MACHINING SYSTEM AND MACHINING METHOD

Abstract

Processing system comprising: a holding device (1) which holds a plurality of workpieces (W); a measuring device (2) which measures a plurality of workpieces (W) held on the holding device (1); and a machining device (3) which machines the workpieces (W) held on the holding device (1), wherein the holding device (1) has a reference part (12) which is positioned or position-detected by the processing device (3), and in which the measuring device (2) has: a measuring unit (21) which measures a positional relationship of the workpieces (W) held on the holding device (1) relative to the reference part (12), and an input unit (22) using a recording medium or communication for inputting position information of the workpieces (W) measured by the measuring unit (21) to the machining device (3), and wherein the processing device (3) comprises: a holding device coordinate system specifying unit (31) that specifies a coordinate system of the holding device (1) by positioning or position measuring the reference part (12) of the holding device (1), and a workpiece coordinate system setting unit (32) that individually sets coordinate systems of each workpiece (W) based on a coordinate system of the fixture (1) specified by the fixture coordinate system specifying unit (31) and the position information input from the input unit (22).

Description

BACKGROUND OF THE INVENTIONField of the invention

[0001] The present invention relates to a machining system and a machining method. State of the art

[0002] When machining a workpiece in a machining device such as a machining center, there are cases where it is necessary to measure the position of a workpiece (including posture information) held in the machining device and determine the relative position between a tool and the workpiece. When measuring the shape of a workpiece within a machining device, since the cycle time increases, there is a concern that machining efficiency will decrease. In addition, if the measurement of a workpiece is performed while pausing long-term machining, the temperature of the machining device will drop during measurement and will rise again during machining; therefore, there is a risk that machining accuracy will decrease due to thermal displacement.

[0003] As a method for measuring positions of a workpiece in a relatively short time, there is a method that uses an image processing technique.For example, Patent Document 1 listed below discloses a machining apparatus including: a mobile means holding a workpiece; a photographing means provided at a photographing area where a machined part of a workpiece held by the mobile means is photographed; a positional displacement detection means that detects a positional displacement of the machined part based on an image photographed by the photographing means; and a workpiece correction device that corrects the positional displacement and moves the workpiece from the photographing area to the machining area by driving the mobile means based on the positional displacement and a predetermined moving distance from the photographing area to a machining area for machining the machined part.

[0004] See also Patent Document 2. Patent document 1: JP 2007 - 265 237 A Patent document 2: US 2017 / 0153621 A1 SUMMARY OF THE INVENTION

[0005] For example, as disclosed in Patent Document 1, when a photographing means is provided within a machining device, there is a concern that one may not be able to adequately photograph a workpiece due to contamination of the photographing means by dust, cutting oil, etc., poor illumination of the workpiece, vibration, etc., and may no longer be able to accurately measure the workpiece position. For this reason, technology capable of accurately measuring the position of a workpiece without prolonging the machining cycle time has been demanded.

[0006] The problem is solved by a processing system having the features of patent claim 1 and by a processing method having the features of patent claim 7.

[0007] According to one aspect of the present disclosure, the machining system can accurately measure the position of a workpiece without increasing the machining cycle time. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic diagram showing the configuration of a machining system according to an embodiment of the present disclosure; Fig. 2 is a schematic plan view showing a holding device of a machining system according to the present disclosure; and Fig. 3 is a flowchart showing a processing sequence of a processing system according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. Fig. 1 is a schematic diagram showing the configuration of a machining system 100 according to an embodiment of the present disclosure. The machining system 100 machines a workpiece W.

[0009] The machining system 100 includes: a holding device 1 that holds a plurality of workpieces W; a measuring device 2 that measures the plurality of workpieces W held on the holding device 1; and a machining device 3 that machines the plurality of workpieces W held on the holding device 1.

[0010] The holding device 1, as in Fig. 2, comprises a plurality of holding parts 11 each holding the workpieces W, and a reference part 12 which is positioned or position-detected by the machining device 3.

