Cutting machine tool with force sensor, use of a cutting machine tool, and method for calibrating a force sensor of a cutting machine tool

Abstract

The present invention relates to a cutting machine tool (1) for cutting and shaping a workpiece (9), wherein the cutting and shaping is performed using a plurality of required tools (14.01-14.06) in a time sequence of manufacturing steps; wherein in each manufacturing step, the required tools (14.01-14.06) can exert a tool force (Kw) on the workpiece (9); the cutting machine tool comprises a tool holder (13) for simultaneously holding the required tools (14.01-14.06) and a tool slide rail (11) for moving the tool holder (13); through the movement of the tool holder (13), In each manufacturing step, the required tool (14.01-14.06) can be oriented on the workpiece (9), and the required tool (14.01-14.06) and the workpiece (9) can be moved relative to each other for cutting and forming; the tool holder (13) has at least two single-component force sensors (12.1, 12.2, 12.3); the single-component force sensors (12.1, 12.2, 12.3) measure the tool force (Kw) applied by one of the required tools (14.01-14.06) during the cutting and forming process of the workpiece (9) in the main force path.

Description

Technical Field

[0001] The present invention relates to a cutting machine tool with a force sensor, the present invention also relates to the application of the cutting machine tool, and the present invention also relates to a method for calibrating the force sensor of the cutting machine tool. Background Art

[0002] Cutting machine tools are well known. Known cutting machine tools are lathes, milling machines, saws, etc. Cutting machine tools are used to cut and shape workpieces, wherein material of the workpiece is removed using a tool with a cutting wedge. The cutting wedge exerts a tool force. The workpiece can be made of any material, such as metal, wood, plastic, etc. The cutting wedge is made of a hard, strong and tough cutting material, such as metal, ceramic, etc. Known tools for cutting and shaping are chisels, turning tools, milling cutters, flat drills, saw blades, etc.

[0003] During the cutting process, the workpiece and the tool move relative to each other. Here, both the workpiece and the tool move in a straight line or in a circle. For this purpose, the cutting machine tool has a plurality of drive units, such as an electric drive unit, a pneumatic drive unit, etc.

[0004] In order to produce workpieces cost-effectively and with consistent quality, it is necessary to measure the tool forces, because the tool forces and the high temperatures that occur during the cutting process cause the cutting wedge to wear. This wear changes the cutting edge geometry of the cutting wedge. A worn cutting wedge requires greater tool forces for cutting the workpiece, which results in higher energy consumption in the cutting machine and also reduces the surface quality and dimensional accuracy of the workpiece.

[0005] Patent document EP 0 433 535 A1 discloses a known arrangement comprising a force sensor for measuring tool forces when cutting and shaping a workpiece in a cutting machine tool. The force sensor is clamped in a non-positive manner in a recess of a machine part.

[0006] A disadvantage of this known arrangement is that the tool force is not measured at its point of action, i.e., on the cutting wedge, but rather at a location remote from the cutting wedge, i.e., in the machine part. And there the tool force is measured indirectly as the mechanical stress occurring in the machine part. The mechanical stress itself is in turn influenced by the size and mass of the machine part.

[0007] The force sensor of this known arrangement is also arranged in a machine part in the force shunt. However, only a small part of the mechanical stresses occurring there can be measured in the force shunt. All this leads to inaccurate measurement of the tool force. The accuracy in measuring the tool force represents the deviation of the measured tool force from the actual tool force; the more accurately the tool force is measured, the smaller the deviation of the measured tool force from the actual tool force.

[0008] Furthermore, the force sensor of the known arrangement measures multiple force components of the tool force. It measures the feed force in the x-direction, the back force in the y-direction and the main cutting force in the z-direction. The multi-component force sensor has at least one piezoelectric element for each force component. The piezoelectric element is oriented so as to be able to detect the force component with high sensitivity. At least three piezoelectric elements are arranged in a housing stacked on top of each other in the z-direction. As a result, the multi-component force sensor has a relatively large structural dimension in the z-direction. Such a multi-component force sensor is commercially available from the applicant under the model designation 9027C and the data sheet 9027C_000-726d-03.10. The multi-component force sensor is hollow cylindrical with an outer diameter of 24.0 mm, an inner diameter of 9.6 mm and a height of 12.0 mm. The purchase cost of the multi-component force sensor is also relatively high.

[0009] At present, the cutting and forming of workpieces is usually carried out using multiple required tools in the chronological order of the production steps. That is, it is necessary to change tools more frequently. In each new manufacturing step, a new tool is oriented on the workpiece. Therefore, in order to quickly and cost-effectively change tools and quickly and cost-effectively orient tools, cutting and forming machines have tool racks. The tool rack simultaneously accommodates all the tools required for the manufacturing steps of cutting and forming. That is, before the cutting and forming process begins, the tool rack is equipped with all the required tools. In this way, it is not necessary to remove the tools from the cutting and forming machine or insert the tools into the cutting and forming machine during cutting and forming. In order to replace with a new tool during cutting and forming and orient the new tool on the workpiece, it is only necessary to move the tool rack relative to the workpiece. After the new tool is oriented on the workpiece, the tool and the workpiece move relative to each other for cutting and forming. Summary of the invention

[0010] The first object of the present invention is to accurately measure the tool force acting when a workpiece is cut and formed in a cutting machine tool by using a force sensor. The second object of the present invention is to arrange the force sensor in a cutting machine tool in a space-saving manner to measure the tool force acting in the process of cutting and forming the workpiece. The third object of the present invention is to measure the tool force acting in the process of cutting and forming the workpiece by using a force sensor at a low cost.

[0011] At least one of the above objects is achieved by the features of the independent claims.

[0012] The present invention relates to a cutting machine tool for cutting and forming a workpiece, wherein the cutting and forming is performed using a plurality of required tools in a time sequence of manufacturing steps; wherein in each manufacturing step, the required tool can apply a tool force to the workpiece; the cutting machine tool has a tool rack for simultaneously accommodating the required tools and a tool slide for moving the tool rack, wherein the required tool can be oriented on the workpiece in each manufacturing step by moving the tool rack, and the required tool and the workpiece can move relative to each other for cutting and forming; wherein the tool rack has at least two single-component force sensors; and wherein the single-component force sensor measures in a main force path the tool force applied by one of the required tools during the cutting and forming process of the workpiece.

