Machine tool axis control system

Abstract

In a machine tool where the NC control unit numerically controls the four axes other than the B axis, the objective is to facilitate manual operation of the B axis. [Solution] The axis control system (1) comprises a sequence control unit (22) that sequence-controls the machine tool, an NC control unit (21) that numerically controls the X, Y, and Z axes, which are reference axes, and the C axis according to an NC program, an operation panel (30) attached to the NC control unit that accepts manual operation of each axis, and a B-axis NC control unit (42) that numerically controls the B axis. In this axis control system, the B-axis NC control unit and the sequence control unit are connected to each other so as to be able to communicate with each other using the same communication standard as the NC control unit, and the sequence control unit includes a memory (22m) that stores angle command information for the B axis specified by the NC control unit, as well as manual operation information for the B axis input via the operation panel. This is characterized in that the B-axis NC control unit makes the B axis manually operable based on the manual operation information written to the memory.

Description

【Technical Field】 【0001】 The present invention relates to an axis control system for a machine tool, and particularly to an axis control system for a 5-axis machine tool. 【Background Art】 【0002】 A 5-axis NC machine tool having X-axis, Y-axis, Z-axis as reference axes of the machine tool, C-axis as a rotation axis, and B-axis as an inclination axis is used for precision machining of parts because it can perform machining of complex three-dimensional curved surfaces and polyhedrons in one setup. The names of the rotating axes A-axis, B-axis, C-axis of the machining center differ depending on the arrangement of the rotary / tilt table. Here, the rotation axis is the C-axis that rotates with respect to the Z-axis, and the inclination axis is the B-axis that rotates with respect to the Y-axis. 【0003】 In the control device of a 5-axis NC machine tool, as disclosed in Japanese Patent Application Laid-Open No. 2011-70483 (Patent Document 1), it is common to control all five axes in a common NC control unit. On the other hand, a technique has also been conventionally proposed in which only four axes other than the B-axis are controlled in the NC control unit, and the NC control of the B-axis is carried out by a separate controller. An example of the separate controller is disclosed in the catalog "CNC ROTARY TABLE SERIES", Nikken Kosakusho Co., Ltd., CAT.NO.814J, published pages P.69 - P.70, searched on March 26, 2026, URL:chrome-extension: / / efaidnbmnnnibpcajpcglclefindmkaj / https: / / www.nikken-kosakusho.co.jp / download / pdf / J_CNC_814J_link.pdf?20230721 (Non-Patent Document 1). The separate controller includes a dedicated NC control unit for the B-axis and an amplifier for the B-axis when performing NC control of the B-axis. 【Prior Art Documents】 【Patent Documents】 【0004】 【Patent Document 1】 Japanese Patent Application Laid-Open No. 2011-70483 [Non-patent literature] 【0005】 [Non-Patent Document 1] Catalog "CNC ROTARY TABLE SERIES", Nikken Kosakusho Co., Ltd., CAT.NO.814J, pages P.69-P.70, accessed March 26, 2026, URL:chrome-extension: / / efaidnbmnnnibpcajpcglclefindmkaj / https: / / www.nikken-kosakusho.co.jp / download / pdf / J_CNC_814J_link.pdf?20230721 [Overview of the Initiative] [Problems that the invention aims to solve] 【0006】 Even when controlling five axes using a 4-axis NC control unit and a separate controller, the NC control unit's extended functions (custom macro function) allow it to send angle command information for the B axis to the separate controller, enabling automatic operation of the five axes according to the NC program. On the other hand, manual operation of the B axis, such as jog operation, required a separate control terminal attached to the separate controller. Therefore, manually operating the five axes required using both the control panel attached to the 4-axis NC control unit and the control terminal attached to the separate controller, resulting in a cumbersome operation. 