Contact dynamic rigidity calculation system, machining estimation device, and machining system

Abstract

The invention relates to a contact dynamic rigidity calculation system, a machining estimation device, and a machining system. A contact dynamic rigidity calculation system (130) calculates contact dynamic rigidity data (Ci, Ki) between a workpiece (W) and a tool (T), which are developed by contact between the workpiece (W) and the tool (T) during machining, in a machining device (2) for machining the workpiece (W) with the tool (T). Furthermore, the contact dynamic rigidity calculation system (130) is provided with: a correspondence relationship storage unit (103) that stores the correspondence relationship between the contact dynamic rigidity data and a machining state index that changes in accordance with the state of machining of the workpiece (W) by the tool (T); a machining state index acquisition unit (124) that acquires a machining state index; and a contact dynamic stiffness calculation unit (121) that calculates the contact dynamic stiffness data on the basis of the acquired machining state index and the correspondence relationship in which the degree of change of the contact dynamic stiffness data with respect to the machining state index varies.

Description

Technical Field

[0001] The invention relates to a contact dynamic rigidity calculation system, a processing inference device and a processing system. Background Art

[0002] In a grinding device for grinding a workpiece by a grinding wheel, in order to accurately infer the processing result, it is necessary to correct the relative position of the workpiece and the grinding wheel during the inference process. In the structure disclosed in patent document 1, in the case of grinding a workpiece by a grinding wheel, in addition to the grinding resistance, the support rigidity of the workpiece, the support rigidity of the grinding wheel and the contact static rigidity between the workpiece and the grinding wheel are also considered, and the relative position of the workpiece and the grinding wheel is corrected with high precision on the premise that the contact static rigidity is proportional to the contact arc length between the workpiece and the grinding wheel, that is, the relationship between the contact static rigidity and the contact arc length is linear, and the processing result of the workpiece is inferred. The contact static rigidity used here is not the value measured when the grinding wheel is stationary, but is calculated using the theoretical contact static rigidity during grinding. The contact static rigidity is represented by the spring constant K between the workpiece and the grinding wheel.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2015-208812

[0004] However, when the inventors of the present application obtained the measured values ​​of the contact static rigidity and the contact arc length to verify their relationship, they found that the relationship between the two is not linear. Moreover, the grinding state when the workpiece is ground by a grinding wheel is different, and the following three states will be mixed, namely, "elastic sliding" in which the grinding wheel slides on the surface of the workpiece, "digging" in which the grinding wheel plastically deforms the workpiece while removing the surface of the workpiece, and "cutting" in which the abrasive grains of the grinding wheel cut into the workpiece and cut off the workpiece. Considering that the existence ratio changes in a complex manner according to the progress of the processing, it is appropriate to infer that the relationship between the contact static rigidity and the contact arc length does not have a simple linear relationship. According to the above insights, in the structure described in Patent Document 1, there is room for improvement due to the low calculation accuracy of the contact static rigidity. Summary of the invention

[0005] The present invention intends to provide a contact dynamic rigidity calculation system capable of calculating contact dynamic rigidity with higher accuracy.

[0006] One embodiment of the present invention is a contact dynamic rigidity calculation system, which, in a processing device for processing a workpiece by a tool, calculates contact dynamic rigidity data between the workpiece and the tool exerted by the contact between the workpiece and the tool during processing, wherein:

[0007] a correspondence storage unit storing a correspondence between a machining state index that changes according to a state of machining of the workpiece by the tool and contact dynamic rigidity data;

[0008] a processing state index obtaining unit that obtains the processing state index; and

[0009] a contact dynamic rigidity determination unit, which determines the contact dynamic rigidity data based on the obtained processing state index and the corresponding relationship,

[0010] In the above correspondence, the degree of change of the above contact dynamic rigidity data relative to the above processing state index changes.

[0011] According to the above embodiment, the contact dynamic rigidity data is determined based on the correspondence between the stored processing state index and the contact dynamic rigidity data and the acquired processing state index. Moreover, the degree of change of the contact dynamic rigidity data relative to the processing state index in the above correspondence varies, so that the contact dynamic rigidity data can be calculated with higher accuracy than when the existing linear relationship between the contact static rigidity and the contact arc length is used.

[0012] As described above, according to the above embodiment, it is possible to provide a machining estimation device that can calculate contact dynamic rigidity with higher accuracy.

[0013] In addition, the reference numerals in parentheses described in the claims indicate the corresponding relationship with the specific mechanisms described in the embodiments described later, and do not limit the technical scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a diagram showing a machining system including a contact dynamic stiffness calculation system and a machining estimation device in the first embodiment.

[0015] Figure 2 This is a functional block diagram of the contact dynamic stiffness calculation system and processing inference device of implementation mode 1.

[0016] Figure 3 This is a schematic diagram showing the interference state between the workpiece and the grinding wheel during grinding.

[0017] Figure 4 The diagram represents the shape of the workpiece in the grinding simulation using a group of radial line segments, and represents the state of interference between the workpiece represented by the radial line segments and the outer peripheral line of the grinding wheel during the grinding process.

[0018] Figure 5 This is a schematic diagram showing the contact dynamic rigidity, workpiece support dynamic rigidity, and tool support dynamic rigidity in grinding.

[0019] Figure 6 (a) is a diagram showing a first example and (b) is a diagram showing a second example of the correspondence relationship between the machining state index and the contact dynamic rigidity data in the first embodiment.

[0020] Figure 7 (a) is a diagram of a third example and (b) is a diagram of a fourth example showing the correspondence relationship between the machining state index and the contact dynamic rigidity data in the first embodiment.

[0021] Figure 8 This is a flowchart showing the process of obtaining contact dynamic rigidity data for creating a correspondence relationship.

[0022] Fig. 9 This is a top view of the grinding machine when obtaining the contact dynamic rigidity for making the correspondence relationship.

[0023] Fig.10 This is a diagram showing the state of the grinding machine in a partial process of contact dynamic rigidity acquisition processing for creating a correspondence relationship.

[0024] Fig.11 This is a diagram showing a machining system including a contact dynamic stiffness calculation system and a machining inference device in a deformation mode.

[0025] Fig.12 This is a schematic diagram showing the interference state of a workpiece, a grinding wheel, and a support device during grinding in a deformation mode. DETAILED DESCRIPTION

[0026] (Implementation Method 1)

[0027] 1. Structure of processing system 1

[0028] Reference Figure 1 The contact dynamic rigidity calculation system 130 , the machining estimation device 3 b , and the machining system 1 of the first embodiment will be described. The machining system 1 targets a machining device that performs grinding machining. The machining system 1 includes a grinding machine 2 as a machining device and a processing unit 3 .

[0029] The grinder 2 rotates the workpiece W, rotates the grinding wheel T as a rotating body, that is, a tool, and brings the grinding wheel T relatively close to the workpiece W in a direction intersecting the axis of the workpiece W, thereby grinding the outer circumference or inner circumference of the workpiece W. The grinder 2 can be a table traverse type grinder, a grinding head traverse type grinder, etc. In addition, the grinder 2 can be a cylindrical grinder, a cam grinder, etc.