[0013] The invention also relates to the application of the cutting machine tool.

[0014] The invention also relates to a method for calibrating a force sensor of such a cutting machine tool.

[0015] Further preferred technical solutions of the present invention are achieved by the features of the dependent claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention is exemplarily described below with reference to the accompanying drawings, wherein:

[0017] Figure 1 A view showing various components of a cutting machine tool according to one embodiment, including a tool holder and a force sensor;

[0018] Figure 2 Shown according to Figure 1 An exploded view of the various parts of a cutting machine tool;

[0019] Figure 3 Schematically shows the Figure 1 A portion of a cross section of a cutting machine tool along line ZZ';

[0020] Figure 4 Schematically shows the Figure 1 A portion of a cross section of a cutting machine tool along line XX';

[0021] Figure 5 shows the calibration according to Figure 1 A flowchart of the method steps of using a force sensor for a cutting machine tool; and

[0022] Figure 6 Schematically illustrates a method for executing Figure 5 A portion of a calibration device for the method steps shown, which has a Figure 1 Tool holder for cutting machine tools.

[0023] In principle, identical components are provided with the same reference symbols in the figures. DETAILED DESCRIPTION

[0024] Figure 1-4 The figure shows several components of a cutting machine tool 1 according to one embodiment for cutting and shaping a workpiece 9. The cutting machine tool 1 is arranged in an orthogonal coordinate system having three axes x, y, z, which are also referred to as transverse axis x, horizontal axis y and vertical axis z.

[0025] The workpiece 9 is made of any material, such as metal, wood, plastic, etc.

[0026] The cutting machine 1 has a plurality of required tools 14.01-14.06. The cutting and shaping of the workpiece 9 is carried out using the required tools 14.01-14.06 in a chronological order of the manufacturing steps. Figure 1-4 In the example of , six tools 14.01-14.06 are required in six manufacturing steps. A first tool 14.01 is required in the first manufacturing step, a second tool 14.02 is required in the second manufacturing step, a third tool 14.03 is required in the third manufacturing step, a fourth tool 14.04 is required in the fourth manufacturing step, a fifth tool 14.05 is required in the fifth manufacturing step, and a sixth tool 14.06 is required in the sixth manufacturing step. Preferably, each required tool 14.01-14.06 has a coolant supply 14.11-14.16.

[0027] During the cutting and forming process of the workpiece 9, the required tool 14.01-14.06 performs a cutting motion in a transverse plane xz unfolded by the transverse axis x and the vertical axis z. And during the cutting and forming process of the workpiece 9, the required tool 14.01-14.06 performs a feed motion along the horizontal axis y. Here, the required tool 14.01-14.06 applies a tool force Kw on the workpiece 9. The tool force Kw has three force components. Due to the cutting motion, the tool force Kw has a main cutting force component Kwx along the transverse axis x direction and a back force component Kwz along the vertical axis z direction. And due to the feed motion, the tool force Kw has a feed force component Kwy along the horizontal axis y direction. In different types of cutting and forming, the main cutting force component Kwx is the force component with the largest value. And, comparing the force components of different types of cutting and forming, the numerical fluctuation of the main cutting force component Kwx is the smallest. Therefore, the main cutting force component Kwx is suitable for use as an indicator of the wear of the tools 14.01-14.06 required for various types of cutting and forming.

[0028] The cutting machine 1 has a tool holder 13. The tool holder 13 holds the tools 14.01-14.06 required for the manufacturing steps at different positions i, i=1...6. Before the cutting process begins, the tool holder 13 is equipped with all the required tools 14.01-14.06, and then the tool holder 13 holds the required tools 14.01-14.06 simultaneously. The tool holder 13 is made of a mechanically resistant material such as steel, tool steel, etc. Figure 1-4 In the example shown, the tool rack 13 holds the six required tools 14.01-14.06.

[0029] The tool rack 13 holds the required tools 14.01-14.06 via the handles of the required tools 14.01-14.06. To this end, the tool rack 13 has a plurality of tool slots 13.01-13.06 and a plurality of holders 13.11-13.16, 13.21-13.26.

[0030] Preferably, each of the six tool slots 13.01-13.06 accommodates the shank of one of the six required tools 14.01-14.06. The holders 13.11-13.16, 13.21-13.26 are threaded connections comprising a holding plate, holes in the holding plate, holding bolts and internal threads in the tool holder 13. Each tool slot 13.01-13.06 is assigned a first holder 13.11-13.16 and a second holder 13.21-13.26. Preferably, each first holder 13.11-13.16 has one holding plate and one holding bolt, and each second holder 13.21-13.26 has one holding plate and two holding bolts. Each first holder 13.11-13.16 rests with a holding plate on the shank of the desired tool 14.01-14.06, and each second holder 13.21-13.26 rests with a holding plate on the shank of the desired tool 14.01-14.06. The outer thread of the holding bolt passes through the hole in the holding plate to the inner thread in the tool holder 13. The threaded connection is parallel to the horizontal axis y. By screwing the outer thread and the inner thread, the holding bolt presses the holding plate against the shank of the desired tool 14.1-14.8 and holds the desired tool 14.01-14.06 in the tool slot 13.01-13.06 by means of a holding force.

[0031] The cutting machine tool 1 has a tool slide 11. The tool slide 11 carries a tool holder 13. According to the principle of action and reaction, the tool slide 11 receives a tool force Kw from the tool holder 13 and applies an equally large reaction force in the opposite direction to the tool holder 13.

[0032] The tool rack 13 equipped with the required tools 14.01-14.06 can be fastened on and removed from the tool slide 11 simply and quickly by means of three first fasteners 13.31, 13.32, 13.33 and three second fasteners 13.41, 13.42, 13.43. Preferably, the tool rack 13 has three first fasteners 13.31, 13.32, 13.33 and three second fasteners 13.41, 13.42, 13.43. These fasteners 13.31, 13.32, 13.33, 13.41, 13.42, 13.43 are threaded connections comprising fastening bolts, holes in the tool rack 13 and internal threads in the tool slide 11. The threaded connection is parallel to the horizontal axis y. The external thread of the fastening bolt passes through the hole in the tool rack 13 to the internal thread in the tool slide 11. The bolt head of the fastening bolt is located in the tool holder 13. By screwing the external thread and the internal thread, the fastening bolt presses the tool holder 13 against the tool slide rail 11 with a tightening force.

