CN117940250A

CN117940250A - Processing device

Info

Publication number: CN117940250A
Application number: CN202180102381.2A
Authority: CN
Inventors: 小林久修; 森知也; 久原淳司
Original assignee: JTEKT Corp
Current assignee: JTEKT Corp
Priority date: 2021-10-05
Filing date: 2021-10-05
Publication date: 2024-04-26
Also published as: WO2023058107A1

Abstract

The present invention relates to a processing apparatus. A processing device (1, 201) for processing a workpiece (W) supported by a workpiece support member (20, 30, 40, 60, 220, 230, 240) by means of a tool (T, T2) is provided with a processing unit (3, 203) which uses dynamic contact stiffness data (Cwc, kwc) between the workpiece (W) and the workpiece support member (20, 30, 40, 60, 220, 230, 240) exhibited by contact of the workpiece (W) with the workpiece support member (20, 30, 40, 220, 230, 240) to control the processing or to infer at least one of the state of the workpiece (W) or the tool (T, T2), the shape of the workpiece (W), the shape of the tool (T, T2), and the mechanical state of the processing device (1, 201) during processing.

Description

Processing device

Technical Field

The present invention relates to a processing apparatus.

Background

Patent document 1 describes a grinding simulation device. The grinding simulation is performed by repeating the steps of calculating the removal amount of the workpiece based on the relative positions of the workpiece and the grinding wheel, calculating the grinding resistance based on the removal amount, and calculating the correction amount of the relative positions based on the grinding resistance. In addition, the support rigidity of the support workpiece and the support rigidity of the support grinding wheel, which are measured in advance, are used for calculation of the correction amount.

Patent document 2 describes that, in the case of grinding a workpiece with a grinding wheel, the depth of grinding marks of the workpiece is calculated in consideration of the contact static rigidity between the workpiece and the grinding wheel. The contact static stiffness used here is not a value measured when the grinding wheel is stationary, but is calculated using the theoretical contact static stiffness at the time of grinding. The contact static stiffness is represented by the spring constant K between the workpiece and the grinding wheel.

Patent document 1: japanese patent application laid-open No. 2018-153907

Patent document 2: japanese patent application laid-open No. 2015-208812

In the apparatuses described in patent documents 1 and 2, the support rigidity of a workpiece support member for supporting a workpiece is considered. The rigidity of the workpiece support member with respect to the support structure of the workpiece varies not only as the rigidity of the workpiece support member but also in accordance with the contact state between the workpiece and the workpiece support member. However, it has been found that in the devices described in patent documents 1 and 2, the contact state change is not considered, and an error occurs in the estimation result of the estimation object.

Disclosure of Invention

The invention provides a processing device for performing a desired object treatment in consideration of a contact state between a workpiece and a workpiece support member.

One embodiment of the present invention provides a machining apparatus for machining a workpiece supported by a workpiece support member by a tool, the machining apparatus including:

And a processing unit that uses dynamic contact stiffness data between the workpiece and the workpiece support member, which is displayed by contact between the workpiece and the workpiece support member, to control machining or to estimate at least one of a state of the workpiece or the tool, a shape of the workpiece, a shape of the tool, and a mechanical state of the machining apparatus during machining.

According to the above embodiment, the processing unit performs the desired processing using the dynamic stiffness data of the contact between the workpiece and the workpiece support member. The desired objective process is a process of performing control of machining or a process of estimating at least one of a state of a workpiece or a tool, a shape of the workpiece, a shape of the tool, and a mechanical state of a machining apparatus at the time of machining.

The contact dynamic stiffness data is represented by the spring constant and damping coefficient between the workpiece and the workpiece support member exhibited by the contact of the workpiece with the workpiece support member. Thus, by using the contact dynamic stiffness data including the spring constant and the damping coefficient, the desired objective process can be performed with high accuracy.

As described above, according to the above embodiment, by taking into consideration the contact state between the workpiece and the workpiece support member, it is possible to provide a processing apparatus that performs a desired target process.

The reference numerals in brackets described in the claims indicate correspondence with specific mechanisms described in the embodiments described below, and do not limit the technical scope of the present invention.

Drawings

Fig. 1 is a diagram showing a processing apparatus according to embodiment 1.

Fig. 2 is a functional block diagram of a processing estimation device constituting the processing device.

Fig. 3 is a schematic view showing an interference state between a workpiece and a grinding wheel during grinding.

Fig. 4 is a diagram showing the shape of a workpiece in grinding simulation by using a radial line segment group, and is a diagram showing a state in which the workpiece, which is shown by a radial line segment, interferes with the outer peripheral line of the grinding wheel at the time of grinding.

Fig. 5 is a schematic diagram showing the workpiece-side dynamic stiffness and the tool-side dynamic stiffness during grinding.

Fig. 6 is a diagram illustrating the relationship between the workpiece and the supporting member and the dynamic contact rigidity.

Fig. 7 is a graph showing a contact dynamic stiffness table obtained by actual measurement.

Fig. 8 is a graph showing a touch dynamic stiffness table obtained by actual measurement and interpolation processing.

Fig. 9 is a diagram showing a processing apparatus according to embodiment 2.

Fig. 10 is a schematic view showing the workpiece-side dynamic stiffness and the tool-side dynamic stiffness in the cutting process.

Detailed Description

(Embodiment 1)

1. Structure of processing device 1

The processing apparatus 1 will be described with reference to fig. 1. The machining device 1 is a machining device that performs grinding. The machining device 1 includes a grinding machine body 2 as a machining device body, and a processing unit 3.

The grinding machine body 2 rotates the workpiece W, rotates the grinding wheel T as a tool serving as a rotating body, and relatively moves the grinding wheel T toward the workpiece W in a direction intersecting the axis of the workpiece W, thereby grinding the outer peripheral surface or the inner peripheral surface of the workpiece W. The grinding machine body 2 can be applied to a horizontal-table grinding machine, a horizontal-wheel-seat grinding machine, or the like. The grinding machine body 2 can be a cylinder grinding machine, a cam grinding machine, or the like.

In the present embodiment, as shown in fig. 1, the workpiece W is exemplified as a shaft-shaped member, for example. However, the workpiece W is not limited to the shaft shape, and may be any shape.

In the present embodiment, the workpiece W is exemplified by a case where the workpiece W includes a shaft portion Wa as a non-processed portion and a plurality of processed portions Wb whose outer peripheral surfaces are grinding targets. The processed portion Wb has, for example, a cylindrical outer peripheral surface coaxial with the shaft portion Wa. However, the workpiece W shown in fig. 1 is an example, and the grinding machine body 2 can take workpieces having various shapes as the objects of grinding processing. 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.

The processing unit 3 includes a control device 3a for controlling the grinding machine body 2, and a machining estimating device 3b for estimating an estimation target related to machining. The control device 3a can control the grinding process by controlling the grinding machine body 2. The machining estimating device 3b estimates at least one of the state of the workpiece W or the grinding wheel T, the shape of the workpiece W, the shape of the grinding wheel T, and the mechanical state of the machining device 1 (corresponding to the mechanical state of the grinding machine body 2) at the time of grinding of the grinding machine body 2. The machining estimation device 3b performs the estimation processing of the estimation object by inputting information used for grinding and performing simulation.

