Working machinery

Abstract

To provide a machine tool that can easily use a plurality of rotary tools depending on various machining conditions. [Solution] The machine includes a plurality of rotating tools Tr for machining a workpiece W, a tool rotation motor Mt that outputs power to rotate the plurality of rotating tools Tr, and a power transmission mechanism that transmits the power output by the tool rotation motor Mt to simultaneously rotate the plurality of rotating tools Tr. The power transmission mechanism is configured so that the rotation speed of at least some of the plurality of rotating tools Tr that rotate simultaneously differs from the rotation speed of the output shaft of the tool rotation motor Mt, and controls the tool rotation motor Mt so that each of the plurality of rotating tools Tr can rotate at a rotation speed commanded to a control unit.

Description

[Technical Field]

[0001] The present invention relates to a machine tool. [Background technology]

[0002] As a conventional machine tool, Patent Document 1 discloses one having a plurality of rotary tools spaced apart in the vertical direction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-82196 Summary of the Invention [Problem to be solved by the invention]

[0004] The machine tool disclosed in Patent Document 1 has a problem in that, because a single motor drives a plurality of rotary tools, it is difficult to use a plurality of rotary tools in accordance with various machining conditions.

[0005] The present invention has been made in view of the above-mentioned problems, and has as its object to provide a machine tool that can easily use a plurality of rotary tools in accordance with various machining conditions. [Means for solving the problem]

[0006] In order to achieve the above object, the machine tool of the present invention comprises a plurality of rotating tools for machining a workpiece, a first actuator that outputs power to rotate the plurality of rotating tools, and a power transmission mechanism that transmits the power output by the first actuator to rotate the plurality of rotating tools simultaneously, wherein the power transmission mechanism is configured so that the rotational speed of at least some of the plurality of rotating tools that rotate simultaneously is different from the rotational speed of the output shaft of the first actuator, and controls the first actuator so that each of the plurality of rotating tools can rotate at a rotational speed commanded to a control unit. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a machine tool that can easily use a plurality of rotary tools in accordance with various machining conditions. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a front view of a machine tool according to a first embodiment. [Figure 2] 1 is a side view of a machine tool according to a first embodiment. [Figure 3] 3 is a cross-sectional view taken along the line III-III in FIG. 2, focusing on a rotary tool device of the machine tool. [Figure 4] 4 is a cross-sectional view of the rotary tool device taken along line IV-IV in FIG. 3. [Figure 5] 4 is a table showing the numbers of teeth of gears provided on the output shaft and rotary tool of the rotary tool device according to the first embodiment. [Figure 6] 4 is a flowchart of a rigid tapping process executed by the machine tool according to the first embodiment. [Figure 7] 7A and 7B are tables used in the rigid tapping process shown in FIG. 6, where (a) is a table showing the acquired processing data and the feed rate calculated from this data, and (b) is a table showing data obtained by correcting the rotational speed of the output shaft based on the number of teeth of the gear shown in FIG. 5. [Figure 8]10 is a table showing the numbers of teeth of gears provided on an output shaft and a rotary tool of a rotary tool device according to a second embodiment. [Figure 9] 10A and 10B are tables used in the rigid tapping process performed by the machine tool according to the second embodiment, where FIG. 10A shows the acquired processing data and the feed rate calculated from the data, and FIG. 10B shows the data obtained by correcting the rotational speed of the output shaft based on the number of teeth of the gear shown in FIG. 8 . DETAILED DESCRIPTION OF THE INVENTION

[0009] (Embodiment 1) Machine tool 1 according to embodiment 1 of the present invention is, for example, a multi-function lathe that processes a cylindrical workpiece W (workpiece) with a spindle (workpiece holder 10, described below). Below, the configuration of machine tool 1 will be explained using X, Y, and Z axes, which are orthogonal to each other as indicated by arrows in the figure. In addition, in each direction indicated by these arrows, the direction in which the arrow points is referred to as the "+" side, and the opposite direction is referred to as the "-" side.

[0010] As shown in FIG. 1, the machine tool 1 includes a bed S, which is the base for the entire machine tool 1, a workpiece holder 10, a Z-axis movement mechanism 20, a tool holder 30, an XY-axis movement mechanism 50, and a control unit 60.

[0011] The workpiece holding unit 10 has a chuck that holds the workpiece W, and a workpiece rotation motor Mw that rotates the workpiece W held by the chuck.

[0012] The Z-axis movement mechanism 20 has a known configuration that moves the workpiece holding part 10 in the Z-axis direction relative to the bed S. The Z-axis movement mechanism 20 rotates a ball screw 22 using a Z-axis movement motor Mz, thereby moving the Z-axis slide part 21, to which the workpiece holding part 10 is fixed, in the Z-axis direction together with the workpiece holding part 10.

[0013] 2, the tool holding unit 30 is configured by attaching a plurality of tools to a rectangular parallelepiped base 42 having a workpiece insertion portion 31 formed in the center and penetrating in the Z-axis direction. The tool holding unit 30 has the base 42, non-driven tool attachment portions 44, 45, 46 provided on the left and right sides of the workpiece insertion portion 31 of the base 42, and a rotary tool device 70.

