Processing machine and control method

Abstract

A processing machine (10) is provided with: a main shaft (14) that rotatably supports a cutting tool (15); a stage (16) on which the workpiece (W) is placed; a measurement unit (17) that measures a physical quantity generated by contact between the cutting tool (15) and the workpiece (W); a comparison unit (111) that calculates the depth of cutting of the workpiece (W) by the cutting tool (15) on the basis of the physical quantity, and compares the calculated depth of cutting with a reference depth of cutting; and an adjustment unit (112) that adjusts the position of at least one of the cutting tool (15), the spindle (14), and the stage (16) on the basis of the result of the comparison by the comparison unit (111).

Description

Technical Field

[0001] The present invention relates to a processing machine and a control method. Background Art

[0002] In a processing machine that uses a cutting tool to process a workpiece, the spindle or the cutting tool undergoes thermal deformation due to heat generated during processing, sometimes resulting in a decline in processing quality. There is a technique for controlling the relative position of the spindle and the stage on which the workpiece is placed in the presence of such thermal deformation (see Patent Document 1).

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Patent No. 7103136

[0006] Non-Patent Documents

[0007] Non-Patent Document 1: Kiyoshi Ohishi, Kouhei Ohnishi, and Kunio Miyachi, “Torque-speed regulation of dc motor based on load torque estimation method,” JIEE / 1983 International Power Electronics Conference, IPEC-TOKYO, Tokyo, Japan, Summary of the Invention

[0008] Problems to be Solved by the Invention

[0009] However, sometimes it is not possible to sufficiently suppress the decline in processing quality even by controlling the relative position of the spindle and the stage.

[0010] Therefore, the present invention provides a processing machine and the like that suppresses a decline in the quality of processing.

[0011] Means for Solving the Problems

[0012] A processing machine according to one aspect of the present invention includes: a spindle that supports a cutting tool in a rotatable manner; a stage that mounts a workpiece; a measurement unit that measures a physical quantity generated due to contact between the cutting tool and the workpiece; a comparison unit that calculates a cutting depth of the cutting tool with respect to the workpiece based on the physical quantity and compares the calculated cutting depth with a reference cutting depth; and an adjustment unit that adjusts the position of at least one of the cutting tool, the spindle, and the stage based on a result of the comparison performed by the comparison unit.

[0013] In addition, these general or specific manners can be implemented either by a system, a method, an integrated circuit, a computer program, or a recording medium such as a computer-readable CD-ROM, or by any combination of a system, a method, an integrated circuit, a computer program, and a recording medium.

[0014] Effects of the Invention

[0015] The processing machine of the present invention can suppress a decrease in the quality of processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram showing the structure of the processing machine in the embodiment.

[0017] Figure 2 It is a flowchart showing the control method of the processing machine in the embodiment.

[0018] Figure 3 It is an explanatory diagram showing an example of the correspondence between the cutting resistance and the cutting depth in the embodiment.

[0019] Figure 4 It is a schematic diagram showing an example of the cutting depth of the cutting performed by the processing machine in the comparative example.

[0020] Figure 5 It is a schematic diagram showing a first example of the cutting depth of the cutting performed by the processing machine in the embodiment.

[0021] Figure 6 It is a schematic diagram showing a second example of the cutting depth of the cutting performed by the processing machine in the embodiment.

[0022] Figure 7 It is a schematic diagram showing the structure of the processing machine in the modification of the embodiment.

[0023] Figure 8 It is a flowchart showing the control method of the processing machine in the modification of the embodiment.

[0024] Figure 9 It is an explanatory diagram showing an example of the correspondence between the cutting force and the cutting depth in the modification of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0025] (Insight underlying the present invention)

[0026] The present inventors have found that the techniques related to the processing machine described in the "BACKGROUND ART" column have the following problems.

[0027] In a processing machine that uses a cutting tool to process a workpiece, thermal deformation sometimes occurs in the spindle or the cutting tool. If thermal deformation occurs in the spindle or the cutting tool, it sometimes leads to a decline in processing quality. The decline in processing quality includes, for example, the cutting depth of the workpiece not being consistent with the reference value, or a pattern (such as a stripe pattern or a spot pattern) being generated on the machined surface (also referred to as the processed surface) of the workpiece.

[0028] In the technology described in Patent Document 1, the relative displacement between the spindle and the stage is calculated by measuring the positions of the spindle and the stage with sensors, and the positions of the spindle or the stage are controlled in a manner that reduces the relative displacement between the spindle and the stage to suppress the decline in processing quality.

[0029] However, sometimes even by controlling the relative position between the spindle and the stage based on the measurement of the positions of the spindle and the stage, it is not possible to sufficiently suppress the decline in processing quality. For example, when the position of the tip of the cutting tool has shifted relative to the appropriate position due to thermal deformation of the spindle or the cutting tool, even if the displacement amount of the spindle is measured, it is not possible to accurately know the displacement amount of the position of the tip of the cutting tool. In this case, sometimes even by controlling the relative position between the spindle and the stage to be appropriate, it is not possible to suppress the decline in processing quality.

[0030] Therefore, the present invention provides a processing machine and the like that suppress the decline in processing quality.

