Rotary table device, machine tool, and brake device

Abstract

To provide a technique capable of regulating rotation of a rotary table, even if power supply is stopped in any one of a state in which rotational motion of the rotary table is regulated and a state in which the rotational motion thereof is permitted.SOLUTION: A rotary table device includes: a support mechanism which rotatably supports a rotary table to a base; and a brake device. A fluid control mechanism provided on the brake device has: a supply flow channel which supplies a fluid pressure to the brake mechanism through a connection flow channel; a discharge flow channel which discharges a fluid pressure from the brake mechanism through the connection flow channel; a first electromagnetic valve which is configured to selectively switch a supply state in which the connection flow channel and the supply flow channel are communicated with each other, and a discharge state in which the flow channels are not communicated with each other; a branch flow channel which is connected to the connection flow channel and to which an accumulator is connected; and a second electromagnetic valve which is provided in a portion between a connection position between the connection flow channel and the branch flow channel and the first electromagnetic valve out of the connection flow channel, and is configured to open the connection flow channel by electromagnetic force during energization, and close the connection flow channel by spring force during non-energization.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a rotary table device, a machine tool, and a brake device. [Background technology]

[0002] Regarding a rotary table device equipped with a rotary table, Patent Document 1 discloses a technique for maintaining a state in which the rotational motion of a rotating body is restricted when the power supply to a machine tool is stopped due to a power outage. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-163959 A Summary of the Invention [Problem to be solved by the invention]

[0004] There is a need for a technique that not only maintains the regulated state when the power supply is stopped in a regulated state in which the rotational movement of the turntable is restricted, but also switches from a permitted state to a regulated state when the power supply is stopped in a permitted state in which the rotational movement of the turntable is permitted. Furthermore, there is a need for a technique that quickly switches from the permitted state to the regulated state. [Means for solving the problem]

[0005] The present disclosure can be realized in the following forms.

