Processing equipment

Abstract

A machining device (1, 201) for machining a workpiece (W), which is supported by a workpiece supporting member (20, 30, 40, 60, 220, 230, 240), with a tool (T, T2), the machining device (1, 201) comprising a processing unit (3, 203) that controls machining, or estimates at least one of the state of the workpiece (W) or the tool (T, T2) during machining, the shape of the workpiece (W), the shape of the tool (T, T2), and a machine state of the machining device (1, 201), using contact dynamic stiffness data (Cwc, Kwc) between the workpiece (W) and the workpiece supporting member (20, 30, 40, 60, 220, 230, 240) provided by the contact between the workpiece (W) and the workpiece supporting member (20, 30, 40, 60, 220, 230, 240).

Description

[Technical Field]

[0001] The present disclosure relates to a processing device. [Background technology]

[0002] Patent Document 1 describes a grinding simulation device. The grinding simulation is performed by repeatedly calculating the amount of workpiece removal based on the relative positions of the workpiece and the grinding wheel, calculating the grinding resistance based on the amount of removal, and calculating a correction amount for the relative position based on the grinding resistance. The calculation of the correction amount uses previously measured support stiffness for supporting the workpiece and the support stiffness for supporting the grinding wheel.

[0003] Patent Document 2 describes that when a workpiece is ground with a grinding wheel, the depth of the grinding marks on the workpiece is calculated taking into account the static contact stiffness between the workpiece and the grinding wheel. The static contact stiffness used here is calculated using the theoretical static contact stiffness during grinding, rather than a value measured when the grinding wheel is stationary. The static contact stiffness is expressed by the spring constant K between the workpiece and the grinding wheel. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2018-153907 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-208812 Summary of the Invention [Problem to be solved by the invention]

[0005] The devices described in Patent Documents 1 and 2 take into consideration the support rigidity of the workpiece support member that supports the workpiece. The rigidity of the support structure for the workpiece by the workpiece support member varies not only depending on the rigidity of the workpiece support member itself, but also on the contact state between the workpiece and the workpiece support member. However, the devices described in Patent Documents 1 and 2 do not take into consideration the change in the contact state, and it was found that errors occur in the estimation results of the estimation target.

[0006] The present disclosure seeks to provide a processing device that performs a desired target process while taking into consideration the contact state between a workpiece and a workpiece support member. [Means for solving the problem]

[0007] One aspect of the present disclosure is a processing apparatus that processes a workpiece supported by a workpiece support member using a tool, a dynamic stiffness determination unit that determines workpiece dynamic stiffness data that is the dynamic stiffness of the workpiece, support member dynamic stiffness data that is the dynamic stiffness of the workpiece support member, and contact dynamic stiffness data between the workpiece and the workpiece support member that is exerted by contact between the workpiece and the workpiece support member; a processing unit that controls machining using the determined workpiece dynamic stiffness data, the support member dynamic stiffness data, and the contact dynamic stiffness data, or that estimates at least one of a state of the workpiece or the tool during machining, a shape of the workpiece, a shape of the tool, and a mechanical state of the machining device; The processing device is provided with: [Effects of the Invention]

[0008] According to the above aspect, the dynamic stiffness determination unit determines workpiece dynamic stiffness data, workpiece support member dynamic stiffness data, and contact dynamic stiffness data between the workpiece and the workpiece support member. The processing unit performs a desired target process using the determined workpiece dynamic stiffness data, workpiece support member dynamic stiffness data, and contact dynamic stiffness data. The desired target process is a process for controlling machining, or a process for estimating at least one of the state of the workpiece or tool during machining, the shape of the workpiece, the shape of the tool, and the mechanical state of the machining device.

[0009] The contact dynamic stiffness data is represented by the spring constant and damping coefficient between the workpiece and the workpiece support member that are exerted by contact between the workpiece and the workpiece support member. By using the contact dynamic stiffness data including the spring constant and damping coefficient, the desired target processing can be performed with high accuracy.

[0010] As described above, according to the above aspect, it is possible to provide a processing device that performs a desired processing by taking into consideration the contact state between the workpiece and the workpiece support member.

[0011] It should be noted that the reference symbols in parentheses in the claims indicate the correspondence with the specific means described in the embodiments to be described later, and do not limit the technical scope of the present invention. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a diagram showing a processing device according to a first embodiment. [Figure 2] FIG. 2 is a functional block diagram of a processing estimation device that constitutes the processing device. [Figure 3] FIG. 2 is a schematic diagram showing interference between a workpiece and a grinding wheel during grinding. [Figure 4] This is a diagram showing the shape of a workpiece in a grinding simulation using a group of radial line segments, and shows how the workpiece, represented by the radial line segments, interferes with the outer circumferential line of the grinding wheel during grinding. [Figure 5]1 is a schematic diagram showing the dynamic stiffness of a workpiece and the dynamic stiffness of a tool in a grinding process; [Figure 6] 10A and 10B are diagrams illustrating the relationship between the workpiece and the support member and the contact dynamic stiffness. [Figure 7] FIG. 10 is a diagram showing a contact dynamic stiffness table obtained by actual measurement. [Figure 8] FIG. 10 is a diagram showing a contact dynamic stiffness table obtained by actual measurement and interpolation processing. [Figure 9] FIG. 10 is a diagram showing a processing device according to a second embodiment. [Figure 10] FIG. 2 is a schematic diagram showing the dynamic stiffness of a workpiece and the dynamic stiffness of a tool in cutting processing. DETAILED DESCRIPTION OF THE INVENTION

[0013] (Embodiment 1) 1. Configuration of processing device 1 The processing device 1 will be described with reference to Fig. 1. The processing device 1 is a processing device that performs grinding. The processing device 1 includes a grinding machine main body 2 as the processing device main body, and a processing section 3.

[0014] The grinding machine main body 2 rotates the workpiece W, rotates the grinding wheel T as a tool that is a rotating body, and moves the grinding wheel T relatively close to the workpiece W in a direction intersecting the axis of the workpiece W, thereby grinding the outer or inner peripheral surface of the workpiece W. The grinding machine main body 2 can be a table traverse type grinding machine, a wheelhead traverse type grinding machine, or the like. The grinding machine main body 2 can also be a cylindrical grinding machine, a cam grinding machine, or the like.

[0015] In this embodiment, the workpiece W is, for example, a member formed in a shaft shape, as shown in Fig. 1. However, the workpiece W is not limited to a shaft shape and can have any shape.

[0016] In this embodiment, the workpiece W has a shaft portion Wa as a non-machined portion and multiple machined portions Wb whose outer circumferential surfaces are to be ground. The machined portions Wb have, for example, a cylindrical outer circumferential surface coaxial with the shaft portion Wa. However, the workpiece W shown in FIG. 1 is just one example, and the grinding machine body 2 can grind workpieces having various shapes. Furthermore, the workpiece W has a spindle-side center hole Wc on one axial end surface and a tailstock-side center hole Wd on the other axial end surface.

[0017] The processing unit 3 includes a control device 3a that controls the grinding machine body 2, and a processing estimation device 3b that estimates an estimation target related to processing. The control device 3a can control the grinding processing by controlling the grinding machine body 2. The processing estimation device 3b estimates at least one of the state of the workpiece W or the grinding wheel T during grinding processing by the grinding machine body 2, the shape of the workpiece W, the shape of the grinding wheel T, and the mechanical state of the processing device 1 (corresponding to the mechanical state of the grinding machine body 2). The processing estimation device 3b performs estimation processing of the above estimation target by inputting information used in the grinding processing and performing a simulation.

