Machining Center

Abstract

To provide a machining center which is advantageous for suppressing mounting errors of a processing tool relative to a main shaft generated for each replacement of the processing tool by an automatic tool replacement device, and is advantageous for improving processing accuracy.SOLUTION: A machining center 10 includes a plurality of main shafts 12A to 12D, a workpiece holding mechanism 14, a moving mechanism 16 for moving the main shafts 12A to 12D and the workpiece holding mechanism 14 in a Z-axis direction that is a relatively axial center direction of the main shaft, and an X-axis direction and a Y axis direction which are perpendicular to the Z-axis direction and are perpendicular to each other, and a substrate 18. The moving mechanism 16 includes a moving mechanism 36 for a main shaft for moving the main shafts 12A to 12D, and a moving mechanism 38 for a workpiece for moving the workpiece holding mechanism 14.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a machining center. [Background technology]

[0002] A machining center processes workpieces by rotating a spindle to which a machining tool (cutting tool) is attached. Machining centers are equipped with an automatic tool changer (ATC) that automatically changes the machining tools attached to the spindle, and by changing multiple types of machining tools onto the spindle, it is possible to perform multiple cutting processes continuously. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-74654 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in such conventional machining centers, an attachment error of about 5 μm to 10 μm occurs in the machining tool relative to the spindle each time the automatic tool changer changes the machining tool relative to the spindle, leaving room for improvement in machining accuracy. The present invention has been made in consideration of the above circumstances, and its object is to provide a machining center that is advantageous in suppressing attachment errors of a machining tool to a spindle that occur each time a machining tool is replaced by an automatic tool changer, and that is advantageous in improving machining accuracy. [Means for solving the problem]

[0005] In order to achieve the above-mentioned object, one embodiment of the present invention is a machining center comprising a spindle to which a machining tool is detachably attached and which is driven to rotate, a work holding mechanism that holds a workpiece to be machined, and a movement mechanism that moves the spindle and the work holding mechanism relatively in a Z-axis direction which is the axial direction of the spindle, and in an X-axis direction and a Y-axis direction which are perpendicular to the Z-axis direction and mutually perpendicular, and is characterized in that a plurality of the spindles are provided. Furthermore, one embodiment of the present invention is characterized in that the movement mechanism is configured to include a spindle movement mechanism that moves the spindle and a work movement mechanism that moves the work holding mechanism, the multiple spindles are supported by a single block, and the spindle movement mechanism includes a spindle Z-axis movement mechanism that moves the block in the Z-axis direction, and a spindle lateral movement mechanism that moves the block in one of the X-axis and Y-axis directions. Moreover, one embodiment of the present invention includes a movement control unit that controls the movement mechanism based on given position control information to control the relative movement amount of the spindle and the workpiece; a positional deviation amount detection unit that detects, corresponding to each of the spindles, a difference between the design center position and the machining center position as a positional deviation amount, when the center position of a predetermined shape formed at a position determined by design of a test workpiece is defined as a design center position, and the center position of the predetermined shape actually machined by the machining tool moved together with the spindle by the position control information and the movement control unit is defined as a machining center position; and a correction amount calculation unit that calculates a correction amount corresponding to each of the spindles based on the positional deviation amount, and the movement control unit controls the relative movement amount of each of the spindles and the workpiece based on the correction amount corresponding to each of the spindles when machining the workpiece. [Effects of the Invention]

[0006] According to one embodiment of the present invention, the workpiece is machined without changing the machining tool on the spindle, which is advantageous in suppressing the attachment error of the machining tool on the spindle that occurs each time the machining tool is changed by the automatic tool changer, and is advantageous in improving machining accuracy. Furthermore, according to one embodiment of the present invention, the configuration of the movement mechanism that moves multiple spindles and workpieces relative to one another can be simplified and made compact, which is advantageous in terms of increasing the commercial value of the machining center. Furthermore, according to one embodiment of the present invention, the amount of positional deviation can be eliminated by the amount of correction corresponding to each spindle, which is more advantageous in improving machining accuracy. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a perspective view of a machining center according to an embodiment. [Figure 2] 1 is a block diagram showing the configuration of a control system of a machining center according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, an embodiment of a machining center according to the present invention will be described with reference to the drawings. As shown in FIG. 1, the machining center 10 includes a plurality of spindles 12A-12D, a workpiece holding mechanism 14, a movement mechanism 16 that moves the spindles 12A-12D and the workpiece holding mechanism 14 relative to one another in the Z-axis direction, which is the axial direction of the spindles, the X-axis direction which is perpendicular to the Z-axis direction and which are mutually perpendicular, and the Y-axis direction, a base plate 18, and a control device 40 (see FIG. 2). A vertical wall 20 is erected on the substrate 18, an X-axis guide section 22 is attached to the vertical wall 20, an X-axis moving body 24 is provided on the X-axis guide section 22 so as to be movable in the X-axis direction, and the X-axis moving body 24 is moved in the X-axis direction by the forward and reverse rotation of an X-axis motor 26 attached to the X-axis guide section 22. In addition, a single block 28 is attached to the X-axis movable body 24 via a Z-axis guide part (not shown) so as to be movable in the Z-axis direction, and the single block 28 is moved in the Z-axis direction by the forward and reverse rotation of a Z-axis motor 30 attached to the X-axis movable body 24. An imaging device 32 is also attached to the block 28 .