【0007】 The present invention was made to solve the above-mentioned problems, and its objective is to provide an axis control system that allows for easy manual operation of the B axis in a machine tool in which the NC control unit numerically controls the four axes other than the B axis. [Means for solving the problem] 【0008】 A machine tool axis control system according to a certain aspect of this invention is an axis control system for a five-axis machine tool having X-axis, Y-axis, and Z-axis as reference axes, C-axis as a rotation axis, and B-axis as a tilt axis, comprising: a sequence control unit for sequence control of the machine tool; an NC control unit that communicates with other devices using a predetermined communication standard and numerically controls the reference axis and C-axis according to an NC program; an operation panel attached to the NC control unit that accepts manual operation of each axis; and a B-axis NC control unit provided independently of the NC control unit for numerically controlling the B-axis. In this axis control system, the B-axis NC control unit and the sequence control unit are connected to each other so as to be able to communicate using the same communication standard as the NC control unit, and the sequence control unit includes a memory that stores angle command information for the B-axis specified by the NC control unit, as well as manual operation information for the B-axis input via the operation panel. As a result, the B-axis NC control unit automatically operates the B-axis based on the angle command information written to the memory, and also enables manual operation of the B-axis based on the manual operation information written to the memory. 【0009】 Preferably, the sequence control unit writes the B-axis position information received from the B-axis NC control unit to memory, and the NC control unit displays the B-axis position information, along with the reference axis and C-axis position information, on the control panel based on the B-axis position information written to memory. 【0010】 More preferably, the sequence control unit writes the control parameters for the B-axis NC control unit received from the NC control unit to memory, and the B-axis NC control unit controls the B-axis based on the control parameters written to memory. 【0011】 An NC control system, including a sequence control unit, an NC control unit, and amplifiers for the reference axis and C axis respectively, is mounted on the control panel. According to the present invention, an NC control unit for the B axis and an amplifier for the B axis can be mounted on this control panel. 【0012】 The aforementioned communication standard should preferably be a LAN communication standard such as Ethernet (registered trademark). [Effects of the Invention] 【0013】 According to the present invention, the NC control unit for the B-axis can read manual operation information for the B-axis via the memory of the sequence control unit. Therefore, manual operation of the B-axis can be easily performed using the control panel attached to the NC control device (NC control unit). [Brief explanation of the drawing] 【0014】 [Figure 1] This is a schematic perspective view showing the main parts of a machine tool according to an embodiment of the present invention. [Figure 2] This is a block diagram showing the functional configuration of an axis control system according to an embodiment of the present invention. [Figure 3] This flowchart shows the processing procedures executed by the NC control unit, PMC, and B-axis NC control unit during automatic operation in an embodiment of the present invention. [Figure 4] This flowchart shows the processing procedure executed by the PMC and the B-axis NC control unit when the B-axis is manually operated in an embodiment of the present invention. [Figure 5] This block diagram shows the functional configuration of a known full 5-axis control type axis control system. [Figure 6] This is a block diagram showing the functional configuration of a known 4-axis + 1-axis independent control type axis control system. [Figure 7] This is a schematic perspective view showing an example of the installation of a known separate controller. [Modes for carrying out the invention] 【0015】 Embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and their descriptions will not be repeated. 【0016】 <Outline configuration> First, the schematic configuration of the machine tool MC according to the present embodiment will be described. FIG. 1 is a perspective view schematically showing the main part of the machine tool MC according to the embodiment of the present invention. The machine tool MC is a five-axis machine tool having an X-axis, a Y-axis, and a Z-axis as reference axes, a C-axis as a rotation axis, and a B-axis as an inclination axis. 【0017】 The machine tool MC is a machining center having a numerical control function and an automatic exchange function for automatically exchanging the tool holder 18. The machine tool MC includes a spindle 11, a rotary table 12, a spindle drive unit 13, a rotary table drive unit 14, a spindle support unit 15, an X-Y table 16, and a tool magazine 17. 【0018】 The spindle drive unit 13 supports the spindle 11 and rotates the spindle 11. The spindle support unit 15 supports the spindle drive unit 13 and moves the spindle drive unit 13 in the vertical direction (Z-axis). The Z-axis movement is performed by a servo motor (not shown) provided in the spindle support unit 15. A tool holder 18 and a cutting tool 19 are attached to the tip of the spindle 11. That is, the spindle 11 is movable in the Z-axis direction and is further rotatable about the Z-axis. 