[0011] The holding part 11 holds each of the workpieces W to be relatively immobile on the holding device 1 until measured in the measuring device 2, and then completes the processing by the processing device 3. For this reason, the holding part 11 may have a configuration that removably holds the workpiece W, such as an electromagnetic force generating means or a clamping means, or may have an engagement structure such that the workpiece W can be held using an additional engagement means such as, for example, a screw.

[0012] In this way, the holding device 1 has a plurality of holding parts 11, and when a plurality of workpieces W are held, it is not easy to accurately position and hold the individual workpieces W in the holding device 1. In other words, the plurality of workpieces W on the holding device 1 may have positioning errors relative to the holding part 11.

[0013] The reference part 12 is configured to be position-detectable or positionable by the measuring device 2 and the processing device 3. More specifically, the reference part 12 may be established as a structure such as a hole, notch, protrusion, or the like, and may be a corner of the outer edge of the holding device 1. Additionally, the reference part 12 may be a marker that allows a position to be optically detected based on the configuration of the measuring device 2 and the processing device 3.

[0014] The reference part 12 may simply be one according to the configuration of the measuring device 2 and the machining device 3; however, a plurality of them are preferably provided. In other words, the holding device 1 preferably has a plurality of reference parts 12. The machining device 3 can thereby detect and compensate for a difference between the posture of the measuring device 2 of the holding device 1 and the posture of the machining device 3.

[0015] The holding device 1 is preferably formed from a material with a small thermal expansion coefficient, such as iron-nickel alloy materials, by machining with the required high precision. Specifically, as an upper limit for the coefficient of linear expansion (absolute value) at 20°C of the material of the holding device 1, it is preferably 10×10 -6 / K and preferably 2×10 -6 / K. By setting the coefficient of linear expansion of the material of the holding device 1 to not more than the upper limit, it is possible to suppress the relative position of the workpiece W from shifting and a machining error from occurring due to a temperature change between the measurement of the workpiece W in the measuring device 2 and the completion of machining by the machining device 3.

[0016] The measuring device 2 includes: a measuring unit 21 that measures the positional relationship of the plurality of workpieces W held on the holding device 1 relative to the reference part 12; an input unit 22 that inputs position information of the plurality of workpieces W measured by the measuring unit 21 to the processing device 3 using a recording medium or communication; and a temperature adjustment unit 23 that adjusts the temperature of the holding device 1 to a temperature substantially equal to the temperature inside the processing device 3.

[0017] While the machining device 3 is machining a workpiece W on the holding device 1, the measuring device 2 preferably measures the position of the workpiece W held on the holding device 1, offered for subsequent machining, and the position of the reference part 12 of the holding device 1. This makes it possible to shorten the machining idle time of the machining device 3 and thus improve the machining cycle time and machining efficiency. In addition, by shortening the machining idle time of the machining device 3, it is possible to suppress a temperature drop due to a machining pause of the machining device 3. It is thereby possible to reduce the machining error caused by thermal displacement of the machining device 3.

[0018] The measuring unit 21 can measure the position of the reference part 12 of the holding device 1 and the position of each workpiece W, and can measure the position of each workpiece W in a state that positions the reference part 12 of the holding device 1 at a predetermined position.

[0019] The measuring unit 21 may be established as a configuration including, for example, a contact probe that contacts the workpiece W and measures the contact position of the contact probe; however, it may be established as a known configuration including a camera 24 that photographs the holding device 1 holding the plurality of workpieces W, and an image processing unit 25 that calculates the positions of the plurality of workpieces W and, if necessary, the position of the reference part 12 based on the image photographed by the camera 24.

[0020] The camera 24 can be configured with a two-dimensional image sensor element, such as a CCD image sensor and a CMOS image sensor. The image processing unit 25 can be implemented, for example, by reading a predetermined image processing program into a computer device including a CPU, memory, etc. By implementing such a configuration, it is possible to measure the positions of the plurality of workpieces W in an extremely short time.

