Method for producing a drill segment, drill segment, and drill bit
Patent Information
- Application Number
- EP2023724755
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-05-11
- Filing Date
- 2023-05-03
- Publication Date
- 2025-03-19
AI Technical Summary
The development of drilling segments with favorable performance characteristics is challenging due to complex relationships between performance indicators, leading to time-consuming and costly test series with uncertain outcomes.
A method for producing drilling segments with abrasive particles arranged in a pre-calculated pattern, using advanced calculations and machine learning to optimize performance characteristics, such as removal rate and wear behavior, allowing for cost-effective and rapid production of segments with improved performance.
This approach significantly reduces the need for extensive testing, saves time and costs, and ensures drilling segments are produced with optimized performance characteristics, enhancing drilling efficiency and longevity.
Smart Images
Figure 1.1
Abstract
Description
[0001] Method for producing a drilling segment, drilling segment and drill bit
[0002] Description
[0003] The invention relates to a method for producing a drilling segment for a drill bit, wherein the drilling segment has at least one layer with a plurality of abrasive particles, wherein the abrasive particles form a pattern within the layer.
[0004] Performance characteristics, such as service life and drilling performance, of drilling segments equipped with abrasive particles, such as diamond drilling segments, can be determined essentially by the arrangement of the abrasive particles contained in them, in particular diamonds.
[0005] However, the search for drill segments with favorable performance characteristics is often difficult, especially when optimization is required with regard to multiple performance characteristics. The relationships between various performance characteristics and the design of the sample are often very complex, so conventional development requires numerous test series, which are correspondingly time-consuming and costly. Nevertheless, uncertainty remains as to whether a tested drill segment actually demonstrates improved and more efficient performance characteristics.
[0006] The object of the present invention is therefore to provide a method for the rapid and cost-effective production, in particular development, of a drilling segment as well as a cost-effective drilling segment for a drill bit which enables core drilling with particularly favorable performance characteristics.
[0007] The object is achieved by a method for producing a drilling segment for a drill bit, wherein the drilling segment has at least one layer with a plurality of abrasive particles, wherein the abrasive particles form a pattern within the layer, wherein firstly at least one performance characteristic of the drilling segment having the pattern is calculated in advance and / or the pattern is determined as a function of a calculation of the performance characteristic, and a drilling segment which has at least one layer with abrasive particles arranged in accordance with the pattern is produced.
[0008] In particular, the drill segment having the pattern can be manufactured when the performance characteristic reaches or exceeds a certain level.
[0009] It is therefore conceivable that among several possible patterns and / or drilling segments with such patterns, at least one drilling segment is selected for production based on the performance characteristic.
[0010] The layer can also be physically distinguishable and / or separable from adjacent areas of the drill segment. Alternatively, the layer can also be formed only virtually; for example, it could be a sectional plane.
[0011] The layer can be flat. Alternatively, it can also be non-flat. In particular, the layer in a finished drill segment can be non-flat, particularly deformed out of a plane.
[0012] By calculating the performance characteristic in advance, complex test series with custom-manufactured drill segments and subsequent performance characteristic measurements can be eliminated. This can save costs and / or time. The risks associated with conducting the test series can be reduced or completely avoided.
[0013] The pattern can comprise at least two identical or at least substantially identical sub-regions that are spaced apart from each other. In particular, a particle-free region, for example a rectangular one, can be located between the two sub-regions. This can improve the performance characteristic, for example, the removal rate and / or wear behavior of the drilling segment.
[0014] The prediction can take into account a behavior and / or a change of at least one particle, the pattern, and / or the drill segment. It can generally be based on features of the drill segment or a part thereof. Alternatively or additionally, a change in a workpiece to be machined by the drill segment, which is made of at least one material, can also be predicted. For example, a cutting depth, a removal depth per revolution, abrasion, a deformation, or the like can be predicted.
[0015] The workpiece used as the basis for the forecast and / or to be machined can comprise at least two materials, in particular a rock, for example a rock composed of at least two different base materials, and a metal. It can, for example, comprise reinforced concrete, particularly steel-reinforced concrete. If the workpiece comprises multiple materials, especially if separate test series are required for each of the materials, a particularly significant reduction in time and / or costs can be achieved due to the forecasts.