[0018] The processing estimation device 3b can function as a simulation device independent of the grinding machine main body 2 and the control device 3a, or as a simulation device that operates in conjunction with the grinding machine main body 2 and the control device 3a. In the former case, the processing estimation device 3b can, for example, determine optimal grinding conditions without actually grinding the workpiece W. In the latter case, the processing estimation device 3b can, for example, correct the grinding conditions or operate to affect various controls by processing in parallel with the grinding of the workpiece W by the grinding machine main body 2. The processing estimation device 3b can also be an embedded system in the grinding machine main body 2 and the control device 3a.

[0019] 2. Configuration of the grinding machine body 2 and the control device 3a An example of the configuration of the grinding machine main body 2 and the control device 3a will be described in detail with reference to Fig. 1. The grinding machine main body 2 is exemplified by a table traverse type cylindrical grinding machine. That is, the grinding machine main body 2 is configured to move the workpiece W in the axial direction of the workpiece W and to move the grinding wheel T in a direction intersecting the axis of the workpiece W. In addition, in this embodiment, the grinding machine main body 2 is exemplified by a case where the grinding wheel T grinds the cylindrical outer peripheral surface of the workpiece W.

[0020] The grinding machine body 2 includes a bed 10, a table 20, a spindle unit 30, a tailstock unit 40, a wheel head 50, and a rest unit 60. The table 20, the spindle unit 30, the tailstock unit 40, and the rest unit 60 function as workpiece support members that support the workpiece W. The wheel head 50 functions as a tool support member that supports the grinding wheel T. In other words, the grinding machine body 2 grinds the workpiece W supported by the workpiece support members with the grinding wheel T supported by the tool support member. The grinding machine body 2 may further include a sizing device (not shown). The grinding machine body 2 may also be configured without the rest unit 60. The components of the grinding machine body 2 are described in detail below.

[0021] The bed 10 is placed on an installation surface. The bed 10 is formed so that the width (length in the Z-axis direction) of the front side in the X-axis direction (lower side in Fig. 1) is long, and the width of the back side in the X-axis direction (upper side in Fig. 1) is short.

[0022] Bed 10 is provided with a Z-axis guide surface 11 extending in the Z-axis direction on the upper surface on the front side in the X-axis direction. Bed 10 also has a Z-axis drive mechanism 12 that drives along Z-axis guide surface 11. In this embodiment, Z-axis drive mechanism 12 includes a ball screw mechanism 12a and a Z-axis motor 12b. Ball screw mechanism 12a extends parallel to Z-axis guide surface 11, and Z-axis motor 12b drives ball screw mechanism 12a.

[0023] A Z-axis drive circuit and Z-axis detector 12c (not shown) are provided to drive Z-axis drive mechanism 12. The Z-axis drive circuit includes an amplifier circuit and drives Z-axis motor 12b. In this embodiment, Z-axis detector 12c is an angle detector such as an encoder, which detects the angle of the rotation shaft of Z-axis motor 12b. Note that Z-axis drive mechanism 12 may also use a linear motor instead of the ball screw mechanism 12a.

[0024] Bed 10 also has a guide surface 13 on its upper surface on the rear side in the X-axis direction, which extends in a direction intersecting the Z-axis direction. In this embodiment, guide surface 13 is an X-axis guide surface that extends in the X-axis direction, which is perpendicular to the Z-axis. Bed 10 also has an X-axis drive mechanism 14 that drives along X-axis guide surface 13. In this embodiment, X-axis drive mechanism 14 includes a ball screw mechanism 14a and an X-axis motor 14b. Ball screw mechanism 14a extends parallel to X-axis guide surface 13, and X-axis motor 14b drives ball screw mechanism 14a.

[0025] An X-axis drive circuit and an X-axis detector 14c (not shown) are provided to drive the X-axis drive mechanism 14. The X-axis drive circuit includes an amplifier circuit and drives the X-axis motor 14b. In this embodiment, the X-axis detector 14c is an angle detector such as an encoder, which detects the angle of the rotation shaft of the X-axis motor 14b. Note that the X-axis drive mechanism 14 may also be configured with a linear motor instead of the ball screw mechanism 14a.

[0026] Table 20 is formed in an elongated shape and is supported movably in the Z-axis direction (horizontal left-right direction) on Z-axis guide surface 11 of bed 10. Table 20 is also fixed to a ball screw nut of Z-axis ball screw mechanism 12a, and moves in the Z-axis direction by rotational driving of Z-axis motor 12b.

[0027] The spindle device 30 constitutes a workpiece support member. The spindle device 30 supports the workpiece W and drives it to rotate. The spindle device 30 is disposed on one end side in the Z-axis direction on the table 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).

[0028] The spindle housing 31 is fixed onto the table 20. The spindle 32 is rotatably supported by the spindle housing 31 via a bearing. The spindle motor 33 drives the spindle 32 to rotate.

[0029] The spindle center 34 (corresponding to the support center) supports the end face of one axial end (the left end in FIG. 1) of the workpiece W. More specifically, the spindle center 34 supports the workpiece W while being pressed in the axial direction against a spindle-side center hole Wc formed in the end face of one axial end of the workpiece W. In this case, the spindle center 34 supports the spindle-side center hole Wc, which is one element of the supported portion of the workpiece W.

[0030] The spindle center 34 is fixed to the spindle 32 and is provided rotatably relative to the spindle housing 31. However, if the spindle device 30 is provided with a turning member such as a cage (not shown), the spindle center 34 may be fixed to the spindle housing 31 and provided so as to be non-rotatable relative to the spindle housing 31. Furthermore, the spindle device 30 may be provided with a chuck that grips the workpiece W, instead of the spindle center 34. The chuck is connected to the spindle 32 and is driven to rotate.

[0031] The spindle detector 35 and the spindle drive circuit are provided to drive the spindle motor 33. In this embodiment, the spindle detector 35 is an angle detector such as an encoder, and detects the angle of the rotation shaft of the spindle motor 33. The spindle drive circuit includes an amplifier circuit and drives the spindle motor 33.

[0032] The tailstock device 40, together with the spindle device 30, constitutes a workpiece support member. The tailstock device 40 is disposed on the other end of the table 20 in the Z-axis direction. The tailstock device 40 is provided so as to be movable in the Z-axis direction on the table 20. The tailstock device 40 includes a tailstock center 41 and an adjustment mechanism 42. Note that when the grinding machine body 2 grinds the inner peripheral surface of the workpiece W, the tailstock device 40 is not necessary.

[0033] The tailstock center 41 (corresponding to a support center) supports the end face of the other axial end (the right end in FIG. 1) of the workpiece W. More specifically, the tailstock center 41 supports the workpiece W while being pressed in the axial direction against a tailstock-side center hole Wd formed in the end face of the other axial end of the workpiece W. In this case, the tailstock center 41 supports the tailstock-side center hole Wd as one of the elements of the supported portion of the workpiece W. The tailstock center 41 may be provided so as to be non-rotatable or so as to be rotatable.

[0034] The tailstock center 41 may be positioned at a fixed position relative to the workpiece W, or may be provided so as to be movable in the axial direction of the workpiece W relative to the workpiece W. In the latter case, the tailstock center 41 may be configured so that the pressing force in the axial direction of the workpiece W against the workpiece W is adjustable. The pressing force can be controlled by means of adjusting a spring force, means of adjusting a fluid pressure, or the like.

[0035] In this embodiment, the tailstock device 40 is equipped with an adjustment mechanism 42, which is formed of, for example, a spring, and is configured so that the tailstock center 41 exerts a pressing force. Here, when the tailstock center 41 generates a pressing force against the workpiece W, the spindle center 34 also exerts a pressing force against the workpiece W as a reaction. In detail, the adjustment mechanism 42 is configured so that the tailstock center 41 and the spindle center 34 can adjust the pressing force against the workpiece W in the axial direction of the workpiece W. In other words, the adjustment mechanism 42 is configured so that the tailstock center 41 and the spindle center 34 can adjust the supporting force of the workpiece W. Here, the pressing force against the workpiece W by the tailstock center 41 and the spindle center 34 can be adjusted by an actuator, or can be adjusted by an operator.