[0033] The tool slide 11 moves the tool holder 13. For this purpose, the tool slide 11 has a drive unit, such as an electric drive unit, a pneumatic drive unit, etc. The drive unit moves the tool holder 13 along three axes x, y and z.

[0034] The cutting machine tool 1 has a force sensor 12. According to the invention, the force sensor 12 is composed of at least two single-component force sensors 12.1, 12.2, 12.3. Figure 1-4 In the example shown in FIG. 1 , the force sensor 12 is composed of three single-component force sensors 12 . 1 , 12 . 2 , and 12 . 3 .

[0035] The single-component force sensor 12.1, 12.2, 12.3 has a housing made of a mechanically resistant material, such as steel, tool steel, etc. The single-component force sensor 12.1, 12.2, 12.3 is hollow cylindrical with two housing end faces, two side faces and a central housing hole. The housing end faces are parallel to the vertical plane xz. The outer side faces define the housing in a radial direction away from the housing. The inner side faces define the housing in a direction toward the housing hole. The longitudinal axis of the housing hole is parallel to the horizontal axis y.

[0036] The single-component force sensors 12.1, 12.2, 12.3 are spatially arranged between the tool holder 13 and the tool slide 11. Figure 1-4 and Figure 6 In the example of FIG. 3 , three single-component force sensors 12 . 1 , 12 . 2 , 12 . 3 are arranged on a line ZZ′ along a transverse axis x.

[0037] The tool holder 13 holds the single-component force sensors 12.1, 12.2, 12.3. To this end, the tool holder 13 has a plurality of cutouts 13.07-13.09. The cutouts 13.07-13.09 are parallel to the vertical plane xz. The diameter of the cutouts 13.07-13.09 is determined to be large enough to allow the single-component force sensors 12.1, 12.2, 12.3 to be inserted into the cutouts 13.07-13.09, and the inserted single-component force sensors 12.1, 12.2, 12.3 are held on the radial outer side in the region of the cutouts 13.07-13.09. The first cutout 13.07 holds the first single-component force sensor 12.1, the second cutout 13.08 holds the second single-component force sensor 12.2, and the third cutout 13.09 holds the third single-component force sensor 12.3. Holding the single-component force sensors 12.1, 12.2, 12.3 in the recesses 13.07-13.09 saves space and is cost-effective, since the predetermined outer dimensions of conventional tool holders can thereby be retained and do not have to be modified.

[0038] In the area of ​​the recesses 13.07-13.09, the tool holder 13 fastened to the tool rail 11 is spaced apart from the tool rail 11 by a gap s. In the area of ​​the second fastening elements 13.41, 13.42, 13.43, the tool holder 13 fastened to the tool rail 11 is in planar contact with the tool rail 11 via the contact surface 13.00.

[0039] The single-component force sensors 12.1, 12.2, 12.3 inserted into the recesses 13.07-13.09 are fastened to the tool rail 11 by means of first fasteners 13.31-13.33. The first fasteners 13.31-13.33 are threaded connections comprising a fastening bolt and an internal thread in the tool rail 11. The diameter of the housing hole is dimensioned to be large enough to allow the fastening bolt to protrude. The external thread of the fastening bolt passes through the housing hole of the single-component force sensor 12.1, 12.2, 12.3 to the internal thread in the tool rail 11. The bolt head of the fastening bolt is located in the tool holder 13. By screwing the external thread and the internal thread, the fastening bolt presses the single-component force sensor 12.1, 12.2, 12.3 against the tool rail 11 with a tightening force. The fastening of the single-component force sensors 12.1, 12.2, 12.3 between the tool holder 13 and the tool slide 11 is non-elastic and brings the following advantages: the tool force Kw to be measured acts on the single-component force sensors 12.1, 12.2, 12.3 essentially without weakening, because the respective elastic deformation would weaken the tool force Kw and distort the measurement of the tool force Kw.

[0040] Such a single-component force sensor 12.1, 12.2, 12.3 is commercially available from the applicant under model 9145B and data sheet 9143B_000-113d-03.16. The single-component force sensor 12.1, 12.2, 12.3 has an outer diameter of 24.0 mm defined by the outer side, an inner diameter of 10.1 mm defined by the inner side, and a height of 3.5 mm along the y-axis between the housing end faces.

[0041] Compared with the aforementioned 9027C multi-component force sensor with a height of 12.0 mm, the height of the 9145B single-component force sensors 12.1, 12.2, 12.3 along the y-axis is more than three times smaller. Figure 4 It can be seen in the true-to-scale cross-section that for such a multi-component force sensor having a height along the y-axis which is more than three times greater, there is no space in the tool holder 13 for being held in the recess there and pressed against the tool slide 11 by the first fastening element.

[0042] The single-component force sensors 12.1, 12.2, 12.3 are in planar contact with the tool holder 13 with their first housing end faces 12.11, 12.21, 12.31, and are in planar contact with the tool rail 11 with their second housing end faces 12.12, 12.22, 12.32. Since the contact surface 13.00 of the tool holder 13 is separated from the tool rail 11 by a gap s in the region of the recesses 13.07-13.09, the single-component force sensors 12.1, 12.2, 12.3 are in planar contact with the tool rail 11 only with their second housing end faces 12.12, 12.22, 12.32.

[0043] Preferably, the sum of the second housing end surfaces 12.12, 12.22, 12.32 of at least two single-component force sensors 12.1, 12.2, 12.3 is larger than the contact surface 13.00 of the tool holder 13. Therefore, the vast majority of the tool force Kw to be measured acts on the tool slide 11 via the sum of the housing end surfaces 12.12, 12.22, 12.32. Only a small part of the tool force Kw to be measured acts on the tool slide 11 via the contact surface 13.00. Therefore, at least two single-component force sensors 12.1, 12.2, 12.3 are spatially arranged between the tool holder 13 and the tool slide 11 in the main force path.