The machining estimation device 3b may exhibit a function as a simulation device independent of the grinding machine body 2 and the control device 3a, or may exhibit a function as a simulation device that operates in conjunction with the grinding machine body 2 and the control device 3 a. In the former case, the machining estimation device 3b can determine, for example, an optimal grinding condition without performing actual grinding of the workpiece W. In the latter case, the processing estimating device 3b can perform processing in parallel with the grinding of the workpiece W by the grinding machine body 2, thereby, for example, correcting the grinding conditions or performing operations to exert an influence on various controls. The machining estimating device 3b may be an embedded system of the grinding machine body 2 and the control device 3 a.

2. Structure of grinding machine body 2 and control device 3a

An example of the structure of the grinder body 2 and the control device 3a will be described in detail with reference to fig. 1. The grinding machine body 2 is exemplified by a bench horizontal cylindrical grinding machine. That is, the grinding machine body 2 is configured to move the workpiece W in the axial direction of the workpiece W and move the grinding wheel T in a direction intersecting the axial direction of the workpiece W. In the present embodiment, the grinding machine body 2 is exemplified by a case where the cylindrical outer peripheral surface of the workpiece W is ground by the grinding wheel T.

The grinding machine body 2 includes a bed 10, a table 20, a spindle device 30, a tailstock device 40, a grinding wheel base 50, and a holder device 60. The table 20, the spindle device 30, the tailstock device 40, and the bracket device 60 function as workpiece support members for supporting the workpiece W. The grinding wheel holder 50 functions as a tool support member that supports the grinding wheel T. That is, the grinding machine body 2 grinds the workpiece W supported by the workpiece support member 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 be configured without the bracket device 60. The structural components of the grinder body 2 are described in detail below.

The bed 10 is disposed on the disposition surface. The bed 10 is formed to have a longer width (Z-axis length) on the front side (lower side in fig. 1) in the X-axis direction and a shorter width on the rear side (upper side in fig. 1) in the X-axis direction.

The upper surface of the bed 10 on the front side in the X-axis direction includes a Z-axis guide surface 11 extending in the Z-axis direction. The bed 10 is provided with a Z-axis driving mechanism 12 that drives along the Z-axis guide surface 11. In the present embodiment, the Z-axis drive mechanism 12 is exemplified by a case where the ball screw mechanism 12a and the Z-axis motor 12b are provided. 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.

A not-shown Z-axis drive circuit and a Z-axis detector 12c are provided to drive the Z-axis drive mechanism 12. 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 an encoder or the like, for example, and detects the angle of the rotation axis of the Z-axis motor 12b. The Z-axis driving mechanism 12 may be a linear motor or the like instead of the structure including the ball screw mechanism 12 a.

The bed 10 includes a guide surface 13 extending in a direction intersecting the Z-axis direction on the upper surface on the back surface side in the X-axis direction. In the present embodiment, the guide surface 13 is an X-axis guide surface extending in an X-axis direction orthogonal to the Z-axis. The bed 10 is further provided with an X-axis driving mechanism 14 that drives along the X-axis guide surface 13. In the present embodiment, the X-axis driving mechanism 14 is exemplified by a case where the ball screw mechanism 14a and the X-axis motor 14b are provided. 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.

In order to drive the X-axis drive mechanism 14, a drive circuit for the X-axis and a detector 14c for the X-axis, which are 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 an angle detector such as an encoder, for example, and detects the angle of the rotation axis of the X-axis motor 14b. The X-axis driving mechanism 14 may be a linear motor or the like instead of the structure including the ball screw mechanism 14a.

The table 20 is formed in a long 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 (horizontal left-right direction). The table 20 is fixed to a ball screw nut of the Z-axis ball screw mechanism 12a, and is moved in the Z-axis direction by the rotational drive of the Z-axis motor 12 b.

The spindle device 30 constitutes a workpiece support member. The spindle device 30 supports the workpiece W and rotationally drives the workpiece W. The spindle device 30 is disposed on one end side of the table 20 in the Z axis direction. 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.

The spindle housing 31 is fixed to the table 20. The spindle 32 is rotatably supported by the spindle housing 31 via a bearing. The spindle motor 33 rotationally drives the spindle 32.

The spindle center 34 (corresponding to a support center) supports an end face of one axial end (left end in fig. 1) of the workpiece W. Specifically, the spindle center 34 is supported by a spindle-side center hole Wc formed in an end surface of one axial end of the workpiece W in a state pressed in the axial direction of the workpiece W. In this case, the spindle center 34 supports a spindle-side center hole Wc, which is one of the members of the supported portion, in the workpiece W.

The spindle center 34 is fixed to the spindle 32 and is provided rotatably with respect to the spindle case 31. However, in the case where the spindle device 30 includes a turning member such as a carrier, not shown, the spindle center 34 may be fixed to the spindle housing 31 so as not to be rotatable with respect to the spindle housing 31. The spindle device 30 may include a chuck for holding the workpiece W instead of the spindle center 34. The chuck is rotationally driven by being coupled to the spindle 32.

The spindle detector 35 and the spindle drive circuit are provided for driving the spindle motor 33. In the present embodiment, the spindle detector 35 is, for example, an encoder or the like, and detects the angle of the rotation axis of the spindle motor 33. The spindle drive circuit includes an amplifier circuit, and drives the spindle motor 33.

The tailstock apparatus 40 constitutes a workpiece support member together with the spindle apparatus 30. The tailstock device 40 is disposed on the other end side 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 apparatus 40 includes a tailstock center 41 and an adjusting mechanism 42. In addition, the grinding machine body 2 does not need the tailstock device 40 when grinding the inner peripheral surface of the workpiece W.

The tailstock center 41 (corresponding to a support center) supports an end face of the other axial end (right end in fig. 1) of the workpiece W. Specifically, the tailstock center 41 is supported by a tailstock-side center hole Wd formed in an end surface of the other end in the axial direction of the workpiece W in a state of being pressed in the axial direction of the workpiece W. In this case, the tailstock center 41 supports a tailstock-side center hole Wd, which is one of the members of the supported portion, in the workpiece W. The tailstock center 41 may be provided so as not to be rotatable or so as to be rotatable.

The tailstock center 41 may be positioned at a fixed position with respect to the workpiece W, or may be provided so as to be movable in the axial direction of the workpiece W with respect to the workpiece W. In the latter case, the tailstock center 41 may be configured to be capable of adjusting the pressing force in the axial direction of the workpiece W with respect 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.