[0016] In general, predictions can be based on a physical model. The physical model can at least approximately represent physical and / or chemical laws.
[0017] The following approach is particularly useful when performance indicators are to be predicted for a large number of patterns:
[0018] First, performance characteristics are predicted for a limited number of desired samples, for example based on a physical model and / or on previous measurement results.
[0019] The acquired data can then be used to train a customized model. This customized model could, for example, include a machine-learning module.
[0020] The machine-learning module can then be trained using the patterns and the resulting performance metrics. The training can be based on experimentally obtained data, data obtained using the physical model, and / or a combination of such data sources.
[0021] Subsequently, further performance indicators for further patterns can be predicted using the adapted model or the - now trained - machine learning module.
[0022] The machine-learning module can, for example, be and / or include a module for executing probabilistic, particularly linear, regressions. The probabilistic design of the module also allows statistical effects, such as the individual position of the abrasive particles, to be at least partially taken into account.
[0023] Using the variants of the procedure described above, it is possible to arrive at performance indicators based on certain patterns and to classify the patterns based on the performance indicators.
[0024] In a class of methods, it may be intended to determine an optimum of the performance characteristic and / or a value corresponding to the optimum of the
[0025] To determine the pattern associated with a performance indicator. This allows for the search for an optimized performance indicator and the identification of a corresponding pattern.
[0026] The optimization calculation can be performed based on the physical model. Calculations based on a physical model can be very computationally intensive. Therefore, a significant acceleration and a significant reduction in resource requirements can be achieved if the optimization calculation is performed based on the adapted model.
[0027] The optimization calculation can be configured to search for a global optimum. It can, for example, use a genetic algorithm and / or a particle swarm.
[0028] The optimization calculation can take boundary conditions into account.
[0029] Domain adaptation can be carried out, for example, on the basis of simulation data, in particular obtained from the preliminary calculation, and / or on the basis of experimentally obtained data.
[0030] If a drill bit with the best performance characteristics has been identified using the above methods, the drill segment can be produced in embodied form with the pattern. For this purpose, several layers, in particular similar ones, can be stacked on top of one another. It is particularly conceivable for several layers to be lined up, in particular stacked, in one step to form the drill segment or a blank of the drill segment. A drill segment can then be produced by forming and / or arranging layers of the identical or at least essentially identical pattern in layers stacked layer by layer. The drill segment can then be heat-treated, e.g., sintered. It can be pressurized, e.g., by hot isotropic pressing.
[0031] The stacking can be congruent; at least one layer can also be arranged and / or formed offset from an adjacent layer; a resulting layer structure can be non-planar, particularly after pressing.
[0032] With regard to the performance characteristic, it is conceivable that this includes at least one wear characteristic.
[0033] Alternatively or additionally, it is conceivable that the at least one performance characteristic comprises a cutting performance characteristic.
[0034] Drill segments and the process for producing them may be of particular interest if the abrasive particles comprise carbon, in particular diamond, graphene and / or carbon nanotubes, for example in the form of aggregated diamond nanorods and / or graphene, tungsten carbide, tungsten boride, and / or boron nitride. The drill segments may therefore be diamond drill segments.
[0035] The invention also includes a drill segment manufactured according to the method described above. The drill segment can be designed for use on a drill bit.
[0036] It may comprise a binder material. The abrasive particles may be incorporated into the binder material. The binder material may at least partially surround the abrasive particles.
[0037] The binder material may have a lower hardness and / or a lower fracture strength than the material of the abrasive particles.
[0038] The drill segment, in particular the binder material, can be pressure- and / or heat-treated. It can, in particular, be a sintered body and / or comprise one.
[0039] The drilling segment can be cuboid-shaped or at least substantially cuboid-shaped. Alternatively, it can be cylindrical-segment-shaped or at least substantially cylindrical-segment-shaped. "Substantially" can also include, in particular, cases in which less than half of the sides of the drilling segment deviate from the respective basic shape, i.e., cuboid-shaped or cylindrical-segment-shaped.
[0040] For example, a side of the drill segment intended primarily to come into contact with a workpiece may have a raised surface. This raised surface may, for example, form a cutting edge of the drill segment.
[0041] The drill segment can have a layered structure. Abrasive particles can be arranged within a layer. The arrangement of the abrasive particles within the layer can form a pattern. Adjacent layers can have the same pattern. Adjacent layers can be congruent or—alternatively and particularly preferably—offset from one another.