[0014] The non-driven tool attachment portion 44 is provided on the +X side (right side in FIG. 2) of the workpiece insertion portion 31. A plurality of non-driven tools Tz are attached to the non-driven tool attachment portion 44, with their tips facing the -Z side.

[0015] The non-driven tool attachment portion 45 is provided on the +X side (right side in FIG. 2) of the workpiece insertion portion 31, and on the −Y side (lower side in FIG. 2) of the non-driven tool attachment portion 44. A plurality of non-driven tools Tx are attached to the non-driven tool attachment portion 45, with their tips facing the −X side.

[0016] The non-driven tool attachment portion 46 is provided on the -X side (left side in FIG. 2) of the workpiece insertion portion 31. A plurality of non-driven tools Tx are attached to the non-driven tool attachment portion 46, with their tips facing the +X side.

[0017] The plurality of non-driven tools Tx attached to the non-driven tool attachment portions 45, 46 are, for example, cutting tools. The plurality of non-driven tools Tz attached to the non-driven tool attachment portion 44 are, for example, four drills. The rotary tools Tr are, for example, drills, taps, milling cutters, etc.

[0018] The XY-axis movement mechanism 50 is a known configuration that moves the tool holding part 30 in the X-axis and Y-axis directions relative to the bed S. The XY-axis movement mechanism 50 includes a fixed base 40 fixed to the bed S, an X-axis movement mechanism 80, and a Y-axis movement mechanism 90. As shown in FIG. 1, a guide bush 66 that assists in holding and moving the workpiece W is attached to the fixed base 40. The X-axis movement mechanism 80 moves the X-axis slide unit 81 (FIG. 1) in the X-axis direction relative to the fixed base 40 by rotating a ball screw (not shown) using the X-axis movement motor Mx shown in FIG. 2. The X-axis movement mechanism 80 moves the tool holding unit 30 in the X-axis direction, thereby feeding the non-driven tool Tx and the rotating tool Tr toward the workpiece W. The Y-axis movement mechanism 90 rotates a ball screw 92 using a Y-axis movement motor My, thereby moving the tool holding part 30 in the Y-axis direction relative to the X-axis slide part 81. The X-axis movement motor Mx and the Y-axis movement motor My are, for example, servo motors, but can be appropriately selected from various actuators.

[0019] The rotary tool device 70 is provided on the -X side (left side in FIG. 2 ) of the workpiece insertion portion 31 and on the -Y side (lower side in FIG. 2 ) of the non-driven tool mounting portion 46. A plurality of rotary tools Tr1, Tr2, Tr3, and Tr4 (hereinafter, these may be collectively referred to as the rotary tools Tr) with their tips facing the +X side are attached to the rotary tool device 70. As shown in FIGS. 3 and 4 , the rotary tool device 70 includes a housing 71 for mounting the rotary tool device 70 to the base 42, a tool rotation motor Mt for driving the rotary tools Tr, tool rotation shafts 73, 74, 75, and 76 for holding the rotary tools Tr, and spur gears 51, 52, 53, 54, 55, and 56 and an intermediate shaft 57 as a power transmission mechanism for transmitting the output of the tool rotation motor Mt to the tool rotation shafts 73, 74, 75, and 76. The housing 71 is formed by combining a first housing 71 a and a second housing 71 b.

[0020] The tool rotation motor Mt is, for example, a servo motor, but can be appropriately selected from various actuators. As shown in FIG. 3, the tool rotation motor Mt rotates an output shaft 72 around a rotation axis A1. The rotation axis A1 is set parallel to the X-axis. A spur gear 51 is attached to the output shaft 72.

[0021] Intermediate shaft 57 is disposed on the +Z side of output shaft 72. Intermediate shaft 57 is supported rotatably around an axis parallel to the X axis within housing 71. Spur gear 52, which meshes with spur gear 51, is attached to the outer periphery of intermediate shaft 57.

[0022] The tool rotation shaft 73 is disposed on the +Z side of the intermediate shaft 57. The tool rotation shaft 73 is supported within the housing 71 so as to be rotatable about an axis parallel to the X axis. A spur gear 53 that meshes with the spur gear 52 is attached to the outer periphery of the tool rotation shaft 73. The tool rotation shaft 73 holds the attached rotary tool Tr2.

[0023] The spur gears 51, 52, and 53 are set to have the same pitch diameter and have 30 teeth (FIG. 5).

[0024] The tool rotation shafts 74, 75, and 76 are arranged in the Y-axis direction as shown in FIG. 4, and are provided on the rear and front sides of the tool rotation shaft 73 in FIG.

[0025] The tool rotation shaft 74 is disposed on the -Y side of the tool rotation shaft 73 shown in Fig. 4. The tool rotation shaft 74 is supported within the housing 71 so as to be rotatable about an axis parallel to the X axis. A spur gear 54 that meshes with the spur gear 53 is attached to the outer periphery of the tool rotation shaft 74. The spur gear 54 has a larger pitch circle diameter than the spur gear 53 and has 45 teeth as shown in Fig. 5. The tool rotation shaft 74 holds the attached rotary tool Tr3.