In the present embodiment, the tailstock apparatus 40 includes an adjustment mechanism 42, and the adjustment mechanism 42 is constituted by, for example, a spring, and is configured to cause the tailstock center 41 to exhibit a pressing force. Here, in a state where the tailstock center 41 generates a pressing force on the workpiece W, the spindle center 34 also exhibits a pressing force on the workpiece W as a reaction. Specifically, the tailstock center 41 and the spindle center 34 can be configured to adjust the pressing force in the axial direction of the workpiece W with respect to the workpiece W by the adjustment mechanism 42. That is, the tailstock center 41 and the spindle center 34 are configured to be able to adjust the supporting force of the workpiece W by the adjusting mechanism 42. Here, the pressing force of the tailstock center 41 and the spindle center 34 against the workpiece W can be adjusted by the actuator or by the operator.

The grinding wheel holder 50 includes a grinding wheel T, and rotationally drives the grinding wheel T. The grinding wheel holder 50 includes a grinding wheel holder body 51, a grinding wheel shaft 52, a grinding wheel motor 53, and a grinding wheel drive circuit, not shown, in addition to the grinding wheel T.

The grinding wheel T is formed in a disc shape. The grinding wheel T is used for grinding the outer peripheral surface or the inner peripheral surface of the workpiece W. The grinding wheel T is formed by fixing a plurality of abrasive grains with a binder. The abrasive grains may be general abrasive grains made of ceramic materials such as alumina and silicon carbide, superabrasive grains such as diamond and CBN, and the like.

The binder includes glass (V), resin (B), rubber (R), silicate (S), shellac (E), metal (M), electrophoresis (P), magnesium cement (Mg), and the like. The grinding wheel T has a structure with air holes and a structure without air holes. The grinding wheel T may have a structure that can be elastically deformed or a structure that can be hardly elastically deformed depending on the kind of the binder and the presence or absence of the air hole. The elastically deformable grinding wheel T has an elastic modulus that varies depending on the type of the binder, the presence or absence of air holes, the porosity, and the like.

The grinding wheel seat main body 51 is formed in a rectangular shape in plan 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-rear direction). The grinding wheel seat body 51 is fixed to a ball screw nut of the X-axis ball screw mechanism 14a, and is moved in the X-axis direction by the rotational drive of the X-axis motor 14 b. The grinding wheel seat body 51 constitutes a tool supporting member that supports the grinding wheel T.

The grinding wheel shaft 52 is rotatably supported by the grinding wheel seat body 51 via a bearing. A grinding wheel T is fixed to the front end of the grinding wheel shaft 52, and rotates by rotation of the grinding wheel shaft 52. The grinding wheel motor 53 rotationally drives the grinding wheel shaft 52. The bearings are hydrostatic bearings, rolling bearings, and the like.

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

The holder device 60 is provided on the upper surface of the bed 10, and constitutes a workpiece support member for supporting the outer peripheral surface of the workpiece W, which is one of the supported portions of the workpiece W. The holder device 60 is configured to be provided with a spring or the like, for example, and can thereby adjust the pressing force against the outer peripheral surface of the workpiece W. That is, the bracket device 60 is configured to be capable of adjusting the rigidity value of the workpiece W. Here, the pressing force of the holder device 60 against the outer peripheral surface of the workpiece W can be adjusted by the actuator, or can be adjusted by the operator.

The control device 3a is a CNC (Computer Numerical Control: computer numerical control) device and a PLC (Programmable Logic Controller: programmable logic controller) device that execute machining control. That is, the control device 3a drives the Z-axis drive mechanism 12 and the X-axis drive mechanism 14 as moving devices based on the grinding program, and performs position control of the table 20 and the grinding wheel holder 50. That is, the control device 3a performs position control of the table 20, the grinding wheel holder 50, and the like, so that the workpiece W and the grinding wheel T are relatively moved closer to and away from each other. The control device 3a controls the spindle device 30 and the grinding wheel holder 50. That is, the control device 3a performs rotation control of the spindle 32 and rotation control of the grinding wheel T.

In the case where the pressing force of the tailstock center 41 and the spindle center 34 in the axial direction of the workpiece W can be adjusted by an actuator, the control device 3a can adjust the pressing force in the axial direction by controlling the actuator. In addition, when the pressing force in the radial direction of the holder device 60 against the outer peripheral surface of the workpiece W can be adjusted by the actuator, the control device 3a can adjust the pressing force in the radial direction by controlling the actuator.

3. Structure of machining estimating device 3b

The structure 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.

The command value acquisition unit 101 acquires a command value for controlling the grinding machine body 2 during grinding. When the machining estimating device 3b is a simulation device independent of the grinding machine body 2 and the control device 3a, the command value obtaining unit 101 generates command values for controlling the respective parts of the grinding machine body 2 by calculation by inputting the grinding program and the structural information of the grinding machine body 2. In addition, when the machining estimating device 3b functions as a simulation device that operates in conjunction with the grinding by the grinding machine body 2 and the control device 3a, the command value obtaining unit 101 can directly obtain the command value from the control device 3 a.

The estimating unit 102 performs grinding simulation using the command value acquired by the command value acquiring unit 101, thereby estimating at least one of the state of the workpiece W or the grinding wheel T, the shape of the workpiece W, the shape of the grinding wheel T, and the mechanical state of the grinding machine body 2 during grinding.

The state of the workpiece W includes, for example, a vibration state, a temperature state, and the like of the workpiece W. The state of the grinding wheel T includes, for example, a vibration state, a temperature state, a grinding resistance generated at each portion of the outer peripheral surface of the grinding wheel T, sharpness of the grinding wheel T, a state of abrasive grains constituting the grinding wheel T, and the like. The state of the abrasive grains includes, for example, an average protrusion amount of the abrasive grains, an abrasive grain distribution, and the like. The shape of the workpiece W includes a shape at a halfway stage of the grinding process and a shape at an end stage of the grinding process. The shape of the grinding wheel T includes a shape at a halfway stage of grinding and a shape at an end stage of grinding. The mechanical state of the grinding machine body 2 includes a vibration state, a temperature state, and the like of a portion constituting the grinding machine body 2.

In the present embodiment, the estimating unit 102 performs the process of gradually changing the shape of the workpiece W by the grinding simulation, and takes the shape of the workpiece W, the state of the workpiece W, and the mechanical state of the grinder body 2 as the estimation targets. In the present embodiment, the grinding wheel T is a non-deformable member, and grinding simulation is performed. In addition to the estimation object, the estimation unit 102 can estimate the grinding resistance generated at each portion of the outer peripheral surface of the grinding wheel T.

The estimating unit 102 includes an interference amount calculating unit 111, a grinding efficiency calculating unit 112, a grinding characteristic determining unit 113, and a grinding resistance calculating unit 114.

The interference amount calculation unit 111 calculates the interference amount 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, which are obtained using the command value acquired by the command value acquisition unit 101. The interference amount corresponds to a grinding amount in the radial direction of the workpiece W at each portion in the circumferential direction of the workpiece W. In other words, the interference amount is a removal amount of the workpiece W ground by the grinding wheel T, and more specifically, a removal amount in the radial direction 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 a portion (hatched portion: interference area of fig. 3) where the work W and the grinding wheel T interfere.