[0042] The layers can be deformed, especially non-planar.
[0043] A largely constant cutting performance can be achieved if corresponding abrasive particles have the same orientation or position in at least two layers with the same pattern.
[0044] A particularly cost-effective production can be achieved if the abrasive particles are arranged arbitrarily, in particular according to a random composition.
[0045] The drilling segments, in particular the layers, can be formed layer by layer using molds, in particular individually filled ones.
[0046] In the drilling segment, the abrasive particles can be formed in at least one layer according to a pattern of at least two spaced-apart subregions. The at least two subregions can have identical subpatterns, each formed from the abrasive particles associated with each subregion.
[0047] At least one of the subregions can have at least one polygonal, in particular a triangular and / or a quadrangular, arrangement of abrasive particles. Such a subregion can result in a particularly balanced relationship between durability and cutting performance of the drill segment.
[0048] The invention also includes a drill bit. The drill bit comprises a preferably tubular shaft, at one end of which a connecting section for connecting the drill bit to a machine tool is arranged and / or formed. At the other end of which at least one of the previously described drilling segments is arranged and / or formed.
[0049] The invention further includes a computer program product. The computer program product can comprise a memory. Executable program code can be stored in the memory so that it can be retrieved on a computer unit. The computer program product, in particular the program code, can be configured to implement the method described above and / or below or at least part of the method described above and / or below, in particular to implement one or more of the features of the physical and / or adapted model described above. In particular, it can be configured to predict at least one performance characteristic of a drilling segment having a pattern and / or to determine the pattern depending on a prediction of the performance characteristic.It can also be designed, in particular if the performance value reaches or exceeds a certain level, to produce a drilling segment which has at least one layer with abrasive particles arranged in accordance with the pattern and / or to control the production of such a drilling segment.
[0050] Further features and advantages of the invention will become apparent from the following detailed description of exemplary embodiments of the invention, based on the figures of the drawing, which illustrate details essential to the invention, and from the claims. The features shown therein are not necessarily to scale and are presented in such a way that the special features of the invention can be clearly seen. The various features can be implemented individually or in combinations in variants of the invention.
[0051] The schematic drawing shows embodiments of the invention and explains them in more detail in the following description.
[0052] They show:
[0053] Fig. 1 shows a drill bit in a schematic side view;
[0054] Fig. 2 shows a section of a drill bit with several drill segments in a perspective oblique view;
[0055] Fig. 3 is a flow chart of a method for manufacturing a drill segment;
[0056] Fig. 4 shows a partial aspect of a variant of the method according to Fig. 3;
[0057] Fig. 5 is a schematic representation of a physical model;
[0058] Fig. 6 is a schematic representation of a segment model;
[0059] Fig. 7a-d Illustrations of considered abrasive particle wear types;
[0060] Fig. 8 Overview of considered abrasive particle geometries;
[0061] Fig. 9a-b Determination of a cutting profile and associated cutting effect;
[0062] Fig. 10a-b perspective views of workpieces and determined cutting contours;
[0063] Fig. 11 a pattern; and
[0064] Fig. 12 shows a diagram of a performance characteristic.
[0065] In the following description of the figures, the same reference numerals are used for identical or functionally corresponding elements to facilitate understanding of the invention.
[0066] Fig. 1 shows a drill bit 10 comprising a tubular shaft 12, at one end of which a connecting portion 14 is formed for connecting the drill bit 10 to a machine tool (not shown in Fig. 1). At the other end of the connecting portion 14 are a plurality of drill segments 16, of which, for simplicity, only one is provided with a reference numeral. The drill segments 16 can be welded or soldered to the shaft 12.
[0067] Fig. 2 shows a section of a drill bit 10 in a perspective view. The drill bit 10 has several drill segments 16, one of which is provided with a reference numeral by way of example. The drill segments 16 are essentially cylindrical segment-shaped. They have cutting edges 20. The drill segments 16 are welded to the rest of the drill bit 10 along weld seams 21. To improve the welding properties of the drill segments 16, the drill segments 16 have no or at least a reduced density of abrasive particles 22 in the vicinity of the weld seams 21.