[0026] The tool rotation shaft 75 is disposed on the -Y side of the tool rotation shaft 74. The tool rotation shaft 75 is supported within the housing 71 so as to be rotatable about an axis parallel to the X axis. A spur gear 55 that meshes with the spur gear 54 is attached to the outer periphery of the tool rotation shaft 75. The spur gear 55 has a larger pitch circle diameter than the spur gear 54, and has 60 teeth as shown in FIG. 5. The tool rotation shaft 75 holds the attached rotary tool Tr4.

[0027] The tool rotation shaft 76 is disposed on the +Y side of the tool rotation shaft 73. The tool rotation shaft 76 is supported within the housing 71 so as to be rotatable about an axis parallel to the X axis. A spur gear 56 that meshes with the spur gear 53 is attached to the outer periphery of the tool rotation shaft 76. The spur gear 56 has the same pitch circle diameter as the spur gear 53 and has 30 teeth (FIG. 5). The tool rotation shaft 74 holds the attached rotary tool Tr1.

[0028] The power output by the tool rotation motor Mt is transmitted from the output shaft 72 to the tool rotation shafts 73-76 via the spur gears 51-56 that form a gear train. The four rotating tools Tr held by the tool rotation shafts 73-76 rotate simultaneously. The spur gears 54 and 55 attached to the rotating tools Tr3 and Tr4 have more teeth than the spur gear 51 attached to the output shaft 72. In other words, the spur gears 54 and 55 form a reduction gear mechanism that reduces the rotation speed of the rotating tools Tr3 and Tr4, thereby increasing torque. In this way, the spur gears 51-56, which form the power transmission mechanism, vary the rotational speeds of some of the rotating tools Tr.

[0029] The machine tool 1 includes a control unit 60, a display unit 77, an operation reception unit 78, and the above-mentioned X-axis movement motor Mx, Y-axis movement motor My, Z-axis movement motor Mz, workpiece rotation motor Mw, and tool rotation motor Mt.

[0030] The control unit 60 controls the overall operation of the machine tool 1. The control unit 60 includes a ROM (Read Only Memory), a RAM (Random Access Memory), a CPU (Central Processing Unit), etc. The CPU functions as a central processing unit that executes processing and calculations related to the control of the machine tool 1. The CPU controls the machine tool 1 based on programs (NC programs, macro programs, etc.) and data stored in storage units such as the ROM and RAM, and on data given to the control unit 60 via the operation reception unit 78.

[0031] The display unit 77 displays various images under the control of the control unit 60. The display unit 77 includes a touch panel, a liquid crystal display, etc. The operation reception unit 78 receives various operations from the user and supplies information indicating the contents of the received operations to the control unit 60. The operation reception unit 78 includes a touch screen, buttons, etc.

[0032] Next, machining of a workpiece W using the machine tool 1 configured as described above will be described. When machining a workpiece W with non-driven tools Tx, Tz, the control unit 60 operates the Y-axis movement motor My to adjust the height of the desired non-driven tools Tx, Tz relative to the workpiece W. The control unit 60 then operates the workpiece rotation motor Mw and the Z-axis movement motor Mz to move the workpiece W in the Z-axis direction while rotating it, and operates the X-axis movement motor Mx to bring the non-driven tools Tx, Tz into contact with the workpiece W. This makes it possible to machine the outer surface of the workpiece W with the non-driven tool Tx, which is, for example, a cutting tool, or to drill a hole in the workpiece W in the Z-axis direction with the non-driven tool Tz, which is a drill.

[0033] Next, we will explain the case where a tap is attached as the rotary tool Tr and rigid tapping is performed on a workpiece W. Here, rigid tapping refers to tapping performed using a normal holder, rather than an extendable tap holder (float tapper). Therefore, in rigid tapping, it is necessary to synchronize the rotation and feed rate of the rotary tool Tr. As described above, the rotary tool device 70 is provided with a reduction gear mechanism. That is, as shown in FIG. 5 , the spur gears 51, 53, and 56 attached to the output shaft 72 and the rotary tools Tr1 and Tr2 each have 30 teeth, whereas the spur gear 54 attached to the rotary tool Tr3 has 45 teeth, and the spur gear 55 attached to the rotary tool Tr4 has 60 teeth. Therefore, the ratio between the rotational speed of the tool rotation shafts 73 to 76 attached to each rotary tool Tr and the rotational speed of the output shaft 72 differs for some rotary tools, making it difficult to synchronize the rotation and feed rate of each rotary tool Tr for rigid tapping. Therefore, the control unit 60 determines the rotation speed n2 (min) of the output shaft 72 during machining of each rotary tool Tr based on the number of teeth of the gear provided on the rotary tool device 70 and the data instructed to the control unit 60. -1 ) and the feed speed V (mm / min). Then, the control unit 60 calculates the calculated rotation speed n2 (min -1 ) and a feed rate V (mm / min), rigid tapping is performed with the rotary tool Tr. The numbers of teeth of the spur gears 51, 53 to 56 referred to by the control unit 60 are stored in advance in a memory unit or the like serving as a data storage unit as a table shown in FIG. 5, or are input by the user via the operation reception unit 78. The numbers of teeth of the spur gears 51, 53 to 56 are association data that associates the rotational speed n2 of the output shaft 72 with the rotational speed of the rotary tool Tr.