[0006] (1) According to a first aspect of the present disclosure, there is provided a rotary table device. The rotary table device includes a base, a rotary table, a support mechanism that supports the rotary table rotatably around an axis along a vertical direction relative to the base, a rotation drive device that drives and rotates the rotary table, and a brake device configured to regulate the rotation of the rotary table. The brake device includes a brake mechanism that is actuated by the supply of fluid pressure to stop the rotation of the rotary table, and a fluid control mechanism configured to supply fluid pressure to the brake mechanism. The fluid control mechanism includes a connection flow path having one end connected to the brake mechanism, a supply flow path connected to a fluid pressure generating unit that generates fluid pressure and supplies fluid pressure to the brake mechanism via the connection flow path, a discharge flow path that discharges fluid pressure from the brake mechanism via the connection flow path, a first solenoid valve that connects the other end of the connection flow path to the supply flow path and the discharge flow path and is configured to selectively switch between a supply state in which the connection flow path and the supply flow path are connected to a discharge state in which the connection flow path and the discharge flow path are connected to a first solenoid valve, a branch flow path connected to the connection flow path and to an accumulator configured to be able to hold fluid pressure for operating the brake mechanism, and a second solenoid valve that is provided in a portion of the connection flow path between a connection position where the connection flow path and the branch flow path are connected and the first solenoid valve, and configured to open the connection flow path by electromagnetic force when energized and close the connection flow path by spring force when energized. In this configuration, for example, when the power supply to the rotary table device or the fluid control mechanism is cut off due to a power outage, the second solenoid valve provided in the connection flow path between the first solenoid valve and the connection position closes the connection flow path. Therefore, even if the power supply to the rotary table device is cut off in either the supply state or the discharge state, the brake mechanism can be operated by the fluid pressure of the accumulator to regulate the rotation of the rotary table. In addition, since the second solenoid valve is an on-off valve, it can close the connection flow path more quickly when the power supply is cut off, compared to a directional control valve such as the first solenoid valve. (2) In the above embodiment, the fluid control mechanism may include a third solenoid valve that is provided in the branch flow path and closes the branch flow path by electromagnetic force when energized and opens the branch flow path by spring force when de-energized. In this embodiment, the branch flow path is closed by the third solenoid valve, so that a drop in the fluid pressure of the accumulator can be suppressed. In addition, when the power supply to the rotary table device or the fluid control mechanism is cut off, the branch flow path is opened by the third solenoid valve, so that the brake mechanism can be operated by the fluid pressure of the accumulator. Since the third solenoid valve is an on-off valve, the branch flow path can be quickly opened when the power supply is cut off. (3) In the above embodiment, the branch flow path may include a bypass flow path connecting the upstream and downstream of the third solenoid valve, and a check valve provided in the bypass flow path to regulate the supply of fluid pressure from the accumulator to the connecting flow path and allow the supply of fluid pressure from the connecting flow path to the accumulator. In this embodiment, in a supply state, the branch flow path is closed by the third solenoid valve, so that the fluid pressure generated by the fluid pressure generating unit can be supplied to the accumulator via the bypass flow path. Therefore, the fluid pressure in the accumulator can be effectively maintained. (4) In the above embodiment, the second solenoid valve may close the connecting passage faster than the third solenoid valve opens the branch passage. In this embodiment, when the power supply to the rotary table device or the fluid control mechanism is interrupted, the second solenoid valve closes the connecting passage before the third solenoid valve opens the branch passage. Therefore, when the power supply to the rotary table device or the fluid control mechanism is interrupted, the fluid pressure in the accumulator can be supplied to the brake mechanism more efficiently. (5) In the above embodiment, the support mechanism may be a hydrostatic bearing. In this embodiment, the rotary table can be rotatably supported by the hydrostatic bearing. Furthermore, even if the power supply is interrupted in either the supply state or the discharge state, the rotation of the rotary table is restricted, so that wear and damage to the support mechanism and the rotary table can be suppressed even if the support mechanism and the rotary table come into direct contact with each other. (6) According to a second embodiment of the present disclosure, a machine tool is provided. The machine tool includes a rotary table device according to any of the above embodiments, a spindle device to which a tool bit for machining a work supported by the rotary table device and a drill for machining the work are replaceably attached, a guide table for supporting the spindle device and guiding the spindle device in a guide direction intersecting a horizontal plane, a vertical feed device for feeding the spindle device in the guide direction relative to the guide table, a cross beam for guiding the guide table in the horizontal direction, a horizontal feed device for feeding the guide table in the horizontal direction relative to the cross beam, and a control device for controlling the rotary drive device, the fluid control mechanism, the vertical feed device, and the horizontal feed device. With this embodiment, the rotary table is permitted to rotate when the tool bit is used to turn the work, and the rotary table is restricted to rotate when the drill is used to drill the work, thereby allowing the machine tool to appropriately cut and drill the work. (7) In the machine tool of the above aspect, the control device may control the fluid control mechanism so as to permit rotation of the rotary table by not supplying the fluid pressure to the brake mechanism when the workpiece is turned with the cutting tool, and to restrict rotation of the rotary table by supplying the fluid pressure to the brake mechanism when the workpiece is drilled with the drill. With this aspect, the workpiece can be appropriately turned and drilled under the control of the control device. The present disclosure may be realized in various forms other than the rotary table device and the machine tool, for example, in a brake device that regulates the rotation of a rotating body, a fluid control mechanism, a control method for a rotary table device, a control method for a machine tool, a control method for a fluid control mechanism, a method for machining a workpiece, a computer program, and a non-transitory recording medium on which a computer program is recorded. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram of a machine tool as viewed from the front. [Diagram 2] FIG. 1 is a block diagram showing a schematic configuration of a machine tool. [Diagram 3] FIG. 2 is a schematic cross-sectional view of a rotary table device. [Figure 4] FIG. 2 is a cross-sectional view illustrating a brake device. [Diagram 5] FIG. 2 is a diagram illustrating a brake hydraulic circuit. [Figure 6] FIG. 4 is an explanatory diagram showing a control pattern of the fluid control mechanism. [Figure 7] 13 is a flowchart of a processing process. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] A. First embodiment: FIG. 1 is a schematic diagram of a machine tool 10 in the first embodiment as viewed from the front. In FIG. 1, an arrow representing the Y axis is shown. The Y axis is a coordinate axis parallel to the vertical direction. The arrow representing the Y axis in FIG. 1 and the arrow representing the Y axis in other figures point in the same direction. When specifying a direction, a positive direction indicated by the arrow is indicated by "+" and a negative direction opposite to the direction indicated by the arrow is indicated by "-", and a positive and negative sign are used in combination to indicate the direction. Hereinafter, the +Y direction is also referred to as "up" and the -Y direction is also referred to as "down". The direction along the horizontal plane is also referred to as the horizontal direction.