[0068] The drill segments 16 comprise a binder material 18, into which a plurality of abrasive particles 22 are embedded. For simplicity, only one of the abrasive particles 22 is provided with a reference symbol. The binder material 18 can comprise a copper- and / or iron-based alloy. The abrasive particles 22 are diamond particles.
[0069] The drilling segment 16 has a layered structure. In particular, the abrasive particles 22 are arranged within layers in the drilling segment 16. Within the respective layers, the respective abrasive particles 22 each form a pattern.
[0070] The drilling segment 16 is manufactured according to the method described below.
[0071] Fig. 3 shows a method 100 for manufacturing the drilling segment 16. For the description of the method, it will be assumed here and below that the drilling segment 16 is designed to cut a material consisting of multiple components, in particular reinforced concrete. For this purpose, the drilling segment 16 is to be optimized with regard to the performance parameters of contact force F and required mechanical power P. One optimization variable is the design and / or selection of the patterns created by the abrasive particles 22.
[0072] First, in a candidate phase 110, several samples Mj to be tested are compiled as test candidates.
[0073] In a pre-calculation phase 120, the performance characteristics F and P of the sample are now pre-calculated for each of the test candidate samples M of the drilling segment 16 to be created.
[0074] The test candidate sample(s) M with the best performance characteristics F and P are determined and selected as result samples in a selection phase 130.
[0075] In a production phase 140, drilling segments 16 are then produced in which at least one layer, preferably all layers, has at least one of the result patterns selected in the preceding phase 130.
[0076] For this purpose, a green compact can first be produced. The green compact can be built up layer by layer using a mold. For this purpose, the mold can have recesses arranged in an arrangement corresponding to the desired resulting pattern. Diamonds can be inserted into these recesses as abrasive particles 22. If the resulting pattern specifies an orientation of the abrasive particles 22, this can be taken into account when inserting the diamonds. The mold and thus the abrasive particles 22 can then be introduced onto or into the layer with binder material 18 in order to position the abrasive particles 22 in the layer according to the resulting pattern. After the desired number of layers have been built up, the green compact can be pressed, heated and / or sintered as required.
[0077] As shown schematically in Fig. 4 and with the aid of dashed arrows, the prediction according to the prediction phase 120 can be carried out on the basis of a physical model 122.
[0078] The physical model 122 can take into account one or more individual factors that can influence the performance parameters F, P to be predicted and combine them appropriately in order to derive the desired performance parameters F, P therefrom.
[0079] However, due to the high number of abrasive particles 22 and the numerous arrangement possibilities for the abrasive particles 22 and thus the high number of degrees of freedom for the patterns M, the determination of the performance characteristics F, P of all candidate patterns M can sometimes lead to a considerable computational effort.
[0080] In order to be able to check a particularly large number of candidate patterns Mi and to minimize the required computing capacity, the predictions for the candidate patterns M can also be carried out, for simplicity, with an adapted model 124 instead of the physical model 122.
[0081] Preferably, the adapted model 124 can be trainable; it can then be taught using the physical model 122.
[0082] For this purpose, the adapted model 124 can, for example, include a probabilistic regression, so that after calibrating the adapted model 124, predictions can be performed considerably faster and, in particular, with less computational effort. Alternatively or additionally, other trainable models are also conceivable, for example, based on neural networks such as deep learning modules or the like. The trainable models can be linear or nonlinear.
[0083] By designing the regression probabilistically, a stochastic distribution of certain properties of the layers or patterns M can be taken into account. For example, for a pattern M that does not define a specific orientation of the abrasive particles 22, so that the abrasive particles 22 assume orientations in a randomly distributed manner, these orientations of the abrasive particles 22 can be based on a corresponding stochastic distribution.
[0084] To calibrate the fitted model 124, the performance values F, P are first determined for a sample of the candidate patterns M using the physical model 122. Using the candidate patterns M as input data and the obtained performance values F, P, regression coefficients and / or other model parameters required for the fitted model 124 can then be calculated, thus calibrating the fitted model 124.
[0085] Performance values of all remaining candidate patterns M can then be estimated by the calibrated, adapted model 124 with little computational effort, so that reductions in computational effort by a factor of 10 or more can be achieved.
[0086] Fig. 5 schematically shows details of the physical model 122. This includes a drill segment model 122.1, a workpiece model 122.2, a process force model 122.3, and a kinematic model 122.4. These models 122.1, 122.2, 122.3, and 122.4 interact with each other.