[0031] Hereinafter, an invention obtained from the disclosure of this specification will be exemplified, and the effects obtained from the present invention and the like will be described.

[0032] (1) A processing machine, comprising: a spindle that supports a cutting tool in a rotatable manner; a stage that mounts a workpiece; a measuring unit that measures a physical quantity generated due to the contact between the cutting tool and the workpiece; a comparing unit that calculates the cutting depth of the cutting tool on the workpiece based on the physical quantity and compares the calculated cutting depth with a reference cutting depth; and an adjusting unit that adjusts the position of at least one of the cutting tool, the spindle, and the stage based on the result of the comparison performed by the comparing unit.

[0033] According to the above method, the processing machine adjusts the position of at least one of the cutting tool, the spindle, and the stage using the cutting depth calculated based on the measured physical quantity. The measured physical quantity changes in relation to the cutting depth of the processing machine. Therefore, the processing machine can calculate the cutting depth estimated based on the physical quantity and control the subsequent cutting depth based on the calculated cutting depth. Thus, without measuring the actual cutting depth, by controlling the cutting depth using a physical quantity that can be measured relatively easily, the decline in processing quality is suppressed. In addition, since there is no need to measure the cutting depth, there is an effect that it can be applied even in a case where it is difficult to measure the cutting depth. In this way, the processing machine according to the present disclosure can suppress the decline in the quality of processing.

[0034] (2) The processing machine according to (1), wherein the adjustment unit adjusts the position of at least one of the cutting tool, the spindle, and the stage based on the result of the comparison performed by the comparison unit so that the cutting depth of the cutting tool on the workpiece approaches the reference cutting depth.

[0035] According to the above method, the processing machine adjusts the position of at least one of the cutting tool, the spindle, and the stage using the cutting depth calculated based on the measured physical quantity, whereby the cutting depth of the processing machine can be made to approach the reference cutting depth, contributing to suppressing the decline in the quality of the processed product. Therefore, the processing machine according to the present disclosure can further suppress the decline in the quality of processing.

[0036] (3) The processing machine according to (1) or (2), wherein the measurement unit measures the cutting resistance exerted on the cutting tool by the workpiece being cut by the cutting tool as the physical quantity, and the comparison unit uses the cutting resistance measured by the measurement unit as the physical quantity for the comparison.

[0037] According to the above method, the processing machine uses the relatively easily measurable cutting resistance as a physical quantity for cutting the workpiece. Therefore, the processing machine according to the present disclosure can more easily suppress the decline in the quality of processing.

[0038] (4) The processing machine according to any one of (1) to (3), wherein the reference cutting depth is: (a) a predetermined target value of the cutting depth of the processing machine on the workpiece, i.e., the target depth, or (b) the cutting depth of the workpiece calculated based on the physical quantity measured by the measurement unit at a certain time point when the processing machine is cutting the workpiece.

[0039] According to the above method, the processing machine can more appropriately control the cutting depth of the workpiece by using the predetermined target depth or the estimated cutting depth at a certain point in the cutting process as the reference cutting depth. For example, by using the predetermined target depth as the reference cutting depth, it helps to achieve the predetermined processing quality. In addition, by using the estimated cutting depth at a certain point in the cutting process as the reference cutting depth, with the above-mentioned point in time as the reference for the processing quality, it helps to achieve the processing quality of this reference. Therefore, the processing machine according to the present disclosure can achieve the specified processing quality while suppressing the deterioration of the processing quality.

[0040] (5) The processing machine according to (1) or (2), wherein the measuring unit measures the position, speed or acceleration of the stage as the physical quantity, and the comparing unit uses the position, the speed or the acceleration measured by the measuring unit to estimate the cutting force exerted by the cutting tool on the workpiece, uses the estimated cutting force to calculate the cutting depth of the cutting tool on the workpiece, and compares the calculated cutting depth with the reference cutting depth.

[0041] According to the above method, the processing machine uses the relatively easily measurable position, speed or acceleration of the stage as the physical quantity to perform the cutting of the workpiece. Therefore, the processing machine according to the present disclosure can more easily suppress the deterioration of the processing quality.

[0042] (6) The processing machine according to (5), wherein the processing machine includes a servo amplifier that drives a motor for moving the stage, and the servo amplifier has the comparing unit.

[0043] According to the above method, the processing machine can reduce the components involved in adjusting the position of at least one of the cutting tool, the spindle and the stage based on the physical quantity measured by the measuring unit, and has the effects of reducing the processing burden, shortening the processing time or reducing the cost. Therefore, the processing machine according to the present disclosure can suppress the deterioration of the processing quality while reducing the processing burden, shortening the processing time or achieving low cost.

[0044] (7) The processing machine according to any one of (1) to (6), wherein the measuring unit measures the average value or effective value of the physical quantity within the time required for the cutting tool to rotate one circle or an integral multiple of the time as the physical quantity.

[0045] According to the above method, the time required for one revolution, which is the minimum unit of the cutting action of the cutting tool, is used as the unit time, and the average value of the physical quantity within this unit time is set as the measured value of the physical quantity. Thus, without being limited by the fluctuations of the physical quantity within a time interval shorter than the time required for one revolution of the cutting tool, the cutting depth can be appropriately controlled based on the action of the physical quantity over a time longer than the time required for one revolution of the cutting tool. Therefore, the processing machine according to the present disclosure can more appropriately suppress the deterioration of the processing quality.