[0030] In this embodiment, if Figure 1As shown, the workpiece W is taken as an example of a case where it has a shaft portion Wa as a non-machined portion and a plurality of machined portions Wb as the outer peripheral surface to be ground. The machined portion Wb has, for example, a cylindrical outer peripheral surface coaxial with the shaft portion Wa. However, Figure 1 The workpiece W shown is an example, and the grinding machine 2 can grind workpieces having various shapes.

[0031] The processing unit 3 includes a control device 3a for controlling the grinding machine 2 and a processing estimation device 3b for estimating a processing result. The control device 3a can control the grinding process by controlling the grinding machine 2. The processing estimation device 3b estimates the processing result of the workpiece W by inputting information for the grinding process and performing simulation.

[0032] The processing inference device 3b can function as a simulation device independent of the grinding machine 2, or can function as a simulation device that operates in conjunction with the grinding machine 2. In the former case, for example, the optimal grinding conditions can be determined without actually grinding the workpiece W. In the latter case, the processing inference device 3b processes in parallel with the grinding of the workpiece W by the grinding machine 2, and can, for example, correct the grinding conditions or operate in a manner that affects various controls. In addition, the processing inference device 3b can also be set as an embedded system of the grinding machine 2 and the control device 3a.

[0033] 2. Structure of the grinding machine 2 and the control device 3a

[0034] Reference Figure 1 An example of the structure of the grinding machine 2 and the control device 3a is described in detail. The grinding machine 2 is an example of a cylindrical grinding machine of a table traverse type. That is, the grinding machine 2 is a structure that moves the workpiece W in the axial direction of the workpiece W and moves the grinding wheel T in a direction intersecting the axis of the workpiece W. In addition, in this embodiment, the grinding machine 2 is an example of a case where the outer peripheral surface of the cylindrical surface of the workpiece W is ground by the grinding wheel T.

[0035] The grinding machine 2 includes a bed 10, a table 20, a spindle device 30, a tailstock device 40, a grinding head 50, a sizing device 60, and a control device 3a. The bed 10 is installed on a setting surface. The bed 10 has a front side ( Figure 1 The width (Z-axis length) of the lower side) is formed longer, and the back side ( Figure 1 The width of the upper side) is formed shorter.

[0036] The bed 10 has a Z-axis guide surface 11 extending in the Z-axis direction on the upper surface of the front side in the X-axis direction. In addition, a Z-axis drive mechanism 12 driven along the Z-axis guide surface 11 is provided on the bed 10. In this embodiment, the Z-axis drive mechanism 12 is taken as an example of a case where it includes a ball screw mechanism 12a and a Z-axis motor 12b. The ball screw mechanism 12a extends parallel to the Z-axis guide surface 11, and the Z-axis motor 12b drives the ball screw mechanism 12a.

[0037] In order to drive the Z-axis drive mechanism 12, a Z-axis drive circuit and a Z-axis detector 12c (not shown) are provided. The Z-axis drive circuit includes an amplifier circuit, and drives the Z-axis motor 12b. In the present embodiment, the Z-axis detector 12c is, for example, an angle detector such as an encoder, and detects the angle of the rotation axis of the Z-axis motor 12b. In addition, the Z-axis drive mechanism 12 may also be replaced with a structure having the ball screw mechanism 12a, and a linear motor or the like may be applied.

[0038] In addition, the upper surface of the bed 10 on the back side in the X-axis direction is provided with a guide surface 13 extending in a direction intersecting the Z-axis direction. In the present embodiment, the guide surface 13 is an X-axis guide surface extending in the X-axis direction orthogonal to the Z-axis. In addition, an X-axis drive mechanism 14 driven along the X-axis guide surface 13 is provided on the bed 10. In the present embodiment, the X-axis drive mechanism 14 is taken as an example of a case where it is provided with a ball screw mechanism 14a and an X-axis motor 14b. The ball screw mechanism 14a extends parallel to the X-axis guide surface 13, and the X-axis motor 14b drives the ball screw mechanism 14a.

[0039] In order to drive the X-axis drive mechanism 14, an X-axis drive circuit and an X-axis detector 14c (not shown) are provided. The X-axis drive circuit includes an amplifier circuit, and drives the X-axis motor 14b. In the present embodiment, the X-axis detector 14c is, for example, an angle detector such as an encoder, and detects the angle of the rotation axis of the X-axis motor 14b. In addition, the X-axis drive mechanism 14 may also be replaced with a structure having the ball screw mechanism 14a, and a linear motor or the like may be applied.

[0040] The worktable 20 is formed in an elongated shape and is supported by the Z-axis guide surface 11 of the bed 10 so as to be movable in the Z-axis direction (horizontally left and right direction). In addition, the worktable 20 is fixed to the ball screw nut of the Z-axis ball screw mechanism 12a and is moved in the Z-axis direction by the rotation drive of the Z-axis motor 12b.

[0041] The spindle device 30 constitutes a workpiece support device. The spindle device 30 supports the workpiece W and rotationally drives the workpiece W. The spindle device 30 is arranged on one end side of the Z-axis direction on the worktable 20. The spindle device 30 includes: a spindle housing 31, a spindle 32, a spindle motor 33, a spindle center 34, a spindle detector 35, and a spindle drive circuit (not shown).

[0042] The spindle housing 31 is fixed on the workbench 20. The spindle 32 is rotatably supported by the spindle housing 31 via a bearing. The spindle motor 33 drives the spindle 32 in rotation. The spindle center 34 supports the end surface of one axial end of the workpiece W. The spindle center 34 is configured to be fixed to the spindle 32 and can rotate relative to the spindle housing 31. However, in the case where the spindle device 30 has a rotating component such as a carrier not shown in the figure, the spindle center 34 can also be configured to be fixed to the spindle housing 31 and cannot rotate relative to the spindle housing 31. In addition, the spindle device 30 can also be provided with a chuck for holding the workpiece W instead of the spindle center 34. In addition, the chuck is rotationally driven by being connected to the spindle 32.

[0043] The spindle detector 35 and the spindle drive circuit are provided to drive the spindle motor 33. In the present embodiment, the spindle detector 35 is an angle detector such as an encoder, and detects the angle of the rotating shaft of the spindle motor 33. The spindle drive circuit includes an amplifier circuit and drives the spindle motor 33.

[0044] The tailstock device 40 constitutes a workpiece support device together with the spindle device 30. The tailstock device 40 is arranged on the other end side of the Z-axis direction on the workbench 20. The tailstock device 40 is configured to be movable along the Z-axis direction on the workbench 20. The tailstock device 40 has a tailstock center 41. The tailstock center 41 supports the end surface of the other axial end of the workpiece W. The tailstock center 41 can also be set to be non-rotatable or rotatable. In addition, when the grinder 2 performs grinding on the inner peripheral surface of the workpiece W, the tailstock device 40 is not required.

[0045] In addition, the tailstock center 41 may be positioned at a fixed position relative to the workpiece W, or may be arranged to be movable relative to the workpiece W in the axial direction of the workpiece W. In the latter case, the tailstock center 41 may also be configured to be able to adjust the pressing force in the axial direction of the workpiece W relative to the workpiece W. The pressing force can be controlled by a mechanism for adjusting the spring force, a mechanism for adjusting the fluid pressure, or the like.