[0009] In this embodiment, four main spindles are provided: a first main spindle 12A, a second main spindle 12B, a third main spindle 12C, and a fourth main spindle 12D. Each spindle is configured to include a spindle body 1202 to which a machining tool is detachably attached via a collet chuck 34, and a rotation drive unit 1204 that is integrally connected to the spindle body 1202 and rotates the spindle body 1202. In this embodiment, the rotation drive unit 1204 is configured by a motor. Each of the main shafts 12A-12D is supported by a block 28 with its axis extending in the vertical direction (Z-axis direction). The main shafts 12A-12D are aligned in a straight line in the horizontal direction (X-axis direction) perpendicular to their respective axes and supported by a block . The distance between the axes of the main shafts 12A-12D is set to a predetermined dimension.

[0010] The workpiece holding mechanism 14 is a portion that holds the workpiece W. The workpiece holding mechanism 14 can employ various conventionally known structures, such as using a clamping member not shown, but in this embodiment, the workpiece W is held by placing it on the upper surface of the mounting plate 1402 and fastening the workpiece W onto the mounting plate 1402 from the underside of the mounting plate 1402 with bolts. The mounting plate 1402 is supported by an XY table 1404 . The XY table 1404 has an X-axis table 1404A that is moved in the X-axis direction on the base plate 18 by the forward and reverse rotation of an X-axis motor 1410 for work, and a Y-axis table 1404B that is moved in the Y-axis direction on the X-axis table 1404A by the forward and reverse rotation of a Y-axis motor 1412 for work, and the mounting plate 1402 is attached to the Y-axis table 1404B with bolts.

[0011] In this embodiment, the movement mechanism 16 that moves the spindle and workpiece holding mechanism 14 relatively in the Z-axis direction, which is the axial direction of the spindle, and in the X-axis direction and Y-axis directions that are perpendicular to the Z-axis direction and mutually perpendicular, is configured to include an X-axis motor 26, a Z-axis motor 30, a workpiece X-axis motor 1410, and a workpiece Y-axis motor 1412. In this embodiment, the moving mechanism 16 is configured to include a spindle moving mechanism 36 that moves the spindle, and a workpiece moving mechanism 38 that moves the workpiece holding mechanism 14. The spindle moving mechanism 36 includes a spindle Z-axis moving mechanism 36A that moves the block 28 in the Z-axis direction, and a spindle lateral moving mechanism 36B that moves the block 28 in one of the X-axis and Y-axis directions. The spindle Z-axis moving mechanism 36A includes the Z-axis motor 30, and the spindle lateral moving mechanism 36B includes the X-axis motor 26. The workpiece moving mechanism 38 includes an X-axis workpiece motor 1410 and a Y-axis workpiece motor 1412 .

[0012] Next, the control system of the machining center 10 will be described with reference to FIG. The control device 40 is configured by a computer. Each computer is configured to include a CPU, ROM, RAM, a hard disk drive, an input / output interface, an external storage device, and the like, all of which are not shown. The ROM stores predetermined control programs, etc., and the RAM provides a working area. The hard disk device stores control programs for implementing a movement control unit 42, a positional deviation detection unit 44, and a correction amount calculation unit 46, which will be described later. The input / output interface is used to interface with the X-axis motor 26 , the Z-axis motor 30 , the work X-axis motor 1410 , the work Y-axis motor 1412 , and the imaging device 32 . An external storage device stores information, and includes an external hard disk drive, an external SSD (Solid State Drive), or a semiconductor recording medium such as a memory card or USB memory.