[0087] Stochastic and / or deterministic variables can be used.
[0088] The description of the embodiment is based on reinforced concrete and thus on concrete, i.e. cement and agglomerates, in combination with steel reinforcement as the material of the workpiece.
[0089] Force F and input power P are determined as performance parameters. It is also conceivable to determine other performance parameters, in particular the amount of material removed, the surface profile, cutting and / or normal forces, wear parameters and / or the like.
[0090] The drill segment model 122.1 provides a detailed geometric description of the abrasive particle-filled drill segment 16, and in particular one of its layers. The kinematic model 122.4 adds kinematic data to this model, allowing interactions between the abrasive particles 22 and the workpiece material, and thus changes in the workpiece surface, to be calculated. Based on this, forces can be calculated using the process force model 122.3, thus completing each calculation loop. The forces can then be fed into the kinematic model 122.4, and the calculation process can be restarted.
[0091] A simplification to reduce the computational effort can be achieved by predicting only a single drilling segment 16 for a drill bit 10. If necessary, the total performance of the drill bit 10 can then be extrapolated based on the actual number of drilling segments 16.
[0092] Drilling segment model 122.1
[0093] The drill segment model 122.1 models the shape of the drill segment 16 and in particular its abrasive particles 22.
[0094] In principle, a plurality of layers can be represented in the drill segment model 122.1, as shown in the upper half of Fig. 6. The upper half of Fig. 6 shows, as an example, three layers 24 of a drill segment 16 (Fig. 1).
[0095] In a preferred alternative, only one layer 24 (see Fig. 6, lower half) is modeled for further simplification and minimization of computational effort. In particular, an outermost layer 24 is modeled for this purpose, which comes into contact with the workpiece and thus functions particularly as a cutting layer.
[0096] In addition to the positions and orientations of the abrasive particles 22, of which in Fig. 6 one in the upper half and one in the lower half of Fig. 6 is marked with a reference symbol, the modeling can also include their sizes, mechanical characteristics such as critical compressive strength, shapes, degrees of wear, types of wear and / or the like.
[0097] Within layer 24, the abrasive particles 22, here diamonds, can be arranged according to pattern M. For example, between 10 and 100, for example 25 or 50, abrasive particles 22 can be arranged in one layer. Variations in the extent to which the individual abrasive particles 22 protrude from layer 24 or the surface of the drill segment, for example, in the range of up to approximately 150 pm, can be taken into account.
[0098] If the pattern M provides for a random distribution of the orientations of the abrasive particles 22, the orientations can be considered as stochastically distributed, e.g. normally distributed, three-dimensional angles.
[0099] The lower half of Fig. 6 also shows that a particle wear degree and / or a particle wear state can be modeled for each individual abrasive particle 22. Considered wear types can include, for example, abrasive blunting (Fig. 7a), microfractures (Fig. 7b), macrofractures (Fig. 7c), and particle extraction from the binder material (Fig. 7d).
[0100] The drill segment model 122.1 may also provide for taking into account different initial shapes of the abrasive particles 22. For the case of diamond abrasive particles 22, Fig. 8 shows examples of such initial shapes.
[0101] Furthermore, it may be provided to model the sizes of the abrasive particles 22 in the drill segment model 122.1 in order to reflect the fact that certain variations are to be expected in the usual selection processes based on screening. Preferably, the size and / or a critical compressive strength distribution of the abrasive particles 22 can also be modeled as a stochastic, for example, normally distributed, size.
[0102] Furthermore, the model can take into account that even placement methods for positioning the abrasive particles 22 can result in certain inaccuracies. Therefore, the position and / or a deviation from a target position can be modeled as a stochastic variable.
[0103] Wear of the drilling segment 16
[0104] To model the wear of the drill segment 16, the four different wear types and degrees mentioned above are modeled analogously to Fig. 7a to Fig. 7d. Abrasive blunting can be modeled as follows:
[0105] Where dW / dt is a wear rate, for example in [mm / s], K is a wear coefficient, B is a dimensionless constant from the Arrhenius equation and takes into account the activation energy and the universal gas constant, F c is a cutting force, v c is a cutting speed and Tgnnd is a temperature in the cutting area.