[0009] Machine tool 10 includes a rotary table device 50 having a rotary table 52 that supports workpiece 120, a first gripping mechanism 30 and a second gripping mechanism 40 that grip a processing tool for processing workpiece 120, a cross beam 20 that supports first gripping mechanism 30 and second gripping mechanism 40 so that they can slide along the horizontal direction, three columns 12, 13, and 14, a control device 90 that controls the operation of machine tool 10, a first oil supply unit 94, and a second oil supply unit 96. Workpiece 120 may be any type, and is, for example, an outer ring or inner ring of a bearing used in a wind power generator or the like.

[0010] The columns 12, 14 at both ends are erected on both sides of the rotary table 52. The central column 13 is erected on the rear side of the rotary table 52. A cross beam 20 is supported by the three columns 12, 13, 14.

[0011] The cross beam 20 is a member extending in the horizontal direction. An LM (Linear Motion) guide 201, a first horizontal feed device 21, and a second horizontal feed device 22 are fixed to the front side of the cross beam 20. The cross beam 20 guides the first gripping mechanism 30 and the second gripping mechanism 40 in the horizontal direction by the LM guide 201. The first horizontal feed device 21 has a ball screw 211 and a servo motor 212, and feeds the first gripping mechanism 30 in the horizontal direction relative to the cross beam 20. The screw shaft of the ball screw 211 is arranged along the horizontal direction and is connected to the output shaft of the servo motor 212 via a coupling (not shown). The second horizontal feed device 22 has a ball screw 221 and a servo motor 222, and feeds the second gripping mechanism 40 in the horizontal direction relative to the cross beam 20. The screw shaft of the ball screw 221 is arranged along the horizontal direction and is connected to the output shaft of the servo motor 222 via a coupling (not shown).

[0012] The first gripping mechanism 30 has a first guide table 31, a first vertical feed device 32, a spindle device 34, and a first horizontal slider 36. The first gripping mechanism 30 performs cutting or drilling of the workpiece 120 according to the type of the first processing tool 35 attached to one end side of the spindle 343 of the spindle device 34. In this embodiment, the spindle device 34 has a spindle 343 that rotates around the axis AX1, and the spindle device 34 has a built-in servo motor 341 that rotates the spindle 343. At least a bit and a drill are interchangeably attached to the spindle 343 as the first processing tool 35. FIG. 1 shows a state in which a bit is attached as the first processing tool 35, and turning is performed with the bit facing the workpiece 120 side, the rotation of the spindle 343 stopped, and the rotary table 52 rotated. When a drill is attached as the first processing tool 35, the spindle device 34 rotates the first processing tool 35 about its axis AX1 by the rotational driving force of the servo motor 341, and can perform drilling while the rotary table 52 is stopped. Note that, hereinafter, the first guide table 31 and the first vertical feed device 32 are also simply referred to as the guide table and the vertical feed device, respectively.

[0013] The first horizontal slider 36, which is circular when viewed from the front, is guided in the horizontal direction by the LM guide 201 on the front side of the cross beam 20. The first horizontal slider 36 is fixed to a ball screw nut of a ball screw 211. The first guide base 31, which is circular when viewed from the front, is supported rotatably on the front side of the first horizontal slider 36. More specifically, the first guide base 31 rotates relative to the first horizontal slider 36 about a rotation axis RA1 in the direction indicated by the arrow Y1a by the rotational driving force of the servo motor 331.