[0046] (8) A control method for a processing machine, wherein the processing machine includes: a spindle that supports a cutting tool in a rotatable manner; and a stage that mounts a workpiece. In the control method, a physical quantity generated due to the contact between the cutting tool and the workpiece is measured; the cutting depth of the cutting tool with respect to the workpiece is calculated based on the physical quantity, and the calculated cutting depth is compared with a reference cutting depth; and the position of at least one of the cutting tool, the spindle, and the stage is adjusted based on the result of the comparison.

[0047] According to the above method, the control method exhibits the same effect as the above processing machine.

[0048] In addition, these general or specific methods can be implemented either by a system, a method, an integrated circuit, a computer program, or a recording medium such as a computer-readable CD-ROM, or by any combination of a system, a method, an integrated circuit, a computer program, or a recording medium.

[0049] Hereinafter, the embodiments will be specifically described with reference to the drawings.

[0050] In addition, the embodiments to be described below all show general or specific examples. The numerical values, shapes, materials, constituent elements, arrangement positions of the constituent elements, connection methods, steps, and the order of the steps shown in the following embodiments are examples and are not intended to limit the present invention. In addition, the constituent elements in the following embodiments that are not described in the independent claims representing the most general concepts are described as optional constituent elements.

[0051] (Embodiment)

[0052] In the present embodiment, a processing machine or the like that suppresses the deterioration of the processing quality will be described.

[0053] Figure 1 FIG. is a schematic diagram showing the structure of the processing machine 10 in the present embodiment. The processing machine 10 is a processing machine that performs cutting processing (also simply referred to as cutting) on a workpiece W.

[0054] In addition, in the following description, explanations using the XYZ coordinate axes shown in the respective drawings are sometimes made. The Z-axis is the vertical direction. The positive side and the negative side of the Z-axis direction are sometimes referred to as up (above) and down (below), respectively.

[0055] As Figure 1 shown, the processing machine 10 includes a control unit 11, servo amplifiers 12A, 12B, and 12C, motors 13A, 13B, and 13C, a spindle 14, a cutting tool 15, a stage 16, and a measurement unit 17. A workpiece W, which is the object to be cut by the processing machine 10, is placed on the stage 16. In addition, a predetermined target value (also referred to as the target depth) of the cutting depth of the workpiece W is assumed to be set for the processing machine 10.

[0056] The control unit 11 controls the components included in the processing machine 10. The control unit 11 includes a processor (e.g., a CPU (Central Processing Unit)) (not shown), and the processor performs the above control by executing a predetermined program using a memory (not shown).

[0057] The control unit 11 controls the position of at least one of the cutting tool 15, the spindle 14, and the stage 16 so that the cutting tool 15 is located at the position for cutting the workpiece W.

[0058] Here, the control unit 11 can control the position of the spindle 14 in the Z-axis direction. In addition, as an example where the control unit 11 can control the position of the stage 16 in the X-axis direction and the Y-axis direction, an explanation will be given. In this case, the processing machine 10 controls the position of the spindle 14 so that the cutting tool 15 is located at an appropriate position (also referred to as the reference position) in the Z-axis direction, and controls the position of the stage 16 so that the workpiece W moves in the negative X-axis direction at an appropriate speed (also referred to as the reference speed) (that is, the stage 16 moves in the negative X-axis direction at the reference speed). The reference position is the position where the cutting tool 15 cuts the workpiece W at the target depth.

[0059] When the control unit 11 controls the position of the spindle 14 or the cutting tool 15 in the Z-axis direction, it sends a signal indicating the controlled position (also referred to as the control position, the same applies hereinafter) of the spindle 14 in the Z-axis direction to the servo amplifier 12A. In addition, when the adjustment unit 112 controls the position of the stage 16, it sends a signal indicating the control position of the stage 16 in at least one of the X-axis direction and the Y-axis direction to the servo amplifier 12C.

[0060] In addition, the control unit 11 controls the rotational speeds of the spindle 14 and the cutting tool 15 so that the cutting tool 15 cuts the workpiece W.

[0061] In addition, the control unit 11 adjusts the position of at least one of the cutting tool 15, the spindle 14, and the stage 16 using the physical quantity generated due to the contact between the cutting tool 15 and the workpiece W. The control unit 11 includes a comparison unit 111 and an adjustment unit 112 as functional units for performing the above adjustments.

[0062] The comparison unit 111 obtains the cutting resistance, which is an example of the physical quantity measured by the measurement unit 17 (described later), from the measurement unit 17, calculates the cutting depth of the cutting tool 15 with respect to the workpiece W based on the obtained cutting resistance, and compares the calculated cutting depth with the reference cutting depth.

