Disturbance variable z (t)-changed Eigenschaften des Formstoffs properties of the molding material Kraft F.sub.s0 =Force F.sub.s0 Festigkeit =Strength Kraft F.sub.s0 =Force F.sub.s0 Kraft-oder Druck-Sensor =Force or pressure sensor FIG 8 (Figur 8): Weg s.sub.0, s.sub.1 =Distance s.sub.0, s.sub.1 Kraft F.sub.s0 (entspricht der =Force F.sub.s0 (corresponds to strength) Festigkeit) F.sub.lst =F.sub.Actual Differenz =Difference F.sub.soll =F.sub.Nominal Weg s =Distance s

[0113] Der Regler 100 reduziert in diesem Fall den Weg fr die nchste Abformung, weil die Kraft in der vorigen Abformung zu hoch gewesen ist.

[0114] =In this case, the control unit 100 reduces the distance for the next molding since the force was too high in the preceding molding.

TABLE-US-00002 FIG. 8a (Figur 8a): Weg s.sub.0 =Distance s.sub.0 Kraft F.sub.s0 =Force F.sub.s0 Weg s =Distance s FIG. 8b (Figur 8b): Weg s.sub.0 =Distance s.sub.0 S.sub.0 = S.sub.0 d.sub.46 S.sub.0 = S.sub.0 d.sub.46 d.sub.46 = Konst. d.sub.46 = constant Kraft F.sub.s0 =Force F.sub.s0 Weg s =Distance s FIG. 9 (Figur 9): Kraft [kN] =Force [kN] Erreichte Kraft F.sub.A =Force F.sub.A achieved bei Sand A with sand A Erreichte Kraft F.sub.B =Force F.sub.B achieved bei Sand B with sand B Grundfestigkeit bei Beginn =Basic strength at the beginning des zweiten Hubs of the second stroke Weg [mm] =Distance [mm] Weg s2 (zweiter Hub) =Distance s2 (second stroke) bei Sand A for sand A Weg s2 =Distance s2 bei Sand A for sand A Grundfestigkeit aus der ersten =Basic strength from the first Phase (dem ersten Hub) der phase (the first stroke) of Konturanpassung adaptation of contour