The interference amount calculation unit 111 geometrically calculates the interference amount by an arithmetic process. 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 in the right part of fig. 4, the outer peripheral surface shape of the workpiece W is represented by a plurality of radial line segment groups 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, as the outer peripheral surface shape of the workpiece W, a plurality of segment groups connecting the dividing points (white points in fig. 4) on the outer peripheral surface divided by the equal angle (α) and the rotation center Ow (origin) of the workpiece W. The division points indicated by white points in fig. 4 are stored as the outer peripheral surface shape of the workpiece W before removal by the grinding wheel T.

The interference amount calculating unit 111 determines the intersection point (black dot in fig. 4) of each line segment representing the workpiece W and the line of the outer peripheral surface shape of the grinding wheel T, based on the relative position (inter-axis distance) between the workpiece W and the grinding wheel T and the outer peripheral surface shape of the grinding wheel T. The interference amount calculating unit 111 stores the determined intersection point (black point in fig. 4) 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 calculating unit 111 changes the shape of the outer peripheral surface of the stored workpiece W.

The interference amount calculation unit 111 subtracts the area of the triangle Δow-a 1-b2 formed by the points b1 and b2 (the intersection point with the grinding wheel T) after removal and the origin Ow from the area of the triangle Δow-a1-a2 formed by the adjacent points a1 and a2 and the origin Ow among points defining the shape of the outer peripheral surface of the workpiece W before removal. The subtracted area is calculated for all adjacent points defining the shape of the outer peripheral surface of the work W.

The interference amount calculating unit 111 calculates an interference amount (removal amount) by integrating the subtracted areas and multiplying the integrated sum area by the thickness of the workpiece W. In the above, the areas of the two triangles are calculated, and the differences in the areas are calculated, thereby calculating the areas of the removed portions. In addition, the area of the removed portion may also be calculated by directly calculating the quadrangles a1-a2-b1-b 2.

As shown in fig. 2, the grinding efficiency calculating section 112 calculates the grinding efficiency Z' based on the interference amount calculated by the interference amount calculating section 111. The grinding efficiency Z' calculates the interference amount per unit time, that is, the volume of the workpiece W to be ground by the grinding wheel T in the unit time.

The grinding characteristic determining unit 113 determines the grinding characteristic kc based on the material of the workpiece W, the abrasive grains of the grinding wheel T, the kind of the binder, the state of the outer peripheral surface of the grinding wheel T, and the like. The state of the outer peripheral surface of the grinding wheel T is expressed by using, for example, an index indicating the state of wear and sharpness of the abrasive grains of the grinding wheel T. Here, the grinding characteristic determination unit 113 stores grinding characteristics in each state by experiments, analysis, and the like in advance.

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').

The grinding characteristic kc has a substantially linear relationship such that the larger the grinding efficiency Z', the larger the grinding resistance Fn in the normal direction (X axis direction) is. Further, the grinding characteristic kc varies, for example, in the case where the grinding wheel T wears. For example, when the grinding wheel T wears, the grinding resistance Fn in the normal direction is changed so as to be larger than the grinding efficiency Z'.

The workpiece-side dynamic stiffness table storage unit 103 stores dynamic stiffness data Cw and Kw related to the workpiece W when the workpiece W and the grinding wheel T are separated from each other at the machining position as a boundary. The workpiece-side dynamic stiffness table storage unit 103 includes a dynamic stiffness table storage unit 103a for the workpiece W, a dynamic stiffness table storage unit 103b for the workpiece support members (20, 30, 40, 60), and a contact dynamic stiffness table storage unit 103c.

The dynamic stiffness table storage unit 103a for the workpiece W stores dynamic stiffness data Cwa and Kwa of the workpiece W (hereinafter referred to as workpiece dynamic stiffness data). The workpiece dynamic stiffness data Cwa, kwa can be obtained by, for example, hammering or FEM analysis for the workpiece W, which are known. When there are multiple kinds 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 kinds of workpieces W.

The dynamic stiffness table storage unit 103b associated with 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 rigidity data Cwb, kwb can be obtained by hammering, FEM analysis, or the like on each of the spindle device 30, the tailstock device 40, and the bracket device 60 that constitute the workpiece support member.

In the case where the grinding machine body 2 is capable of changing the arrangement of the plurality 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 workpiece support members (20, 30, 40, 60). When the support member dynamic stiffness data Cwb, kwb changes according to the machining conditions or the like, the dynamic stiffness table storage unit 103b stores the correspondence relation between the machining conditions or the like and the support member dynamic stiffness data Cwb, kwb.

The contact dynamic stiffness table storage unit 103c stores contact dynamic stiffness data Cwc, kwc between the workpiece W and the workpiece support members (20, 30, 40, 60). Since the contact dynamic stiffness data Cwc and Kwc change according to the machining conditions and the like, the contact dynamic stiffness table storage unit 103c stores the correspondence between the machining conditions and the like and the contact dynamic stiffness data Cwc and Kwc.

The contact dynamic stiffness data Cwc, kwc contains contact dynamic stiffness data between the central holes Wc, wd and the support centers 34, 41. It is assumed that, when the grinder body 2 includes a chuck for holding the workpiece W, the contact dynamic stiffness data Cwc and Kwc include contact dynamic stiffness data between the workpiece W and the chuck. The contact dynamic stiffness data Cwc, kwc includes contact dynamic stiffness data between the outer peripheral surface of the workpiece W and the holder device 60. When the holder device 60 is not provided in the grinder body 2, the contact dynamic stiffness data Cwc, kwc do not include contact dynamic stiffness data between the outer peripheral surface of the workpiece W and the holder device 60.

The grinding wheel side dynamic stiffness table storage unit 104 stores dynamic stiffness data Ct, kt (tool side dynamic stiffness data) concerning the grinding wheel T side when the workpiece W side and the grinding wheel T side are divided into the workpiece W side and the grinding wheel T side with the machining portion as a boundary. That is, the grinding wheel side dynamic stiffness table storage unit 104 stores dynamic stiffness data Ct, kt of the grinding wheel mount 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.

In the case where the grinding wheel T is supported by a hydrostatic bearing and the pressure of the hydrostatic bearing can be controlled, the grinding wheel-side dynamic stiffness data Ct and Kt may be data that varies according to the pressure of the hydrostatic bearing. Therefore, the grinding wheel side dynamic stiffness table storage unit 104 may store the damping coefficient Ct and the spring constant Kt as processing conditions according to the pressure of the hydrostatic bearing. When the dynamic stiffness data Ct, kt changes depending on the machining conditions or the like, the grinding wheel side dynamic stiffness table storage unit 104 stores the correspondence between the machining conditions or the like and the grinding wheel side dynamic stiffness data Ct, kt.

The workpiece-side dynamic rigidities (Cw, kw) and the grinding wheel-side dynamic rigidities (Ct, kt) are described with reference to fig. 5. The workpiece-side dynamic rigidities (Cw, kw) include dynamic rigidities of the workpiece W on the workpiece W side with respect to the table 20, the spindle device 30, the tailstock device 40, and the bracket device 60.