[0044] Preferably, at least two single-component force sensors 12.1, 12.2, 12.3 are arranged such that the distance to the required tool 14.01-14.06 is shorter than the contact surface 13.00. Figure 4In the true proportional cross section, the distance from the single-component force sensor 12.3 to the desired tool 14.06 is only 66% of the distance from the contact surface 13.00 to the desired tool 14.06. It can be seen that the vast majority of the tool force Kw to be measured acts on at least two single-component force sensors 12.1, 12.2, 12.3, and only a small part of the tool force Kw to be measured acts on the contact surface 13.00. Therefore, at least two single-component force sensors 12.1, 12.2, 12.3 are also spatially arranged between the tool holder 13 and the tool slide 11 in the main force path.

[0045] Such a main force path cannot be obtained when a single multi-component force sensor is used instead of at least two single-component force sensors 12.1, 12.2, 12.3, because the multi-component force sensor of type 9027C mentioned at the beginning has the same outer diameter of 24.0 mm as the single-component force sensors 12.1, 12.2, 12.3 of type 9145B. The second housing end face of the multi-component force sensor is smaller than the contact surface 13.00 of the tool holder 13, and the multi-component force sensor is spatially arranged in the main force path between the tool holder 13 and the tool slide 11.

[0046] The total contact surface formed by the second housing end surfaces 12.12, 12.22, 12.32 of the at least two single-component force sensors 12.1, 12.2, 12.3 and the contact surface 13.00 of the tool holder 13 is at least half as large as the total contact surface 11.00 of the tool slide 11 in the vertical plane xz. Therefore, the tool holder 13 and the tool slide 11 are in contact over a large area, which has the advantage that the cutting machine 10 has a high rigidity and a high natural frequency, because mechanical bending (Durchbiegen) cannot occur in the vertical plane xz. Such advantages cannot be achieved when a single multi-component force sensor is used instead of the at least two single-component force sensors 12.1, 12.2, 12.3. This is because the 9027C multi-component force sensor mentioned at the beginning has the same outer diameter of 24.0 mm as the 9145B single-component force sensors 12.1, 12.2, 12.3. The total contact surface formed by the second housing end surface of the multi-component force sensor and the contact surface 13 . 00 of the tool holder 13 is smaller than half of the total contact surface 11 . 00 of the tool slide 11 in the vertical plane xz.

[0047] The single-component force sensors 12.1, 12.2, 12.3 are piezoelectric force sensors having a piezoelectric material made of a single crystal, such as quartz (SiO 2 ), calcium gallium germanate (Ca 3 Ga 2 Ge 4 O 14 or CGG), lanthanum gallium silicate (La 3 Ga5 SiO 14 or LGS), tourmaline, gallium phosphate, etc., and lead zirconate titanate (Pb[Zr x Ti 1-x ]O 3 ,0≤x≤1) and other piezoelectric ceramics.

[0048] The piezoelectric material is hollow cylindrical and has an end face parallel to the end face of the shell and therefore parallel to the transverse plane xz. Therefore, the tool force Kw to be measured acts on the end face of the piezoelectric material 12.12. The piezoelectric material is oriented so that it has the highest sensitivity to the tool force Kw to be measured on the end face on which the tool force Kw acts. In the present invention, sensitivity refers to the ratio of the number of polarization charges generated under the action of the tool force Kw to the magnitude of the tool force Kw acting on the piezoelectric material. At the highest sensitivity, the piezoelectric material generates the maximum number of polarization charges. Therefore, the piezoelectric material 12.12 made of a single crystal is directionally cut into a hollow cylinder so that it generates the maximum number of polarization charges for the tool force Kw acting on the end face. Therefore, the piezoelectric material made of piezoelectric ceramics is polarized in an electric field and formed into a hollow cylinder by mechanical pressing, thereby generating the maximum number of polarization charges for the tool force Kw acting on the end face.

[0049] Preferably, at least two single-component force sensors 12.1, 12.2, 12.3 measure the same force component of the tool force Kw. Preferably, the force component of the main cutting force in the x-direction is measured. In the following, the force component of the main cutting force in the x-direction is also referred to as the main cutting force component Kwx. To this end, each of the at least two single-component force sensors 12.1, 12.2, 12.3 has a piezoelectric material that is oriented so that it generates an electric polarization charge with maximum sensitivity for the main cutting force component Kwx. Therefore, the main cutting force component Kwx is measured redundantly. In accordance with Figure 1-4 In the example of , three single-component force sensors 12.1, 12.2, 12.3 are arranged with their housing end faces parallel to the vertical plane xz. Each of the three single-component force sensors 12.1, 12.2, 12.3 measures the same main cutting force component Kwx as shear force along the transverse axis x according to the transverse shear effect.

[0050] The measurement of the tool force Kw is now specific to the position i of the desired tool 14.01-14.06. Figure 1-4In the example of , the tool holder 13 holds six required tools 14.01-14.06 at six different positions i, i=1...6, and the cutting machine 1 has three single-component force sensors 12.1, 12.2, 12.3. Each of the six required tools 14.01-14.06 is at a different distance from each of the three single-component force sensors 12.1, 12.2, 12.3. The different distances from each required tool 14.01-14.06 to each single-component force sensor 12.1, 12.2, 12.3 result in: the force flow of the tool force Kw is specific to the position i of the required tool 14.01-14.06 relative to each single-component force sensor 12.1, 12.2, 12.3, and each single-component force sensor 12.1, 12.2, 12.3 easily measures a tool force Kw with slightly different values. Typically, the value of the measured tool force Kw fluctuates in the range of 0.75 to 1.25. This position-specific measurement of tool force Kw The tool force Kw is reduced by redundantly measuring the tool force Kw by at least two single-component force sensors 12.1, 12.2, 12.3. This is because the measurement signals of the single-component force sensors 12.1, 12.2, 12.3 are added to form a position-specific average measurement signal.

[0051] The electric polarization charge must be picked up from the end face. For this purpose, the single-component force sensors 12.1, 12.2, 12.3 have electrodes. The electrodes are made of a conductive material such as copper, gold, etc. and are hollow cylindrical. Each electrode is arranged directly on one of the end faces of the piezoelectric material.