[0013] The CPU executes the control program for the hard disk drive, thereby realizing a movement control unit 42, a positional deviation detection unit 44, and a correction amount calculation unit 46. The movement control unit 42 controls the relative movement amount of the spindles 12A-12D and the workpiece W by controlling the movement mechanism 16 based on position control information (also called a numerical control program, or NC program) provided from the outside via an input / output interface. In other words, the movement control unit 42 controls the amount of rotation of the X-axis motor 26, the Z-axis motor 30, the workpiece X-axis motor 1410, and the workpiece Y-axis motor 1412 based on the position control information, thereby controlling the amount of movement of the X-axis moving body 24, the block 28, the X-axis table 1404A, and the Y-axis table 1404B caused by each of these motors. The movement control section 42 controls the relative movement amounts of the spindles 12A-12D and the workpiece W, whereby machining of the workpiece W is carried out by the machining tools 46A-46D.

[0014] The positional deviation detection unit 44 detects the difference between the design center position P1 and the machining center position P2 as the amount of positional deviation for each of the spindles 12A-12D. Here, the design center position P1 refers to the center position of a predetermined shape formed at a position determined in the design of the test workpiece. Moreover, machining center position P2 refers to the center position of a predetermined shape actually machined by machining tools 46A-46D moved together with spindles 12A-12D by the position control information and movement control section 42. Specifically, when machining a predetermined shape at a position determined by the design of a test workpiece, for example, when machining a hole of diameter D, the diameter D and center position of the hole are set by the position control information. In this case, the center position of the hole (predetermined shape) is specified by a coordinate position defined by the X-axis and Y-axis coordinate axes, and this center position is set as the design center position P1(x1, y1). Then, the test workpiece is actually machined by the machining tools 46A-46D moved together with the spindles 12A-12D by the position control information and movement control unit 42, and a hole (of a predetermined shape) is machined in the test workpiece. The coordinate position of the center position of this actually machined hole (predetermined shape) is set as the machining center position P2 (x2, y2). Therefore, the positional deviation amount ΔE is the difference between the design center position P1 and the processing center position P2, and is given by ΔE=((x2-x1), (y2-y1)).

[0015] In this embodiment, the positional deviation amount detection unit 44 calculates the design center position P1 based on the position control information, and also calculates the machining center position P2 based on the center position of the hole (predetermined shape) extracted without image processing from the image information of the test workpiece including the hole (predetermined shape) photographed by the imaging device 32. This machining center position P2 is calculated corresponding to each of the spindles 12A-12D.

[0016] The correction amount calculation unit 46 calculates the correction amount C necessary to eliminate the positional deviation amount ΔE for each of the spindles 12A to 12D, based on the positional deviation amount ΔE corresponding to each of the spindles 12A to 12D calculated by the positional deviation amount detection unit 44. Then, the movement control unit 42 controls the relative movement amount between each of the spindles 12A-12D and the workpiece W based on the correction amount C corresponding to each of the spindles 12A-12D when machining the workpiece W. As a result, the workpiece W is machined by the machining tools 46A-46D attached to each of the spindles 12A-12D with the above-mentioned positional deviation amount ΔE eliminated.

[0017] Next, how to use the machining center 10 will be described. First, a desired machining tool is attached to each of the spindles 12A-12D via the collet chuck 34. Specifically, a first machining tool 46A is attached to the first spindle 12A, a second machining tool 46B is attached to the second spindle 12B, a third machining tool 46C is attached to the third spindle 12C, and a fourth machining tool 46D is attached to the fourth spindle 12D. Next, the test workpiece is attached to the workpiece holding mechanism 14 . Then, based on preset position control information, the movement control unit 42 moves the XY table 1404 using the movement mechanism 16 to position the test workpiece on the X and Y axes, and also positions the first spindle 12A on the X and Y axes using the movement mechanism 16. In other words, the movement mechanism 16 is controlled so that the center position of the first predetermined shape to be formed by the first machining tool 46A coincides with the design center position P1 (x1, y1) of the test workpiece. Next, the first spindle 12A is moved in the Z-axis direction, and a first predetermined shape is machined on the test workpiece by the first machining tool 46A attached to the first spindle 12A.