[0106] Micro- and macro-fractures are modeled in similar ways, although the two fracture types can differ essentially in terms of penetration depth.
[0107] Fracture occurs when the resulting stress acting on the abrasive particle 22 exceeds its inherent compressive strength. A failure-induced stress for brittle materials without elastic deformation can be modeled as follows: where cr w is a normal stress, calculated as: with F N as a normal force and A± is a projection surface or cutting surface orthogonal to the cutting direction (see also below with reference to Fig. 9a). at corresponds to a stress in the cutting direction, modeled as: where F c the cutting force and A cu t is a particle cross-section orthogonal to the cutting direction. T yz corresponds to the shear stress in the abrasive particle and is represented by:
[0108] -
[0109] Tyz A ±
[0110] The direction in which the fracture propagates is defined stochastically, depending on the cutting depth of particle 22 or the diamond. Once the points of the orthogonal plane for fracture generation have been defined, the modeled fracture generation occurs in a 2D plane (orthogonal to the plane in the cutting direction, Fig. 9a), resulting in a new abrasive particle geometry and, subsequently, a projected area.
[0111] Two cases can be distinguished for modeling particle extraction.
[0112] If, after a fracture of the particle 22 or due to abrasive wear, the cutting profile is reduced to 30% compared to an intact profile, pull-out occurs due to the reduction of the contact area between the binder material and the surface of the particle 22.
[0113] The second case considers wear of the binder material. For this purpose, a wear rate of the binder material can be estimated. This influences the threshold or critical force at which the abrasive particle 22 breaks out. This can be modeled as follows:
[0114] = _ K m mc c - ' N ' L
[0115] V H ■ A
[0116] Where A^ is the wear coefficient, / V is the normal force, L is the distance traveled, / - / is the material hardness and A is the contact area.
[0117] Kinematic model 122.4
[0118] The kinematic model 122.4 depicts the movement of the drill segment 16 as a movement in three-dimensional space. When the drill bit 10 rotates, the drill segment 16 rotates around an x-axis and moves along a feed direction, similar to the kinematics of drills.
[0119] This allows a cutting speed of v cand a feed rate v f calculate as follows: and v f = n ■ a e (2.2) [cm / min] where n is the number of revolutions of the drill bit 10 per minute, d is its diameter and a e one penetration depth per revolution.
[0120] Another important parameter of the kinematic model 122.4 describes the passage time or the journal t s , with which the drilling segment 16 drills the workpiece with the material width m w , the core drill outer radius r cö and the core drill rotation frequency f C b passes through.
[0121] The following relationship can be assumed: t _ m w 2Tt-f cb' r cb
[0122] Process force model 122.3
[0123] The process force model 122.3 models the forces occurring between the drill segment 16 and the respective workpiece during cutting. Using an adapted Kienzle equation, the forces acting during the cutting process can be modeled:
[0124] Fei = k cl .! ■ A™ c where kd.i is a specific cutting force, A is an orthogonal cutting area and m c is a workpiece material coefficient of the cutting force increase. These parameters are calculated based on the individual abrasive particles 22 and their interaction with the respective workpiece. The total force acting can be determined by summing all individual forces Fd:
[0125] The normal force component perpendicular to the cutting direction results from the cutting force ratio p as follows:
[0126] The specific cutting force k c ii, the workpiece material coefficient m cand the cutting force ratio can be determined experimentally, for example by means of scratch and core drilling tests, as well as for example by linear regression.
[0127] This allows the magnitudes of the forces to be determined; the corresponding force directions can then be determined separately, as explained below.
[0128] Workpiece model 122.2
[0129] The workpiece model 122.2 models the shape of the workpiece and its changes due to the cutting process.
[0130] In order to model the effect on the workpiece caused by the abrasive particles 22, a cutting profile is first determined for each individual abrasive particle 22. As shown in Fig. 9a, the cutting profile is calculated from the projection area of the particle 22 parallel to the direction of the cutting speed v c determined.
[0131] The surface of the workpiece to be machined, in the example case a concrete or steel surface, is modeled using mesh points.
[0132] Within the time step t s The determined cutting profile is guided across the mesh with the defined kinematics, for example, along the arrow shown in Fig. 9a. Along the mesh points traversed, the surface is modified according to the cutting profile, resulting in an updated surface profile of the machined workpiece. This approach converts a three-dimensional grain into a two-dimensional grain, resulting in a significant reduction in simulation time for the model.