[0034] Hereinafter, with reference to the flowchart (FIG. 6), a rigid tapping process performed by the rotary tool Tr while the control unit 60 is executing the NC program will be described.

[0035] First, the control unit 60 acquires command data instructed to the control unit 60 by the NC program (step S101). The acquired command data includes, for example, data for specifying the rotary tool Tr used in machining (for example, tool number (Tr1 to Tr4)), the rotation speed n1 (min) of the rotary tool Tr during machining shown in FIG. -1 ), the pitch P (mm) of the screw to be formed, and the depth d (mm) of the screw hole to be formed. An example of the command data given to the control unit 60 is shown in FIG. 7(a), and the rotation speed n1 is set to 500 (min -1 ), the screw pitch P = 0.5 (mm), and the screw hole depth d = 10 (mm).

[0036] Next, the control unit 60 acquires the number of teeth of the spur gears 51, 53 to 56 provided on the instructed rotary tool Tr from the table shown in FIG. 5 stored in the storage unit or the like (step S102).

[0037] Next, the control unit 60 executes the macro program to determine the feed rate of the rotary tool Tr during the rigid tapping process (step S103). Here, the feed rate is V (mm / min), the pitch of the rigid tap is P (mm), and the rotation speed of the rotary tool Tr is n1 (min -1 ), the control unit 60 calculates V=P(0.5(mm))×n1(500(min -1 )), the feed rate V is calculated as 250 (mm / min) (Fig. 7(a)).

[0038] Subsequently, the control unit 60 executes the macro program and calculates the instructed speed ratio of the rotary tool Tr (step S104). Here, if the speed ratio of the rotary tool Tr is defined as (number of teeth of the output shaft 72 (Z0)) / (number of teeth of the rotary tool Tr (Zi)), the speed ratio of each rotary tool Tr is calculated as follows from the table shown in FIG. 5 stored in a memory unit or the like. Speed ​​ratio of rotating tool Tr1 i1 = 30 / 30 = 1.0 Speed ​​ratio of rotary tool Tr2 i2 = 30 / 30 = 1.0 Speed ​​ratio of rotary tool Tr3 i3 = 30 / 45 = 0.67 Speed ​​ratio of rotary tool Tr4 i4 = 30 / 60 = 0.5

[0039] Next, the control unit 60 executes the macro program to correct the rotation speed of the output shaft 72 of the tool rotation motor Mt (step 105). -1 ) is a step of appropriately correcting the rotation speed n2 of the output shaft 72. Specifically, the control unit 60 calculates the rotation speed n2 of the output shaft 72 from "rotation speed n1 of the rotating tool Tr / speed ratio i." That is, the control unit 60 calculates the rotation speed n2 of the output shaft 72 by multiplying the rotation speed n1 of the rotating tool Tr by the reciprocal of the speed ratio i (a value according to the speed ratio i).

[0040] When the commanded rotating tool is the rotating tool Tr1 or the rotating tool Tr2, the control unit 60 sets the rotation speed of the output shaft n2=500 / 1.0=500(min -1 ) is calculated (FIG. 7(b)). When the speed ratio is 1.0, the rotation speed n1 of the rotating tool Tr and the rotation speed n2 of the output shaft 72 are the same, so the rotation speed n1 of the rotating tool Tr may be replaced with the rotation speed n2 of the output shaft 72 without multiplying the rotation speed n1 of the rotating tool Tr by the reciprocal of the speed ratio i.

[0041] When the commanded rotary tool is the rotary tool Tr3, the control unit 60 sets the rotation speed of the output shaft 72 to n2=500 / 0.67=750 (min -1 ) is calculated (Figure 7(b)). When the commanded rotary tool is the rotary tool Tr4, the control unit 60 sets the rotation speed of the output shaft 72 to n2=500 / 0.5=1000 (min -1 ) is calculated (Figure 7(b)). The rotation speed n2 of the output shaft 72 calculated in this manner is calculated with less cancellation, and may differ slightly from the result calculated directly using the formula shown.