The workpiece-side dynamic rigidities (Cw, kw) are dynamic rigidities exhibited in a state where the workpiece W is supported by the spindle device 30, the tailstock device 40, and the bracket device 60, which are workpiece support members constituting the grinder body 2. The workpiece-side dynamic stiffness (Cw, kw) is defined by the damping coefficient Cw and the spring constant Kw. The attenuation coefficient Cw is a value indicating a relation between a relative speed of the workpiece W with respect to a reference position of the grinder body 2 and an 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 to the reference position of the grinder body 2 and the external force applied to the workpiece W.

As shown in fig. 5, the workpiece-side dynamic rigidities (Cw, kw) can be decomposed into workpiece dynamic rigidities (Cw, kwa), support member dynamic rigidities (Cwb, kwb), and contact dynamic rigidities (Cwc, kwc) between the workpiece W and the workpiece support members (20, 30, 40, 60).

The contact dynamic stiffness (Cwc, kwc) is the dynamic stiffness between the workpiece W and the workpiece support member (20, 30, 40, 60), and is the dynamic stiffness exhibited by the contact of the workpiece W with the workpiece support member (20, 30, 40, 60). The dynamic stiffness of contact (Cwc, kwc) is defined by the damping coefficient Cwc and the spring constant Kwc. The damping coefficient Cwc is a value indicating a relation between a relative speed between the workpiece W and the workpiece support members (20, 30, 40, 60) and an external force applied to the workpiece W. The spring constant Kwc is a value indicating the relationship between the relative position of the work W and the work support members (20, 30, 40, 60) and the external force applied to the work W.

Here, the contact dynamic rigidities (Cwc, kwc) are different depending on the adjustment member related to the supporting force generated by the workpiece supporting members (20, 30, 40, 60) and the member of the supported portion of the workpiece W. The relationship between the contact dynamic rigidities (Cwc, kwc) and the supporting force adjusting member and the member of the supported portion of the workpiece W will be described with reference to fig. 6.

Fig. 6 (a) shows a case where the workpiece W has a small diameter shaft shape, and the sizes (opening diameters) of the spindle side center hole Wc and the tailstock side center hole Wd formed in both end surfaces of the workpiece W are small. Fig. 6b shows a case where the workpiece W is in a large diameter shaft shape, and the sizes (opening diameters) of the spindle side center hole Wc and the tailstock side center hole Wd formed in both end surfaces of the workpiece W are large. The sizes of the center holes Wc, wd serve as an index of the opening diameters of the center holes Wc, wd.

In fig. 6 (a), the pressing force of the spindle center 34 and the tailstock center 41 in the axial direction of the workpiece W is F1. In fig. 6 (a), the pressing force in the radial direction of the holder device 60 against the outer peripheral surface of the workpiece W is F2. In fig. 6 (b), the pressing force of the spindle center 34 and the tailstock center 41 in the axial direction of the workpiece W is F11. In fig. 6 (b), the pressing force in the radial direction of the holder device 60 against the outer peripheral surface of the workpiece W is F12.

In fig. 6 (a) and (b), the relationship between the pressing forces 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). In addition, fig. 6 (b) is larger than fig. 6 (a) in terms of the contact area between the outer peripheral surface of the workpiece W and the holder device 60.

Here, the contact dynamic rigidities (Cwc, kwc) vary by the force with which the contacted members are pressed against each other. The contact state between the center holes Wc, wd of the workpiece W and the support centers 34, 41 changes due to the change in the pressing force of the spindle center 34 and the tailstock center 41 in the axial direction of the workpiece W, and the dynamic contact stiffness (Cwc, kwc) changes according to the change in the contact state. The contact state between the outer peripheral surface of the workpiece W and the holder device 60 changes due to a change in the pressing force of the holder device 60 in the radial direction of the workpiece W, and the contact dynamic rigidities (Cwc, kwc) change in response to the change in the contact state.

In the structure in which the workpiece W is gripped by the chuck, the contact state of the workpiece W with the chuck changes due to a change in the gripping force of the chuck on the workpiece W, and the contact dynamic rigidities (Cwc, kwc) change in response to the change in the contact state.

The dynamic contact rigidities (Cwc, kwc) also vary according to the contact area. The size of the spindle-side center hole Wc and the size of the tailstock-side center hole Wd of the member as the supported portion are different, and thus the contact area changes, and the dynamic contact stiffness (Cwc, kwc) changes as the contact area changes. The contact area changes due to the difference in the size of the support surface of the holder device 60 and the outer diameter of the workpiece W, and the contact dynamic stiffness (Cwc, kwc) changes as the contact area changes.

In the structure in which the workpiece W is gripped by the chuck, the size of the gripping surface of the chuck and the gripping diameter of the workpiece W are different, and thus the contact area between the workpiece W and the chuck changes, and the dynamic contact stiffness (Cwc, kwc) changes as the contact area changes.

As shown in fig. 5, the grinding wheel side dynamic stiffness is dynamic stiffness related to the grinding wheel mount 50 including the grinding wheel T. The grinding wheel side dynamic stiffness is defined by the damping coefficient Ct and the spring constant Kt. The attenuation coefficient Ct is a value indicating a relation between a relative speed of the grinding wheel T with respect to a reference position of the grinding wheel mount 50 and an external force applied to the grinding wheel T. The spring constant Kt represents a value of a relation between a relative position of the grinding wheel T with respect to a reference position of the grinding wheel mount 50 and an external force applied to the grinding wheel T. The dynamic stiffness (Ct, kt) on the grinding wheel side includes dynamic stiffness (Cta, kta) of the grinding wheel T and dynamic stiffness (Ctb, ktb) exhibited when the grinding wheel T is supported by the grinding wheel seat body 51.

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

In fig. 7, the adjustment means related to the supporting force of the workpiece W is the adjustment means related to the supporting force of the workpiece supporting means (20, 30, 40, 60) on the workpiece W. For example, the supporting force adjusting means includes a center pressing force based on the spindle center 34 and the tailstock center 41. The supporting force adjusting means includes a pressing force by the holder device 60. Therefore, the conditions A1, A2, A3 of the supporting force adjusting member are conditions for changing the center pressing force and the bracket pressing force, respectively.

In addition, in the case where the holder device 60 is not provided, the holder pressing force is not taken into consideration. In addition, when the workpiece support member is a chuck for gripping the workpiece W and is configured to be capable of adjusting the gripping force, the adjusting means relating to the support force of the workpiece W is based on the gripping force of the chuck.

In fig. 7, the member of the supported portion of the workpiece W is a member of the portion of the workpiece W that contacts the spindle center 34, the tailstock center 41, and the holder device 60. For example, the members of the supported portion of the workpiece W include the sizes (opening diameters) of the center holes Wc, wd. The member of the supported portion of the workpiece W includes an area (bracket contact area) of the portion of the outer peripheral surface of the workpiece W that contacts the bracket device 60. The holder contact area is a value that varies depending on the structure of the holder device 60, the outer diameter of the workpiece W, and the like. Therefore, the conditions B1, B2, and B3 for the members of the supported portion of the workpiece W are conditions for changing the sizes of the center holes Wc and Wd and the bracket contact areas, respectively.