[0046] The grinding head 50 includes a grinding wheel T as a tool, and rotationally drives the grinding wheel T. The grinding head 50 includes, in addition to the grinding wheel T, a grinding head body 51 , a grinding wheel spindle 52 , a grinding wheel motor 53 , and a grinding wheel drive circuit (not shown).

[0047] The grinding wheel T is formed in a disc shape. The grinding wheel T is used to grind the outer peripheral surface or the inner peripheral surface of the workpiece W. The grinding wheel T is composed of a plurality of abrasive grains fixed by a binder. The abrasive grains can be general abrasive grains formed of ceramic materials such as aluminum oxide and silicon carbide, super abrasive grains such as diamond and CBN, etc.

[0048] The binder includes glass (V), resin (B), rubber (R), silicate (S), shellac (E), metal (M), electrophoresis (P), magnesium cement (Mg), etc. In addition, the grinding wheel T has a structure with pores and a structure without pores. The grinding wheel T has a structure that can be elastically deformed and a structure that is almost not elastically deformed, depending on the type of the binder and the presence or absence of pores. In the elastically deformable grinding wheel T, the elastic modulus is different depending on the type of the binder, the presence or absence of pores, the porosity, etc.

[0049] The grinding head body 51 is formed into a rectangular shape in a top view, for example, and is supported by the X-axis guide surface 13 of the bed 10 so as to be movable in the X-axis direction (horizontal front-back direction). In addition, the grinding head body 51 is fixed to the ball screw nut of the X-axis ball screw mechanism 14a, and is moved in the X-axis direction by the rotation drive of the X-axis motor 14b. The grinding head body 51 constitutes a tool support device that supports the grinding wheel T.

[0050] The grinding wheel shaft 52 is rotatably supported by the grinding head body 51 via a bearing. A grinding wheel T is fixed to the front end of the grinding wheel shaft 52, and the grinding wheel T rotates by the rotation of the grinding wheel shaft 52. The grinding wheel motor 53 drives the grinding wheel shaft 52 to rotate. The bearing uses a static pressure bearing, a rolling bearing, etc.

[0051] The grinding wheel motor 53 transmits the rotational driving force to the grinding wheel shaft 52 via a belt, for example. However, the grinding wheel motor 53 may be arranged coaxially with the grinding wheel shaft 52. Generally, the rotation speed of the grinding wheel T generated by the driving of the grinding wheel motor 53 is higher than the rotation speed of the workpiece W generated by the driving of the spindle motor 33. The grinding wheel driving circuit is provided to drive the grinding wheel motor 53. The grinding wheel driving circuit includes an amplifier circuit and drives the grinding wheel motor 53.

[0052] The sizing device 60 is provided on the upper surface of the bed 10 and measures the outer diameter of the workpiece W. The sizing device 60 includes, for example, a pair of contacts that can contact the outer peripheral surface of the workpiece W and measures the outer diameter of the contact portion with the workpiece W.

[0053] The control device 3a is a CNC (Computer Numerical Control) device and a PLC (Programmable Logic Controller) device that performs processing control. That is, the control device 3a drives the Z-axis drive mechanism 12 and the X-axis drive mechanism 14 as the moving device based on the grinding process program and the measurement results of the sizing device 60 to control the position of the worktable 20 and the grinding head 50. That is, the control device 3a makes the workpiece W and the grinding wheel T relatively close to and separated by performing position control of the worktable 20 and the grinding head 50. In addition, the control device 3a controls the spindle device 30 and the grinding head 50. That is, the control device 3a controls the rotation of the spindle 32 and the rotation of the grinding wheel T.

[0054] 3. Structure of the processing estimation device 3b

[0055] Reference Figure 2 The structure of the processing estimation device 3b is described. The processing estimation device 3b includes: an instruction value acquisition unit 101, an estimation unit 102, a contact dynamic rigidity table storage unit (correspondence storage unit) 103, a workpiece support dynamic rigidity table storage unit 104, a tool support dynamic rigidity table storage unit 105, a processing condition acquisition unit 106, a dynamic rigidity determination unit 107, a correction amount calculation unit 108, an output unit 109, and a processing condition optimization unit 110.

[0056] The command value acquisition unit 101 acquires the command value for controlling the grinding machine 2 during the grinding process. When the processing estimation device 3b is a simulation device independent of the grinding machine 2, the command value acquisition unit 101 receives the grinding process program and the configuration information of the grinding machine 2, and generates the command value for controlling each part of the grinding machine 2 through calculation. In addition, when the processing estimation device 3b functions as a simulation device that operates in conjunction with the grinding process of the grinding machine 2, the command value acquisition unit 101 can directly acquire the command value from the control device 3a of the grinding machine 2.

[0057] The estimation unit 102 performs grinding simulation using the command value acquired by the command value acquisition unit 101 to estimate at least one of the state of the workpiece W or the grinding wheel T during grinding, the shape of the workpiece W, the shape of the grinding wheel T, and the mechanical state of the grinding machine 2 .

[0058] The state of the workpiece W includes, for example, the vibration state and temperature state of the workpiece W. The state of the grinding wheel T includes, for example, the vibration state and temperature state of the grinding wheel T, the grinding resistance generated at each portion of the outer peripheral surface of the grinding wheel T, the sharpness of the grinding wheel T, the state of the abrasive grains constituting the grinding wheel T, etc. The state of the abrasive grains includes, for example, the average protrusion amount of the abrasive grains and the distribution of the abrasive grains. The shape of the workpiece W includes the shape in the middle stage of the grinding process and the shape in the end stage of the grinding process. The shape of the grinding wheel T includes the shape in the middle stage of the grinding process and the shape in the end stage of the grinding process. The mechanical state of the grinding machine 2 includes the vibration state and temperature state of the portions constituting the grinding machine 2.

[0059] In this embodiment, the inference unit 102 uses a grinding simulation to process the shape of the workpiece W in sequence, and takes the shape of the workpiece W, the state of the workpiece W, and the mechanical state of the grinding machine 2 as the inference object. In this embodiment, the grinding wheel T is set as a non-deformable component to perform the grinding simulation. In addition, the inference unit 102 can also infer the grinding resistance generated at each portion of the outer peripheral surface of the grinding wheel T in addition to the above-mentioned inference objects.

[0060] The estimation unit 102 includes an interference amount calculation unit 111 , a grinding efficiency calculation unit 112 , a grinding characteristic determination unit 113 , and a grinding resistance calculation unit 114 .

[0061] The interference amount calculation unit 111 calculates the interference amount between the workpiece W and the grinding wheel T based on the relative position of the workpiece W and the grinding wheel T obtained using the command value obtained by the command value acquisition unit 101, the outer peripheral surface shape of the workpiece W, and the outer peripheral surface shape of the grinding wheel T. The interference amount is equivalent to the radial grinding amount of the workpiece W at each circumferential portion of the workpiece W. In other words, the interference amount is the amount of workpiece W removed by grinding with the grinding wheel T, and more specifically, the radial removal amount of the workpiece W at each circumferential portion of the workpiece W. Figure 3 As shown, the interference is the interference between the workpiece W and the grinding wheel T ( Figure 3 The shaded part: the volume of the interference area).