[0052] In the first single-component sensor 12.1, the first signal electrode picks up the electric polarization charge from the first end face as an analog measurement signal Sa 1 , the first ground electrode picks up the electric polarization charge from the second end face. In the second single-component sensor 12.2, the second signal electrode picks up the electric polarization charge from the first end face as the analog measurement signal Sa 2 , the second ground electrode picks up the electric polarization charge from the second end face. In the third single-component sensor 12.3, the third signal electrode picks up the electric polarization charge from the first end face as the analog measurement signal Sa 3 , the third ground electrode picks up the polarization charge from the second end surface. Analog measurement signal Sa 1 , Sa 2 , Sa 3 Proportional to the tool force Kw.

[0053] The three signal electrodes are electrically insulated relative to the housing, and the three ground electrodes are electrically connected to the housing and are at the ground potential of the housing. Since the three ground electrodes are all at the same ground potential, they have the same reference numerals.

[0054] The single-component force sensors 12.1, 12.2, 12.3 are electrically connected to the signal socket 12.4 via signal lines 12.10, 12.20, 12.30. The first signal line 12.10 connects the first signal electrode of the first single-component force sensor 12.1 to the signal socket 12.4, the second signal line 12.20 connects the second signal electrode of the second single-component force sensor 12.2 to the signal socket 12.4, and the third signal line 12.30 connects the third signal electrode of the third single-component force sensor 12.3 to the signal socket 12.4. The three signal lines 12.10, 12.20, 12.30 are laid in at least one cavity 13.10 of the tool rack 13. Preferably, when the tool rack 13 is fastened to the tool slide rail 11, the cavity 13.10 is closed to the outside by the tool rack 13. The signal lines 12.10, 12.20, 12.30 laid in the cavity 13.10 are protected by the closure from harmful external influences during the cutting and shaping process. The signal socket 12.4 is mounted on the tool holder 13 on the outside.

[0055] The signal cable 12.5 can be electrically contacted with the signal socket 12.4 from the outside. Each time the tool holder 13 is fastened to the tool slide 11, the signal cable 12.5 can also be easily and quickly electrically contacted with the signal socket 12.4 by means of a quick connector. Conversely, when the tool holder 13 is removed from the tool slide 11, the signal cable 12.5 can also be easily and quickly electrically disconnected from the signal socket 12.4 by means of a quick connector. The signal cable 12.5 electrically contacting the signal socket 12.4 transmits the analog measurement signal Sa 1 , Sa 2 , Sa 3 The signal is transmitted from the signal socket 12 . 4 to the evaluation unit 16 .

[0056] For each production step using the required tool 14.01-14.06, the first single-component force sensor 12.1 generates a first analog measurement signal Sa for the main cutting force component Kwx 1 For each manufacturing step using the required tool 14.01-14.06, the second single-component force sensor 12.2 generates a second analog measurement signal Sa for the main cutting force component Kwx 2 And for each manufacturing step using the required tool 14.01-14.06, the third single-component force sensor 12.3 generates a third analog measurement signal Sa for the main cutting force component Kwx 3 Each manufacturing step lasts from 1 second to 100 seconds. The single-component force sensors 12.1, 12.2, 12.3 generate analog measurement signals Sa with a time resolution in the frequency range of 1 kHz to 50 kHz. 1 , Sa 2 , Sa 3 .

[0057] In order that the electrode can pick up all the generated electric polarization charges from the end face of the piezoelectric material and that no electric polarization charges remain on the end face of the piezoelectric material and distort the measurement of the tool force Kw, the electrode is mechanically preloaded on the end face of the piezoelectric material. By mechanically preloading the single-component force sensors 12.1, 12.2, 12.3, the micropores between the electrode and the end face of the piezoelectric material are closed. The mechanical preloading of the single-component force sensors 12.1, 12.2, 12.3 inserted into the recesses 13.07-13.09 is achieved by fastening the tool holder 13 to the tool slide 11 using first fasteners 13.31, 13.32, 13.33.

[0058] The analysis unit 16 has at least one converter unit 16 . 1 , at least one computer 16 . 2 , at least one input unit 16 . 3 and at least one output unit 16 .

[0059] The single-component force sensors 12.1, 12.2, 12.3 are electrically connected to the converter unit 16.1 via a signal cable 12.5. The converter unit 16.1 converts the analog measurement signal Sa derived from the signal electrode into 1 , Sa 2 , Sa 3 Converted into digital measurement signal Sd 1 , Sd 2 , Sd 3 .

[0060] The computer 16.2 has at least one data processor and at least one data memory. The computer 16.2 can be operated via an input unit 16.3. The input unit 16.3 can be a keyboard for inputting control commands. In the present invention, the verb "operate" means that the computer 16.2 is started, controlled and shut down by a person using control commands via the input unit 16.3. The computer 16.2 reads the digital measurement signal Sd 1 , Sd 2 , Sd 3 The computer 16.2 reads the digital measurement signal Sd 1 , Sd 2 , Sd 3 The summation forms the position-specific averaged measurement signal (Sd 1 +Sd 2 +Sd 3 The computer 16.2 displays the location-specific averaged measurement signal (Sd) on the output unit 16.4. 1 +Sd 2 +Sd 3 ). The output unit 16.4 can be a screen for graphically displaying the analyzed digital measurement signal.

[0061] In analyzing the digital measurement signal Sd 1 , Sd 2 , Sd 3 When the computer 16.2 reads the reference signal R and the location-specific calibration factor α i .

[0062] The reference signal R is specific to the material of the workpiece 9 and the material to be cut by the required tools 14.01-14.06. The properties of the material and the material to be cut are decisive here, such as strength, toughness and hardness. However, the reference signal R is also specific to the process parameters of the cutting process. These process parameters include feed speed, feed rate, tool geometry, etc. Preferably, the reference signal R is stored in the data memory of the computer 16.2 for the material of the workpiece 9, the material to be cut by the required tools 14.01-14.06, respectively, and the individual process parameters of the cutting process, and can be read out of the data memory by the computer 16.2.

[0063] In order to further reduce the position-specificity when measuring the tool force Kw, a specific calibration factor α is stored for each position i in the data memory of the computer 16.2. i , and can be read from the data memory by the computer 16.2.

[0064] For the analysis, the computer 16.2 calculates the position-specific averaged measurement signals (Sd) of the desired tools 14.01-14.06 at position i. 1 +Sd 2 +Sd 3 ) is calibrated by multiplying it by the position-specific calibration factor α for the position i of the desired tool 14.01-14.06 i For each method step, the computer 16.2 generates a position-averaged measurement signal (Sd specific to the position i) 1 +Sd 2 +Sd 3 ) and the difference Δ between the read reference signal R for the material of the workpiece 9 and the cut material of the desired tool 14.01-14.06 at position i.