[0042] The control unit 60 rotates the output shaft 72 at the rotation speed n2 calculated in this way, thereby rotating the commanded rotary tools Tr1, Tr2, Tr3, and Tr4 at the desired rotation speed n1=500 (min -1 ), and rigid tapping is performed at a feed rate of 250 (mm / min) (S106). Specifically, when rigid tapping is performed, the control unit 60 operates the Y-axis movement motor My to move the tool holding unit 30 so that the selected rotary tool Tr is at a desired height relative to the workpiece W. Then, the control unit 60 operates the Z-axis movement motor Mz to move the workpiece W in the Z-axis direction to a position where tapping is performed and stops the workpiece W. Then, the control unit 60 operates the tool rotation motor Mt and the X-axis movement motor Mx to rotate the rotary tool Tr at a rotation speed n1 and feed it in the X-axis direction at a feed rate V. In this way, tapping is performed on the workpiece W. In this way, by correcting the rotation speed of the output shaft 72 in accordance with the number of teeth of the spur gears 51, 53 to 56, the rotation speed and feed rate of each rotary tool Tr can be synchronized in rigid tapping. Note that, before tapping, a pilot hole is drilled in the workpiece W. The tool used to drill the pilot hole is a drill that is separate from the rotary tool Tr used to perform the tapping.

[0043] Furthermore, even when a drill or a milling cutter is used as the rotary tool Tr, appropriate machining can be achieved with each rotary tool Tr by correcting the rotational speed of the output shaft 72 according to the number of teeth of the spur gears 51, 53-56. When performing drilling or milling, the control unit 60 operates the Y-axis movement motor My to move the tool holder 30 so that the selected rotary tool Tr is at a desired height relative to the workpiece W. The control unit 60 then operates the Z-axis movement motor Mz to move the workpiece W in the Z-axis direction and stop it. The control unit 60 then operates the tool rotation motor Mt and the X-axis movement motor Mx to rotate the rotary tool Tr at a rotational speed n1 and bring it into contact with the workpiece W. Furthermore, as necessary, the control unit 60 also operates the work rotation motor Mw to rotate the workpiece W or the Y-axis movement motor My to move the rotary tool Tr in the Y-axis direction. This allows, for example, a rotary tool Tr such as a drill to drill a hole in the workpiece W in the X-axis direction, or a rotary tool Tr such as a milling cutter to drill a groove in the workpiece W.

[0044] (effect) According to the embodiment described above, the following effects are achieved. (1) In the above embodiment, the system includes a plurality of rotating tools Tr for machining the workpiece W, a first actuator (tool rotation motor Mt) that outputs power to rotate the plurality of rotating tools Tr, and a power transmission mechanism (spur gears 51-56) that transmits the power output by the first actuator (tool rotation motor Mt) to simultaneously rotate the plurality of rotating tools Tr, and the power transmission mechanism (spur gears 51-56) is configured so that the rotational speed of at least some of the plurality of rotating tools Tr that rotate simultaneously is different from the rotational speed of the output shaft 72 of the first actuator (tool rotation motor Mt), and controls the first actuator (tool rotation motor Mt) so that each of the plurality of rotating tools Tr can rotate at the rotational speed commanded to the control unit 60. This configuration provides the following advantages (a) to (e). (a) When performing machining that places a load on the rotary tool Tr, it is possible to use a rotary tool Tr with a slow rotation speed and high torque among the multiple rotary tools Tr. On the other hand, when performing machining that places less load on the rotary tool, it is possible to use a rotary tool Tr with a fast rotation speed among the multiple rotary tools Tr, thereby increasing the machining speed. In this way, it is possible to use multiple rotary tools appropriately while taking into consideration various machining conditions. (b) Even if the power transmission mechanism is configured so that the rotational speed of at least some of the rotating tools Tr differs from the rotational speed of the output shaft 72 of the first actuator (tool rotation motor Mt), each of the multiple rotating tools Tr can rotate at the rotational speed commanded to the control unit 60. Therefore, the desired machining can be performed with high precision with each of the multiple rotating tools Tr. (c) Furthermore, since each of the multiple rotating tools Tr can be set to the rotation speed commanded to the control unit 60, even if there are many variations in rotation speed during various machining operations, it is possible to deal with these by appropriately controlling the rotation speed of each rotating tool Tr without separately increasing the number of rotating tools Tr. This makes it possible to prevent the rotary tool device 70 from becoming larger. (d) Furthermore, since any rotating tool Tr can be set to the rotation speed commanded to the control unit 60, the degree of freedom in arranging the rotating tools Tr can be increased. Also, even if two rotating tools are too large to be arranged adjacent to each other and therefore cannot be used for machining, the present invention makes it possible to perform machining by arranging the two rotating tools at positions apart from each other. (e) In addition, the degree of freedom in arranging the rotary tools Tr is increased, making it easier to arrange the rotary tools Tr in accordance with the order of the machining steps of the rotary tools Tr. As a result, the time required to call up the rotary tools Tr during machining can be reduced, thereby shortening the machining time.

[0045] (2) In the machine tool according to the above embodiment, a second actuator (motor Mx for X-axis movement) is provided that outputs power for feeding a plurality of rotary tools Tr toward a workpiece W, and at least one of the plurality of rotary tools Tr is a tap, and the rotation by the first actuator (motor Mt for tool rotation) and the feeding by the second actuator (motor Mx for X-axis movement) are synchronized to perform tapping on the workpiece. With this configuration, the rotation and feed of the rotary tool Tr can be synchronized, making it possible to perform rigid tapping without using a tap holder with an extendable function (float tapper).Furthermore, this type of rigid tapping can be performed with all rotary tools Tr.