【0019】 The rotary table 12 is, for example, a circular table, and a workpiece (not shown) is fixed thereto. The rotary table drive unit 14 incorporates two servo motors 141 and 142 and indexes the rotary table 12. One servo motor 141 is a driving means for rotating the rotary table 12 in the C direction around the X-axis, and the other servo motor 142 is a driving means for tilting the rotary table 12 in the B direction around the Y-axis. The X-Y table 16 supports the rotary table 12 and the rotary table drive unit 14. 【0020】 The tool magazine 17 supplies the tool holder 18 and the cutting tool 19 to the spindle 11 and receives the tool holder 18 and the cutting tool 19 from the spindle 11, thereby assisting in the detachment and exchange of the tool holder 18 attached to the spindle 11. 【0021】 The machine tool MC is equipped with a control panel 2 located behind the spindle support 15. The control panel 2 incorporates an NC control device 20. The NC control device 20 is electrically connected to an operation panel 30 located outside the control panel 2. The operation panel 30 includes a display unit 31 for displaying the machining status of the machine tool MC, and an operation unit 32 for receiving instructions from the operator. The operation panel 30 further includes an operation terminal 33 that can be grasped by the operator. The operation unit 32 and the operation terminal 33 constitute operating means that are operated when the machine tool MC is operated manually. 【0022】 The axis control system 1 according to this embodiment includes an NC control device 20 and an operation panel 30, as well as a separate controller 40 (controller body 41) described later. First, a known axis control system will be explained with reference to a diagram. 【0023】 <Regarding known axis control systems> Figure 5 is a block diagram showing the functional configuration of the fully 5-axis control type axis control system 100A. 【0024】 The NC control device 20A of the axis control system 100A comprises an NC control unit 21, a PMC (Programmable Machine Controller) 22 which is a sequence control unit, a high-voltage circuit 23, and amplifiers 24 to 28 corresponding to each of the five axes. 【0025】 The NC control unit 21 communicates with other devices using a predetermined communication standard and performs 5-axis numerical control (position control) according to the NC program. This communication standard is a LAN communication (network communication) standard, such as Ethernet®. Other devices include, for example, a management server that manages various information about the machine tool. The management server stores and manages the NC program and also manages the machine tool's operating history information. 【0026】 The NC control unit 21 performs numerical control of each axis via the 5-axis amplifiers 24-28. The amplifiers 24-26 for the reference axes, X, Y, and Z, are connected to their respective servo motors (not shown). The amplifier 27 for the rotation axis, C-axis, is connected to servo motor 141, and the amplifier 28 for the tilt axis, B-axis, is connected to servo motor 142. 【0027】 The PMC22 performs 5-axis sequence control and tool holder 18 replacement operations. The PMC22 controls the operation and stopping of each drive unit (tool magazine, door opening / closing unit, etc.) via the high-voltage circuit 23. 【0028】 When 5-axis automatic operation is performed according to the NC program, the NC control unit 21 displays the position information of the 5 axes on the display unit 31 of the control panel 30. When manual operation (such as jog operation) of any axis is performed using the operation unit 32 of the control panel 30 (or a handheld operation terminal 33), an operation signal is sent to the PMC 22, and the PMC 22 sends an axis movement request signal to the NC control unit 21. Upon receiving the axis movement request signal, the NC control unit 21 controls the servo motor corresponding to the selected axis. 【0029】 Figure 6 is a block diagram showing the functional configuration of the 4-axis + 1-axis independent control type axis control system 100B. 【0030】 The axis control system 100B comprises an NC control device 20B and a separate controller 40. The NC control device 20B does not include an amplifier 28 for the B axis; therefore, the NC control unit 21 performs numerical control of the four axes other than the B axis. The separate controller 40 includes an amplifier 28 for the B axis and a single-axis NC control unit (hereinafter referred to as the "B axis NC control unit") 42. The amplifier 28 and the B axis servo motor 142 are connected by a power cable 46. The B axis NC control unit 42 performs numerical control of the B axis by driving the servo motor 142 via the amplifier 28. 