[0063] Before the machining machine 10 performs cutting, the comparison unit 111 pre-holds the correspondence relationship between the cutting resistance exerted by the workpiece W on the cutting tool 15 during cutting and the cutting depth of the cutting tool 15 with respect to the workpiece W. The correspondence relationship between the cutting resistance and the cutting depth is, for example, expressed as a table obtained by associating a plurality of cutting resistances with the cutting depths respectively corresponding to the plurality of cutting resistances. This case will be described as an example. In this case, the cutting depth corresponding to the cutting resistance not recorded in the table can be calculated by interpolation (more specifically, linear interpolation, etc.). In addition, other than the above, the correspondence relationship between the cutting resistance and the cutting depth may also be expressed as a mathematical formula representing the relationship between the cutting resistance and the cutting depth.

[0064] The reference cutting depth is a target depth determined in advance, or the cutting depth of the workpiece W calculated based on the cutting resistance measured by the measurement unit 17 at a certain point in time when the machining machine 10 is cutting the workpiece W.

[0065] The adjustment unit 112 adjusts the position of at least one of the cutting tool 15, the spindle 14, and the stage 16. When the adjustment unit 112 adjusts the position of the spindle 14 or the cutting tool 15, it sends a signal representing the adjusted position of the spindle 14 in the Z-axis direction (also referred to as the adjustment position, the same hereinafter) to the servo amplifier 12A. In addition, when the adjustment unit 112 adjusts the position of the stage 16, it sends a signal representing the adjusted position of the stage 16 in at least one of the X-axis direction and the Y-axis direction to the servo amplifier 12C.

[0066] Specifically, the adjustment unit 112 adjusts the position of at least one of the cutting tool 15, the spindle 14, and the stage 16 based on the result of the comparison performed by the comparison unit 111. At this time, the adjustment unit 112 performs the following control: adjusting the position of at least one of the cutting tool 15, the spindle 14, and the stage 16 based on the result of the comparison performed by the comparison unit 111 so that the cutting depth of the cutting tool 15 with respect to the workpiece W approaches the reference cutting depth.

[0067] In addition, when the adjustment unit 112 adjusts the rotation speed of the main shaft 14, it can send a signal indicating the adjusted rotation speed of the main shaft 14 (also referred to as the adjustment rotation speed, the same hereinafter) to the servo amplifier 12B.

[0068] The servo amplifier 12A is a servo amplifier that drives the motor 13A by supplying power to the motor 13A. When the servo amplifier 12A receives a signal indicating the adjusted position of the main shaft 14 in the Z-axis direction from the control unit 11, it calculates the driving amount of the motor 13A for positioning the main shaft 14 at that position, and supplies power to the motor 13A to drive the motor 13A with the calculated driving amount. In addition, the servo amplifier 12A can receive information indicating the position of the main shaft 14 in the Z-axis direction as feedback from the motor 13A, and can use the feedback to adjust the position of the main shaft 14 in the Z-axis direction.

[0069] The motor 13A is a motor that controls the position of the main shaft 14 in the Z-axis direction. The motor 13A is driven by the power supplied from the servo amplifier 12A, thereby controlling the position of the main shaft 14 in the Z-axis direction. In addition, the motor 13A can feedback information indicating the position of the main shaft 14 in the Z-axis direction to the servo amplifier 12A.

[0070] The servo amplifier 12B is a servo amplifier that drives the motor 13B by supplying power to the motor 13B. When the servo amplifier 12B receives a signal indicating the adjusted rotation speed of the main shaft 14 from the control unit 11, it calculates the driving amount of the motor 13B for rotating the main shaft 14 at the adjusted rotation speed, and supplies power to the motor 13B to drive the motor 13B with the calculated driving amount. In addition, the servo amplifier 12B can receive the rotation speed of the main shaft 14 as feedback from the motor 13B, and can use the feedback to adjust the rotation speed of the main shaft 14.

[0071] The motor 13B is a motor that controls the rotation speed of the main shaft 14. The motor 13B is driven by the power supplied from the servo amplifier 12B, thereby controlling the rotation speed of the main shaft 14. In addition, the motor 13B can feedback information indicating the rotation speed of the main shaft 14 to the servo amplifier 12B.

[0072] The servo amplifier 12C is a servo amplifier that drives the motor 13C by supplying power to the motor 13C. When the servo amplifier 12C receives a signal from the control unit 11 indicating the adjustment position of the stage 16 in at least one of the X-axis direction and the Y-axis direction, it calculates the driving amount of the motor 13C for positioning the stage 16 at the adjustment position, and supplies power to the motor 13C to drive the motor 13C with the calculated driving amount. In addition, the servo amplifier 12C can receive the positions of the stage 16 in the X-axis direction and the Y-axis direction as feedback from the motor 13C, and can use the feedback to adjust the position of the stage 16 in at least one of the X-axis direction and the Y-axis direction.

[0073] The motor 13C is a motor that controls the positions of the spindle 14 in the X-axis direction and the Y-axis direction. The motor 13C is driven by the power supplied from the servo amplifier 12C, thereby controlling the position of the spindle 14 in at least one of the X-axis direction and the Y-axis direction. In addition, the motor 13C can feed back information indicating the positions of the spindle 14 in the X-axis direction and the Y-axis direction to the servo amplifier 12C.

[0074] The spindle 14 supports the cutting tool 15 in a manner that enables the cutting tool 15 to rotate. Specifically, the spindle 14 has fixtures such as chucks for gripping the cutting tool 15, and uses the fixtures to grip the cutting tool 15. In addition, the spindle 14 rotates the cutting tool 15 about a rotation axis parallel to the Z-axis (in other words, self-rotates). The rotational speed is, for example, around 1000 rpm to 40000 rpm, but is not limited thereto.