[0014] The vertical guide base 38 is attached to the front of the first guide base 31, and the vertical guide base 38 guides and supports the vertical feed base 381 in a first guide direction intersecting with the rotation axis RA1. The first vertical feed device 32 feeds the vertical feed base 381 in the first guide direction relative to the vertical guide base 38. In this embodiment, the vertical feed base 381 is guided in the axis AX1 direction by an LM guide 311 provided on the front side of the vertical guide base 38, and is fed in the axis AX1 direction relative to the vertical guide base 38 by the first vertical feed device 32. The first vertical feed device 32 in this embodiment is configured as a ball screw mechanism, and has a ball screw 321 fixed to the vertical guide base 38 and a servo motor 322. The screw shaft of the ball screw 321 is arranged along the axis AX1 direction and is connected to the output shaft of the servo motor 322 via a coupling (not shown). The ball screw nut of the ball screw 321 is connected to the vertical feed base 381. The spindle device 34 is attached to the front surface of the vertical feed table 381. Hereinafter, the first guide direction will also be simply referred to as the guide direction.

[0015] With the configuration of the first gripping mechanism 30 described above, the first guide table 31 in this embodiment is guided horizontally together with the first horizontal slider 36 by the cross beam 20. Also, the spindle unit 34 is rotated together with the first guide table 31 about the rotation axis RA1, whereby the inclination of the spindle unit 34 with respect to the Y-axis is adjusted.

[0016] The second gripping mechanism 40 has a second guide table 41, a second vertical feed device 42, a grinding wheel head 44, and a second horizontal slider 46. The second gripping mechanism 40 performs special shape processing to process the workpiece 120 into a special shape by grinding the workpiece 120 using a second processing tool 45 attached to a rotating shaft portion 47 of the grinding wheel head 44. In the example shown in FIG. 1, the second processing tool 45 is a grinding wheel. The rotating shaft portion 47 can rotate the second processing tool 45 around its axis AX2 by transmitting the rotational driving force of the grinding wheel drive motor 471 to the rotating shaft portion 47 via a pulley 473.

[0017] The second horizontal slider 46, which is circular when viewed from the front, is guided in the horizontal direction by the LM guide 201 on the front side of the cross beam 20, similar to the first horizontal slider 36. The second horizontal slider 46 is fixed to a ball screw nut of a ball screw 221. A second guide base 41, which is circular when viewed from the front, is supported rotatably on the front side of the second horizontal slider 46. More specifically, the second guide base 41 rotates relative to the second horizontal slider 46 about a rotation axis RA2 in the direction indicated by arrow Y1b by the rotational driving force of a servo motor 431.

[0018] The vertical guide base 48 is attached to the front of the second guide base 41, and the vertical guide base 48 guides and supports the vertical feed base 481 in a second guide direction intersecting with the rotation axis RA2. The second vertical feed device 42 feeds the vertical feed base 481 in the second guide direction relative to the vertical guide base 48. In this embodiment, the vertical feed base 481 is guided along a direction d1 perpendicular to the axis AX2 by an LM guide 411 provided on the front side of the vertical guide base 48, and is fed along the direction d1 relative to the vertical guide base 48 by the second vertical feed device 42. The second vertical feed device 42 in this embodiment is configured as a ball screw mechanism, and has a ball screw 421 fixed to the vertical guide base 48 and a servo motor 422. The screw shaft of the ball screw 421 is arranged along the direction d1 and is connected to the output shaft of the servo motor 422 via a coupling (not shown). The ball screw nut of the ball screw 421 is connected to the vertical feed base 481. The grindstone head 44 is attached to the front of the vertical feed table 481 .

[0019] With the configuration of the second gripping mechanism 40 described above, the second guide table 41 in this embodiment is guided horizontally together with the second horizontal slider 46 by the cross beam 20. Also, the wheel head 44 is rotated together with the second guide table 41 about the rotation axis RA2, whereby the inclination of the wheel head 44 with respect to the Y-axis is adjusted.