【0031】 Figure 7 schematically shows an example of the installation of the separate controller 40. The separate controller 40 includes a controller body 41 equipped with an NC control unit 42 for the B axis and an amplifier 28, and a handheld operation terminal (pendant) 43. The operation terminal 43 is equipped with a display unit 44 that displays B axis position information and an operation unit 45 that accepts manual operation of the B axis. 【0032】 The separate controller 40 and the NC control unit 20B are connected by a communication cable 49 and an M signal cable 48. As shown in Figure 6, the communication cable 49 is connected to the NC control unit 21, and the M signal cable 48 is connected to the PMC 22 via the high-voltage circuit 23. The communication standard between the B-axis NC control unit 42 and the NC control unit 21 is a serial communication standard (for example, RS-232C), which differs from the LAN communication standard. 【0033】 The NC control unit 21's custom macro function allows it to send angle command signals for the B-axis to the B-axis NC control unit 42 via the communication cable 49. The B-axis NC control unit 42 can also receive a start signal from the PMC 22 via the M signal cable 48 and send a completion signal to the PMC 22. Therefore, by using the separate controller 40, the B-axis can be automatically operated according to the NC program, similar to the four axes controlled by the NC control unit 21. The B-axis position information is displayed on the display unit 44 of the operation terminal 43. 【0034】 On the other hand, when manually operating the B-axis, it is necessary to use a dedicated operating terminal 43 (operating unit 45). Therefore, in order to manually operate the 5 axes, the operating panel 30 (including the operating terminal 33) attached to the NC control device 20B and the operating terminal 43 attached to the separate controller 40 must be used in combination. 【0035】 In contrast, the axis control system 1 according to this embodiment is characterized by eliminating the need for a dedicated operating terminal 43 and enabling manual operation of the B axis from the control panel 30. 【0036】 <Configuration of the axis control system according to an embodiment of the present invention> Referring to Figures 1 and 2, the functional configuration of the axis control system 1 according to this embodiment will be described. Figure 2 is a block diagram showing the functional configuration of the axis control system 1 according to this embodiment. The axis control system 1 is a 4-axis + 1-axis independent control type, similar to the axis control system 100B shown in Figure 6. Note that the description of the configuration similar to the known axis control system 100B will not be repeated. 【0037】 The axis control system 1 according to this embodiment includes an NC control device 20, a control panel 2, and a separate controller 40 (i.e., the controller body 41) excluding the operation terminal 43 shown in Figure 7. As shown by dashed lines in Figure 1, the NC control device 20 and the separate controller 40 are mounted in the control panel 2. 【0038】 As shown in Figure 2, in this embodiment, the B-axis NC control unit 42 and the NC control unit 21 do not communicate directly, but communicate via a memory (hereinafter referred to as "PMC memory") 22m provided in the PMC 22. For this reason, there is no communication cable 49 as shown in Figure 6, and the B-axis NC control unit 42 and the PMC 22 are connected to communicate via a LAN standard communication cable (hereinafter referred to as "LAN cable") 47. 【0039】 The communication standard of the LAN cable 47 is typically Ethernet (registered trademark). In this way, the B-axis NC control unit 42 and the PMC 22 are connected in a way that allows them to communicate using the same communication standard as the NC control unit 21. As a result, various types of information can be read from and written to the PMC memory 22m from both the NC control unit 21 and the B-axis NC control unit 42. 【0040】 <Operation of the axis control system according to an embodiment of the present invention> (Operations during autonomous driving) The operation of the axis control system 1 during automatic operation of the machine tool MC will be explained with reference to Figure 3. Figure 3 is a flowchart showing the processing procedures executed by the NC control unit 21, PMC 22, and B-axis NC control unit 42 during automatic operation. 【0041】 During the automatic operation of the machine tool MC, the NC control unit 21 numerically controls the four axes other than the B axis according to the NC program (step S11), and writes the angle command information for the B axis to the PMC memory 22m at regular time intervals (step S21). Specifically, the NC control unit 21 instructs the PMC 22 to write the angle command information for the B axis. 