[0021] The input unit 22 may be configured to input the position information of each workpiece W measured by the measuring unit 21 to the machining device 3 as the coordinates in the coordinate system of the holding device 1 set based on the coordinate of the reference part 12, or as a combination of coordinates of each workpiece W and coordinates of the reference part 12 in the coordinate system of the measuring device 2.

[0022] The recording medium used to input the position information to the machining device 3 is not particularly limited; however, it may be an IC tag installed on the fixture 1, or the like. Communication used by the input unit 22 to input the position information to the machining device 3 may be performed by a communication means used to transmit various information necessary for causing the operation of the measuring device 2 and the operation of the machining device 3 to cooperate, and may be wireless communication or wired communication.

[0023] The temperature adjustment unit 23 adjusts the temperature of the holding fixture 1 within the measuring device 2 to a temperature substantially equal to the temperature of the location where the holding fixture 1 is held during the processing of the workpiece W within the processing device 3. Since the temperature within the processing device 3 becomes higher than the ambient temperature during processing, the temperature adjustment unit 23 may be configured to include a heater 26. The heater 26 may conduct heat directly to the holding fixture 1, may heat the holding fixture 1 by radiant heat, or may heat the air surrounding the holding fixture 1.

[0024] The temperature adjustment unit 23 may be configured to include a machining device temperature detection section 27 that detects the temperature Tt inside the machining device 3, a measuring device temperature detection section 28 that detects the temperature Tm inside the measuring device 2, and a heater control section 29 that controls the output of the heater 26 to reduce the difference between the temperature Tt inside the machining device 3 and the temperature Tm inside the measuring device 2. In addition, the temperature adjustment unit 23 may further include a means for cooling the fixture 1, such as a cooling fan or the like that draws in outside air and blows it onto the fixture 1.

[0025] The temperature adjustment unit 23 is preferably configured to be able to adjust the temperature of the jig 1 on which the position measurement of the workpiece W is performed, and preferably the temperature of the jig 1 on which the position measurement of the workpiece W is performed, and the temperature of the jig 1 during standby, in which the position measurement of the workpiece W is subsequently performed. Since the time for temperature adjustment of the jig 1 will thereby not prolong the measurement cycle time by the measuring unit 21, the measuring device 2 will not become a reason for prolonging the processing cycle time of the processing device 3.

[0026] As the upper limit for the difference between the temperature of the fixture 1 during measurement by the measuring unit 21 and the temperature inside the machining device 3, 10°C is preferred. By setting the difference between the temperature of the fixture 1 during measurement by the measuring unit 21 and the temperature inside the machining device 3 to not more than the upper limit, it is possible to suppress the machining error due to thermal displacement. It should be noted that even in a case where the thermal expansion coefficient of the fixture 1 is sufficiently small that there is a possibility of thermal displacement occurring in the workpiece W, it is preferable to adjust the temperature of the fixture 1 in the measuring device 2 by means of the temperature adjustment unit 23, regardless of the material of the fixture 1.

[0027] The machining apparatus 3 includes: a fixture coordinate system specifying unit 31 that specifies the coordinate system during machining of the fixture 1 by means of the positioning or position measurement of the reference part 12 of the fixture 1; a workpiece coordinate system setting unit 32 that individually sets the coordinate system of each of the plurality of workpieces W based on the position information input from the input unit; and a machining unit 33 that machines the workpiece W using the coordinate system of the workpiece set by the workpiece coordinate system setting unit 32.

[0028] The fixture coordinate system specification unit 31 specifies the coordinate system of the fixture 1 relative to the coordinate system of the machining device 3, that is, specifies the position and posture of the fixture 1 within the machining device 3.

[0029] The workpiece coordinate system setting unit 32 sets the coordinate systems of individual workpieces W, that is, converts the machining coordinates specified by the machining program into the coordinates of the workpiece W coordinate system, respectively.

[0030] The machining unit 33 adjusts the operation of the tool according to the arrangement of each workpiece W using the coordinate system of the workpiece set by the workpiece coordinate system setting unit 32, and machines each workpiece W appropriately.

[0031] Although the processing performed by the processing unit 33 is not particularly limited, it is possible to exemplify drilling, laser processing, grinding, etc.