[0018] Next, the correction amount is calculated based on the formed first predetermined shape. That is, the movement control unit 42 positions the imaging device 32 on the X-axis and Y-axis using the movement mechanism 16 so that the imaging device 32 can capture an image of the first predetermined shape of the test workpiece. Then, the positional deviation detection unit 44 calculates the design center position P1 (x1, y1) based on the position control information, and calculates the machining center position P2 (x2, y2) based on image information including the first predetermined shape of the test workpiece imaged by the imaging device 32, and calculates the positional deviation ΔE1 = ((x2 - x1), (y2 - y1)) corresponding to the first spindle 12A from the difference between the design center position P1 and the machining center position P2. Next, the correction amount calculation unit 46 calculates a correction amount C1 corresponding to the first spindle 12A based on the positional deviation amount ΔE1 calculated by the positional deviation amount detection unit 44.

[0019] Next, as in the case of machining the first predetermined shape, the movement control unit 42 similarly positions the second, third, and fourth spindles 12B, 12C, and 12D individually on the X-axis and Y-axis using the movement mechanism 16 based on preset position control information, and forms the second, third, and fourth predetermined shapes at the design center position P1 of the test workpiece using the second, third, and fourth machining tools 46B, 46C, and 46D, and then calculates correction amounts C2, C3, and C4 for the second, third, and fourth spindles 12B, 12C, and 12D based on the second, third, and fourth predetermined shapes. In this embodiment, the design center positions P1 of the first, second, third, and fourth predetermined shapes are the same position.

[0020] As described above, the correction amounts C1, C2, C3, and C4 calculated by the correction amount calculation unit 44 are set in the movement control unit 42 corresponding to the first, second, third, and fourth spindles 12A, 12B, 12C, and 12D, respectively. In this way, the process of setting the correction amounts corresponding to the spindles 12A to 12D using the test workpiece is completed.

[0021] Once the process of setting the correction amount is completed, the workpiece W to be machined is attached to the workpiece holding mechanism 14 in place of the test workpiece. Then, position control information for machining the workpiece W is provided to the movement control unit 42, which then controls the relative movement of each spindle 12A-12D and the workpiece W based on the correction amounts C1, C2, C3, and C4 corresponding to each spindle 12A-12D, and the workpiece W is continuously machined by the machining tools 46A-46D attached to each spindle 12A-12D. For example, the workpiece W is machined by a first machining tool 46A attached to the first spindle 12A, then the workpiece W is machined by a second machining tool 46B attached to the second spindle 12B, then the workpiece W is machined by a third machining tool 46C attached to the third spindle 12C, and then the workpiece W is machined by a fourth machining tool 46D attached to the fourth spindle 12D, completing the series of machining operations. In this embodiment, predetermined shapes are formed on the workpiece W by first, second, third and fourth machining tools 46A, 46B, 46C and 46D attached to first, second, third and fourth spindles 12A, 12B, 12C and 12D, respectively. For example, if the first machining tool 46A is a pilot hole drill and the second machining tool 46B is a finishing drill, the pilot hole, which is the first predetermined shape, disappears when the second predetermined shape is formed by the second machining tool 46B. In other words, the number of predetermined shapes ultimately formed by the first, second, third, and fourth machining tools 46A, 46B, 46C, and 46D may not match the number of machining tools.

[0022] As described above, according to this embodiment, machining of the workpiece W is performed without changing the machining tools for the spindles 12A-12D. This is advantageous in suppressing errors in mounting the machining tools for the spindles 12A-12D that occur each time the automatic tool changer changes the machining tools, and is advantageous in improving machining accuracy.

[0023] Furthermore, in this embodiment, the movement mechanism 16 is configured to include a spindle movement mechanism 36 that moves the spindles 12A-12D and a work movement mechanism 38 that moves the work holding mechanism 14, and the multiple spindles 12A-12D are supported by a single block 28, and the spindle movement mechanism 36 is equipped with a spindle Z-axis movement mechanism 36A that moves the block 28 in the Z-axis direction, and a spindle lateral movement mechanism 36B that moves the block 28 in one of the X-axis and Y-axis directions, but a block that supports each spindle 12A-12D may be provided for each spindle 12A-12D, and each of these blocks may be moved individually in the Z-axis direction. However, in the present embodiment, the configuration of the moving mechanism 16 that moves the multiple spindles 12A-12D and the workpiece W relative to one another can be simplified and made more compact, which is advantageous in increasing the commercial value of the machining center 10.