[0036] The wheel head 50 is provided with a grinding wheel T and rotates the grinding wheel T. In addition to the grinding wheel T, the wheel head 50 is provided with a wheel head body 51, a grinding wheel spindle 52, a grinding wheel motor 53, and a grinding wheel drive circuit (not shown).

[0037] The grinding wheel T is formed in a disk shape. The grinding wheel T is used to grind the outer or inner surface of the workpiece W. The grinding wheel T is composed of multiple abrasive grains fixed with a binder. The abrasive grains used include general abrasive grains made of ceramic materials such as alumina and silicon carbide, and super abrasive grains such as diamond and CBN.

[0038] Binders include vitrified (V), resinoid (B), rubber (R), silicate (S), shellac (E), metal (M), electroplated (P), and magnesia cement (Mg). Furthermore, grinding wheels T are available in porous and non-porous configurations. Depending on the type of binder and the presence or absence of pores, grinding wheels T can be elastically deformable or virtually non-elastically deformable. Elastic modulus of elasticity of elastically deformable grinding wheels T varies depending on the type of binder, the presence or absence of pores, and the porosity.

[0039] The wheel head body 51 is formed, for example, in a rectangular shape in a plan view, and is supported on the X-axis guide surface 13 of the bed 10 so as to be movable in the X-axis direction (horizontal front-to-back direction). The wheel head body 51 is also fixed to the ball screw nut of the X-axis ball screw mechanism 14a, and moves in the X-axis direction by the rotational drive of the X-axis motor 14b. The wheel head body 51 constitutes a tool support member that supports the grinding wheel T.

[0040] The grinding wheel spindle 52 is rotatably supported by the wheel head body 51 via a bearing. A grinding wheel T is fixed to the tip of the grinding wheel spindle 52, and the grinding wheel T rotates as the grinding wheel spindle 52 rotates. A grinding wheel motor 53 drives the grinding wheel spindle 52 to rotate. The bearing may be a hydrostatic bearing, a rolling bearing, or the like.

[0041] The grinding wheel motor 53 transmits the rotational driving force to the grinding spindle 52 via, for example, a belt. However, the grinding wheel motor 53 may be arranged coaxially with the grinding spindle 52. In general, the rotation speed of the grinding wheel T driven by the grinding wheel motor 53 is higher than the rotation speed of the workpiece W driven by the spindle motor 33. A grinding wheel drive circuit is provided to drive the grinding wheel motor 53. The grinding wheel drive circuit includes an amplifier circuit and drives the grinding wheel motor 53.

[0042] The rest device 60 is provided on the upper surface of the bed 10 and constitutes a workpiece support member that supports the outer peripheral surface of the workpiece W, which is one of the elements of the supported portion of the workpiece W. The rest device 60 is configured to be able to adjust the pressing force against the outer peripheral surface of the workpiece W, for example, by including a spring or the like. In other words, the rest device 60 is configured to be able to adjust the rigidity value of the workpiece W. Here, the pressing force by the rest device 60 against the outer peripheral surface of the workpiece W can be adjusted by an actuator, or can also be adjusted by the operator.

[0043] The control device 3a is a CNC (Computer Numerical Control) device and a PLC (Programmable Logic Controller) device that executes machining control. That is, the control device 3a drives the Z-axis drive mechanism 12 and the X-axis drive mechanism 14, which serve as moving devices, based on a grinding program to control the positions of the table 20 and the wheel head 50. That is, the control device 3a controls the positions of the table 20, the wheel head 50, etc., thereby moving the workpiece W and the grinding wheel T closer to or farther apart from each other. Furthermore, the control device 3a controls the spindle device 30 and the wheel head 50. That is, the control device 3a controls the rotation of the spindle 32 and the grinding wheel T.

[0044] Furthermore, if the axial pressing force applied to the workpiece W by the tailstock center 41 and the spindle center 34 can be adjusted by an actuator, the control device 3a can adjust the axial pressing force by controlling the actuator. Furthermore, if the radial pressing force applied to the outer peripheral surface of the workpiece W by the rest device 60 can be adjusted by an actuator, the control device 3a can adjust the radial pressing force by controlling the actuator.

[0045] 3. Configuration of the processing estimation device 3b The configuration of the machining estimation device 3b will be described with reference to Fig. 2. The machining estimation device 3b includes a command value acquisition unit 101, an estimation unit 102, a workpiece side dynamic stiffness table storage unit 103, a grinding wheel side dynamic stiffness table storage unit 104, a dynamic stiffness determination condition acquisition unit 105, a dynamic stiffness determination unit 106, a correction amount calculation unit 107, and an output unit 108.

[0046] The command value acquisition unit 101 acquires command values ​​for controlling the grinding machine body 2 in the grinding process. When the processing estimation device 3b is a simulation device independent of the grinding machine body 2 and the control device 3a, the command value acquisition unit 101 inputs a grinding program and configuration information of the grinding machine body 2, and generates command values ​​by calculation for controlling each part of the grinding machine body 2. When the processing estimation device 3b functions as a simulation device that operates in conjunction with the grinding process performed by the grinding machine body 2 and the control device 3a, the command value acquisition unit 101 can acquire command values ​​directly from the control device 3a.

[0047] The estimation unit 102 performs a grinding simulation using the command values ​​acquired by the command value acquisition unit 101, thereby estimating 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 main body 2.

[0048] 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 part of the outer surface of the grinding wheel T, the sharpness of the grinding wheel T, and the state of the abrasive grains that make up the grinding wheel T. The state of the abrasive grains includes, for example, the average protrusion amount of the abrasive grains and the abrasive grain distribution. The shape of the workpiece W includes the shape at an intermediate stage of grinding processing and the shape at an end of grinding processing. The shape of the grinding wheel T includes the shape at an intermediate stage of grinding processing and the shape at an end of grinding processing. The mechanical state of the grinding machine main body 2 includes the vibration state and temperature state of the parts that make up the grinding machine main body 2.

[0049] In this embodiment, the estimation unit 102 performs a grinding simulation in which the shape of the workpiece W changes sequentially, and thereby estimates the shape of the workpiece W, the state of the workpiece W, and the mechanical state of the grinding machine main body 2. In this embodiment, the grinding simulation is performed assuming that the grinding wheel T does not deform. Note that the estimation unit 102 can also estimate the grinding resistance generated at each location on the outer circumferential surface of the grinding wheel T, in addition to the above estimation targets.

[0050] 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 .

[0051] The interference amount calculation unit 111 calculates the amount of interference between the workpiece W and the grinding wheel T based on the relative positions 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 obtained using the command value acquired by the command value acquisition unit 101. The interference amount corresponds to the amount of radial grinding of the workpiece W at each portion in the circumferential direction of the workpiece W. In other words, the interference amount is the amount of removal of the workpiece W ground by the grinding wheel T, more specifically, the amount of radial removal of the workpiece W at each portion in the circumferential direction of the workpiece W. As shown in FIG. 3, the interference amount is the volume of the portion where the workpiece W interferes with the grinding wheel T (the shaded portion in FIG. 3: the interference area).