[0065] α i *(Sd l +Sd 2 +Sd 3 )-R=Δ≤T=10%*R

[0066] In the data memory of the computer 16.2 at least one predefined tolerance variable T is stored, which is read for each manufacturing step. For each manufacturing step the difference Δ is compared with the predefined tolerance variable T. If the difference Δ is less than / equal to the predefined tolerance variable T, the required tool 14.01-14.06 is not worn and will continue to be used; if the difference Δ is greater than the predefined tolerance variable T, the required tool 14.01-14.06 is worn and will be replaced. As a first approximation, the predefined tolerance variable T is equal to 10% of the reference signal R.

[0067] Figure 5 shows the calibration according to Figure 1 Flow chart of method steps 210 - 260 for a single-component force sensor 12 . 1 , 12 . 2 , 12 . 3 of a cutting machine tool 10 . Figure 6 shows the method for executing Figure 5 A part of an embodiment of a calibration device 20 of the method shown has a Figure 1 The tool holder 13 of the cutting machine tool 10 is provided.

[0068] The calibration device 20 has a calibration contact 21 , a calibration force sensor 21 , a calibration drive unit 20 and an evaluation unit 26 .

[0069] In a first method step 210, a tool holder 13 is provided with at least one required tool 14.01-14.06 and at least two single-component force sensors 12.1, 12.2, 12.3. Figure 6 In the example of FIG. 1 , the cutting machine tool 10 has three single-component force sensors 12 . 1 , 12 . 2 , 12 . 3 .

[0070] In a next method step 220, the at least two single-component force sensors 12.1, 12.2, 12.3 are contacted with an evaluation unit 26. The evaluation unit 26 has at least one converter unit 26.1, at least one computer 26.2, at least one input unit 26.3 and at least one output unit 26.4.

[0071] In a next method step 230 , a calibration force Kk is exerted on the required tool 14 . 01 - 14 . 06 by means of the calibration device 20 .

[0072] The calibration device 20 has a calibration drive unit 21 , a calibration contact 23 and a calibration force sensor 22 .

[0073] The calibration drive unit 21 is an electric drive unit, a pneumatic drive unit, etc. The calibration drive unit 21 moves the calibration contact 23 and the calibration force sensor 22 along the three axes x, y and z. The calibration drive unit 21 accurately positions the calibration contact 23 on the desired tool 14.01-14.06 located in the position i of the tool holder 13 and applies the calibration force Kk on the desired tool 14.01-14.06. The calibration force Kk has a main cutting force calibration component Kkx along the transverse axis x direction.

[0074] In accordance with Figure 6 In the example of FIG. 4 , the calibration contact 23 is finger-shaped and has a tip for applying the calibration force Kk. The calibration contact 23 is made of a mechanically resistant material, such as steel, tool steel or the like.

[0075] The calibration force sensor 22 measures the main cutting force calibration component Kkx. The calibration force sensor 22 can work according to any measurement principle. The condition for calibration is that the calibration force sensor 22 measures the main cutting force calibration component Kkx with an accuracy that is at least one order of magnitude higher than the accuracy of the at least two single-component force sensors 12.1, 12.2, 12.3. The calibration force sensor 22 is electrically connected to the converter unit 26.2 via a calibration signal cable 22.5.

[0076] In a next method step 240, the main cutting force calibration component Kkx is measured by means of the at least two single-component force sensors 12.1, 12.2, 12.3 and the calibration force sensor 22 of the calibration device 20. Figure 6 In the example of FIG. 1 , the first single-component force sensor 12 . 1 generates a first analog measurement signal Sa for the main cutting force calibration component Kkx. 1 The second single-component force sensor 12.2 generates a second analog measurement signal Sa for the main cutting force calibration component Kkx 2 The third single-component force sensor 12.3 generates a third analog measurement signal Sa for the main cutting force calibration component Kkx 3 The calibration force sensor 22 generates an analog calibration signal Ka for the main cutting force calibration component Kkx.

[0077] In a next method step 250 , the analog measurement signals Sa of the at least two single-component force sensors 12 . 1 , 12 . 2 , 12 . 3 are 1 , Sa 2 , Sa 3 The analog calibration signal Ka of the calibration force sensor 22 is transmitted to the evaluation unit 26 .

[0078] The converter unit 26.1 converts the derived analog measurement signal Sa 1 , Sa 2 , Sa 3Converted into digital measurement signal Sd 1 , Sd 2 , Sd 3 . In accordance with Figure 6 In the embodiment of the present invention, the converter unit 26.1 converts the first analog measurement signal Sa 1 Converted into a first digital measurement signal Sd 1 , the converter unit 26.1 converts the second analog measurement signal Sa 2 Converted into a second digital measurement signal Sd 2 , the converter unit 26.1 converts the third analog measurement signal Sa 3 Converted into a third digital measurement signal Sd 3 .

[0079] The converter unit 26 . 1 converts the analog calibration signal Ka derived from the calibration force sensor 22 via the signal cable 22 . 14 into a digital calibration signal Kd.

[0080] In the next method step 260 , the digital measurement signal Sd is conditioned in the evaluation unit 26 1 , Sd 2 , Sd 3 And the digital calibration signal Kd.

[0081] The computer 26.2 has at least one data processor and at least one data memory. The computer 26.2 can be operated via an input unit 26.3. The input unit 26.3 can be a keyboard for inputting control commands. In the present invention, the verb "operate" means that the computer 26.2 is started, controlled and shut down by a person using control commands via the input unit 26.3. The computer 26.2 reads the digital measurement signal Sd 1 , Sd 2 , Sd 3 And digital calibration signal Kd. Computer 26.2 converts digital measurement signal Sd 1 , Sd 2 , Sd 3 The summation forms the position-specific averaged measurement signal (Sd 1 +Sd 2 +Sd 3 The computer 26.2 displays the position-averaged measurement signal (Sd) on the output unit 26.4. 1 +Sd 2 +Sd 3 ). The output unit 26.4 may be a screen for graphically displaying the analyzed digital measurement signal.