[0046] (3) In the machine tool according to the above embodiment, a data storage unit (e.g., a memory unit in the control unit 60) is provided that stores associated data (e.g., the number of teeth of the spur gears 51, 53 to 56) that associates the rotational speed n2 of the output shaft 72 of the first actuator (motor Mt for rotating tools) with the rotational speed n1 of the multiple rotating tools Tr, and the first actuator (motor Mt for rotating tools) is controlled based on the associated data (e.g., the number of teeth of the spur gears 51, 53 to 56) so that the multiple rotating tools Tr rotate at the rotational speed n1 instructed to the control unit 60. With this configuration, even when the rotary tool device 70 of the machine tool 1 is replaced with another one, the replacement work can be simplified by simply rewriting the associated data stored in the data storage unit as new information. Furthermore, when controlling the first actuator, the control unit 60 can perform machining under appropriate conditions by referring to the rewritten associated data.

[0047] (4) In the machine tool according to the above embodiment, the rotational speed n2 of the output shaft 72 of the first actuator (motor Mt for rotating tools) is corrected by multiplying the rotational speed of the commanded rotating tool Tr by a value corresponding to the speed ratio between the output shaft 72 of the first actuator (motor Mt for rotating tools) and the rotating tool Tr commanded to the control unit 60 among the multiple rotating tools Tr, based on related data (for example, the number of teeth of spur gears 51, 53 to 56). According to this configuration, by the simple method of multiplying the rotation speed of the rotating tool Tr by a value corresponding to the speed ratio, it becomes possible to rotate each of the rotating tools Tr at the rotation speed instructed to the control unit 60. Furthermore, the calculation of the rotation speed can be performed by the simple method of multiplying a value, which simplifies the control.

[0048] (5) In the machine tool according to the above embodiment, a feed rate V is calculated based on the rotational speed n1 of the rotary tool Tr used for tapping commanded to the control unit 60 and the thread pitch P commanded to the control unit 60, and the second actuator (X-axis moving motor Mx) is operated to feed the rotary tool Tr at the calculated feed rate V. According to this configuration, the control unit 60 automatically calculates the feed speed V based on the rotation speed n1 commanded to the control unit 60 of the rotary tool Tr and the thread pitch P, thereby eliminating the need for the operator to perform the calculation himself and simplifying the command content to the machine tool 1.

[0049] (Embodiment 2) Next, a machine tool 1 according to a second embodiment will be described, in which the number of teeth of the power transmission mechanism (spur gears 51 to 56) is different from that of the first embodiment. Note that in this embodiment, only the number of teeth of the gears is different, and the other configurations are the same as those of the above-described embodiment, so that corresponding configurations are given common reference numerals and redundant explanations will be omitted.

[0050] In this embodiment, as shown in FIG. 8 , the number of teeth of the spur gear 51 on the output shaft 72 is different from the number of teeth of all the spur gears 53 to 56 attached to the rotary tools Tr. Specifically, the spur gears 53, 54, and 56 attached to the rotary tools Tr1, Tr2, and Tr3 have fewer teeth than the spur gear 51 attached to the output shaft 72. That is, the spur gears 53, 54, and 56 constitute a speed-increasing gear mechanism, which increases the rotation speed of the rotary tools Tr1, Tr2, and Tr3. On the other hand, the spur gear 55 attached to the rotary tool Tr4 has more teeth than the spur gear 51 attached to the output shaft 72. That is, the spur gear 55 constitutes a speed-reducing gear mechanism, which decelerates the rotary tool Tr4 to increase its torque. In this way, the machine tool 1 of this embodiment 2 is provided with both a speed-increasing gear mechanism and a speed-reducing gear mechanism.

[0051] Next, a case will be described in which a tap is attached as the rotary tool Tr and rigid tapping is performed on the workpiece W. The control unit 60 determines the rotation speed n2 (min) of the output shaft 72 during processing of each rotary tool Tr based on the number of teeth of the gear provided on the rotary tool device 70 and the data commanded to the control unit 60. -1 ) and the feed speed V (mm / min). Then, the control unit 60 calculates the calculated rotation speed n2 (min -1 ) and a feed rate V (mm / min), rigid tapping is performed with the rotary tool Tr. The numbers of teeth of the spur gears 51, 53 to 56 referenced by the control unit 60 are stored in advance in a memory unit serving as a data storage unit in the table shown in FIG. 8, or are input by the user via the operation reception unit 78. The numbers of teeth of the spur gears 51, 53 to 56 are association data that associates the rotational speed n2 of the output shaft 72 with the rotational speed of the rotary tool Tr.

[0052] Hereinafter, with reference to the flowchart (FIG. 6), a rigid tapping process performed by the rotary tool Tr while the control unit 60 is executing the NC program will be described.