[0052] The interference amount calculation unit 111 geometrically calculates the amount of interference through 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. As shown on the right side of FIG. 4, the outer peripheral surface shape of the workpiece W is expressed by a group of multiple radial line segments on a polar coordinate system with the rotation center Ow of the workpiece W as the origin. In other words, the interference amount calculation unit 111 stores, as the outer peripheral surface shape of the workpiece W, a group of multiple line segments connecting division points (white dots in FIG. 4) on the outer peripheral surface obtained by dividing the workpiece W equiangularly (α) with the rotation center Ow (origin) of the workpiece W. The division points indicated by white dots in FIG. 4 are stored as the outer peripheral surface shape of the workpiece W before removal by the grinding wheel T.

[0053] The interference amount calculation unit 111 determines the intersections (black dots in FIG. 4) between each line segment of the workpiece W and the line representing the outer peripheral surface shape of the grinding wheel T from the relative position (center distance) between the workpiece W and the grinding wheel T and the outer peripheral surface shape of the grinding wheel T. The interference amount calculation unit 111 stores the determined intersections (black dots in FIG. 4) as the outer peripheral surface shape of the workpiece W after it has been removed by the grinding wheel T. In other words, the interference amount calculation unit 111 changes the stored outer peripheral surface shape of the workpiece W.

[0054] The interference amount calculation unit 111 then subtracts the area of ​​a triangle △Ow-b1-b2 formed by points b1 and b2 (intersections with the grinding wheel T) after removal and the origin Ow from the area of ​​a triangle △Ow-a1-a2 formed by adjacent points a1 and a2 among the points defining the outer peripheral surface shape of the workpiece W before removal and the origin Ow. The areas after subtraction are calculated for all adjacent points that define the outer peripheral surface shape of the workpiece W.

[0055] The interference amount calculation unit 111 then adds up the areas after each subtraction and multiplies the total area by the thickness of the workpiece W to calculate the interference amount (removal amount). In the above, the area of ​​the portion to be removed is calculated by calculating the areas of two types of triangles and then calculating the difference between the areas. Alternatively, the area of ​​the portion to be removed may be calculated by directly calculating the quadrangle a1-a2-b1-b2.

[0056] 2, the grinding efficiency calculation unit 112 calculates the grinding efficiency Z' based on the amount of interference calculated by the interference amount calculation unit 111. The grinding efficiency Z' is calculated by calculating the amount of interference per unit time, that is, the volume of the workpiece W ground by the grinding wheel T in unit time.

[0057] The grinding characteristic determination unit 113 determines the grinding characteristic kc based on the material of the workpiece W, the types of abrasive grains and binder of the grinding wheel T, and the condition of the outer circumferential surface of the grinding wheel T. The condition of the outer circumferential surface of the grinding wheel T is expressed, for example, using an index that indicates the wear state and sharpness of the abrasive grains of the grinding wheel T. Here, the grinding characteristic determination unit 113 stores the grinding characteristics in each state in advance through experiments, analysis, etc.

[0058] Based on the grinding efficiency Z' and the grinding characteristic kc, 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. The grinding resistance Fn is obtained by multiplying the grinding efficiency Z' by the grinding characteristic kc (Fn = kc × Z').

[0059] The grinding characteristics kc have a substantially linear relationship such that the grinding resistance Fn in the normal direction (X-axis direction) increases as the grinding efficiency Z' increases. The grinding characteristics kc change in 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 to increase with respect to the grinding efficiency Z'.

[0060] The workpiece side dynamic stiffness table storage unit 103 stores dynamic stiffness data Cw, Kw related to the workpiece W side when the workpiece W side and the grinding wheel T side are separated by the machining portion as a boundary. The workpiece side dynamic stiffness table storage unit 103 includes a dynamic stiffness table storage unit 103a related to the workpiece W, a dynamic stiffness table storage unit 103b related to the workpiece support members (20, 30, 40, 60), and a contact dynamic stiffness table storage unit 103c.

[0061] The dynamic stiffness table storage unit 103a for the workpiece W stores dynamic stiffness data Cwa, Kwa of the workpiece W (hereinafter referred to as workpiece dynamic stiffness data). The workpiece dynamic stiffness data Cwa, Kwa can be acquired, for example, by known hammering or FEM analysis of the workpiece W. When there are multiple types of workpieces W to be ground, the dynamic stiffness table storage unit 103a stores the workpiece dynamic stiffness data Cwa, Kwa for each of the multiple types of workpieces W.

[0062] The dynamic stiffness table storage unit 103b for the workpiece support members (20, 30, 40, 60) stores dynamic stiffness data Cwb, Kwb (hereinafter referred to as support member dynamic stiffness data) of the workpiece support members (20, 30, 40, 60). The support member dynamic stiffness data Cwb, Kwb can be obtained by hammering or FEM analysis of each of the spindle unit 30, tailstock unit 40, and rest unit 60 that constitute the workpiece support member.

[0063] When the grinding machine body 2 is capable of changing the setup of a plurality of types of workpiece support members (20, 30, 40, 60), the dynamic stiffness table storage unit 103b stores support member dynamic stiffness data Cwb, Kwb for each of the plurality of types of workpiece support members (20, 30, 40, 60). In addition, when the support member dynamic stiffness data Cwb, Kwb change depending on the machining conditions, etc., the dynamic stiffness table storage unit 103b stores the correspondence between the machining conditions, etc. and the support member dynamic stiffness data Cwb, Kwb.

[0064] The contact dynamic stiffness table storage unit 103c stores contact dynamic stiffness data Cwc, Kwc between the workpiece W and the workpiece support member (20, 30, 40, 60). Because the contact dynamic stiffness data Cwc, Kwc change depending on the machining conditions, etc., the contact dynamic stiffness table storage unit 103c stores the correspondence between the machining conditions, etc. and the contact dynamic stiffness data Cwc, Kwc.

[0065] The contact dynamic stiffness data Cwc, Kwc includes contact dynamic stiffness data between the center holes Wc, Wd and the support centers 34, 41. If the grinding machine body 2 is equipped with a chuck that grips the workpiece W, the contact dynamic stiffness data Cwc, Kwc will include contact dynamic stiffness data between the workpiece W and the chuck. In addition, the contact dynamic stiffness data Cwc, Kwc includes contact dynamic stiffness data between the outer peripheral surface of the workpiece W and the rest device 60. If the grinding machine body 2 is not equipped with the rest device 60, the contact dynamic stiffness data Cwc, Kwc does not include contact dynamic stiffness data between the outer peripheral surface of the workpiece W and the rest device 60.

[0066] The grinding wheel side dynamic stiffness table storage unit 104 stores dynamic stiffness data Ct, Kt (tool side dynamic stiffness data) related to the grinding wheel T side when the workpiece W side and the grinding wheel T side are separated by the machining portion. In other words, the grinding wheel side dynamic stiffness table storage unit 104 stores dynamic stiffness data Ct, Kt for the grinding wheel head 50 including the grinding wheel T. The grinding wheel side dynamic stiffness table storage unit 104 stores grinding wheel side dynamic stiffness data Ct, Kt for each type of grinding wheel T, for example.

[0067] Furthermore, if the grinding wheel T is supported by a hydrostatic bearing and the pressure of the hydrostatic bearing is controllable, the grinding wheel dynamic stiffness data Ct, Kt may change depending on the pressure of the hydrostatic bearing. Therefore, the grinding wheel dynamic stiffness table storage unit 104 may store the damping coefficient Ct and spring constant Kt depending on the pressure of the hydrostatic bearing as a processing condition. If the dynamic stiffness data Ct, Kt change depending on the processing conditions, etc., the grinding wheel dynamic stiffness table storage unit 104 stores the correspondence between the processing conditions, etc. and the grinding wheel dynamic stiffness data Ct, Kt.

[0068] The workpiece-side dynamic stiffness (Cw, Kw) and the grinding wheel-side dynamic stiffness (Ct, Kt) will be described with reference to Fig. 5. The workpiece-side dynamic stiffness (Cw, Kw) is the dynamic stiffness on the workpiece W side, including the workpiece W, related to the table 20, the spindle unit 30, the tailstock unit 40, and the rest unit 60.