【0042】 The B-axis NC control unit 42 reads angle command information from the PMC 22 in the PMC memory 22m via the LAN cable 47 at regular time intervals (step S31). The B-axis NC control unit 42 numerically controls the B-axis by driving the servo motor 142 based on the read angle command information (step S33). This allows the B-axis to be operated automatically, just like the other four axes. 【0043】 During automatic operation of each axis, the NC control unit 21 displays the position information of the four axes on the display unit 31 of the control panel 30 in real time (step S13). The NC control unit 42 for the B axis writes the position information of the B axis to the PMC memory 22m at regular time intervals (step S35). The NC control unit 21 reads the position information of the B axis from the PMC memory 22m (step S23) and displays the position information of the B axis on the display unit 31 of the control panel 30 in real time (step S25). 【0044】 In other words, the NC control unit 21 displays the position information of the B axis along with the position information of the reference axis and the C axis on the control panel 30. It is desirable that the position information of all five axes be displayed aligned on the same screen on the control panel 30. This allows the position information of all five axes to be checked simultaneously, making it easy to understand the machining status of the workpiece by the machine tool MC. 【0045】 (Operation of the B axis when manually operated) The operation of the axis control system 1 during manual operation of the B-axis of a machine tool MC will be explained with reference to Figure 4. Figure 4 is a flowchart showing the processing procedures executed by the PMC22 and the B-axis NC control unit 42 during manual operation of the B-axis. Manual operation includes mode selection, feed operation using the jog button, magnification selection, manual pulse feed operation, homing operation, and clamp / unclamping operation (M function). 【0046】 As shown in Figure 4, when the B-axis is manually operated by the operator via the control panel 30 (including the operation terminal 33) (step S41), the PMC 22 acquires the operation signal (step S51) and writes the manual operation information for the B-axis corresponding to the acquired operation signal to the PMC memory 22m at regular time intervals (step S53). While the B-axis is being manually operated, the processes in steps S51 and S53 are repeatedly executed. 【0047】 The B-axis NC control unit 42 reads manual operation information from the PMC 22 in the PMC memory 22m via the LAN cable 47 at regular time intervals (step S61). The B-axis NC control unit 42 controls the B-axis according to the read manual operation information (step S63). In this way, manual operation of the B-axis can be performed from the control panel 30, just like the other four axes, improving operability. In addition, the B-axis dedicated operation terminal 43 shown in Figure 6 can be eliminated. 【0048】 Even during manual operation, the position information of the B-axis is displayed on the display unit 31 of the control panel 30 in the same manner as during automatic operation. Specifically, the NC control unit 42 for the B-axis writes the position information of the B-axis to the PMC memory 22m at regular time intervals (step S65). The NC control unit 21 reads the position information of the B-axis from the PMC memory 22m (step S55), and displays the position information of the B-axis (along with the position information of the other four axes) in real time on the display unit 31 of the control panel 30 (step S57). 【0049】 Furthermore, in this embodiment, for ease of understanding, only manual operation information for the B axis is written to the PMC memory 22m during manual operation. However, all manual operation information via the control panel 30 may be written to the PMC memory 22m, and the B axis NC control unit 42 may read only the manual operation information related to the B axis from the PMC memory 22m. In this case, the manual operation information may further include, in addition to the operation information described above, axis selection operations for selecting the axis to be manually operated, and manual tool change operations (M function). 【0050】 As explained above, by connecting the PMC22 and the B-axis NC control unit 42 with a LAN cable 47, and using the PMC memory 22m as a relay point for communication between the NC control device 20 and PMC22 and the B-axis NC control unit 42, automatic and manual operation of the B-axis can be performed in the same way as the other four axes. 