[0020] The rotary table device 50 includes a base 110 , a rotary table 52 , a support mechanism 60 , a rotary drive device 130 , and a brake device 140 .

[0021] The base 110 is cylindrical and is disposed on the installation surface so that its lower surface contacts the installation surface. The base 110 supports the rotary table 52 rotatably about an axis RX along the vertical direction. A bearing, which is a support mechanism 60 that rotatably supports the rotary table 52, is provided between the base 110 and the rotary table 52. The bearing in this embodiment is a hydrostatic bearing. The hydrostatic bearing will be described in detail later.

[0022] The base 110 has a disk-shaped member main body 62 and a bearing member 70 fixed to the upper surface side of the member main body 62. The rotary table 52 has a table main body 53, a chuck 54 installed on the upper surface of the table main body 53, and a rotating shaft 180 inserted into the bearing member 70. The table main body 53 is disk-shaped. A plurality of chucks 54 are arranged at equal intervals in the circumferential direction of the table main body 53. The chuck 54 grips the workpiece 120 placed on the table main body 53. Details of the rotating shaft 180 will be described later.

[0023] The rotary drive device 130 drives the rotary table 52 to rotate around an axis RX along the vertical direction. The rotary drive device 130 in this embodiment has a table side gear 139, a servo motor 131, and a reduction mechanism 133 having a plurality of gears. The servo motor 131 and the reduction mechanism 133 are installed on an installation surface around the rotary table 52. The rotary drive device 130 rotates the rotary table 52 by transmitting the rotational driving force of the servo motor 131 to the rotary table 52 via the reduction mechanism 133 and the table side gear 139. The table side gear 139 is fixed to the lower surface of the rotary table 52. The table side gear 139 meshes with the final gear 134 of the reduction mechanism 133.

[0024] The brake device 140 is configured to be able to regulate the rotation of the turntable 52. The brake device 140 has a brake mechanism 141 and a fluid control mechanism 150. The brake mechanism 141 is actuated by the supply of fluid pressure to stop the rotation of the turntable 52. The fluid control mechanism 150 is configured to be able to supply fluid pressure to the brake mechanism 141. In this embodiment, the first oil supply unit 94 functions as the fluid control mechanism 150, which will be described later.

[0025] The first oil supply unit 94 has an oil tank that stores hydraulic oil for operating the brake mechanism 141, and pressurizes the hydraulic oil and supplies it to the brake mechanism 141. The second oil supply unit 96 has an oil tank that stores bearing oil for the bearings of the support mechanism 60, and pressurizes the bearing oil and supplies it to the bearings of the support mechanism 60.

[0026] FIG. 2 is a block diagram showing a schematic configuration of the machine tool 10 in this embodiment. As shown in FIG. 2, the control device 90 has a CNC (Computerized Numerical Control) device 901 that performs program control, a PLC (Programmable Logic Controller) 902 that performs sequence control, and a power switch (not shown) that turns on or off the power of the entire machine tool 10. The CNC device 901 is composed of a computer including one or more processors 91, a memory 92 consisting of a main storage device and an auxiliary storage device, an external interface 93 that inputs and outputs signals to and from the outside, and an internal bus. The processor 91, the memory 92, and the external interface 93 are connected via the internal bus so as to be able to communicate bidirectionally. The CNC device 901 has a display unit 97 and an operation panel 98, and the display unit 97 and the operation panel 98 are connected to the internal bus via an interface 99. The operation panel 98 has, for example, a keyboard (not shown) as an input device, an emergency stop button 961, and an operation preparation button 962. The PLC 902 is electrically connected to the CNC device 901, the emergency stop button 961, the operation preparation button 962, the fluid control mechanism 150, and the hydraulic pump group PG. The hydraulic pump group PG includes hydraulic pumps 159, 811, which will be described later. The memory 92 stores, for example, a machining program for machining the workpiece W. The processor 91 executes the machining program stored in the memory 92 to sequentially perform various machining operations on the workpiece W. When a code indicating the type of machining described in the machining program is read, an execution program for each code is pre-installed, which issues a command to activate the brake and a command to release the brake according to the type of code. The CNC device 901 issues a command to activate the brake and a command to release the brake to the PLC 902 as a result of the execution program. A sequence for activating the brake and a sequence for releasing the brake are installed in the PLC 902.