[0069] The workpiece-side dynamic stiffness (Cw, Kw) is the dynamic stiffness exhibited when the workpiece W is supported by the spindle device 30, tailstock device 40, and rest device 60, which are workpiece support members that make up the grinding machine body 2. The workpiece-side dynamic stiffness (Cw, Kw) is defined by the damping coefficient Cw and spring constant Kw. The damping coefficient Cw is a value that represents the relationship between the relative speed of the workpiece W with respect to the reference position of the grinding machine body 2 and the external force that the workpiece W receives. The spring constant Kw is a value that represents the relationship between the relative position of the workpiece W with respect to the reference position of the grinding machine body 2 and the external force that the workpiece W receives.

[0070] As shown in FIG. 5, the workpiece-side dynamic stiffness (Cw, Kw) can be decomposed into the workpiece dynamic stiffness (Cwa, Kwa), the support member dynamic stiffness (Cwb, Kwb), and the contact dynamic stiffness (Cwc, Kwc) between the workpiece W and the workpiece support member (20, 30, 40, 60).

[0071] The contact dynamic stiffness (Cwc, Kwc) is the dynamic stiffness between the workpiece W and the workpiece support members (20, 30, 40, 60), and is the dynamic stiffness exerted by contact between the workpiece W and the workpiece support members (20, 30, 40, 60). The contact dynamic stiffness (Cwc, Kwc) is defined by the damping coefficient Cwc and the spring constant Kwc. The damping coefficient Cwc is a value that represents the relationship between the relative velocity between the workpiece W and the workpiece support members (20, 30, 40, 60) and the external force that the workpiece W receives. The spring constant Kwc is a value that represents the relationship between the relative position between the workpiece W and the workpiece support members (20, 30, 40, 60) and the external force that the workpiece W receives.

[0072] Here, the contact dynamic stiffness (Cwc, Kwc) differs depending on adjustment factors related to the supporting force of the workpiece support members (20, 30, 40, 60) and factors of the supported portion of the workpiece W. The relationship between the contact dynamic stiffness (Cwc, Kwc), the adjustment factors for the supporting force, and factors of the supported portion of the workpiece W will be described with reference to FIG. 6.

[0073] Figure 6(a) shows a case where the workpiece W is a small-diameter shaft and the sizes (opening diameters) of the spindle-side center hole Wc and tailstock-side center hole Wd formed on both end faces of the workpiece W are small. Figure 6(b) shows a case where the workpiece W is a large-diameter shaft and the sizes (opening diameters) of the spindle-side center hole Wc and tailstock-side center hole Wd formed on both end faces of the workpiece W are large. The sizes of the center holes Wc, Wd are determined using the opening diameters of the center holes Wc, Wd as an index.

[0074] In Fig. 6(a), the axial pressing force applied to the workpiece W by the spindle center 34 and tailstock center 41 is F1. Also in Fig. 6(a), the radial pressing force applied to the outer peripheral surface of the workpiece W by the rest device 60 is F2. In Fig. 6(b), the axial pressing force applied to the workpiece W by the spindle center 34 and tailstock center 41 is F11. Also in Fig. 6(b), the radial pressing force applied to the outer peripheral surface of the workpiece W by the rest device 60 is F12.

[0075] In FIGS. 6(a) and 6(b), the relationship of each pressing force is F1 < F11 and F2 < F12. Further, the contact area between the center holes Wc, Wd and the support centers 34, 41 is larger in FIG. 6(b) than in FIG. 6(a). Also, the contact area between the outer peripheral surface of the workpiece W and the rest device 60 is larger in FIG. 6(b) than in FIG. 6(a).

[0076] Here, the contact dynamic rigidity (Cwc, Kwc) changes depending on the force by which the contacting members press against each other. Due to the change in the axial pressing force on the workpiece W by the spindle center 34 and the center punch 41, the contact state between each center hole Wc, Wd of the workpiece W and each support center 34, 41 changes, and as the contact state changes, the contact dynamic rigidity (Cwc, Kwc) changes. Also, due to the change in the radial pressing force on the workpiece W by the rest device 60, the contact state between the outer peripheral surface of the workpiece W and the rest device 60 changes, and as the contact state changes, the contact dynamic rigidity (Cwc, Kwc) changes.

[0077] In a configuration where the workpiece W is gripped by a chuck, due to the change in the gripping force of the chuck on the workpiece W, the contact state between the workpiece W and the chuck changes, and as the contact state changes, the contact dynamic rigidity (Cwc, Kwc) changes.

[0078] Furthermore, the contact dynamic rigidity (Cwc, Kwc) also changes depending on the contact area. Due to the difference in the size of the spindle-side center hole Wc and the size of the center punch-side center hole Wd as elements of the supported part, the contact area changes, and as the contact area changes, the contact dynamic rigidity (Cwc, Kwc) changes. Also, due to the difference in the size of the support surface of the rest device 60 and the outer diameter of the workpiece W, the contact area changes, and as the contact area changes, the contact dynamic rigidity (Cwc, Kwc) changes.

[0079] Also, in a configuration where the workpiece W is gripped by a chuck, due to the difference in the size of the gripping surface of the chuck and the gripping diameter of the workpiece W, the contact area between the workpiece W and the chuck changes, and as the contact area changes, the contact dynamic rigidity (Cwc, Kwc) changes.

[0080] As shown in FIG. 5, the grinding wheel dynamic stiffness is the dynamic stiffness related to the wheel head 50, including the grinding wheel T. The grinding wheel dynamic stiffness is defined by a damping coefficient Ct and a spring constant Kt. The damping coefficient Ct is a value that represents the relationship between the relative speed of the grinding wheel T with respect to a reference position on the wheel head 50 and the external force that the grinding wheel T receives. The spring constant Kt is a value that represents the relationship between the relative position of the grinding wheel T with respect to the reference position on the wheel head 50 and the external force that the grinding wheel T receives. The grinding wheel dynamic stiffness (Ct, Kt) includes the dynamic stiffness (Cta, Kta) of the grinding wheel T and the dynamic stiffness (Ctb, Ktb) that the wheel head main body 51 exerts when supporting the grinding wheel T.

[0081] The contact dynamic stiffness table storage unit 103c will be described in detail with reference to Fig. 7 and Fig. 8. The contact dynamic stiffness table storage unit 103c stores a contact dynamic stiffness table including contact dynamic stiffness data Cwc and Kwc. Specifically, as shown in Fig. 7, the contact dynamic stiffness table is a table including contact dynamic stiffness data Cwc and Kwc corresponding to conditions A1, A2, and A3 regarding adjustment elements related to the supporting force of the workpiece W and conditions B1, B2, and B3 regarding elements of the supported portion of the workpiece W. Note that the contact dynamic stiffness table may also be a table including mass M in addition to damping coefficient Cwc and spring constant Kw.

[0082] In Fig. 7, the adjustment factors related to the support force of the workpiece W are adjustment factors related to the support force of the workpiece W by the workpiece support members (20, 30, 40, 60). For example, the adjustment factors of the support force include the center pressing force by the spindle center 34 and the tailstock center 41. The adjustment factors of the support force also include the pressing force by the rest device 60. Therefore, the conditions A1, A2, and A3 for the adjustment factors of the support force are conditions in which the center pressing force and the rest pressing force are changed, respectively.

[0083] It should be noted that if the rest device 60 is not provided, the rest pressing force is not taken into consideration. Also, if the workpiece support member is a chuck that grips the workpiece W and is configured to have an adjustable gripping force, the adjustment factor for the support force of the workpiece W is the gripping force of the chuck.