【0051】 Furthermore, manual operation of the B-axis can also be performed using the control panel 30 attached to the NC control device 20 (NC control unit 21), just like the other four axes. Therefore, the controller body 41 (NC control unit 42 for the B-axis and amplifier 28) of the separate controller 40 can be installed together with the NC control device 20 within the control panel 2. Consequently, the NC control device 20 according to this embodiment can function in the same way as the complete 5-axis NC control device 20A. 【0052】 <Other> As described above, the PMC memory 22m in this embodiment stores B-axis angle command information (macro variables), at least B-axis manual operation information, and B-axis position information (coordinate information). A separate storage area may be allocated for each type of information. 【0053】 The PMC memory 22m may also store control parameters for the B-axis NC control unit 42 that are written from the NC control unit 21. These control parameters include, for example, rapid traverse speed, acceleration / deceleration time constant, and total reduction ratio. As a result, the B-axis NC control unit 42 reads the control parameters stored in the PMC memory 22m from the PMC 22 and sets the B-axis parameters based on the read control parameters (control parameters written by the NC control unit 21). In this way, the B-axis NC control unit 42 can control the B-axis according to the control parameters specified from the NC control unit 21. Note that the control parameters can be set in other devices (such as a management server) that communicate with the NC control unit 21. 【0054】 The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than by the foregoing description, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of symbols] 【0055】 1: Axis control system 2: Control panel 20: NC control device 21: NC Control Unit 22: PMC (Sequence Control Unit) 22m: PMC Memory 24-28: Amplifier 30: Control panel 31: Display section 32:Operation unit 33: Operating terminal 40: Separate controller 41: Controller body 42: NC control unit for B-axis 43: Operating terminal 44:Display section 45:Operation unit 46: Power Cable 47: LAN cable 48: M signal cable 100A: Axis control system 100B: Axis control system 141: Servo motor 142: Servo motor MC: Machine tool

Claims

[Claim 1] A five-axis machine tool axis control system having X-axis, Y-axis, and Z-axis as reference axes, C-axis as a rotation axis, and B-axis as a tilt axis, A sequence control unit for sequentially controlling the machine tool, An NC control unit communicates with other devices using a predetermined communication standard and numerically controls the X-axis, Y-axis, Z-axis, and C-axis, which are the reference axes, according to an NC program. An operating panel attached to the NC control unit, which accepts manual operation of each axis, It comprises a B-axis NC control unit provided independently of the NC control unit, which numerically controls the B-axis, The B-axis NC control unit and the sequence control unit are connected to each other so that they can communicate using the same communication standard as the NC control unit. The sequence control unit includes a memory for storing angle command information for the B axis specified by the NC control unit, and manual operation information for the B axis input via the control panel. A machine tool axis control system characterized in that the NC control unit for the B axis automatically operates the B axis based on the angle command information written to the memory, and also enables manual operation of the B axis based on the manual operation information written to the memory. [Claim 2] The axis control system for a machine tool according to claim 1, wherein the NC control unit displays the position information of the B axis, along with the position information of the reference axis and the C axis, on the control panel based on the position information of the B axis written to the memory by the B axis NC control unit. [Claim 3] The NC control unit for the B-axis sets the parameters of the B-axis and controls the B-axis based on the control parameters written to the memory by the NC control unit, the axis control system for a machine tool according to claim 1. [Claim 4] The sequence control unit, the NC control unit, and the NC control device including the amplifiers for the reference axis and the C axis are mounted on the control panel. The axis control system for a machine tool according to claim 1, wherein the NC control unit for the B axis and the amplifier for the B axis are mounted on the control panel. [Claim 5] The aforementioned communication standard is a LAN communication standard, the axis control system for a machine tool according to any one of claims 1 to 4.

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