[0062] The interference amount calculation unit 111 geometrically calculates the interference amount by arithmetic processing. Here, the interference amount calculation unit 111 stores the outer peripheral surface shape of the workpiece W and the outer peripheral surface shape of the grinding wheel T. Figure 4 As shown in the right part of , the outer peripheral shape of the workpiece W is represented by a plurality of radial line segments on the polar coordinates with the rotation center Ow of the workpiece W as the origin. That is, the interference amount calculation unit 111 stores the outer peripheral shape of the workpiece W by connecting the division points ( Figure 4 The white dots of the workpiece W) and the rotation center Ow (origin) of the workpiece W. Figure 4The division points indicated by the white dots in are stored as the outer peripheral surface shape of the workpiece W before being removed by the grinding wheel T.

[0063] The interference amount calculation unit 111 determines the intersection points ( Figure 4 The interference amount calculation unit 111 calculates the determined intersection point ( Figure 4 The black dots (black dots) are stored as the outer peripheral surface shape of the workpiece W after the workpiece W is removed by the grinding wheel T. That is, the interference amount calculation unit 111 changes the stored outer peripheral surface shape of the workpiece W.

[0064] The interference amount calculation unit 111 subtracts the area of ​​the triangle △Ow-b1-b2 formed by the points b1 and b2 (intersection points with the grinding wheel T) after removal and the origin Ow from the area of ​​the triangle △Ow-a1-a2 formed by the adjacent points a1 and a2 and the origin Ow among the points defining the outer peripheral surface shape of the workpiece W before removal. The area after subtraction is calculated for all adjacent points defining the outer peripheral surface shape of the workpiece W.

[0065] Furthermore, the interference amount calculation unit 111 accumulates the areas after each subtraction, and calculates the interference amount (removal amount) by multiplying the accumulated total area by the thickness of the workpiece W. In addition, in the above, the areas of the two triangles are calculated, and the difference between the areas is calculated to calculate the area of ​​the removed portion. In addition, the area of ​​the removed portion can also be calculated by directly calculating the quadrilateral a1-a2-b1-b2.

[0066] like Figure 2 As shown, the grinding efficiency calculation unit 112 calculates the grinding efficiency (machining efficiency) Z' based on the interference amount calculated by the interference amount calculation unit 111. The grinding efficiency Z' calculates the volume of the workpiece W removed by the grinding wheel T per unit time and per unit width.

[0067] The grinding characteristic determination unit 113 determines the grinding characteristic kc based on the material of the workpiece W, the abrasive grains of the grinding wheel T, the type of the bonding agent, and the state of the outer peripheral surface of the grinding wheel T. The state of the outer peripheral surface of the grinding wheel T is represented by, for example, the wear state of the abrasive grains of the grinding wheel T and an index indicating the sharpness. Here, the grinding characteristic determination unit 113 stores the grinding characteristics of each state through preliminary experiments, analysis, etc.

[0068] The grinding resistance calculation unit 114 calculates the grinding resistance Fn in the normal direction (X-axis direction) of the outer peripheral surface of the workpiece W based on the grinding efficiency Z' and the grinding characteristic kc. The grinding resistance Fn is obtained by multiplying the grinding efficiency Z' by the grinding characteristic kc (Fn=kc×Z').

[0069] In addition, the grinding characteristic kc has a substantially linear relationship such that the higher the grinding efficiency Z′, the greater the grinding resistance Fn in the normal direction (X-axis direction). Moreover, the grinding characteristic kc changes this relationship, for example, when the grinding wheel T is worn. For example, when the grinding wheel T is worn, the grinding resistance Fn in the normal direction changes in a manner that becomes larger relative to the grinding efficiency Z′.

[0070] The contact dynamic rigidity table storage unit 103 stores the contact dynamic rigidity data Ci, Ki between the workpiece W and the grinding wheel T. In particular, the correspondence storage unit 103 constitutes a correspondence storage unit that stores the correspondence between the machining state index described later and the data Ci, Ki in the contact dynamic rigidity. The workpiece support dynamic rigidity table storage unit 104 stores the workpiece support dynamic rigidity data Cw, Kw of the spindle device 30 and the tailstock device 40 as the workpiece support device. In particular, the workpiece support dynamic rigidity table storage unit 104 stores the correspondence between the machining conditions and the workpiece support dynamic rigidity data Cw, Kw. The tool support dynamic rigidity table storage unit 105 stores the tool support dynamic rigidity data Ct, Kt (tool support dynamic rigidity data) of the grinding head body 51 as the grinding wheel support device. In particular, the tool support dynamic rigidity table storage unit 105 stores the correspondence between the machining conditions and the tool support dynamic rigidity data Ct, Kt.

[0071] 4. Acquisition of processing conditions

[0072] like Figure 2 As shown in FIG. 1 , the machining condition acquisition unit 106 acquires the machining conditions when the grinding machine 2 performs the grinding process. Specifically, the machining condition acquisition unit 106 acquires the machining conditions when the inference unit 102 performs the inference (when the object is processed). The machining conditions acquired by the machining condition acquisition unit 106 are information used by the dynamic rigidity determination unit 107 to calculate each dynamic rigidity. The acquired machining conditions are, for example, the type of the workpiece W, the type of the workpiece support member, the type of the grinding wheel T, the pressing force of the spindle center 34 and the tailstock center 41, and the like.

[0073] When the processing estimation device 3b is a simulation device independent of the grinding machine 2, the processing condition acquisition unit 106 acquires the conditions for determining the dynamic rigidity by inputting the mechanical structure and grinding process program of the grinding machine 2. In addition, when the processing estimation device 3b functions as a simulation device that operates in conjunction with the grinding process of the grinding machine 2, the processing condition acquisition unit 106 may acquire the conditions for determining the dynamic rigidity by inputting the mechanical structure and grinding process program of the grinding machine 2 from the control device 3a, or may directly acquire information related to the conditions from the control device 3a of the grinding machine 2.

[0074] 5. Configuration of Dynamic Stiffness Determining Unit 107

[0075] The dynamic rigidity determination unit 107 determines the dynamic rigidity data affecting the grinding process. The dynamic rigidity determination unit 107 determines Figure 5 The contact dynamic rigidity data Ci, Ki, the workpiece support dynamic rigidity data Cw, Kw, and the tool support dynamic rigidity data Ct, Kt are shown. That is, the dynamic rigidity determination unit 107 includes a contact dynamic rigidity determination unit 121, a workpiece support dynamic rigidity determination unit 122, and a tool support dynamic rigidity determination unit 123.

[0076] Reference Figure 5 The contact dynamic rigidity (Ci, Ki), the workpiece support dynamic rigidity (Cw, Kw) and the tool support dynamic rigidity (Ct, Kt) are described. The contact dynamic rigidity (Ci, Ki) is the dynamic rigidity between the workpiece W and the grinding wheel T. The workpiece support dynamic rigidity (Cw, Kw) is the dynamic rigidity of the workpiece W side including the workpiece W and related to the worktable 20, the spindle device 30 and the tailstock device 40. In addition, the tool support dynamic rigidity (Ct, Kt) is the dynamic rigidity including the grinding wheel T and related to the grinding head 50. They are described in detail below.