[0053] First, the control unit 60 acquires command data instructed to the control unit 60 by the NC program (step S101). The acquired command data includes, for example, data for specifying the rotary tool Tr used in machining (for example, tool number (Tr1 to Tr4)), the rotation speed n1 (min) of the rotary tool Tr during machining shown in FIG. -1 ), the pitch P (mm) of the screw to be formed, and the depth d (mm) of the screw hole to be formed. An example of the command data given to the control unit 60 is shown in FIG. 9(a), and the rotation speed n1 is set to 500 (min -1 ), the screw pitch P = 0.5 (mm), and the screw hole depth d = 10 (mm).

[0054] Next, the control unit 60 acquires the number of teeth of the spur gears 51, 53 to 56 provided on the instructed rotary tool Tr from a table shown in FIG. 8 stored in the storage unit or the like (step S102).

[0055] Next, the control unit 60 executes the macro program to determine the feed rate of the rotary tool Tr during the rigid tapping process (step S103). Here, the feed rate is V (mm / min), the pitch of the rigid tap is P (mm), and the rotation speed of the rotary tool Tr is n1 (min -1 ), the control unit 60 calculates V=P(0.5(mm))×n1(500(min -1 )), the feed rate V is calculated as 250 (mm / min) (Fig. 9(a)).

[0056] Subsequently, the control unit 60 executes the macro program and calculates the instructed speed ratio of the rotary tool Tr (step S104). Here, if the speed ratio of the rotary tool Tr is defined as (number of teeth of the output shaft 72 (Z0)) / (number of teeth of the rotary tool Tr (Zi)), the speed ratio of each rotary tool Tr is calculated as follows from the table shown in FIG. 8 stored in the memory unit. Speed ​​ratio of rotating tool Tr1 i1 = 50 / 30 = 1.65 Speed ​​ratio of rotary tool Tr2 i2 = 50 / 40 = 1.25 Speed ​​ratio of rotary tool Tr3 i3 = 50 / 45 = 1.11 Speed ​​ratio of rotary tool Tr4 i4 = 50 / 60 = 0.83

[0057] Next, the control unit 60 executes the macro program to correct the rotation speed of the output shaft 72 of the tool rotation motor Mt (step 105). -1 ) is a step of appropriately correcting the rotation speed n2 of the output shaft 72. Specifically, the control unit 60 calculates the rotation speed n2 of the output shaft 72 from "rotation speed n1 of the rotating tool Tr / speed ratio i." That is, the control unit 60 calculates the rotation speed n2 of the output shaft 72 by multiplying the rotation speed n1 of the rotating tool Tr by the reciprocal of the speed ratio i (a value according to the speed ratio i).

[0058] When the commanded rotary tool is the rotary tool Tr1, the control unit 60 sets the rotation speed n2 of the output shaft 72 to n2=500 / 1.65=300 (min -1 ) is calculated (Figure 9(b)). When the commanded rotary tool is the rotary tool Tr2, the control unit 60 sets the rotation speed of the output shaft 72 to n2=500 / 1.25=400 (min -1 ) is calculated (Figure 9(b)). When the commanded rotary tool is the rotary tool Tr3, the control unit 60 sets the rotation speed of the output shaft 72 to n2=500 / 1.11=450 (min -1 ) is calculated (Figure 9(b)). When the commanded rotary tool is the rotary tool Tr4, the control unit 60 sets the rotation speed of the output shaft 72 as n2=500 / 0.83=600 (min -1 ) is calculated (Figure 9(b)). The rotation speed n2 of the output shaft 72 calculated in this manner is the result of calculation with less cancellation, and differs from the result of calculation directly using the formula shown.

[0059] The control unit 60 rotates the output shaft 72 at the rotation speed n2 calculated in this way, thereby rotating the commanded rotary tools Tr1, Tr2, Tr3, and Tr4 at the desired rotation speed n1=500 (min -1 ), and rigid tapping is performed at a feed rate of 250 (mm / min) (S106). In this way, by correcting the rotational speed of the output shaft 72 in accordance with the number of teeth of the spur gears 51, 53 to 56, the rotational speed and feed rate of each rotary tool Tr can be synchronized during rigid tapping.

[0060] The machine tool 1 according to the second embodiment can also achieve the same effects as those of the first embodiment.

[0061] The present invention is not limited to the above-described embodiments and drawings. Modifications (including the omission of components) can be made as appropriate within the scope of the present invention. An example of a modification will be described below.

[0062] The rotary tool device 70 of this embodiment has been described as a multi-axis rotary tool device 70 having a plurality of rotary tools Tr with their tips facing the +X side, perpendicular to the longitudinal direction (Z-axis direction) of the long workpiece W. However, the rotary tool device to be attached may be of another type, for example, a rotary tool device that can rotate around a B-axis set parallel to the Y-axis and that can change the orientation of the rotary tools Tr.