[0032] In the machining system 100, the method of machining the plurality of workpieces W (machining method according to the embodiment of the present disclosure) includes as shown in Fig.3: a step of holding the plurality of workpieces W in the holding device 1 (step S01: holding step); a step of supplying the holding device 1 to the measuring device 2 (step S02: fixture supply step); a step of adjusting the temperature of the holding device 1 (step S03: temperature adjustment step); a step of measuring the positions of the plurality of workpieces W held by the holding device 1 (step S04: measuring step); a step of moving the holding device 1 to the machining device 3 (step S05: fixture moving step); a step of inputting the position information of the workpiece W from the measuring device 2 to the machining device 3 (step S06: position information input step); a step of specifying the coordinate system of the holding device 1 (step S07: fixture coordinate system specifying step);a step of setting the coordinate system of each workpiece W (step S08: workpiece coordinate system setting step); a step of machining each workpiece W (step S09: machining step); and a step of removing the jig 1 from the machining device 3 (step S10: jig removal step).

[0033] In the holding step of step S01, the respective workpieces W are held in the holding part 11 of the holding device 1. This holding step may be performed successively and may cause the plurality of workpieces W to be held each in a plurality of holding devices 1 in advance.

[0034] In the fixture supply step of step S02, the fixture 1 holding the plurality of workpieces W in the holding step is supplied to the measuring device 2.

[0035] In the temperature adjustment step of S03, the temperature of the holding device 1 holding the workpieces W is adjusted to be a temperature substantially equal to the temperature inside the processing device 3 by means of the temperature adjustment unit 23.

[0036] In the measuring step of step S04, the positional relationship of the plurality of workpieces W held by the holding device 1 relative to the reference part 12 of the holding device 1 is measured by the measuring unit 21.

[0037] In the jig movement step of step S03, the jig 1 measuring the position of the workpiece W is caused to move from the measuring device 2 to the machining device 3. This movement can be performed manually by the operator; however, it is preferable to perform it automatically using, for example, a transport system or the like.

[0038] In the position information input step of S06, the position information of the workpiece W measured in the measuring step is input from the measuring device 2 to the machining device 3 through the input unit 22.

[0039] In the jig coordinate system specifying step of step S07, the coordinates of the reference part 12 of the jig 1 are specified by the jig coordinate system specifying unit 31. In other words, in the position information inputting step, by measuring the position of the reference part 12 or positioning the reference part 12 at a predetermined position, the coordinate system of the machining device 3 is made convertible into the coordinate system of the jig 1.

[0040] In the workpiece coordinate system setting step of step S08, the coordinate systems of the respective workpieces W are made individually adjustable, that is, the coordinate system of the machining device 3 is caused to be converted into the coordinate system of each workpiece W based on the position information inputted by the input unit 22 and the coordinate system of the holding device 1 specified in the holding device coordinate system specifying step by the workpiece coordinate system setting unit 32.

[0041] In the machining step of step S09, each workpiece W is machined by the machining unit 33 using the coordinate system of that workpiece W. In other words, the machining unit 33 precisely machines the workpiece W by converting machining data, which is decided based on a machining program and represented as the relative motion between the workpiece W and the tool in the coordinate system of the workpiece W to be machined, into the coordinate system of the machining device 3.

[0042] In the jig removal step of step S10, the jig 1 holding the machined workpiece W is ejected from the machining device 3. The machining device 3 holding the next workpiece W to be machined becomes capable of receiving it. Therefore, before completing this jig removal step, it is preferable to perform each step in parallel so that the measuring step for the jig 1 holding the next workpiece W to be machined ends.

[0043] In the above manner, the machining system 100 of the present embodiment confirms the positioning error of the plurality of workpieces W relative to the jig 1 in the measuring device 2, and by performing only one positioning or position measurement of the reference part 12 of the jig 1 in the machining device 3, it is possible to specify and precisely machine the position of each of the plurality of workpieces W. For this reason, the machining system 100 can shorten the machining interval in the machining device 3 and improve production efficiency. In addition, the machining system 100 can suppress a temperature change of the machining device 3 and reduce a machining error caused by thermal displacement by shortening the machining interval in the machining device 3.