[0077] 5-1. Contact dynamic rigidity and processing state index

[0078] The contact dynamic rigidity is the dynamic rigidity between the workpiece W and the grinding wheel T, and is the dynamic rigidity exerted by the contact between the workpiece W and the grinding wheel T during grinding. The contact dynamic rigidity is defined by the attenuation coefficient Ci and the spring constant Ki. In addition, the contact static rigidity data, which is different from the contact dynamic rigidity, is represented only by the spring constant K and does not include the attenuation coefficient C. The attenuation coefficient Ci in the contact dynamic rigidity is a value indicating the relationship between the relative speed of the workpiece W and the grinding wheel T and the external force applied to the workpiece W or the grinding wheel T. The spring constant Ki is a value indicating the relationship between the relative position of the workpiece W and the grinding wheel T and the external force applied to the workpiece W or the grinding wheel T.

[0079] Furthermore, the contact dynamic rigidity corresponds to a machining state index that changes according to the state of machining of the workpiece W by the tool (grinding wheel T) during grinding in the machining device 2. The machining state index may be, for example, machining efficiency (grinding efficiency Z′), contact arc length L, g / a (abrasive grain penetration depth / abrasive grain cutting edge interval), etc. The corresponding relationship between the machining state index and the contact dynamic rigidity data Ci and Ki can be obtained by performing actual measurements. In addition, as Figure 3 As shown, the contact arc length L is the length of the circular arc in contact with the workpiece W on the outer peripheral surface of the grinding wheel T during grinding in the cross section in the direction perpendicular to the axis of the grinding wheel T. The contact arc length L varies depending on the feed speed of the grinding wheel T in the X-axis direction, the outer diameter of the grinding wheel T, the outer diameter of the workpiece W, and the like.

[0080] exist Figure 6 (a) and (b), Figure 7 (a) and (b) show examples of the corresponding relationship between the machining state index and the contact dynamic rigidity data Ci and Ki. Figure 6 In the examples shown in (a) and (b), the grinding efficiency Z′ is used as the processing state index, and the attenuation coefficient Ci in the contact dynamic rigidity and the spring constant Ki are not linearly related (proportional) to the grinding efficiency Z′ but have a nonlinear relationship. In more detail, the correspondence between the processing state index and the contact dynamic rigidity data (Ci, Ki) is the relationship between the change degree of the contact dynamic rigidity data (Ci, Ki) relative to the processing state index. For example, in a quadratic plane where the horizontal axis is set to the processing state index and the vertical axis is set to the contact dynamic rigidity data (Ci or Ki), a function representing a curve with a continuously changing slope can be specified as an approximate formula. The approximate formula can be set to a high-order function, for example, Figure 6 The curves shown in (a) and (b) are curves defined by cubic functions.

[0081] exist Figure 7 In the examples shown in (a) and (b), the contact arc length L is used as the machining state index. In this case, although the trend is substantially the same as when the machining state index is set to the grinding efficiency Z′, there is a tendency that it is not easy to fit the curve represented by the cubic function compared to the case where the machining state index is set to the grinding efficiency Z′. On the other hand, Figure 6 As shown in (a) and (b), when the machining state index is set to grinding efficiency, it is easy to fit the curve represented by the cubic function, and the creation of the approximate formula becomes easy, so it is preferable to use the grinding efficiency Z' as the machining state index. In addition, even when the machining state index is set to g / a, the corresponding relationship between the machining state index and the contact dynamic rigidity data Ci and Ki is also shown to be consistent with Figure 6 The grinding efficiency Z' shown in (a) and (b) has a substantially similar trend. In addition, the above correspondence relationship may be replaced by the above curve, and a plurality of straight lines may be connected together in the above quadratic plane. In addition, the above correspondence relationship may be replaced by a function such as an approximate expression, and may be in the form of a data table consisting of the correspondence relationship of a plurality of data.

[0082] The machining state index is acquired by the machining state index acquisition unit 124 included in the contact dynamic rigidity determination unit 121, and the correspondence between the machining state index and the contact dynamic rigidity data (Ci, Ki) is stored in the correspondence storage unit 103. Furthermore, the contact dynamic rigidity data (Ci, Ki) is determined by the contact dynamic rigidity determination unit 121 based on the machining state index acquired by the machining state index acquisition unit 124. That is, the contact dynamic rigidity calculation system 130 is constituted by the machining state index acquisition unit 124, the correspondence storage unit 103, and the contact dynamic rigidity determination unit 121.

[0083] 5-2. Contact dynamic rigidity acquisition process for corresponding relationship creation

[0084] Reference Figure 8 to Figure 10 The process of obtaining the contact dynamic rigidity for creating the above correspondence relationship is described below. Figure 8 As shown in FIG. 1 , in the contact dynamic rigidity acquisition process, the measuring fixture 4 is first installed on the grinding machine 2 and the workpiece W ( S1 ). The measuring fixture 4 is a non-contact vibrator, which is a device that applies a vibration force to the workpiece W. Fig. 9 As shown, the measuring jig 4 is provided on the upper surface of the table 20. The measuring jig 4 can be adjusted on the upper surface of the table 20 to be fixed in the Z-axis direction.

[0085] The measuring jig 4 holds the workpiece W in a state where the workpiece W is inserted. Specifically, a portion of the shaft portion Wa, which is a non-machined portion of the workpiece W, is inserted into the measuring jig 4, and a plurality of machined portions Wb to be ground are located outside the measuring jig 4. The workpiece W inserted into and held by the measuring jig 4 is supported by the spindle device 30 and the tailstock device 40, as in the case of normal grinding.

[0086] Here, refer to Fig.10 (a)~ Fig.10 (c) The structure of the measuring jig 4 is described. The measuring jig 4 includes a housing 131, an electromagnet 132, a rotor 133, a lock nut 134, a displacement sensor 135, and a control device 136. The housing 131 is fixed to the upper surface of the table 20 of the grinding machine 2. The housing 131 is formed with a hole 131a that penetrates in the Z-axis direction.

[0087] The electromagnet 132 is embedded in the housing 131. The rotor 133 is mounted on the outer peripheral surface of the workpiece W and is provided integrally with the workpiece W. The rotor 133 is formed of a magnetic body and moves by the magnetic force generated by the electromagnet 132. The rotor 133 is formed in a cylindrical shape, and the outer peripheral surface of the rotor 133 is arranged with a predetermined gap relative to the inner peripheral surface of the housing 131. The gap becomes the distance that the rotor 133 can move relative to the housing 131. The inner peripheral surface of the rotor 133 is formed according to the shape of the outer peripheral surface of the workpiece W. The locking nut 134 is a component for fixing the rotor 133 to the workpiece W. The fixing method of the rotor 133 is not limited to the mechanism using the locking nut 134, and various mechanisms can be used.

[0088] The displacement sensor 135 is provided at a position close to the inner circumferential surface of the housing 131, and measures the distance from the outer circumferential surface of the rotor 133. That is, the displacement sensor 135 measures the displacement of the rotor 133 in the direction of approaching and separating the rotor 133 from the inner circumferential surface of the housing 131 (hereinafter referred to as radial displacement) when the rotor 133 is vibrated by the electromagnet 132.