In addition, in the case where the bracket device 60 is not provided, the bracket contact area is not considered. In addition, when the workpiece support member is a chuck for gripping the workpiece W, the member of the supported portion of the workpiece W is based on the gripping area of the chuck.

The dynamic contact stiffness table shown in fig. 7 is a data table obtained by actually measuring the first conditions (conditions A1, A2, A3, and conditions B1, B2, B3), and is therefore a table limited to the first conditions under which actual measurement is performed.

However, the conditions for practical use are various, and therefore there is a possibility that the contact dynamic stiffness table shown in fig. 7 is insufficient. Therefore, the portion shown by the hatching of fig. 8 is supplemented by interpolation processing using the measured contact dynamic stiffness table.

That is, as shown in fig. 7, the contact dynamic stiffness table storage unit 103c stores in advance the correspondence relation between the first conditions (conditions A1, A2, A3 and conditions B1, B2, B3) and the actual measured contact dynamic stiffness data Cwc, kwc as a precondition. Then, interpolation processing is performed using the contact dynamic stiffness data Cwc, kwc concerning the first condition (conditions A1, A2, A3 and conditions B1, B2, B3), thereby generating the contact dynamic stiffness data Cwc, kwc concerning the second condition (conditions A1h, A2h and conditions B1h, B2 h) different from the first condition. The contact dynamic stiffness table storage unit 103c additionally stores the generated contact dynamic stiffness data Cwc, kwc.

For example, an experimental formula defining the relationship between the adjustment member for the supporting force of the workpiece W, the member for the supported portion of the workpiece W, the damping coefficient Cwc, and the spring constant Kwc can be used for the interpolation processing. In addition, machine learning, theoretical calculation, and the like may be used for the interpolation processing.

As shown in fig. 2, the dynamic rigidity determination condition obtaining unit 105 obtains dynamic rigidity determination conditions at the time of grinding processing by the grinding machine body 2. Specifically, the dynamic rigidity determination condition acquisition unit 105 acquires the dynamic rigidity determination condition at the time of estimation (at the time of processing object) by the estimation unit 102. The dynamic stiffness determination condition acquired by the dynamic stiffness determination condition acquisition unit 105 is information for the dynamic stiffness determination unit 106 to calculate each dynamic stiffness. The dynamic rigidity determination conditions to be obtained 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 by the support centers 34 and 41, the pressing force by the holder device 60, and the like.

In the case where the machining 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 structure of the grinding machine body 2 and the grinding machining program. In the case where the machining estimating device 3b functions as a simulator that operates in conjunction with the grinding by the grinding machine body 2, the dynamic stiffness determination condition acquiring unit 105 may acquire the conditions for determining the dynamic stiffness by inputting the mechanical structure of the grinding machine body 2 and the grinding program from the control device 3a, or may acquire information on the conditions directly from the control device 3a of the grinding machine body 2.

The dynamic stiffness determination unit 106 determines dynamic stiffness data that affects the grinding process. The dynamic stiffness determination unit 106 determines the workpiece-side dynamic stiffness data Cw, kw and the grinding wheel-side dynamic stiffness data Ct, kt, respectively. That is, the dynamic stiffness determining unit 106 includes a workpiece-side dynamic stiffness determining unit 121 and a grinding wheel-side dynamic stiffness determining unit 122.

The workpiece-side dynamic stiffness determining unit 121 determines workpiece dynamic stiffness data Cwa, kwa corresponding to the type of the workpiece W acquired by the dynamic stiffness determining condition acquiring unit 105 from the dynamic stiffness table stored in the dynamic stiffness table storage unit 103a related to the workpiece W. The workpiece-side dynamic stiffness determination unit 121 determines support member dynamic stiffness data Cwb, kwb corresponding to the type of the workpiece support member acquired by the dynamic stiffness determination condition acquisition unit 105 from the dynamic stiffness table stored in the dynamic stiffness table storage unit 103b related to the workpiece support member (20, 30, 40, 60).

The workpiece-side dynamic stiffness determination unit 121 obtains conditions for determining the contact dynamic stiffness data Cwc and Kwc from the dynamic stiffness determination condition obtaining unit 105. As shown in fig. 7 and 8, the workpiece-side dynamic stiffness determining unit 121 obtains a supporting force adjusting member and a member of a supported portion of the workpiece W. The workpiece-side dynamic stiffness determining unit 121 determines the contact dynamic stiffness Cwc, kwc corresponding to the supporting-force adjusting member and the member of the supported portion of the workpiece W from the contact dynamic stiffness table stored in the contact dynamic stiffness table storing unit 103 c.

The grinding wheel side dynamic stiffness determination unit 122 determines dynamic stiffness data Ct, kt corresponding to the type of the 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 storage unit 104.

The correction amount calculating unit 107 calculates a 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 Fn based on the respective dynamic stiffness data determined by the dynamic stiffness determining unit 106. The correction amount related to the displacement can be obtained from each dynamic stiffness data and the grinding resistance Fn. That is, the correction amount regarding the displacement can be calculated from the grinding resistance Fn, the workpiece-side dynamic stiffness data Cw, kw, and the grinding wheel-side dynamic stiffness data Ct, kt.

However, in the present embodiment, the workpiece-side dynamic stiffness data Cw and Kw include the workpiece dynamic stiffness data Cwa and Kwa, the support member dynamic stiffness data Cwb and Kwb, and the contact dynamic stiffness data Cwc and Kwc, respectively. That is, the correction amount related to the displacement is calculated from the grinding resistance Fn, the workpiece-side dynamic stiffness data Cwa, kwa, cwb, kwb, cwc, kwc, and the grinding wheel-side dynamic stiffness data Ct, kt.

The correction amount calculation unit 107 outputs the calculated correction amount to the estimation unit 102. As described above, the estimating unit 102 estimates the estimation target 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, which are acquired by the command value acquiring unit 101. However, the relative position of the workpiece W and the grinding wheel T is different from the relative position based on the command value due to the grinding resistance Fn.

Therefore, the estimating unit 102 uses, as the relative position between the workpiece W and the grinding wheel T, the relative position to which the correction amount calculated by the correction amount calculating unit 107 is added, in addition to the relative position acquired by the command value acquiring unit 101, at the time of estimating the estimation target. That is, the estimating unit 102 estimates the estimation target based on the relative position of the command value and the correction amount calculated using each dynamic stiffness data.

In particular, in the present 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 interference amount 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, which are 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 Fn.

Therefore, the interference amount calculation unit 111 uses, as the relative position of the work W and the grinding wheel T used for calculation of the interference amount, the relative position to which the correction amount calculated by the correction amount calculation unit 107 is added, in addition to the relative position acquired by the command value acquisition unit 101. 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 stiffness data.

In order for the interference amount calculation unit 111 to calculate the interference amount in consideration of the correction amount, the grinding efficiency calculation unit 112, the grinding characteristic determination unit 113, and the grinding resistance calculation unit 114 acquire the grinding efficiency Z', the grinding characteristic kc, and the grinding resistance Fn obtained based on the interference amount in consideration of the correction amount.