[0075] The cutting tool 15 is a tool for cutting the workpiece W. The cutting tool 15 is supported by the spindle 14 in a manner that enables it to rotate about a rotation axis parallel to the Z-axis. The rotating cutting tool 15 cuts the workpiece W by contacting the workpiece W. In addition, with the position of the cutting tool 15 in the Z-axis direction being constant, the stage 16 moves in the X-axis direction and the Y-axis direction, thereby cutting the upper surface of the workpiece W.

[0076] When the cutting tool 15 is cutting the workpiece W, if the position of the cutting tool 15 in the Z-axis direction changes, the cutting depth of the workpiece W (in other words, the distance from the surface of the workpiece W to the tip of the cutting tool 15 that is cutting the workpiece W) changes. The smaller the Z coordinate of the cutting tool 15, the greater the cutting depth of the workpiece W.

[0077] The stage 16 is a stage for placing the workpiece W. The stage 16 can move in the horizontal direction, that is, in the X-axis direction and the Y-axis direction, and the position in at least one of the X-axis direction and the Y-axis direction is changed by being driven by the motor 13C. The workpiece W is fixed on the stage 16, and the workpiece W also moves as the stage 16 moves.

[0078] The measurement unit 17 measures a physical quantity generated due to the contact between the cutting tool 15 and the workpiece W. For example, the physical quantity is the cutting resistance exerted on the cutting tool 15 by the workpiece W being cut by the cutting tool 15, and this case will be described as an example. In addition, the use of other physical quantities will be described in a modified example described later.

[0079] The cutting resistance has the same magnitude as the cutting force, which is the force exerted by the cutting tool 15 cutting the workpiece W on the workpiece W, and is a force in the direction opposite to the direction of the cutting force. The measurement unit 17 can measure the cutting resistance using, for example, a cutting dynamometer.

[0080] The measurement unit 17 supplies the measured cutting resistance to the control unit 11 (more specifically, the comparison unit 111).

[0081] In addition, the measurement unit 17 may set the average value or effective value of the cutting resistance within the time required for one rotation of the cutting tool 15 (for example, about 0.0015 seconds to 0.06 seconds) or an integral multiple of the above time as the measured value of the cutting resistance.

[0082] Figure 2 It is a flowchart showing the control method of the processing machine 10 in the present embodiment. Figure 3 It is an explanatory diagram showing an example of the correspondence relationship between the cutting resistance and the cutting depth in the present embodiment. Refer to Figure 2 and Figure 3 to describe the control method of the processing machine 10.

[0083] Before executing step S101, the comparison unit 111 previously stores a table showing the correspondence relationship between the cutting resistance and the cutting depth (refer to Figure 3 ).

[0084] In Figure 3 , a plurality of cutting resistances are associated with the cutting depths respectively corresponding to the plurality of cutting resistances. For example, in Figure 3 , the cutting depth D1 is associated with the cutting resistance R1, and the cutting depth D2 is associated with the cutting resistance R2.

[0085] The processing machine 10 starts the process of step S101 in a state where cutting has been performed.

[0086] In step S101, the measurement unit 17 measures the cutting resistance. The measurement unit 17 supplies the measured cutting resistance to the control unit 11 (more specifically, the comparison unit 111).

[0087] In step S102, the comparison unit 111 calculates the cutting depth based on the cutting resistance measured and provided in step S101. When calculating the cutting depth based on the cutting resistance, the comparison unit 111 uses a table showing the correspondence between the cutting resistance and the cutting depth (refer to Figure 3 ). That is, when the comparison unit 111 finds a cutting resistance in the above table that is the same as the cutting resistance measured in step S101, it obtains the cutting depth associated with this cutting resistance. When it does not find a cutting resistance in the above table that is the same as the cutting resistance measured in step S101, it obtains the cutting depth associated with this cutting resistance by interpolation using the above table, thereby calculating the cutting depth.

[0088] In step S103, the comparison unit 111 compares the cutting depth calculated in step S102 with the reference cutting depth.

[0089] In step S104, the adjustment unit 112 performs the following control: Based on the comparison result in step S103, it adjusts the position of at least one of the cutting tool 15, the spindle 14, and the stage 16. Specifically, the adjustment unit 112 performs the following control: calculates the adjustment position of at least one of the cutting tool 15, the spindle 14, and the stage 16, and drives the motor 13A, etc. via the servo amplifier 12A, etc., thereby adjusting the position of at least one of the cutting tool 15, the spindle 14, and the stage 16.

[0090] In this way, the processing machine 10 can suppress the deterioration of the processing quality.

[0091] After that, while comparing the cutting situation of the workpiece W by the processing machine in the comparative example and the cutting situation by the processing machine 10 in the present embodiment, the cutting depth of the workpiece W will be described.

[0092] Figure 4 is a schematic diagram showing an example of the cutting depth of the cutting performed by the processing machine in the comparative example. The processing machine in the comparative example is a processing machine that performs the same cutting process as the processing machine 10 in the present embodiment.