[0089] like Fig.10 As shown in (c), the control device 136 supplies a driving current to the electromagnet 132 so that the electromagnet 132 applies a vibration force. In addition, the control device 136 obtains the displacement measured by the displacement sensor 135, that is, the radial displacement of the rotor 133.

[0090] Therefore, in Figure 8 In S1, Fig.10 As shown in (a), the shaft portion Wa, which is the non-machined portion of the workpiece W, is inserted into the rotor 133 of the measuring jig 4. Then, as shown in FIG. Fig.10 As shown in (b), the rotor 133 is fixed to the workpiece W by a lock nut 134.

[0091] Then, the housing 131 of the measuring jig 4 is mounted on the table 20. Furthermore, the workpiece W with the rotor 133 mounted thereon is supported by the spindle device 30 and the tailstock device 40. Fig.10 As shown in (b), the position of the housing 131 is adjusted so that the outer peripheral surface of the rotor 133 and the inner peripheral surface of the housing 131 of the measuring jig 4 face each other.

[0092] Next, grinding is started ( S2 ). That is, while the workpiece W and the grinding wheel T are rotated, the grinding wheel T is moved in the X-axis direction, and the outer peripheral surface of the processing portion Wb of the workpiece W is ground.

[0093] Next, a vibration force is applied by the measuring fixture 4 (S3). The vibration force applied by the measuring fixture 4 is performed while the workpiece W is ground by the grinding wheel T. The applied vibration force may be a pulse vibration or a sweep vibration in which the vibration frequency is continuously changed. The vibration force is applied by supplying a current to the electromagnet 132 by the control device 136 of the measuring fixture 4. Moreover, the vibration force is controlled by the current supplied to the magnet 132 by the control device 136.

[0094] Next, while the vibration force is applied while the grinding process is being performed, the radial displacement of the rotor 133 is measured by the displacement sensor 135 of the measuring jig 4 (S4). Here, the displacement of the rotor 133 is consistent with the radial displacement of the portion of the workpiece W fixed to the rotor 133. Therefore, when the vibration force is applied to the workpiece W, the displacement sensor 135 of the measuring jig 4 measures the radial displacement of the workpiece W.

[0095] Next, when the measurement by the displacement sensor 135 is completed, the grinding process is completed ( S5 ).

[0096] Next, the total dynamic rigidity data Ccom, Kcom during grinding are calculated (S6). The total dynamic rigidity data Ccom, Kcom are the total (composite) dynamic rigidity data represented by the above-mentioned contact dynamic rigidity data Ci, Ki, the workpiece support dynamic rigidity data Cw, Kw, and the tool support dynamic rigidity data Ct, Kt. The total dynamic rigidity data Ccom, Kcom are represented by the added value of the above-mentioned contact dynamic rigidity data Ci, Ki, the workpiece support dynamic rigidity data Cw, Kw, and the tool support dynamic rigidity data Ct, Kt.

[0097] As described above, the radial displacement measured by the displacement sensor 135 of the measuring jig 4 is measured when the vibration force is applied to the workpiece W during grinding. Therefore, the measured displacement is affected by the contact dynamic rigidity data Ci, Ki, the workpiece support dynamic rigidity data Cw, Kw, and the tool support dynamic rigidity data Ct, Kt. Therefore, the calculation of the total dynamic rigidity data Ccom, Kcom becomes data generated by the relationship between the vibration force and the radial displacement of the workpiece W when the vibration force is applied to the workpiece W during grinding.

[0098] Next, workpiece support dynamic rigidity data Cw, Kw and tool support dynamic rigidity data Ct, Kt are acquired (S7). The workpiece support dynamic rigidity data Cw, Kw and tool support dynamic rigidity data Ct, Kt are acquired in advance by a hammer test or the like.

[0099] Next, the contact dynamic rigidity data Ci and Ki are calculated (S8). The contact dynamic rigidity data Ci and Ki are obtained by subtracting the workpiece support dynamic rigidity data Cw and Kw and the tool support dynamic rigidity data Ct and Kt from the total dynamic rigidity data Ccom and Kcom.

[0100] Next, the contact dynamic rigidity data Ci, Ki are interpolated (S9). Interpolation is the process of using the contact dynamic rigidity data Ci, Ki obtained through actual measurement to obtain the contact dynamic rigidity data Ci, Ki under grinding conditions different from the actual measurement. For example, an experimental formula that defines the relationship between the contact arc length L, the attenuation coefficient Ci and the spring constant Ki can be used. In addition, interpolation can also apply experimental formulas, machine learning, theoretical calculations, etc. In this way, using the obtained contact dynamic rigidity data Ci, Ki, it is possible to produce Figure 6 (a) and (b) show the corresponding relationship with the processing state index (grinding efficiency).

[0101] 5-3. Dynamic rigidity of workpiece support

[0102] The dynamic rigidity of the workpiece support is Figure 1The dynamic rigidity related to the support in the spindle device 30 and the tailstock device 40 shown in the figure is the dynamic rigidity exerted when the workpiece W is supported by the spindle device 30 and the tailstock device 40 as the workpiece support device constituting the grinding machine 2. Figure 5 As shown in FIG. 1 , the workpiece support dynamic rigidity is defined by the damping coefficient Cw and the spring constant Kw. The damping coefficient Cw is a value indicating the relationship between the relative speed of the workpiece W relative to the reference position of the spindle device 30 and the tailstock device 40 and the external force applied to the workpiece W. The spring constant Kw is a value indicating the relationship between the relative position of the workpiece W relative to the reference position of the spindle device 30 and the tailstock device 40 and the external force applied to the workpiece W.

[0103] As described above, the workpiece support dynamic rigidity data Cw and Kw are stored in the workpiece support dynamic rigidity table storage unit 104 in a manner corresponding to the above-mentioned processing conditions. For example, in a case where the tailstock center 41 can control the pressing force in the axial direction of the workpiece W relative to the workpiece W, the workpiece support dynamic rigidity data Cw and Kw are data that change as the contact state between the tailstock center 41 and the workpiece W changes due to the change in the pressing force applied by the tailstock center 41. The workpiece support dynamic rigidity data Cw and Kw can be obtained by changing the pressing force of the tailstock center 41 and performing a hammer test, for example, in a state where the workpiece W is supported by the spindle center 34 and the tailstock center 41.

[0104] Then, the workpiece support dynamic rigidity determination unit 122 determines the workpiece support dynamic rigidity data Cw and Kw corresponding to the machining conditions acquired by the machining condition acquisition unit 106 based on the workpiece support dynamic rigidity table stored in the workpiece support dynamic rigidity table storage unit 104 .

[0105] 5-4. Dynamic rigidity of tool support

[0106] The dynamic rigidity of the tool support is Figure 1 The dynamic rigidity related to the support in the grinding head main body 51 shown is the dynamic rigidity exerted when the grinding wheel T is supported by the grinding head main body 51 as the grinding wheel support device constituting the grinding machine 2. Figure 5 As shown in FIG. 1 , the tool support dynamic rigidity is defined by the damping coefficient Ct and the spring constant Kt. The damping coefficient Ct is a value indicating the relationship between the relative speed of the grinding wheel T relative to the reference position of the grinding head body 51 and the external force applied to the grinding wheel T. The spring constant Kt is a value indicating the relationship between the relative position of the grinding wheel T relative to the reference position of the grinding head body 51 and the external force applied to the grinding wheel T.