[0082] The computer 26.2 uses the digital calibration signal Kd to adjust the digital measurement signal Sd 1 , Sd 2 , Sd3 This adjustment is carried out in particular for the position i of the required tool 14.01-14.06. Information about the position i can be input via the input unit 26.3. Figure 6 In the example of FIG. 1 , the calibration contact 23 applies the calibration force Kk to the third desired tool 14.3 in the third tool slot 13.03. The third tool slot 13.03 is in the third position i=3, and the desired tool 14.3 is in the third position i=3.

[0083] The computer 26.2 uses the digital calibration signal Kd for position i to adjust the position-specific averaged measurement signal (Sd 1 +Sd 2 +Sd 3 ). The result of this adjustment is the calibration factor α at position i i :

[0084] α i *(Sd i +Sd 2 +Sd 3 )=Kd i=1...6

[0085] The position-specific averaged measured signal (Sd 1 +Sd 2 +Sd 3 ) is the same as the digital calibration signal Kd, the calibration factor α i =1.00. Usually, the calibration factor α i Fluctuates in the range of 0.85 to 1.15. Calibration factor α i It can be stored in a data memory of the computer 16 of the evaluation unit 16 .

[0086] Reference numerals list

[0087] 9 Workpiece

[0088] 10 Cutting machine tools

[0089] 11 Tool slide

[0090] 11.00 Total contact area

[0091] 12 Force Sensor

[0092] 12.1, 12.2, 12.3 Single-component force sensor

[0093] 12.10, 12.20, 12.30 signal line

[0094] 12.11, 12.21, 12.31 First shell end surface

[0095] 12.12, 12.22, 12.32 Second shell end face

[0096] 12.4 Signal Socket

[0097] 12.5 Signal Cable

[0098] 13 Tool Rack

[0099] 13.00 Contact surface

[0100] 13.01-13.06 Tool Slot

[0101] 13.07-13.09 Leave blank

[0102] 13.10 Cavity

[0103] 13.11-13.16 First retaining member

[0104] 13.26-13.26 Second retaining member

[0105] 13.31-13.33 First fastener

[0106] 13.41-13.43 Second fastener

[0107] 14.01-14.06 Required Tools

[0108] 16,26 Analysis Unit

[0109] 16.1, 26.1 Converter Unit

[0110] 16.2, 26.2 Computer

[0111] 16.3, 26.3 Input unit

[0112] 16.4, 26.4 output units

[0113] 20 Calibration device

[0114] 21 Calibrate drive unit

[0115] 22 Calibration contacts

[0116] 23 Calibrate the force sensor

[0117] 23.5 Calibration Signal Cable

[0118] 210-260 Methods and Steps

[0119] α i Location-specific calibration factors

[0120] Δ Difference

[0121] i Position

[0122] Kw Tool force

[0123] Kwx Main cutting force component

[0124] Kwy Back force component

[0125] Kwz Feed force component

[0126] Kk Calibration force

[0127] Kkx Main cutting force calibration component

[0128] Sa 1 , Sa 2 , Sa 3 Analog measurement signal

[0129] Sd 1 , Sd 2 , Sd 3 Digital measurement signal

[0130] (Sd 1 +Sd 2 +Sd 3 ) Position-specific averaged measurement signal

[0131] R Reference signal

[0132] Ka analog calibration signal

[0133] Kd Digital calibration signal

[0134] s Gap

[0135] T Predefined tolerance variables

[0136] x horizontal axis

[0137] y horizontal axis

[0138] z vertical axis

[0139] xy transverse plane

[0140] xz vertical plane.

Claims

1. A cutting machine tool (1) for cutting and shaping a workpiece (9), wherein the cutting and shaping is performed using a plurality of required tools (14.01-14.06) in a time sequence of manufacturing steps, wherein in each manufacturing step, a required tool (14.01-14.06) can exert a tool force (Kw) on a workpiece (9); the cutting machine tool has a tool holder (13) for simultaneously holding the plurality of required tools (14.01-14.06) and a tool slide (11) for moving the tool holder (13), wherein by moving the tool holder (13), in each manufacturing step, one of the required tools (14.01-14.06) can be oriented on a workpiece (9), and the required tool (14.01-14.06) and the workpiece (9) can move relative to each other for cutting and shaping; wherein, The tool holder (13) has at least two single-component force sensors (12.1, 12.2, 12.3); and the single-component force sensors (12.1, 12.2, 12.3) measure the tool force (Kw) applied by one of the required tools (14.01-14.06) in the main force path during the cutting and shaping process of a workpiece (9); The tool rack (13) has a plurality of openings (13.07-13.09) and at least one cavity (13.10); the single-component force sensors (12.1, 12.2, 12.3) are inserted into the openings (13.07-13.09); the single-component force sensors (12.1, 12.2, 12.3) are electrically connected to a signal socket (12.4) via a signal line (12.10, 12.20, 12.30); and the signal line (12.10, 12.20, 12.30) is laid in the cavity (13.10); The tool rack (13) has a first fastener (13.31, 13.32, 13.33) and a second fastener (13.41, 13.42, 13.43); and the tool rack (13) is fastened to the tool slide rail (11) by the first fastener (13.31, 13.32, 13.33) and the second fastener (13.41, 13.42, 13.43); It is characterized in that the tool holder (13) fastened to the tool slide rail (11) is separated from the tool slide rail (11) by a gap (s) in the area of ​​the recess (13.07-13.09); and the single-component force sensor (12.1, 12.2, 12.3) inserted into the recess (13.07-13.09) is in planar contact with the tool slide rail (11) with a second shell end face (12.12, 12.22, 12.32) in the area of ​​the recess (13.07-13.09).

2. The cutting machine tool (1) according to claim 1, characterized in that: The tool rack (13) fastened to the tool slide rail (11) is in planar contact with the tool slide rail (11) via a contact surface (13.00) in the area of ​​the second fastening member (13.41, 13.42, 13.43); and the tool slide rail (11) closes the cavity (13.10) of the tool rack (13) fastened to the tool slide rail (11) outwardly.

3. The cutting machine tool (1) according to claim 2, characterized in that: The sum of the second housing end surfaces (12.12, 12.22, 12.32) of the single-component force sensors (12.1, 12.2, 12.3) is larger than the contact surface (13.00) of the tool holder (13).