[0133] By comparing the network before and after the magazine t s It is also possible to determine the volume of workpiece material removed.
[0134] With the information obtained on the cutting profile and the removed volume, the direction of the cutting force can also be determined:
[0135] Each surface of a particle 22 is defined by normal vectors n t * characterizable, as can be seen from the respective shape of particle 22.
[0136] From these normal vectors The direction of the effective total force and thus the total force vector can then be derived by summation:
[0137] Where n corresponds to the total number of surfaces in the abrasive particle 22 in question, V corresponds to the volume extracted from the respective surfaces; V t corresponds to the entire in this journal t s withdrawn volume. Total volume.
[0138] It is conceivable to consider additional effects. For example, it is conceivable to further improve the process by integrating thermal and mechanical influences, such as cutting temperature, friction, elastic material behavior, crack propagation, and the like.
[0139] With the simplifications presented here, the volume of removed workpiece material depends on the area of interaction between the mesh or workpiece and the cutting profile, as well as the distance traveled. Thus, the modeled notch of the workpiece corresponds to a negative of the cutting profile. The superposition of the grooves modeled by the notch thus results in a respective cutting contour with the corresponding surface roughness.
[0140] Fig. 10a, for a steel reinforcement, and Fig. 10b, for a concrete element, each show workpieces with modeled cutting contours resulting from the cutting process. Fig. 11 shows a schematic representation of a pattern for the drill segment 16 designed as a diamond drill segment.
[0141] The pattern has alternating columns of diamond abrasive particles 22 with 3 or 2 layers.
[0142] For the drilling segment 16 with such a pattern, measurements of performance parameters such as forces, torques, etc. were carried out.
[0143] The experimentally obtained measurement results were compared with performance characteristics obtained using a physical model based on the previously described physical model. Overall, a very good agreement was found.
[0144] By varying various parameters of the pattern, for example the size of the diamond abrasive particles 22, a total of 192 modified patterns were simulated.
[0145] A sample with approximately 20% lower forces was identified.
[0146] A sample sample can be considered identical or at least substantially identical to a comparison sample if the distances between abrasive particles 22 of the sample sample deviate from the corresponding distances of the sample sample by at most 10%, in particular by at most 5%, particularly preferably by at most 1%. Alternatively or additionally, the two samples can be considered identical or at least substantially identical to one another if their numbers of abrasive particles 22 deviate from one another by at most 20%, in particular by at most 10%, particularly preferably by at most 5%, very particularly preferably by at most 1%. According to another conceivable definition of sample similarity, properties of the abrasive particles 22 can also be taken into account alternatively or additionally.For example, the sample and the comparison sample can be considered identical or essentially identical if the average particle diameters and / or sieve sizes for sieving the abrasive particles 22 differ by no more than 20%, in particular by no more than 10%, preferably by no more than 5%. It is also conceivable to use the occurrence and / or a quantitative proportion of abrasive particles 22 of a specific shape as a property of the abrasive particles 22.
[0147] The comparison of patterns of drilling segments 16 may preferably relate to the arrangement of the abrasive particles 22 in the respective green compacts of the respective drilling segments 16.
[0148] In general, it is conceivable that the properties of the patterns include, for example, an average, a most frequent and / or a maximum particle size, for example a maximum diameter of the abrasive particles, for example in the range from 0.1 to 3 mm, in particular diameters less than 0.5 mm or greater than 1 mm, a number of layers, in particular with reference to Fig. 11 a number of rows, for example between 1 and 20, in particular between 3 and 8, a concentration ratio between a volume occupied by the abrasive particles 22 and / or a surface area occupied by them in relation to the corresponding volume or the corresponding surface area of the binder material of the drilling segment 16, for example in the range between 20% and 80% abrasive particles 22 to binder material,
[0149] - at least one geometry of the abrasive particles 22, for example the most frequently occurring geometry, in particular before the first use of the drilling segment 16 and / or
[0150] - to consider at least one orientation of the abrasive particles 22, for example the most frequently occurring orientation, in particular before the drilling segment 16 is used for the first time.