[0084] 7, the elements of the supported portion of the workpiece W are elements of the portions of the workpiece W that come into contact with the spindle center 34, the tailstock center 41, and the rest device 60. For example, the elements of the supported portion of the workpiece W include the sizes (opening diameters) of the center holes Wc and Wd. The elements of the supported portion of the workpiece W also include the area of ​​the portion of the outer surface of the workpiece W that comes into contact with the rest device 60 (rest contact area). The rest contact area varies depending on the configuration of the rest device 60 and the outer diameter of the workpiece W. Therefore, conditions B1, B2, and B3 for the elements of the supported portion of the workpiece W are conditions in which the sizes of the center holes Wc and Wd and the rest contact area are changed, respectively.

[0085] If the rest device 60 is not provided, the rest contact area is not taken into consideration. Also, if the workpiece support member is a chuck that grips the workpiece W, the element of the supported portion of the workpiece W is the gripping area of ​​the chuck.

[0086] The contact dynamic stiffness table shown in FIG. 7 is a data table obtained by performing actual measurements for the first conditions (conditions A1, A2, A3, and conditions B1, B2, B3), and is therefore a table limited to the first conditions for which actual measurements were performed.

[0087] However, since the conditions actually used are diverse, there is a possibility that the contact dynamic stiffness table shown in Fig. 7 may not be sufficient. Therefore, the hatched portion in Fig. 8 is supplemented by performing interpolation processing using a contact dynamic stiffness table based on actual measurements.

[0088] 7, the contact dynamic stiffness table storage unit 103c stores in advance the correspondence between first conditions (conditions A1, A2, A3, and conditions B1, B2, B3) and actually measured contact dynamic stiffness data Cwc and Kwc. Then, by performing an interpolation process using the contact dynamic stiffness data Cwc and Kwc for the first conditions (conditions A1, A2, A3, and conditions B1, B2, B3), contact dynamic stiffness data Cwc and Kwc for second conditions (conditions A1h, A2h, and conditions B1h, B2h) different from the first conditions are generated. The contact dynamic stiffness table storage unit 103c then additionally stores the generated contact dynamic stiffness data Cwc and Kwc.

[0089] The interpolation process may use, for example, an empirical formula that defines the relationship between the adjustment factors for the support force of the workpiece W, the factors of the supported portion of the workpiece W, the damping coefficient Cwc, and the spring constant Kwc. Alternatively, the interpolation process may use machine learning or theoretical calculation.

[0090] 2, the dynamic stiffness determination condition acquisition unit 105 acquires the dynamic stiffness determination conditions when grinding is performed by the grinding machine main body 2. In detail, the dynamic stiffness determination condition acquisition unit 105 acquires the dynamic stiffness determination conditions at the time of estimation (time to be processed) by the estimation unit 102. The dynamic stiffness determination conditions acquired by the dynamic stiffness determination condition acquisition unit 105 are information used by the dynamic stiffness determination unit 106 to calculate each dynamic stiffness. The acquired dynamic stiffness determination conditions include, for example, the type of workpiece W, the type of workpiece support member, the type of grinding wheel T, the pressing force by the support centers 34 and 41, the pressing force by the rest device 60, etc.

[0091] When the processing estimation device 3b is a simulation device independent of the grinding machine body 2, the dynamic stiffness determination condition acquisition unit 105 acquires conditions for determining dynamic stiffness by inputting the mechanical configuration and grinding program of the grinding machine body 2. When the processing estimation device 3b functions as a simulation device that operates in conjunction with the grinding process by the grinding machine body 2, the dynamic stiffness determination condition acquisition unit 105 may acquire conditions for determining dynamic stiffness by inputting the mechanical configuration and grinding program of the grinding machine body 2 from the control device 3a, or may acquire information regarding the conditions directly from the control device 3a of the grinding machine body 2.

[0092] The dynamic stiffness determiner 106 determines dynamic stiffness data that affect the grinding process. The dynamic stiffness determiner 106 separately determines workpiece-side dynamic stiffness data Cw, Kw and grinding wheel-side dynamic stiffness data Ct, Kt. That is, the dynamic stiffness determiner 106 includes a workpiece-side dynamic stiffness determiner 121 and a grinding wheel-side dynamic stiffness determiner 122.

[0093] The workpiece side dynamic stiffness determiner 121 determines workpiece dynamic stiffness data Cwa, Kwa corresponding to the type of workpiece W acquired by the dynamic stiffness determination condition acquirer 105 from the dynamic stiffness table stored in the dynamic stiffness table storage unit 103a for the workpiece W. Furthermore, the workpiece side dynamic stiffness determiner 121 determines support member dynamic stiffness data Cwb, Kwb corresponding to the type of workpiece support member acquired by the dynamic stiffness determination condition acquirer 105 from the dynamic stiffness table stored in the dynamic stiffness table storage unit 103b for the workpiece support member (20, 30, 40, 60).

[0094] Furthermore, the workpiece side dynamic stiffness determiner 121 acquires conditions for determining the contact dynamic stiffness data Cwc, Kwc from the dynamic stiffness determination condition acquirer 105. Then, the workpiece side dynamic stiffness determiner 121 acquires the adjustment factors for the supporting force and the elements of the supported portion of the workpiece W, as shown in Fig. 7 and Fig. 8. The workpiece side dynamic stiffness determiner 121 determines the contact dynamic stiffnesses Cwc, Kwc corresponding to the adjustment factors for the supporting force and the elements of the supported portion of the workpiece W from the contact dynamic stiffness table stored in the contact dynamic stiffness table storage unit 103c.

[0095] The grinding wheel side dynamic stiffness determination unit 122 determines the dynamic stiffness data Ct, Kt corresponding to the type of grinding wheel T acquired by the dynamic stiffness determination condition acquisition unit 105 from the grinding wheel side dynamic stiffness table stored in the grinding wheel side dynamic stiffness table memory unit 104.

[0096] The correction amount calculation unit 107 calculates the correction amount for the relative displacement of the grinding wheel T and workpiece W in the X-axis direction due to the grinding force Fn, based on each dynamic stiffness data determined by the dynamic stiffness determination unit 106. The correction amount for the displacement can be found from each dynamic stiffness data and the grinding force Fn. In other words, the correction amount for the displacement can be calculated from the grinding force Fn, workpiece-side dynamic stiffness data Cw, Kw, and grinding wheel-side dynamic stiffness data Ct, Kt.

[0097] In this embodiment, however, the workpiece dynamic stiffness data Cw, Kw include the workpiece dynamic stiffness data Cwa, Kwa, the support member dynamic stiffness data Cwb, Kwb, and the contact dynamic stiffness data Cwc, Kwc. In other words, the correction amount for displacement is calculated from the grinding force Fn, the workpiece dynamic stiffness data Cwa, Kwa, Cwb, Kwb, Cwc, Kwc, and the grinding wheel dynamic stiffness data Ct, Kt.

[0098] The correction amount calculation unit 107 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 between 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, due to the grinding resistance Fn, the relative position between the workpiece W and the grinding wheel T is different from the relative position determined by the command value.

[0099] Therefore, when estimating the estimation target, the estimation unit 102 uses, as the relative position between the workpiece W and the grinding wheel T, the relative position obtained by adding the correction amount calculated by the correction amount calculation unit 107 to the relative position acquired by the command value acquisition unit 101. In other words, the estimation unit 102 estimates the estimation target based on the relative position according to the command value and the correction amount calculated using each dynamic stiffness data.

[0100] In particular, in this embodiment, the correction amount calculation unit 107 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 amount of interference between the workpiece W and the grinding wheel T based on the relative position between 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, due to the grinding resistance Fn, the relative position between the workpiece W and the grinding wheel T will be different from the relative position determined by the command value.