The output unit 108 outputs the estimation target estimated by the estimating unit 102. That is, the output unit 108 estimates at least one of the state of the workpiece W or the grinding wheel T at the time of grinding, the shape of the workpiece W, the shape of the grinding wheel T, and the mechanical state of the machining device 1 (corresponding to the mechanical state of the grinding machine body 2). The output unit 108 may teach the estimation result to a teaching device, not shown, for example. The output unit 108 may output the estimation result to the control device 3a of the grinding machine body 2. In this case, the control device 3a can correct the grinding conditions, for example, using the estimation result. That is, the control device 3a can control the grinding process using the estimation result.

The control device 3a may control the adjustment mechanism 42 of the tailstock device 40 using the estimation result to adjust the pressing force generated in the spindle center 34 and the tailstock center 41. In the case where the grinder body 2 includes a chuck, the control device 3a may adjust the gripping force of the chuck using the estimation result. The control device 3a may adjust the pressing force generated by the holder device 60 using the estimation result. The control device 3a may appropriately select a control target using the estimation result.

The control device 3a performs the above-described various processes using the estimation result. The control device 3a may control the machining by using various dynamic rigidities determined by the dynamic rigidity determining unit 106, instead of the estimation result. For example, the control device 3a may adjust the pressing force generated in the spindle center 34 and the tailstock center 41, the gripping force of the chuck, the pressing force of the holder device 60, and the like, by using various dynamic rigidities determined by the dynamic rigidity determining unit 106, instead of the estimation result.

4. Effects of

According to the present embodiment, the control device 3a of the processing unit 3 performs a desired process using the dynamic contact stiffness data Cwc, kwc between the workpiece W and the workpiece support members (20, 30, 40, 60). The desired target process is a process of performing control of machining or a process of estimating at least one of the state of the workpiece W or the grinding wheel T, the shape of the workpiece W, the shape of the grinding wheel T, and the mechanical state of the machining device 1 during machining.

The contact dynamic stiffness data Cwc, kwc is represented by a spring constant Kwc and an attenuation coefficient Cwc between the work W and the work support member (20, 30, 40, 60) exhibited by the contact of the work W with the work support member (20, 30, 40, 60). Thus, by using the contact dynamic stiffness data Cwc, kwc including the spring constant Kwc and the damping coefficient Cwc, the desired target processing can be performed with high accuracy.

As shown in fig. 7 and 8, the dynamic contact stiffness table stores in advance the correspondence between the adjustment member related to the supporting force generated by the workpiece supporting members (20, 30, 40, 60), the member of the supported portion of the workpiece W, and the dynamic contact stiffness data Cwc, kwc. Therefore, the workpiece-side dynamic stiffness determination unit 121 can easily determine the contact dynamic stiffness data Cwc, kwc using the correspondence between the adjustment member and the member of the supported portion at the time of processing, and the contact dynamic stiffness table stored in the contact dynamic stiffness table.

As shown in fig. 8, the contact dynamic stiffness table storage unit 103c additionally stores contact dynamic stiffness data obtained by performing interpolation processing. By generating the contact dynamic stiffness data Cwc, kwc concerning the non-actually measured condition in this way, the estimation target or the control target can be estimated with high accuracy.

The workpiece-side dynamic stiffness data is divided into workpiece dynamic stiffness data Cwa, kwa, support member dynamic stiffness data Cwb, kwb, and contact dynamic stiffness data Cwc, kwc. In this way, by separating each dynamic stiffness data, the determination of each dynamic stiffness data becomes easy. For example, even when the workpiece W and the workpiece support members (20, 30, 40, 60) are identical, only the contact dynamic stiffness data Cwc, kwc are changed when only the pressing force generated by the support centers 34, 41 is adjusted. Therefore, the arithmetic processing becomes easy. 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, the calculation processing is performed at a high speed, whereby the grinding processing with high accuracy can be realized.

(Embodiment 2)

A processing device 201 according to the present embodiment will be described with reference to fig. 9. The machining device 201 is a machining device that performs cutting machining. The machining device 201 includes a lathe body 202 as a machining device body, and a processing unit 203.

The lathe body 202 rotates the workpiece W and moves the cutting tool T2 relative to the workpiece W to turn the workpiece W. The processing unit 203 includes a control device 203a for controlling the lathe body 202, and a machining estimating device 203b for estimating an estimation target related to machining. The control device 203a can control the cutting process by controlling the lathe body 202. The machining estimating device 203b estimates at least one of the state of the workpiece W or the cutting tool T2, the shape of the workpiece W, the shape of the cutting tool T2, and the mechanical state of the machining device 201 (corresponding to the mechanical state of the lathe body 202) at the time of cutting of the lathe body 202. The machining estimation device 203b performs the estimation processing of the estimation object by inputting information for cutting machining and performing simulation.

The lathe body 202 includes, for example, a lathe bed 210, a spindle device 220, a tailstock device 230, a holder device 240, and a tool table 250. The spindle assembly 220, tailstock assembly 230, and bracket assembly 240 function as workpiece support members. The spindle device 220 is fixed to the upper surface of the bed 210, supports one end of the workpiece W, and rotationally drives the workpiece W. The spindle device 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.

The spindle housing 221 is fixed to the bed 210. The spindle 222 is rotatably supported by the spindle case 221 via a bearing. The spindle motor 223 rotationally drives the spindle 222. A chuck 224 is fixed to the spindle 222 and holds one end of the workpiece W. The spindle detector 225 and the spindle drive circuit are provided for driving the spindle motor 223.

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

The holder 240 is fixed to the bed 210 and supports the outer peripheral surface of the axial intermediate portion of the workpiece W. In particular, the holder device 320 is disposed at a position that resists the cutting load applied to the workpiece W from the cutting tool T2.

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

The X-axis slide table 252 is supported by an X-axis guide surface 251a on the Z-axis slide table 251 so as to be movable in the X-axis direction, and is movable in the X-axis direction by an X-axis drive mechanism 251b provided on the Z-axis slide table 251. The turntable 253 is rotatably provided on the X-axis slide table 252 about an axis parallel to the Z-axis direction. A plurality of cutting tools T2 are fixed to the outer peripheral surface of the turntable 253. The plurality of cutting tools T2 may be different types of tools.

The control device 203a is a CNC (Computer Numerical Control: computer numerical control) device and a PLC (Programmable Logic Controller: programmable logic controller) device that execute machining control. That is, the control device 203a drives the Z-axis drive mechanism 212 and the X-axis drive mechanism 251b, which are moving devices, based on the cutting program, and performs position control of the cutting tool T2. That is, the control device 203a performs position control of the cutting tool T2 and the like, thereby relatively moving the workpiece W and the cutting tool T2. The control device 203a performs rotation control of the spindle 222 and rotation control of the turntable 253.

The machining estimation device 203b of the present embodiment has the same configuration as the machining estimation device 3b of embodiment 1 shown in fig. 2. However, the grinding in embodiment 1 is changed to cutting, and the grinding wheel T is changed to a cutting tool T2.