[0151] Fig. 12 shows a diagram of a portion of the data obtained from the 192 simulations. In particular, the resulting cutting forces are shown for different cutting depths between 7.5 pm and 60 pm and different grain sizes of the diamond abrasive particles 22.
[0152] It can be seen that complex dependencies have arisen, which have a particularly strong impact on deep cutting depths.
[0153] In the example shown in Fig. 12, for example, it was found that for cutting depths of approximately 60 pm, a particle size of the abrasive particles 22 of approximately 0.4 mm can lead to approximately 20%, in particular corresponding to 1669 / 2109, lower required cutting forces than a particle size of approximately 0.8 mm.
[0154] In general, particularly low forces were required for drilling segments 16 with 5 rows (see Fig. 11) and with diamond particles with a maximum diameter in the range of 0.3 mm to 0.6 mm, in particular 0.4 mm.
[0155] List of reference symbols
[0156] 10 core bits
[0157] 12 shaft
[0158] 14 connecting section
[0159] 16 drilling segment
[0160] 18 Binder material
[0161] 20 cutting edge
[0162] 21 Weld seam
[0163] 22 abrasive particles
[0164] 24 shift
[0165] 100 procedures
[0166] 110 candidate phase
[0167] 120 Prediction phase
[0168] 122 Physical model
[0169] 122.1 Drilling segment model
[0170] 122.2 Workpiece model
[0171] 122.3 Process force model
[0172] 122.4 Kinematic model
[0173] 124 Adapted model
[0174] 130 Selection phase
[0175] 140 Production Phase
Claims
Claims: Method (100) for producing a drill segment (16) for a drill bit (10), in particular for a drill bit (10) for machining reinforced concrete, wherein the drill segment (16) has at least one layer (24) with a plurality of abrasive particles (22), wherein the abrasive particles (22) form a pattern within the layer (24), characterized in that at least one performance characteristic of the drill segment (16) having the pattern is first pre-calculated and / or the pattern is determined as a function of a pre-calculation of the performance characteristic and, in particular, if the performance characteristic reaches or exceeds a certain level, a drill segment (16) having at least one layer (24) with abrasive particles (22) arranged according to the pattern is produced.A method according to the preceding claim, characterized in that the pattern comprises at least two identical or at least substantially identical sub-areas that are spaced apart from one another. A method according to any of the preceding claims, characterized in that a change in a workpiece to be processed by the drilling segment (16), which is made of at least one material, is predicted. A method according to any of the preceding claims, characterized in that the workpiece to be processed comprises at least two materials, in particular a rock and a metal. A method according to any of the preceding claims, characterized in that a machine learning module is first trained for the prediction. A method according to any of the preceding claims, characterized in that a probabilistic regression is performed.Method according to one of the preceding claims, characterized in that an optimum of the performance indicator and / or a pattern corresponding to the optimum of the performance indicator are determined on the basis of an optimization calculation.
8. Method according to one of the preceding claims, characterized in that several layers (24) are arranged one after the other, in particular stacked, to form the drill segment (16) or a raw body of the drill segment (10).
9. Method according to one of the preceding claims, characterized in that the at least one performance parameter includes a wear parameter.
10. Method according to one of the preceding claims, characterized in that the at least one performance parameter comprises a cutting performance parameter.
11. Method according to one of the preceding claims, characterized in that the abrasive particles (22) comprise carbon, in particular diamond, graphene and / or carbon nanotubes such as, for example, aggregated diamond nanorods and / or graphene, tungsten carbide, tungsten boride and / or a boron nitride.
12. Drilling segment (16) for a drill bit (10) comprising abrasive particles (22) incorporated into a binder material (18), produced according to a method (10) according to one of the preceding claims.
13. Drilling segment according to the preceding claim, characterized in that the abrasive particles (22) are formed in at least one layer (24) according to a pattern of at least two identical, spaced-apart sub-areas.
14. Drilling segment according to the preceding claim, characterized in that the sub-area has at least one polygonal, in particular a triangular and / or a quadrilateral, arrangement of abrasive particles (22).
15. Drill bit (10) comprising a preferably tubular shaft (12) at one end of which a connecting section (14) for connecting the drill bit (10) to a machine tool is arranged and / or formed, and at the other end of which at least one drill segment (16) according to one of claims 10 to 12 is arranged and / or formed.