[0027] The above-mentioned servo motors 131, 212, 222, 322, 331, 341, 422, 431 and the grindstone drive motor 471 are electrically connected to drive circuits 132, 213, 223, 323, 332, 342, 423, 432, 472, respectively, and are controlled by the control device 90 via each drive circuit.

[0028] FIG. 3 is a diagram showing a cross section of the rotary table device 50. In addition to the rotary table device 50, FIG. 5 shows a second oil supply unit 96. In this embodiment, a support mechanism 60 is provided between the base 110 and the rotary table 52, and the support mechanism 60 has thrust bearings 69, 79 that support the rotary table 52 in the thrust direction and a radial bearing 75 that supports the rotary table 52 in the radial direction. The thrust bearing 69 is provided between the lower surface of the table main body 53 and the upper surface of the member main body 62. The thrust bearing 79 is provided between the upper surface of the flange portion 184 of the rotary shaft 180 and the lower surface of the bearing member 70. The radial bearing 75 is provided between the outer periphery of the rotary shaft 180 and the inner periphery of the bearing member 70.

[0029] As shown in FIG. 3, the thrust bearing 69 has a plurality of bearing pockets 63, 66 provided on the upper surface of the member body 62 and supplied with pressure oil, and a throttle provided between the lower surface (land) of the table body 53 and the upper surface (land) of the member body 62 and formed around the bearing pockets 63, 66. The bearing pocket 63 is disposed on the inside of the bearing pocket 66 in the radial direction of the member body 62. Hereinafter, the bearing pocket 63 is also referred to as the inner peripheral pocket 63, and the bearing pocket 66 is also referred to as the outer peripheral pocket 66. In this embodiment, the plurality of inner peripheral pockets 63 are provided at equal intervals so as to equally divide the member body 62 along its circumferential direction. In addition, in this embodiment, the plurality of outer peripheral pockets 66 are provided at equal intervals outside the inner peripheral pockets 63 so as to equally divide the member body 62 along its circumferential direction.

[0030] Each of the bearing pockets 63, 66 is configured as a concave pocket with the upper surface of the member body 62 recessed downward. A nozzle (not shown) for discharging pressurized bearing oil supplied from the second oil supply unit 96 is provided at the bottom of the bearing pockets 63, 66. When the pressurized bearing oil is discharged into the bearing pockets 63, 66 through the nozzle, the rotary table 52 is slightly lifted so that its lower surface is separated from the upper surface of the member body 62. At this time, when the lower surface of the table body 53 and the upper surface of the member body 62 are separated, the hydraulic pressure in the throttle formed around the bearing pockets 63, 66 is lowered, so that the lower surface of the table body 53 and the upper surface of the member body 62 tend to approach each other. Conversely, when the lower surface of the table body 53 and the upper surface of the member body 62 are closer to each other, the hydraulic pressure in the throttle formed around the bearing pockets 63, 66 is higher, so that the lower surface of the table body 53 and the upper surface of the member body 62 tend to separate from each other. In this manner, the thrust bearing 69, which is a hydrostatic bearing, supports the rotary table 52 in the vertical direction by the hydrostatic pressure of the bearing oil.

[0031] 3, the rotating shaft 180 has an upper end 181 fixed to the table main body 53 and a flange portion 184 at its lower end. An intermediate portion 183 of the rotating shaft 180 between the upper end 181 and the flange portion 184 is inserted into the bearing member 70 as described below. The rotating shaft 180 rotates around the axis RX together with the table main body 53 by the rotational driving force of the rotation drive device 130.

[0032] The bearing member 70 is cylindrical, and is disposed between the member body 62 and the table body 53 of the rotary table 52, and is fixed to the upper surface of the member body 62 at the center of the member body 62. An intermediate portion 183 of the rotary shaft 180 is inserted into the bearing member 70. As shown in Figs. 3 and 4, the bearing member 70 has a plurality of bearing pockets 71 and a plurality of bearing pockets 76 that suppress the floating of the rotary table 52.