Next, in the present embodiment, the workpiece-side dynamic rigidities (Cw, kw) and the tool-side dynamic rigidities (Ct, kt) will be described with reference to fig. 10. The workpiece-side dynamic rigidities (Cw, kw) are dynamic rigidities exhibited in a state where the workpiece W is supported by the spindle device 220, the tailstock device 230, and the bracket device 240, which are workpiece support members constituting the lathe body 202. The workpiece-side dynamic stiffness (Cw, kw) is defined by the damping coefficient Cw and the spring constant Kw. The damping coefficient Cw is a value indicating a relation between a relative speed of the workpiece W with respect to the reference positions of the spindle device 220, the tailstock device 230, and the bracket device 240 and an 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 to the reference positions of the spindle device 220, the tailstock device 230, and the bracket device 240 and the external force applied to the workpiece W.

Further, as in embodiment 1, the workpiece-side dynamic rigidities (Cw, kw) can be decomposed into workpiece dynamic rigidities (Cw, kwa), support member dynamic rigidities (Cwb, kwb), and contact dynamic rigidities (Cwc, kwc) between the workpiece W and the workpiece support members (20, 30, 40, 60).

The tool-side dynamic stiffness (Ct, kt) is the dynamic stiffness associated with the tool table 250 including the cutting tool T2. Tool side dynamic stiffness (Ct, kt) is defined by the damping coefficient Ct and the spring constant Kt. The attenuation coefficient Ct is a value indicating a relation between a relative velocity of the cutting tool T2 with respect to the reference position of the tool table 250 and an external force applied to the cutting tool T2. The spring constant Kt is a value indicating a relationship between a relative position of the cutting tool T2 with respect to the reference position of the tool table 250 and an external force applied to the cutting tool T2.

The processing device 201 of the present embodiment achieves the same effects as the processing device 1 of embodiment 1.

(Others)

In the above embodiment, the grinding process using the grinding machine body 2 and the cutting process using the lathe body 202 have been described as examples. However, the present invention can be similarly applied to cutting processing using a machining center, except for these.

Claims

1. A machining device (1, 201) for machining a workpiece (W) supported by a workpiece support member (20, 30, 40, 60, 220, 230, 240) by means of a tool (T, T2), is characterized by comprising:

And a processing unit (3, 203) that uses dynamic contact stiffness data (Cwc, kwc) between the workpiece and the workpiece support member, which is displayed by the contact between the workpiece and the workpiece support member, to control processing or estimate at least one of the state of the workpiece or the tool, the shape of the workpiece, the shape of the tool, and the mechanical state of the processing device during processing.

2. The processing apparatus according to claim 1, further comprising:

A contact dynamic stiffness table storage unit (103 c) that stores in advance the correspondence between the adjustment members (34, 41, 60, 224, 231, 240) related to the supporting force of the workpiece supporting member, the members (W, wc, wd) of the supported portion of the workpiece, and the contact dynamic stiffness data (Cwc, kwc); and

A dynamic stiffness determination unit (106) for determining the contact dynamic stiffness data using the correspondence between the adjustment member and the member of the supported portion and the correspondence stored in the contact dynamic stiffness table storage unit at the time of processing the object,

The processing unit controls the machining or estimates at least one of a state of the workpiece or the tool, a shape of the workpiece, a shape of the tool, and a mechanical state of the machining device at the time of the machining using the contact dynamic stiffness data determined by the dynamic stiffness determining unit.

3. The processing apparatus according to claim 2, wherein,

The contact dynamic stiffness table storage unit stores in advance a first condition (A1, A2, A3, B1, B2, B3) concerning the adjustment member and the member of the supported portion, a correspondence relation between the first condition and the contact dynamic stiffness data measured under the first condition,

Further, interpolation processing is performed using the contact dynamic stiffness data concerning the first condition, whereby the contact dynamic stiffness data acquired for a second condition (A1 h, A2h, B1h, B2 h) different from the first condition is additionally stored.

4. A processing apparatus according to claim 2 or 3, wherein,

The supported part members are center holes (Wc, wd) formed in the axial end surfaces of the work,

The workpiece support member includes support centers (34, 41, 231) for pressing the workpiece in the axial direction with respect to the center hole,

The contact dynamic stiffness data is contact dynamic stiffness data between the center hole and the support center.

5. The processing apparatus according to claim 4, wherein,

The support center is configured to be capable of adjusting a pressing force in an axial direction of the workpiece with respect to the workpiece,

The contact dynamic stiffness data is data which changes with a change in a contact state between the center hole of the work and the support center, the contact state between the center hole of the work and the support center changes due to a change in the pressing force by the support center,

The processing unit estimates at least one of a state of the workpiece or the tool, a shape of the workpiece, a shape of the tool, and a mechanical state of the processing device during processing using the contact dynamic stiffness data, and adjusts the pressing force by the support center based on the estimation result.

6. The processing apparatus according to any one of claim 1 to 3, wherein,

The workpiece support member is a chuck (224) for holding the workpiece,

The contact dynamic stiffness data is contact dynamic stiffness data between the workpiece and the chuck.

7. The processing apparatus according to claim 6, wherein,

The chuck is configured to be capable of adjusting a gripping force of the workpiece,

The dynamic contact stiffness data is data that changes in response to a change in a contact state between the workpiece and the chuck, the contact state between the workpiece and the chuck changes due to a change in the holding force by the chuck,

The processing unit estimates at least one of a state of the workpiece or the tool, a shape of the workpiece, a shape of the tool, and a mechanical state of the processing device during processing using the contact dynamic stiffness data, and adjusts the gripping force by the chuck based on the estimation result.

8. The processing apparatus according to any one of claim 1 to 3, wherein,

The workpiece support member is a bracket device (60, 240) for supporting the outer peripheral surface of the workpiece formed in a shaft shape,

The contact dynamic stiffness data is contact dynamic stiffness data between the outer peripheral surface of the workpiece and the holder device.

9. The processing apparatus according to claim 8, wherein,

The holder device is configured to be able to adjust a pressing force to an outer peripheral surface of the work,

The contact dynamic stiffness data is data which changes with a change in a contact state between the outer peripheral surface of the workpiece and the holder device, the contact state between the outer peripheral surface of the workpiece and the holder device changes due to a change in the pressing force by the holder device,

The processing unit estimates at least one of a state of the workpiece or the tool, a shape of the workpiece, a shape of the tool, and a mechanical state of the processing device during processing using the contact dynamic stiffness data, and adjusts the pressing force by the holder device based on the estimation result.

10. The processing apparatus according to any one of claims 1 to 9, wherein,

The processing part uses

The above-mentioned dynamic rigidity data (Cwc, kwc),

Dynamic rigidity data (Cwb, kwb) of the support member, which is dynamic rigidity of the workpiece support member, and

The dynamic stiffness of the workpiece is the dynamic stiffness data (Cwa, kwa) of the workpiece,

Control of machining is performed, or at least one of a state of the workpiece or the tool, a shape of the workpiece, a shape of the tool, and a mechanical state of the machining device is estimated at the time of machining.