[0024] Furthermore, according to this embodiment, when the center position of a predetermined shape formed at a position determined by the design of a test workpiece is defined as the design center position P1, and the center position of the predetermined shape actually machined by the machining tools 46A-46D moved together with the spindles 12A-12D by the position control information and the movement control unit 42 is defined as the machining center position P2, the difference between the design center position P1 and the machining center position P2 is detected as the positional deviation amount ΔE1-ΔE4 for each of the spindles 12A-12D, and correction amounts C1-C4 corresponding to each of the spindles 12A-12D are calculated based on the detected positional deviation amounts ΔE1-ΔE4, and the movement control unit 42 controls the relative movement amount of each of the spindles 12A-12D and the workpiece W based on the correction amounts C1-C4 corresponding to each of the spindles 12A-12D when machining the workpiece W. Therefore, the positional deviations ΔE1 to ΔE4 can be eliminated by the correction amounts C1 to C4 corresponding to the spindles 12A to 12D, which is more advantageous in improving the machining accuracy.

[0025] In this embodiment, a case where a plurality of predetermined shapes are formed on the same axis of the workpiece W has been described, but it is also possible to form a plurality of predetermined shapes at different locations on the workpiece W, for example. In this case, when calculating the correction amount, machining is performed using machining tools 46A-46D attached to spindles 12A-12D corresponding to different locations of the test workpiece corresponding to different locations of the workpiece W, and positional deviation amounts ΔE1-ΔE4 corresponding to each of the different locations are calculated by positional deviation amount detection unit 44, and correction amount calculation unit 46 calculates correction amounts C1-C4 corresponding to each of spindles 12A-12D based on each of these positional deviation amounts ΔE1-ΔE4. Furthermore, the number of main shafts 12A-12D is not limited to four, but may be two or more. [Explanation of symbols]

[0026] 10 Machining Center 12A 1st spindle 12B 2nd spindle 12C 3rd spindle 12D 4th spindle 1202 Spindle body 1204 Rotation drive unit 14 Work holding mechanism 1402 Mounting plate 1404 XY table 1404A X-axis table 1404B Y-axis table 1410 X-axis motor for work 1412 Y-axis motor for work 16 Moving mechanism 18 PCB 20 Vertical Wall 22 X-axis guide 24 X-axis moving body 26 X-axis motor 28 blocks 30 Z-axis motor 32 Imaging device 34 Collet chuck 36 Spindle movement mechanism 36A Movement mechanism for spindle Z-axis direction 36B Spindle lateral movement mechanism 38 Workpiece moving mechanism 40 Control device 42 Movement control unit 44 Position deviation detection unit 44 Correction value calculation unit 46A 1st processing tool 46B 2nd processing tool 46C 3rd processing tool 46D 4th processing tool double work

Claims

1. A machining center comprising: a spindle to which a machining tool is detachably attached and which is driven to rotate; a workpiece holding mechanism which holds a workpiece to be machined; and a movement mechanism which moves the spindle and the workpiece holding mechanism relatively in a Z-axis direction which is an axial direction of the spindle, an X-axis direction which is perpendicular to the Z-axis direction and which are perpendicular to each other, and a Y-axis direction, Three or more spindles are provided, and different types of machining tools are attached to the spindles, respectively; the movement mechanism is configured to include a spindle movement mechanism that moves the spindle and a workpiece movement mechanism that moves the workpiece holding mechanism, the three or more main shafts are supported by a single block; the spindle movement mechanism includes a spindle Z-axis direction movement mechanism that moves the block in the Z-axis direction, and a spindle lateral direction movement mechanism that moves the block in one of the X-axis direction and the Y-axis direction, the workpiece moving mechanism is configured to move the workpiece holding mechanism in the X-axis direction and the Y-axis direction; An imaging device is attached to the block, which captures an image of the workpiece machined by the machining tool and generates image information. A machining center characterized by:

2. a movement control unit that controls the movement mechanism based on given position control information to control the relative movement amount between the spindle and the workpiece; a positional deviation amount detection unit that detects a difference between the design center position and the machining center position as a positional deviation amount corresponding to each of the spindles, when the center position of a predetermined shape formed at a position determined by design of a test workpiece is defined as a design center position and the center position of the predetermined shape actually machined by the machining tool moved together with the spindle by the position control information and the movement control unit is defined as a machining center position; a correction amount calculation unit that calculates a correction amount corresponding to each of the spindles based on the positional deviation amount, the movement control unit controls the relative movement amount between each of the spindles and the workpiece based on the correction amount corresponding to each of the spindles during machining of the workpiece; the positional deviation amount detection unit calculates the processing center position based on the image information; 2. The machining center according to claim 1, wherein:

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