[0107] As described above, the tool support dynamic rigidity data Ct and Kt are stored in the tool support dynamic rigidity table storage unit 105 in a manner corresponding to the above-mentioned processing conditions. The tool support dynamic rigidity table storage unit 105 stores the tool support dynamic rigidity data Ct and Kt, for example, in units of the type of grinding wheel T. In addition, in a structure in which the grinding wheel T is supported by a hydrostatic bearing, when the pressure of the hydrostatic bearing can be controlled, when the tool support dynamic rigidity data Ct and Kt vary according to the processing conditions, the tool support dynamic rigidity table storage unit 105 may also store the corresponding relationship between the processing conditions and the tool support dynamic rigidity data Ct and Kt.

[0108] Then, the tool support dynamic rigidity determination unit 123 determines the tool support dynamic rigidity data Cw and Kw corresponding to the machining conditions acquired by the machining condition acquisition unit 106 based on the tool support dynamic rigidity table stored in the tool support dynamic rigidity table storage unit 105 .

[0109] 6. Correction amount calculation unit 108

[0110] The correction amount calculation unit 108 calculates the correction amount of the relative displacement of the grinding wheel T and the workpiece W in the X-axis direction due to the grinding resistance based on the dynamic rigidity data determined by the dynamic rigidity determination unit 107. The correction amount related to the displacement can be obtained based on the dynamic rigidity data and the grinding resistance. That is, the correction amount related to the displacement can be calculated based on the grinding resistance, the contact dynamic rigidity data Ci, Ki, the workpiece support dynamic rigidity data Cw, Kw, and the tool support dynamic rigidity data Ct, Kt.

[0111] The correction amount calculation unit 108 outputs the calculated correction amount to the estimation unit 102. As described above, the estimation unit 102 estimates the estimation target based on the relative position of the workpiece W and the grinding wheel T, the outer peripheral surface shape of the workpiece W, and the outer peripheral surface shape of the grinding wheel T acquired by the command value acquisition unit 101. However, the relative position of the workpiece W and the grinding wheel T is different from the relative position of the command value due to the grinding resistance.

[0112] Therefore, when estimating the estimation object, the estimation unit 102 uses, as the relative positions of the workpiece W and the grinding wheel T, the relative positions obtained by the command value acquisition unit 101 and the relative positions obtained by adding the correction amount calculated by the correction amount calculation unit 108. That is, the estimation unit 102 estimates the estimation object based on the relative position of the command value and the correction amount calculated using each dynamic rigidity data.

[0113] In particular, in the first embodiment, the correction amount calculation unit 108 outputs the calculated correction amount to the interference amount calculation unit 111 of the estimation unit 102. As described above, the interference amount calculation unit 111 calculates the interference amount between the workpiece W and the grinding wheel T based on the relative position of the workpiece W and the grinding wheel T acquired by the command value acquisition unit 101, the outer peripheral surface shape of the workpiece W, and the outer peripheral surface shape of the grinding wheel T. However, the relative position of the workpiece W and the grinding wheel T becomes a position different from the relative position of the command value due to the grinding resistance.

[0114] Therefore, the interference amount calculation unit 111 uses, as the relative positions of the workpiece W and the grinding wheel T for calculating the interference amount, in addition to the relative position acquired by the command value acquisition unit 101, the relative position obtained by adding the correction amount calculated by the correction amount calculation unit 108. That is, the interference amount calculation unit 111 calculates the interference amount based on the relative position of the command value and the correction amount calculated using each dynamic rigidity data.

[0115] The interference amount calculation unit 111 calculates the interference amount considering the correction amount, so the grinding efficiency calculation unit 112, the grinding characteristic determination unit 113, and the grinding resistance calculation unit 114 obtain the grinding efficiency Z′, the grinding characteristic kc, and the grinding resistance Fn based on the interference amount considering the correction amount.

[0116] The output unit 109 outputs the inference object inferred by the inference unit 102. That is, the output unit 109 infers at least one of the state of the workpiece W or the grinding wheel T during grinding, the shape of the workpiece W, the shape of the grinding wheel T, and the mechanical state of the machining system 1 (equivalent to the mechanical state of the grinding machine 2). The output unit 109 may teach the inference result to a teaching device (not shown), for example.

[0117] The processing condition optimization unit 110 optimizes the processing conditions based on the inference result of the inference unit 102. Moreover, the processing condition optimization unit 110 can output the optimized processing conditions to the control device 3a of the grinding machine 2. In this case, the control device 3a can use the optimized processing conditions to perform grinding. In addition, the control device 3a can also use various dynamic rigidity data determined by the dynamic rigidity determination unit 107 to control the processing regardless of the inference result.

[0118] 7. Effects

[0119] According to the contact dynamic rigidity calculation system 130 of the present embodiment 1, the contact dynamic rigidity data is calculated based on the correspondence between the stored processing state index and the contact dynamic rigidity data, and the acquired processing state index. Moreover, since the degree of change of the contact dynamic rigidity data relative to the processing state index in the above correspondence varies, the contact dynamic rigidity data can be calculated with higher accuracy than when the existing linear relationship between the contact static rigidity and the contact arc length is used.

[0120] In the contact dynamic rigidity calculation system 130 of the first embodiment, the contact dynamic rigidity data in the above correspondence relationship is data generated from the relationship between the vibration force and the displacement of the workpiece W when the vibration force is applied to the workpiece W while the workpiece W is being machined by the tool T. Therefore, the contact dynamic rigidity data is data that correctly represents the dynamic rigidity between the workpiece W and the grinding wheel T.

[0121] In the contact dynamic rigidity calculation system 130 of the first embodiment, the machining state index is the machining efficiency of the tool T on the workpiece W. The machining efficiency is closely related to the machining state of the workpiece W, so by using the machining efficiency as the machining state index, the contact dynamic rigidity data can be calculated according to the machining state of the workpiece W with high accuracy.

[0122] In addition, in the contact dynamic rigidity calculation system 130 of the first embodiment, the above correspondence relationship is defined as an approximate expression of a function representing a curve whose slope changes continuously in a quadratic plane in which the horizontal axis is set as the machining state index and the vertical axis is set as the contact dynamic rigidity. In this way, by defining the correspondence relationship as an approximate expression of a function representing a curve having a nonlinear relationship, the contact dynamic rigidity data can be calculated with higher accuracy than in the case of having a conventional linear relationship.

[0123] In addition, in the contact dynamic rigidity calculation system 130 of the present embodiment 1, the processing device 2 is a cylindrical grinder that grinds the cylindrical outer peripheral surface of the workpiece W using a grinding wheel T as a tool, and is provided with a workpiece support device consisting of a spindle device 30 that supports one axial end of the workpiece W and is driven to rotate, and a tailstock center 41 that supports the other axial end of the workpiece W. Moreover, the processing state index is the grinding efficiency Z′ of the grinding wheel T on the workpiece W. Therefore, when the processing state index is set to the grinding efficiency, the contact dynamic rigidity data is easily adapted to a curve represented by a cubic function, the preparation of an approximate formula becomes easy, and the contact dynamic rigidity data can be calculated with higher accuracy.