[0063] Furthermore, the mounting position of the rotary tool device 70 and the direction of movement for machining are not limited to those in the above embodiment. In the above embodiment, the rotary tool device 70 is provided on the -X side of the workpiece insertion portion 31, but it may be provided on the +X side, for example, with the tip of the rotary tool Tr facing either the -X side or the -Z side. Also, the rotary tool device 70 may be provided on the +Y side of the workpiece insertion portion 31 with the tip of the rotary tool Tr facing either the -Y side or the -Z side. The rotary tool device 70 can be mounted in any location depending on the desired machining.

[0064] Although the power transmission mechanism that transmits the power of the tool rotation motor Mt to rotate the rotary tool Tr is described as a gear mechanism, any other transmission mechanism may be used. For example, the power of the tool rotation motor Mt may be transmitted by a belt mechanism.

[0065] Furthermore, in embodiment 1, a constant velocity gear mechanism and a reduction gear mechanism are provided, and in embodiment 2, a reduction gear mechanism and a speed-up gear mechanism are provided, but it is also possible to provide any type of gear mechanism, and only a speed-up gear mechanism may be provided in the rotary tool device 70.

[0066] Furthermore, the rigid tapping process has been described with reference to the flowchart shown in Fig. 6, but as long as there are no inconsistencies in the steps, the order of the steps is not limited to that of the flowchart in Fig. 6 and can be changed as appropriate. For example, the order of the step 103 related to "determining the feed rate" and the step 105 related to "correcting the rotational speed of the output shaft" can be reversed.

[0067] Furthermore, although the rotary tools Tr provided in the rotary tool device 70 are arranged in a single row in the Y-axis direction, other arrangements are also possible, for example, they may be arranged in multiple rows in the X-axis direction. Furthermore, the rotary tools Tr may not only be arranged linearly in the Y-axis direction, but may also be arranged along a curved line or on a jagged line.

[0068] In the above embodiment, the rotation speed of the rotary tools Tr is corrected by multiplying the rotation speed of the output shaft by a "value corresponding to the speed ratio" between the output shaft 72 of the tool rotation motor Mt and the multiple rotary tools Tr. This "value corresponding to the speed ratio" is not limited to a value directly derived from the speed ratio calculated as described above, but also includes a value related to the speed ratio. The value related to the speed ratio may be, for example, the ratio of the number of teeth between the output shaft 72 and the rotary tools Tr, or the ratio of the diameters of the gears provided on the output shaft 72 and the rotary tools Tr. [Explanation of symbols]

[0069] 1...machine tool, 10...workpiece holding portion, 20...Z-axis movement mechanism, 21...Z-axis slide portion, 22...ball screw, 30...tool holding portion, 31...workpiece insertion portion, 40...fixed base, 42...base, 44, 45, 46...non-driven tool mounting portion, 50...XY-axis movement mechanism, 51, 52, 53, 54, 55, 56...spur gear, 57...intermediate shaft, 60...control portion, 66...guide bush, 70...rotary tool device, 71...casing, 72...output shaft, 73, 74, 75, 76...Tool rotation axis, 77...Display unit, 78...Operation reception unit, 80...X-axis movement mechanism, 81...X-axis slide unit, 90...Y-axis movement mechanism, 92...Ball screw, A1...Rotation axis, S...Bed, W...Workpiece, Mt...Tool rotation motor, Mw...Workpiece rotation motor, Mx...X-axis movement motor, Tr, Tr1, Tr2, Tr3, Tr4...Rotating tool, My...Y-axis movement motor, Mz...Z-axis movement motor, Tx, Tz...Non-driven tool

Claims

1. a plurality of rotary tools for machining the workpiece; a first actuator that outputs power for rotating the plurality of rotary tools; a power transmission mechanism that transmits power output by the first actuator to simultaneously rotate the plurality of rotary tools, the power transmission mechanism is configured such that a rotational speed of at least some of the rotary tools among the plurality of rotary tools that rotate simultaneously is different from a rotational speed of the output shaft of the first actuator; controlling the first actuator so that each of the plurality of rotary tools can rotate at a rotation speed instructed by a control unit; Machine tools.

2. a second actuator that outputs power for feeding the plurality of rotary tools toward a workpiece; At least one of the plurality of rotary tools is a tap, and the rotation by the first actuator and the feed by the second actuator are synchronized to perform tapping on the workpiece. The machine tool according to claim 1.

3. a data storage unit that stores association data that associates the rotation speed of the output shaft of the first actuator with the rotation speeds of the plurality of rotary tools; controlling the first actuator based on the associated data so that the plurality of rotary tools rotate at a rotation speed instructed to a control unit; 3. The machine tool according to claim 1 or 2.

4. correcting the rotational speed of the output shaft of the first actuator by multiplying the rotational speed of the commanded rotary tool by a value corresponding to a speed ratio between the output shaft of the first actuator and one of the plurality of rotary tools commanded to the control unit based on the related data; The machine tool according to claim 3.

5. Calculating a feed rate based on a rotation speed commanded to a control unit of a rotary tool used for tapping and a thread pitch commanded to the control unit; activating the second actuator to feed the rotary tool at the calculated feed rate; The machine tool according to claim 2.

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