4. The cutting machine tool (1) according to any one of claims 1 to 3, characterized in that: By fastening the tool holder (13) to the tool slide rail (11), the first fasteners (13.31, 13.32, 13.33) mechanically preload the single-component force sensor (12.1, 12.2, 12.3) inserted into the recess (13.07-13.09).

5. The cutting machine tool (1) according to any one of claims 1 to 3, characterized in that: The single-component force sensors (12.1, 12.2, 12.3) measure the same force components of the tool force (Kw).

6. An application of a cutting machine tool (1) according to any one of claims 1 to 5 for cutting and shaping a workpiece (9), wherein the cutting and shaping is performed using a plurality of required tools (14.01-14.06) in a chronological order of manufacturing steps; wherein in each manufacturing step, a required tool (14.01-14.06) applies a tool force (Kw) on the workpiece (9); the cutting machine tool has a tool holder (13) for simultaneously holding the plurality of required tools (14.01-14.06) and a tool slide (11) for moving the tool holder (13), wherein the movement of the tool holder (13) enables one of the required tools (14.01-14.06) to be oriented on a workpiece (9) in each manufacturing step, and the required tool (14.01-14.06) and the workpiece (9) to be moved relative to each other for cutting and shaping; characterized in that The tool holder (13) has at least two single-component force sensors (12.1, 12.2, 12.3); and the single-component force sensors (12.1, 12.2, 12.3) measure the tool force (Kw) applied by one of the required tools (14.01-14.06) in the main force path during the cutting and shaping process of a workpiece (9).

7. The use according to claim 6, characterized in that: The required tool (14.01-14.06) performs cutting movement along the direction of the transverse axis (x) during the cutting and forming process of the workpiece (9), whereby the tool force (Kw) has a main cutting force component (Kwx) along the direction of the transverse axis (x); each single-component force sensor (12.1, 12.2, 12.3) measures the tool force (Kw) as the main cutting force component (Kwx) independently of other single-component force sensors (12.1, 12.2, 12.3) in each manufacturing step; and the single-component force sensor (12.1, 12.2, 12.3) generates an analog measurement signal (Sa1, Sa2, Sa3) for the measured main cutting force component (Kwx).

8. The use according to claim 7, characterized in that: The tool holder (13) holds the required tools (14.01-14.06) at different positions (i); during the cutting and forming process, a force flow of the tool force (Kw) is specific to the corresponding position (i) of a required tool (14.01-14.06) relative to each single-component force sensor (12.1, 12.2, 12.3), and the single-component force sensors (12.1, 12.2, 12.3) respectively measure the tool force (Kw) in a position-specific manner.

9. The use according to claim 8, characterized in that: The cutting machine tool (1) has at least one converter unit (16.1), which converts analog measurement signals (Sa1, Sa2, Sa3) into digital measurement signals (Sd1, Sd2, Sd3) for each manufacturing step using a required tool (14.01-14.06); and the cutting machine tool (1) has at least one computer (16.2), which adds the digital measurement signals (Sd1, Sd2, Sd3) for each manufacturing step to form a position-specific average measurement signal (Sd1+Sd2+Sd3).

10. The use according to claim 9, characterized in that: Reference signals (R) for the material of the workpiece (9) and for the cut material of the required tool (14.01-14.06) are stored in the computer (16.2), the computer (16.2) reading a reference signal (R) for each manufacturing step; calibration factors (α) for the position (i) of the required tool (14.01-14.06) relative to the single-component force sensor (12.1, 12.2, 12.3) are stored in the computer (16.2). i ); the computer (16.2) reads a calibration factor (α) for each manufacturing step i ); the computer (16.2) multiplies the position-specific averaged measurement signal (Sd1+Sd2+Sd3) by the calibration factor (α) read for each manufacturing step i ); and for each manufacturing step, the computer (16.2) generates a calibration factor (α i ) and the difference (Δ) between the position-specific averaged measurement signal (Sd1+Sd2+Sd3) multiplied by ) and the read reference signal (R).

11. The use according to claim 9, characterized in that: A predefined tolerance variable (T) is stored in the computer (16.2); the computer (16.2) reads the predefined tolerance variable (T) for each manufacturing step; the computer (16.2) compares the difference (Δ) with the predefined tolerance variable (T) for each manufacturing step; if the difference (Δ) is less than / equal to the predefined tolerance variable (T), the required tool (14.01-14.06) is not worn and continues to be used; and if the difference (Δ) is greater than the predefined tolerance variable (T), the required tool (14) is worn and will be replaced.

12. A method for calibrating a single-component force sensor (12.1, 12.2, 12.3) of a cutting machine tool (1) according to any one of claims 1 to 5 using a calibration force sensor (22), characterized in that: In a first method step (210), a tool holder (13) of the cutting machine tool (1) is provided, the tool holder (13) having at least one required tool (14.01-14.06) and at least two single-component force sensors (12.1, 12.2, 12.3), the required tool (14.01-14.06) being arranged at a position (i) relative to the single-component force sensors (12.1, 12.2, 12.3); in a next method step (230), ), applying a calibration force (Kk) to the desired tool (14.01-14.06); in a next method step (240), measuring the calibration force (Kk) using the single-component force sensor (12.1, 12.2, 12.3) and the calibration force sensor (22); the single-component force sensor (12.1, 12.2, 12.3) generates an analog measurement signal (Sa1, Sa2, Sa3) for the measured calibration force (Kk); the calibration force sensor The device (22) generates an analog calibration signal (Ka) for the measured calibration force (Kk); converts the analog measurement signal (Sa1, Sa2, Sa3) into a digital measurement signal (Sd1, Sd2, Sd3); converts the analog calibration signal (Ka) into a digital calibration signal (Kd); and in a next method step (260), adds the digital measurement signals (Sd1, Sd2, Sd3) to form a position-specific averaged measurement signal (Sd1+Sd2+Sd3); and and using the digital calibration signal (Kd) of the position (i) of the desired tool (14.01-14.06) to adjust the position-averaged measurement signal (Sd1+Sd2+Sd3) specific to the position (i) of the desired tool (14.01-14.06), wherein the result of the adjustment is a calibration factor (α) specific to the position (i) of the desired tool (14.01-14.06) relative to the single-component force sensor (12.1, 12.2, 12.3) i ).

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