[0124] In the contact dynamic rigidity calculation system 130 of the first embodiment, the processing device 2 is a cylindrical grinder that grinds the cylindrical outer peripheral surface of the workpiece W using a grinding wheel T as a tool, and includes a workpiece support device composed of a spindle device 30 that supports one axial end of the workpiece W and drives the workpiece W to rotate, and a tailstock center 41 that supports the other axial end of the workpiece W. Furthermore, the processing state index is the contact arc length L of the grinding wheel T with the workpiece W. Thus, the processing state index can be easily obtained, and the calculation load can be reduced.

[0125] In addition, the processing estimation device 3b of the present embodiment 1 is constituted by a contact dynamic rigidity calculation system 130, and includes: a contact dynamic rigidity determination unit 121 that determines contact dynamic rigidity data between the tool T and the workpiece W; a workpiece support dynamic rigidity determination unit 122 that determines workpiece support dynamic rigidity data of the workpiece support devices 30 and 40 that are exerted when the workpiece W is supported by the workpiece support devices 30 and 40 constituting the processing device 2; a tool support dynamic rigidity determination unit 123 that determines tool support dynamic rigidity data of the tool support device 51 that is exerted when the tool T is supported by the tool support device 51 constituting the processing device 2; a correction amount calculation unit 108 that calculates a correction amount of the relative position of the tool T and the workpiece W based on the contact dynamic rigidity data, the tool support dynamic rigidity data, and the workpiece support dynamic rigidity data; and an estimation unit 102 that estimates a processing result of the tool T on the workpiece W based on a command value and the correction amount for processing the workpiece W. Thus, the processing estimation device 3b uses the contact dynamic rigidity data calculated with high accuracy based on the contact dynamic rigidity calculation system 130, so that the processing result can be estimated with high accuracy.

[0126] In addition, in the machining system 1 of the present first embodiment, the machining estimation device 3b further includes a machining condition optimization unit 110, which optimizes the machining conditions of the workpiece W based on the machining result estimated by the estimation unit 102, and the machining device 2 is configured to perform machining of the workpiece W by the tool T based on the optimized machining conditions. Thus, the workpiece W can be machined under the machining conditions optimized based on the machining result estimated with high precision, so that the workpiece W can be stably manufactured with high precision, and the manufacturing cost can be reduced.

[0127] As described above, according to the above embodiment, it is possible to provide the contact dynamic rigidity calculation system 130 , the machining estimation device 3 b , and the machining system 1 which are capable of calculating the contact dynamic rigidity with higher accuracy.

[0128] Instead of the case of the present embodiment 1, Fig.11 In the illustrated variant, the processing device 2 is provided with a support device 70. Fig.12As shown, the support device 70 includes a first arm 71 and a second arm 72, and is configured to slide and support the lower portion W1 of the workpiece W and a side portion W2 opposite to the tool T at the same position in the spindle direction as the grinding wheel T by the two arms 71 and 72. The support device 70 prevents the workpiece W from being displaced away from the grinding wheel T during machining.

[0129] In the case of this modified form, it is also possible to achieve the same effects as those of the first embodiment. In addition, when the support device 70 is provided, the workpiece W may be supported by either cantilever support or double-sided support.

[0130] In the above embodiment, although the cutting process using grinding is illustrated as an example, the grinding process uses the grinder 2 as the processing device, but in addition, the cutting process using a lathe or a machining center can also be applied in the same manner. In the case of cutting, cutting efficiency, cutting depth, etc. can be used as the processing state index.

Claims

1. A contact dynamic rigidity calculation system (130) for calculating contact dynamic rigidity data (Ci, Ki) between the workpiece and the tool during machining in a machining device (2) for machining a workpiece (W) by means of a tool (T), wherein: have: a correspondence storage unit (103) storing a correspondence between a machining state index that changes according to a state of machining of the workpiece by the tool and contact dynamic rigidity data; a processing state index obtaining unit (124) for obtaining the processing state index; and A contact dynamic rigidity determination unit (121) determines the contact dynamic rigidity data based on the obtained processing state index and the corresponding relationship. In the above correspondence, the degree of change of the above contact dynamic rigidity data relative to the above processing state index changes.

2. The contact dynamic stiffness calculation system according to claim 1, wherein: The contact dynamic rigidity data in the corresponding relationship is data generated based on the relationship between the vibration force and the displacement of the workpiece when the workpiece is machined by the tool and the vibration force is applied to the workpiece.

3. The contact dynamic stiffness calculation system according to claim 1 or 2, wherein: The machining state index includes any one of machining efficiency of the tool on the workpiece, contact arc length between the tool and the workpiece, abrasive cutting depth / abrasive cutting edge interval of the tool, and cutting depth of the tool.

4. The contact dynamic stiffness calculation system according to claim 1 or 2, wherein: The above correspondence relationship specifies a function representing a curve with a continuously changing slope as an approximate expression in a quadratic plane in which the horizontal axis is the above machining state index and the vertical axis is the above contact dynamic rigidity data.

5. The contact dynamic rigidity calculation system according to claim 1 or 2, wherein: The processing device (2) is a cylindrical grinding machine for grinding the cylindrical outer peripheral surface of the workpiece using a grinding wheel as the tool, and is provided with a workpiece supporting device consisting of a spindle device (30) supporting one axial end of the workpiece and driving the workpiece to rotate, and a tailstock center (41) supporting the other axial end of the workpiece. The machining state index is the grinding efficiency (Z') of the grinding wheel on the workpiece.

6. The contact dynamic rigidity calculation system according to claim 1 or 2, wherein: The processing device (2) is a cylindrical grinding machine for grinding the cylindrical outer peripheral surface of the workpiece using a grinding wheel as the tool, and is provided with a workpiece supporting device consisting of a spindle device (30) supporting one axial end of the workpiece and driving the workpiece to rotate, and a tailstock center (41) supporting the other axial end of the workpiece. The machining state index is the contact arc length (L) between the grinding wheel and the workpiece.

7. A processing inference device (3b), wherein: have: A contact dynamic rigidity determination unit (121), which is composed of the contact dynamic rigidity calculation system described in claim 1 or 2, and determines the contact dynamic rigidity data between the tool and the workpiece; a workpiece support dynamic rigidity determination unit (122) for determining workpiece support dynamic rigidity data of the workpiece support device when the workpiece is supported by the workpiece support device (30, 40) constituting the processing device; a tool support dynamic rigidity determination unit (123) for determining tool support dynamic rigidity data of the tool support device when the tool is supported by the tool support device (51) constituting the processing device; a correction amount calculation unit (108) for calculating a correction amount of a relative position between the tool and the workpiece based on the contact dynamic rigidity data, the workpiece support dynamic rigidity data, and the tool support dynamic rigidity data; and An inference unit (102) infers a result of machining the workpiece by the tool based on a command value for machining the workpiece and the correction amount.

8. A processing system (1), wherein: have: A processing inference device, which is the processing inference device according to claim 7, further comprising a processing condition optimization unit (110) for optimizing the processing conditions of the workpiece based on the processing result inferred by the inference unit; and The above-mentioned processing device processes the above-mentioned workpiece by the above-mentioned tool based on the above-mentioned optimized processing conditions.

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