[0093] The processing machine in the comparative example is equipped with a sensor S1 that measures the position of the spindle 94 in the Z-axis direction, and can adjust the position of the spindle 94 in the Z-axis direction based on the measurement value obtained by the sensor S1. In addition, the processing machine in the comparative example is equipped with sensors S2 that measure the positions of the stage 96 in the X-axis and Y-axis directions, and can adjust the positions of the stage 96 in the X-axis and Y-axis directions based on the measurement values obtained by the sensors S2. The processing machine in the comparative example does not have the comparison unit 111 and the adjustment unit 112 that the processing machine 10 has.

[0094] In Figure 4Elementary components (such as the main shaft 94, the cutting tool 95, and the stage 96, etc.) around the workpiece W at the start of cutting are shown in (a).

[0095] The main shaft 94 included in the processing machine in the comparative example is located at the reference position. In addition, the stage 96 moves in the negative X-axis direction at the reference speed. When the workpiece W approaches and contacts the cutting tool 95, the cutting tool 95 cuts the workpiece W at the cutting depth D1. The cutting depth D1 corresponds to the reference cutting depth.

[0096] In Figure 4 Elementary components (such as the main shaft 94, the cutting tool 95, and the stage 96, etc.) around the workpiece W at a certain time point when the processing machine in the comparative example is performing cutting after the state shown in (a) of Figure 4 are shown in (b) of

[0097] As Figure 4 shown in (b) of Figure 4 , when cutting the workpiece W, thermal deformations V1 or V2 may occur. The position of the cutting tool 95 in the Z-axis direction moves to a position lower (negative Z-axis direction) than that in (a) of

[0098] due to the deformations V1 and V2. The deformation V1 may be, for example, a deformation caused by heat generated by the drive motors 13A and 13B. The deformation V2 may be a deformation caused by heat generated by cutting the workpiece W.

[0099] As a result, the cutting tool 15 cuts the workpiece W at a cutting depth D2 larger than the cutting depth D1.

[0100] In this way, the processing machine in the comparative example cuts at a cutting depth D2 larger than the cutting depth D1 as the reference cutting depth, and the processing quality is relatively low.

[0101] Figure 5 And Figure 6 are schematic diagrams showing examples of the cutting depth of the cutting performed by the processing machine 10 in the present embodiment.

[0102] In Figure 5 , elementary components (such as the main shaft 14, the cutting tool 15, and the stage 16, etc.) around the workpiece W at the start of cutting are shown.

[0103] The spindle 14 provided in the machine tool 10 is in the reference position. In addition, the stage 16 moves in the negative X-axis direction at the reference speed. When the workpiece W approaches and contacts the cutting tool 15, the cutting tool 15 cuts the workpiece W at the cutting depth D1. The cutting depth D1 corresponds to the reference cutting depth. At this time, the workpiece W exerts a cutting resistance R1 on the cutting tool 15.

[0104] In Figure 6 (a) shows the components (such as the spindle 14, the cutting tool 15, and the stage 16) around the workpiece W at a certain time point when the machine tool 10 is performing cutting after the state shown in Figure 5 .

[0105] As Figure 6 (a) shows, when cutting the workpiece W, similar to the case of Figure 4 (b), thermal deformations V1 or V2 may occur. The position of the cutting tool 15 in the Z-axis direction moves to a position lower (negative Z-axis direction) than the case in Figure 5 due to the deformations V1 and V2.

[0106] When the machine tool 10 has thermal deformations V1 or V2, the cutting tool 15 cuts the workpiece W at the cutting depth D2. At this time, the workpiece W exerts a cutting resistance RA on the cutting tool 15. The cutting resistance RA is greater than the cutting resistance R1.

[0107] The measuring unit 17 measures the cutting resistance RA and provides it to the control unit 11. The comparing unit 111 calculates the cutting depth DA based on the provided cutting resistance RA, and compares the cutting depth D1 as the reference cutting depth with the cutting depth DA. The adjusting unit 112 adjusts the position of the spindle 14 upward (positive Z-axis direction) by a distance D3 so that the cutting depth approaches D1.

[0108] In Figure 6 (b) shows the structure (such as the spindle 14, the cutting tool 15, and the stage 16) around the workpiece W at a certain time point after the position of the spindle 14 is adjusted. In Figure 6 (b), as a result of adjusting the position of the spindle 14 upward (positive Z-axis direction) by a distance D3 compared with the case in Figure 6 (a), the cutting tool 15 cuts the workpiece W at the cutting depth D1.

[0109] In addition, in reality, the difference in the magnitude between the cutting resistance R1 and the cutting resistance RA is extremely small with respect to the magnitude of the cutting resistance R1. Therefore, the difference between the cutting depth D1 and the cutting depth DA is also extremely small with respect to the cutting depth D1. Thus, the difference between the cutting depth D1 and the cutting depth DA does not cause a deterioration in the machining quality.

[0110] In this way, the processing machine 10 can machine the workpiece W while maintaining the cutting depth D1 as the reference cutting depth, and the machining quality is relatively high.

[0111] In addition, in the present embodiment, it is described that the control unit 11 includes a comparison unit 111 and an adjustment unit 112, but it may also be that the servo amplifiers 12A, 12B, or 12C include the comparison unit 111 and the adjustment unit 112.