[0044] Although an embodiment of a machining system and machining method according to the present disclosure has been explained above, the machining system and machining method according to the present disclosure are not limited to the aforementioned embodiment.

[0045] In addition, the effects described in the present embodiment list only the most preferable effects produced by the present disclosure, and the effects from the machining system and the machining method according to the present disclosure are not limited to those described in the present embodiment.

[0046] In the machining system according to the present disclosure, the temperature adjustment unit can be omitted. Additionally, in the machining system according to the present disclosure, the temperature adjustment unit can adjust the temperature of only a single jig. In the machining method according to the present disclosure, the holding step can be performed after the jig supply step. In other words, in the machining method according to the present disclosure, the workpiece can be held after the jig is arranged in the measuring device. EXPLANATION OF REFERENCE SYMBOLS 1 holding device 2 measuring device 3 Processing device 11 Holding part 12 Reference section 21 measuring unit 22 Input unit 23 Temperature adjustment unit 24 Camera 25 Image processing unit 26 stokers 27 Machining device temperature detection section 28 Measuring device temperature detection section 29 Heater control section 31 Fixture coordinate system specification unit 32 Workpiece coordinate system setting unit 33 Processing device 100 processing system W workpiece

Claims

[1] Processing system comprising: a holding device (1) which holds a plurality of workpieces (W); a measuring device (2) which measures a plurality of workpieces (W) held on the holding device (1); and a machining device (3) which machines the workpieces (W) held on the holding device (1), wherein the holding device (1) has a reference part (12) which is positioned or position-detected by the processing device (3), and in which the measuring device (2) has: a measuring unit (21) which measures a positional relationship of the workpieces (W) held on the holding device (1) relative to the reference part (12), and an input unit (22) using a recording medium or communication for inputting position information of the workpieces (W) measured by the measuring unit (21) to the machining device (3), and wherein the processing device (3) comprises: a holding device coordinate system specifying unit (31) that specifies a coordinate system of the holding device (1) by positioning or position measuring the reference part (12) of the holding device (1), and a workpiece coordinate system setting unit (32) that individually sets coordinate systems of each workpiece (W) based on a coordinate system of the fixture (1) specified by the fixture coordinate system specifying unit (31) and the position information input from the input unit (22). [2] Machining system according to claim 1, wherein the holding device (1) has a plurality of reference parts (12). [3] A machining system according to claim 1 or 2, wherein the measuring device (2) comprises a temperature adjusting unit (23) which adjusts the temperature of the holding device to a temperature equal to a temperature inside the machining device (3). [4] Machining system according to one of claims 1 to 3, wherein a linear expansion coefficient of the material of the holding device (1) is not greater than 10×10 -6 / K is. [5] The machining system according to any one of claims 1 to 4, wherein the measuring unit (21) comprises: a camera (24) that photographs the holding device (1) holding the workpieces (W), and an image processing unit (25) that calculates a position of the workpieces (W) and a position of the reference part (12) based on the image photographed by the camera (24). [6] Machining system according to one of claims 1 to 5, wherein the measuring device (2) performs a measurement of the workpiece (W) held on the holding device (1) which is supplied to the subsequent machining while the machining device (3) is machining. [7] Processing method comprising the steps: Holding a plurality of workpieces (W) in a holding device (1) having a reference part (12) which is positioned or position-detected by a processing device (3); Measuring a positional relationship of the workpieces (W) held on the holding device (1) relative to the reference part (12); Moving the holding device (1) to the processing device (3); Specifying a coordinate system of the holding device (1) by positioning or measuring the position of the reference part (12) of the holding device (1) in the processing device (3); Setting the coordinate systems of each of the workpieces (W) individually, based on the coordinate system of the holding device (1), and the positional relationship of the workpieces (W) relative to the reference part (12); and Machining the workpiece (W) by means of the machining device (3) using the coordinate system of the workpiece (W).

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