[0101] Therefore, the interference amount calculation unit 111 uses the relative position between the workpiece W and the grinding wheel T used to calculate the amount of interference as the relative position obtained by the command value acquisition unit 101 plus the correction amount calculated by the correction amount calculation unit 107. In other words, the interference amount calculation unit 111 calculates the amount of interference based on the relative position obtained by the command value and the correction amount calculated using each dynamic stiffness data.

[0102] The interference amount calculation unit 111 calculates the amount of interference taking the amount of correction into consideration, and the grinding efficiency calculation unit 112, grinding characteristic determination unit 113, and grinding resistance calculation unit 114 obtain the grinding efficiency Z', grinding characteristic kc, and grinding resistance Fn based on the amount of interference taking the amount of correction into consideration.

[0103] The output unit 108 outputs the estimation target estimated by the estimation unit 102. That is, the output unit 108 estimates 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 processing device 1 (corresponding to the mechanical state of the grinding machine main body 2). The output unit 108 may, for example, teach the estimation result to a teaching device (not shown). The output unit 108 can also output the estimation result to the control device 3a of the grinding machine main body 2. In this case, the control device 3a can use the estimation result to correct, for example, the grinding conditions. That is, the control device 3a can control the grinding process using the estimation result.

[0104] The control device 3a can also use the estimation results to control the adjustment mechanism 42 of the tailstock device 40 to adjust the pressing force of the spindle center 34 and the tailstock center 41. If the grinding machine body 2 is equipped with a chuck, the control device 3a can also use the estimation results to adjust the gripping force of the chuck. The control device 3a can also use the estimation results to adjust the pressing force of the rest device 60. The control device 3a can appropriately select a control target using the estimation results.

[0105] Furthermore, the control device 3a performs the various processes described above using the estimation results. In addition, the control device 3a can also control machining using various dynamic stiffnesses determined by the dynamic stiffness determination unit 106, regardless of the estimation results. For example, the control device 3a can also adjust the pressing force of the spindle center 34 and tailstock center 41, the gripping force of the chuck, and the pressing force of the rest device 60, using the various dynamic stiffnesses determined by the dynamic stiffness determination unit 106, regardless of the estimation results.

[0106] 4.Effects According to this embodiment, the control device 3a of the processing unit 3 performs a desired target process using the contact dynamic stiffness data Cwc, Kwc between the workpiece W and the workpiece support member (20, 30, 40, 60). The desired target process is a process for controlling the machining, or a process for estimating at least one of the state of the workpiece W or the grinding wheel T during machining, the shape of the workpiece W, the shape of the grinding wheel T, and the mechanical state of the machining device 1.

[0107] The contact dynamic stiffness data Cwc, Kwc are represented by the spring constant Kwc and damping coefficient Cwc between the workpiece W and the workpiece support member (20, 30, 40, 60) that are exerted by contact between the workpiece W and the workpiece support member (20, 30, 40, 60). In this way, by using the contact dynamic stiffness data Cwc, Kwc that includes the spring constant Kwc and damping coefficient Cwc, it is possible to perform the desired target processing with high accuracy.

[0108] 7 and 8, the contact dynamic stiffness table stores in advance the correspondence relationships between the contact dynamic stiffness data Cwc and Kwc and the adjustment factors related to the supporting force of the workpiece support members (20, 30, 40, 60) and the factors of the supported portions of the workpiece W. Therefore, the workpiece-side dynamic stiffness determiner 121 can easily determine the contact dynamic stiffness data Cwc and Kwc using the adjustment factors and the factors of the supported portions at the time of processing, and the correspondence relationships stored in the contact dynamic stiffness table.

[0109] 8, the contact dynamic stiffness table storage unit 103c additionally stores contact dynamic stiffness data acquired by performing interpolation processing. In this way, by generating contact dynamic stiffness data Cwc, Kwc for conditions that have not been actually measured, it becomes possible to estimate an estimation target and control a control target with high accuracy.

[0110] Furthermore, the workpiece dynamic stiffness data is separated into workpiece dynamic stiffness data Cwa, Kwa, support member dynamic stiffness data Cwb, Kwb, and contact dynamic stiffness data Cwc, Kwc. Separating each dynamic stiffness data in this manner facilitates the determination of each dynamic stiffness data. For example, even if the workpiece W and workpiece support members (20, 30, 40, 60) are the same, adjusting only the pressing force of the support centers 34, 41 changes only the contact dynamic stiffness data Cwc, Kwc. This facilitates calculation processing. For example, when the estimation processing by the processing estimation device 3b and the control of the grinding processing by the control device 3a are performed simultaneously, high-precision grinding processing can be achieved by performing calculation processing at high speed.

[0111] (Embodiment 2) A processing apparatus 201 of this embodiment will be described with reference to Fig. 9. The processing apparatus 201 is a processing apparatus that performs cutting. The processing apparatus 201 includes a lathe body 202 as the processing apparatus body, and a processing section 203.

[0112] The lathe body 202 turns the workpiece W by rotating the workpiece W and moving the cutting tool T2 relative to the workpiece W. The processing unit 203 includes a control device 203a that controls the lathe body 202, and a processing estimation device 203b that estimates an estimation target related to processing. The control device 203a can control the cutting processing by controlling the lathe body 202. The processing estimation device 203b estimates at least one of the state of the workpiece W or the cutting tool T2 during cutting processing on the lathe body 202, the shape of the workpiece W, the shape of the cutting tool T2, and the mechanical state of the processing device 201 (corresponding to the mechanical state of the lathe body 202). The processing estimation device 203b performs an estimation process of the above estimation target by inputting information used in cutting processing and performing a simulation.

[0113] The lathe main body 202 includes, for example, a bed 210, a spindle unit 220, a tailstock unit 230, a rest unit 240, and a tool rest 250. The spindle unit 220, the tailstock unit 230, and the rest unit 240 function as workpiece support members. The spindle unit 220 is fixed to the upper surface of the bed 210, supports one end of the workpiece W, and drives the workpiece W to rotate. The spindle unit 220 includes a spindle housing 221, a spindle 222, a spindle motor 223, a chuck 224, a spindle detector 225, and a spindle drive circuit (not shown).

[0114] The spindle housing 221 is fixed onto the bed 210. The spindle 222 is rotatably supported by the spindle housing 221 via a bearing. The spindle motor 223 drives the spindle 222 to rotate. The chuck 224 is fixed to the spindle 222 and grips one end of the workpiece W. The spindle detector 225 and the spindle drive circuit are provided to drive the spindle motor 223.

[0115] The tailstock device 230 is disposed on the bed 210 so as to face the spindle device 220 in the Z-axis direction. The tailstock device 230 is provided on the bed 210 so as to be movable in the Z-axis direction. The tailstock device 230 includes a tailstock center 231 that supports the other end of the workpiece W.

[0116] The rest device 240 is fixed on the bed 210 and supports the outer peripheral surface of the axially intermediate portion of the workpiece W. In particular, the rest device 320 is disposed at a position where the workpiece W can resist the cutting load received from the cutting tool T2.

[0117] The tool table 250 includes a Z-axis slide table 251, an X-axis slide table 252, a turret (a swivel-type tool rest) 253, and a plurality of cutting tools T2. The Z-axis slide table 251 is supported on a Z-axis guide surface 211 of the bed 210 so as to be movable in the Z-axis direction, and is moved in the Z-axis direction by a Z-axis drive mechanism 212 provided on the bed 210.

[0118] X-axis slide base 252 is supported on X-axis guide surface 251a on Z-axis slide base 251 so as to be movable in the X-axis direction, and is moved in the X-axis direction by X-axis drive mechanism 251b provided on Z-axis slide base 251. Turret 253 is provided on X-axis slide base 252 so as to be rotatable around an axis parallel to the Z-axis direction. Multiple cutting tools T2 are fixed to the outer peripheral surface of turret 253. The multiple cutting tools T2 may be different types of tools.