[0112] More specifically, the servo amplifier 12C that drives the motor 13C for controlling the position of the stage 16 in the X-axis direction or the Y-axis direction may also include the comparison unit 111. By doing so, it is possible to reduce the components involved in the control of the position of the stage 16 in the X-axis direction or the Y-axis direction based on the measurement value of the measurement unit 17, and it has the effects of reducing the processing burden, reducing the processing time, or reducing the cost.

[0113] (Modification example of the embodiment)

[0114] In this modification example, a processing machine or the like that suppresses a decrease in machining quality will be described. In contrast to the case where the processing machine 10 in the above-described embodiment uses the cutting resistance to adjust the cutting depth, the processing machine in this modification example uses the influence of the thermal deformation on the position of the stage.

[0115] Figure 7 It is a schematic diagram showing the structure of the processing machine 10A in this modification example. In addition, the same reference numerals are given to the same components as those in the processing machine 10 in the above-described embodiment, and detailed descriptions may sometimes be omitted.

[0116] As Figure 7 shown, the processing machine 10A includes a control unit 11A, servo amplifiers 12A, 12B, and 12C, motors 13A, 13B, and 13C, a spindle 14, a cutting tool 15, a stage 16, and a measurement unit 17A. A workpiece W to be machined by the processing machine 10W is placed on the stage 16.

[0117] The difference between the processing machine 10A and the processing machine 10 in the above-described embodiment is that it includes a control unit 11A and a measurement unit 17A. These components will be described in detail.

[0118] The control unit 11A controls the components included in the processing machine 10 in the same manner as the control unit 11 in the above-described embodiment. In addition, the control unit 11A controls the position of at least one of the cutting tool 15, the spindle 14, and the stage 16 so that the cutting tool 15 is located at the position for machining the workpiece W.

[0119] Specifically, the control unit 11A includes a comparison unit 114 and an adjustment unit 112.

[0120] The comparison unit 114 obtains the speed of the stage 16, which is an example of the physical quantity measured by the measurement unit 17A, from the measurement unit 17A, and estimates the cutting force applied by the cutting tool 15 to the workpiece W based on the obtained speed. In addition, the comparison unit 114 uses the estimated cutting force to calculate the cutting depth of the cutting tool 15 with respect to the workpiece W. Then, the comparison unit 114 compares the calculated cutting depth with a reference cutting depth.

[0121] The adjustment unit 112 included in the control unit 11A is the same as the adjustment unit 112 in the above-described embodiment, and thus detailed description thereof is omitted.

[0122] The measurement unit 17A measures the influence of thermal deformation on the position of the stage 16. Specifically, the measurement unit 17A measures the position, speed, or acceleration of the stage 16. When the deformation V1 or V2 as thermal deformation occurs, the influence of the deformation V1 or V2 spreads to the position, speed, or acceleration of the stage 16, and thus the position, speed, or acceleration measured by the measurement unit 17A is affected by thermal deformation. The measurement unit 17A can use a position sensor, a speed sensor, or an acceleration sensor for the measurement of position, speed, or acceleration, respectively.

[0123] Here, the case where the measurement unit 17A measures the speed of the stage 16 will be described as an example.

[0124] In addition, when the measurement unit 17A measures the position of the stage 16, it can calculate the speed of the stage 16 by differentiating the measured position with respect to time, and can perform the same processing as in the case where the measurement unit 17A measures the speed of the stage 16 using the calculated speed.

[0125] Further, when the measurement unit 17A measures the acceleration of the stage 16, it can calculate the speed of the stage 16 by integrating the measured acceleration, and can perform the same processing as in the case where the measurement unit 17A measures the speed of the stage 16 using the calculated speed.

[0126] Figure 8 It is a flowchart showing a control method of the machine tool 10A in this modification example. Figure 9 It is an explanatory diagram showing an example of the correspondence between the cutting force and the cutting depth in this modification example. Refer to Figure 8 and Figure 9 to describe the control method of the machine tool 10A.

[0127] The comparison unit 114 preliminarily stores a table showing the correspondence between the cutting force and the cutting depth (refer to Figure 9 ).

[0128] In Figure 9In this case, a plurality of cutting forces are associated with the cutting depths respectively corresponding to the plurality of cutting forces. For example, in Figure 9 the cutting depth D1 is associated with the cutting force P1, and the cutting depth D2 is associated with the cutting force P2.

[0129] The processing machine 10A starts the processing of step S101A in a state where cutting has been performed.

[0130] In step S101A, the measuring unit 17A measures the speed of the stage 16. The measuring unit 17A provides the measured speed of the stage 16 to the control unit 11A (more specifically, the comparison unit 114).

[0131] In step S101B, the comparison unit 114 estimates the cutting force based on the speed measured and provided in step S101A. When estimating the cutting force based on the speed of the stage 16, the estimation by the disturbance observer can be used (Non-Patent Document 1).

[0132] In step S102A, the comparison unit 114 calculates the cutting depth based on the cutting force estimated in step S101B. When calculating the cutting depth based on the cutting force, the comparison unit 114 uses a table showing the correspondence between the cutting force and the cutting depth (refer to Figure 9 ).

[0133] In step S103, the comparison unit 114 compares the cutting depth calculated in step S102A with the reference cutting depth.

[0134] In step S104, the adjustment unit 112 adjusts the position of at least one of the cutting tool 15, the spindle 14, and the stage 16 based on the comparison result in step S103. Specifically, the adjustment unit 112 calculates the position of at least one of the cutting tool 15, the spindle 14, and the stage 16 after adjustment, and drives the motor 13A, etc. via the servo amplifier 12A, etc., thereby adjusting the position of at least one of the cutting tool 15, the spindle 14, and the stage 16.

[0135] In this way, the processing machine 10A can suppress the deterioration of the machining quality.

[0136] In addition, in the above-described embodiments and modification examples, each component may be constituted by dedicated hardware or may be implemented by executing a software program suitable for each component. Each component may also be implemented by a program execution unit such as a CPU or a processor reading and executing a software program recorded in a recording medium such as a hard disk or a semiconductor memory. Here, the software for implementing the control method, etc. of the processing machine of the above-described embodiments and modification examples is a program as follows.

[0137] That is, the program is for causing a computer to execute a control method of a processing machine, the processing machine including: a spindle that supports a cutting tool so that the cutting tool can rotate; and a stage that mounts a workpiece. In the control method, a physical quantity generated due to contact between the cutting tool and the workpiece is measured; a cutting depth of the cutting tool with respect to the workpiece is calculated based on the physical quantity, and the calculated cutting depth is compared with a reference cutting depth; and based on the comparison result, the position of at least one of the cutting tool, the spindle, and the stage is adjusted.

[0138] As described above, the processing machine and the like according to one or more aspects have been described based on the embodiments. However, the present invention is not limited to these embodiments. As long as it does not deviate from the gist of the present invention, aspects obtained by making various modifications conceived by those skilled in the art to these embodiments, and aspects constructed by combining constituent elements in different embodiments can also be included within the scope of one or more aspects.

[0139] Industrial Applicability

[0140] The present invention can be used for a processing machine that performs cutting processing on a workpiece.

[0141] Description of Reference Numerals

[0142] 10, 10A: Processing machine; 11, 11A: Control unit; 12A, 12B, 12C: Servo amplifier; 13A, 13B, 13C: Motor; 14, 94: Spindle; 15, 95: Cutting tool; 16, 96: Stage; 17, 17A: Measuring unit; 111, 114: Comparison unit; 112: Adjusting unit; R1, RA: Cutting resistance; S1, S2: Sensor; V1, V2: Deformation; W: Workpiece.

Claims

1. A processing machine, comprising: A main shaft that supports a cutting tool in a manner enabling the cutting tool to rotate; A stage on which a workpiece is placed; A measuring unit that measures a physical quantity generated due to contact between the cutting tool and the workpiece; A comparison unit that calculates a cutting depth of the cutting tool with respect to the workpiece based on the physical quantity and compares the calculated cutting depth with a reference cutting depth; And An adjustment unit that adjusts the position of at least one of the cutting tool, the main shaft, and the stage based on a result of the comparison performed by the comparison unit.

2. The processing machine according to claim 1, wherein The adjustment unit adjusts the position of at least one of the cutting tool, the main shaft, and the stage based on a result of the comparison performed by the comparison unit so that the cutting depth of the cutting tool with respect to the workpiece approaches the reference cutting depth.

3. The processing machine according to claim 1, wherein The measuring unit measures a cutting resistance exerted by the workpiece being cut by the cutting tool on the cutting tool as the physical quantity, The comparison unit uses the cutting resistance measured by the measuring unit as the physical quantity to perform the comparison.

4. The processing machine according to claim 1, wherein The reference cutting depth is: (a) A predetermined target value, i.e., a target depth, of the cutting depth of the processing machine with respect to the workpiece, or (b) A cutting depth of the workpiece calculated based on the physical quantity measured by the measuring unit at a time point when the processing machine is cutting the workpiece.

5. The processing machine according to claim 1, wherein The measuring unit measures a position, speed, or acceleration of the stage as the physical quantity, The comparison unit uses the position, speed, or acceleration measured by the measuring unit to estimate a cutting force exerted by the cutting tool on the workpiece, uses the estimated cutting force to calculate a cutting depth of the cutting tool with respect to the workpiece, and compares the calculated cutting depth with the reference cutting depth.

6. The processing machine according to claim 5, wherein The processing machine includes a servo amplifier that drives a motor for moving the stage, The servo amplifier has the comparison unit.

7. The processing machine according to any one of claims 1 to 6, wherein The measuring unit measures an average value or effective value of the physical quantity within a time required for one rotation of the cutting tool or a time that is an integer multiple of the time as the physical quantity.

8. A control method for a processing machine, wherein The processing machine includes: A main shaft that supports a cutting tool in a manner enabling the cutting tool to rotate; and A stage on which a workpiece is placed, In the control method, A physical quantity generated due to contact between the cutting tool and the workpiece is measured; A cutting depth of the cutting tool with respect to the workpiece is calculated based on the physical quantity and compared with a reference cutting depth; And Adjust the position of at least one of the cutting tool, the spindle, and the stage based on the result of the comparison.

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