[0119] The control device 203a is a CNC (Computer Numerical Control) The control device 203a is a Z-axis drive mechanism 212 and an X-axis drive mechanism 251b, which serve as moving devices, based on a cutting program, to control the position of the cutting tool T2. In other words, the control device 203a moves the workpiece W and the cutting tool T2 relative to each other by controlling the positions of the cutting tool T2 and the like. Furthermore, the control device 203a controls the rotation of the spindle 222 and the turret 253.

[0120] The processing estimation device 203b of this embodiment has the same configuration as the processing estimation device 3b of the first embodiment shown in Fig. 2. However, the grinding in the first embodiment is changed to cutting, and the grinding wheel T is changed to a cutting tool T2.

[0121] Next, the workpiece-side dynamic stiffness (Cw, Kw) and the tool-side dynamic stiffness (Ct, Kt) in this embodiment will be described with reference to FIG. 10 . The workpiece-side dynamic stiffness (Cw, Kw) is the dynamic stiffness exhibited when the workpiece W is supported by the spindle unit 220, tailstock unit 230, and rest unit 240, which serve as workpiece support members constituting the lathe main body 202. The workpiece-side dynamic stiffness (Cw, Kw) is defined by a damping coefficient Cw and a spring constant Kw. The damping coefficient Cw is a value that represents the relationship between the relative speed of the workpiece W with respect to the reference positions of the spindle unit 220, tailstock unit 230, and rest unit 240, and the external force that the workpiece W receives. The spring constant Kw is a value that represents the relationship between the relative position of the workpiece W with respect to the reference positions of the spindle unit 220, tailstock unit 230, and rest unit 240, and the external force that the workpiece W receives.

[0122] As in embodiment 1, the workpiece side dynamic stiffness (Cw, Kw) can be decomposed into the workpiece dynamic stiffness (Cwa, Kwa), the support member dynamic stiffness (Cwb, Kwb), and the contact dynamic stiffness (Cwc, Kwc) between the workpiece W and the workpiece support member (20, 30, 40, 60).

[0123] The tool-side dynamic stiffness (Ct, Kt) is the dynamic stiffness related to the tool table 250, including the cutting tool T2. The tool-side dynamic stiffness (Ct, Kt) is defined by a damping coefficient Ct and a spring constant Kt. The damping coefficient Ct is a value that represents the relationship between the relative speed of the cutting tool T2 with respect to a reference position on the tool table 250 and the external force that the cutting tool T2 receives. The spring constant Kt is a value that represents the relationship between the relative position of the cutting tool T2 with respect to a reference position on the tool table 250 and the external force that the cutting tool T2 receives.

[0124] The processing device 201 in this embodiment has the same effects as the processing device 1 in the first embodiment.

[0125] (others) In the above embodiment, examples have been described for grinding using the grinding machine body 2 and cutting using the lathe body 202. In addition to these, the present invention can also be applied to cutting using a machining center.

Claims

1. In a processing device (1, 201) that processes a workpiece (W) supported by a workpiece support member (20, 30, 40, 60, 220, 230, 240) with a tool (T, T2), a dynamic stiffness determination unit (106) that determines workpiece dynamic stiffness data (Cwa, Kwa) that is the dynamic stiffness of the workpiece, support member dynamic stiffness data (Cwb, Kwb) that is the dynamic stiffness of the workpiece support member, and contact dynamic stiffness data (Cwc, Kwc) between the workpiece and the workpiece support member that is exerted by contact between the workpiece and the workpiece support member; a processing unit (3, 203) that controls machining using the determined workpiece dynamic stiffness data, the support member dynamic stiffness data, and the contact dynamic stiffness data, or that estimates at least one of a state of the workpiece or the tool during machining, a shape of the workpiece, a shape of the tool, and a mechanical state of the machining device; A processing device (1, 201) comprising:

2. moreover, a contact dynamic stiffness table storage unit (103c) that stores in advance a correspondence relationship between adjustment elements (34, 41, 60, 224, 231, 240) related to the supporting force of the workpiece supporting member, elements (W, Wc, Wd) of the supported portion of the workpiece, and the contact dynamic stiffness data (Cwc, Kwc), the dynamic stiffness determiner determines the contact dynamic stiffness data using the adjustment elements and elements of the supported portion at the time of processing, and the correspondence relationship stored in the contact dynamic stiffness table storage unit; 2. The machining device according to claim 1, wherein the processing unit uses the contact dynamic stiffness data determined by the dynamic stiffness determination unit to control machining, or estimate at least one of a state of the workpiece or the tool during machining, a shape of the workpiece, a shape of the tool, and a mechanical state of the machining device.

3. The contact dynamic stiffness table storage unit a correspondence relationship between first conditions (A1, A2, A3, B1, B2, B3) related to the adjustment elements and the elements of the supported portion and the contact dynamic stiffness data actually measured under the first conditions is stored in advance; 3. The machining device according to claim 2, further comprising: an interpolation process performed using the contact dynamic stiffness data for the first condition, wherein the contact dynamic stiffness data acquired for a second condition (A1h, A2h, B1h, B2h) different from the first condition is additionally stored.

4. the elements of the supported portion are center holes (Wc, Wd) formed on the axial end surfaces of the workpiece, The workpiece support member includes a support center (34, 41, 231) that presses the workpiece axially against the center hole, 4. The machining device according to claim 2, wherein the contact dynamic stiffness data is data on contact dynamic stiffness between the center hole and the support center.

5. the support center is configured to be able to adjust a pressing force of the workpiece in an axial direction of the workpiece, the contact dynamic stiffness data is data that changes in accordance with a change in the contact state between the center hole of the workpiece and the support center due to a change in the pressing force of the support center, 5. The machining device according to claim 4, wherein the processing unit uses the contact dynamic stiffness data to estimate at least one of a state of the workpiece or the tool during machining, a shape of the workpiece, a shape of the tool, and a mechanical state of the machining device, and adjusts the pressing force of the support center based on the estimation result.

6. The workpiece support member is a chuck (224) that grips the workpiece; 4. The processing device according to claim 1, wherein the contact dynamic stiffness data is data on contact dynamic stiffness between the workpiece and the chuck.

7. The chuck is configured to be able to adjust the gripping force on the workpiece, the contact dynamic stiffness data is data that changes in accordance with a change in the contact state between the workpiece and the chuck due to a change in the gripping force of the chuck, 7. The machining device according to claim 6, wherein the processing unit uses the contact dynamic stiffness data to estimate at least one of a state of the workpiece or the tool during machining, a shape of the workpiece, a shape of the tool, and a mechanical state of the machining device, and adjusts the gripping force of the chuck based on an estimation result.

8. the workpiece support member is a rest device (60, 240) that supports the outer peripheral surface of the workpiece formed in a shaft shape, 4. The processing device according to claim 1, wherein the contact dynamic stiffness data is data on contact dynamic stiffness between the outer peripheral surface of the workpiece and the rest device.

9. the rest device is configured to be able to adjust a pressing force against an outer peripheral surface of the workpiece, the contact dynamic stiffness data is data that changes in accordance with a change in the contact state between the outer peripheral surface of the workpiece and the rest device due to a change in the pressing force applied by the rest device, 9. The machining device according to claim 8, wherein the processing unit uses the contact dynamic stiffness data to estimate at least one of a state of the workpiece or the tool during machining, a shape of the workpiece, a shape of the tool, and a mechanical state of the machining device, and adjusts the pressing force by the rest device based on an estimation result.

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