[0033] The radial bearing 75 is provided on the inner circumference of the bearing member 70, and has a plurality of bearing pockets 71 and a throttle provided between the outer circumference (land) of the rotating shaft 180 and the inner circumference (land) of the bearing member 70, and formed around the bearing pockets 71. Each bearing pocket 71 faces the outer circumference surface of the intermediate portion 183 inserted into the bearing member 70. In this embodiment, the plurality of bearing pockets 71 are provided at equal intervals so as to equally divide the bearing member 70 along its circumferential direction. Each bearing pocket 71 is configured as a concave pocket in which the inner circumference surface of the bearing member 70 is recessed toward the outside in the radial direction. A nozzle (not shown) is provided at the bottom of each bearing pocket 71 for discharging pressurized bearing oil supplied from the second oil supply unit 96. The pressurized bearing oil discharged into the pocket through the nozzle generates a static pressure between the outer circumference surface of the rotating shaft 180 and the inner circumference surface of the bearing member 70, which pushes the rotating shaft 180 toward the inside in the radial direction. When the outer periphery of the rotating shaft 180 and the inner periphery of the bearing member 70 move away from each other on one side in the radial direction, the hydraulic pressure in the throttle formed around the bearing pocket 71 decreases, so that the outer periphery of the rotating shaft 180 and the inner periphery of the bearing member 70 move closer to each other on the other side in the radial direction. Conversely, when the outer periphery of the rotating shaft 180 and the inner periphery of the bearing member 70 move closer to each other, the hydraulic pressure in the throttle formed around the bearing pocket 71 increases, so that the outer periphery of the rotating shaft 180 and the inner periphery of the bearing member 70 move away from each other. In this way, the radial bearing 75, which is a hydrostatic bearing, supports the rotating shaft 180 in the radial direction while maintaining a balance in the radial direction by the hydrostatic pressure of the bearing oil. As a result, the rotating shaft 180 can rotate stably around the axis RX.

[0034] The thrust bearing 79, which suppresses the lifting of the rotary table 52, is provided on the lower surface of the bearing member 70 and has a plurality of bearing pockets 76 to which pressure oil is supplied, and a throttle provided between the upper surface (land) of the flange portion 184 and the lower surface (land) of the bearing member 70 and formed around the bearing pockets 76. Each bearing pocket 76 faces the upper surface of the flange portion 184. In this embodiment, the plurality of bearing pockets 76 are provided at equal intervals so as to equally divide the bearing member 70 along its circumferential direction. Each bearing pocket 76 has a concave shape in which the lower surface of the bearing member 70 is recessed upward, and discharges pressurized bearing oil supplied from the second oil supply unit 96. The pressurized bearing oil discharged from the bearing pockets 76 pressurizes the upper surface of the flange portion 184 downward. Pressurized bearing oil is discharged through the nozzle into the bearing pockets 63, 66, and the lower surface of the turntable 52 is slightly lifted away from the upper surface of the member body 62, causing the upper surface of the flange portion 184 and the lower surface of the bearing member 70 to approach each other. When the upper surface of the flange portion 184 and the lower surface of the bearing member 70 approach each other, the oil pressure in the throttle formed around the bearing pocket 76 increases, causing the upper surface of the flange portion 184 and the lower surface of the bearing member 70 to attempt to separate from each other. As a result, the floating of the turntable 52 is suppressed.

[0035] The second oil supply unit 96 pressurizes the bearing oil stored in the tank and supplies it to each of the bearing pockets 63, 66, 71, and 76. The second oil supply unit 96 pressurizes the bearing oil and supplies it to the bearing pockets 63, 66, 71, and 76.

[0036] The second oil supply unit 96 has a pressure reducing valve 812, a filter 813, and a hydraulic pump 811 that is energized and controlled under the PLC 902, and supplies bearing oil stored in a tank of the second oil supply unit 96 to each of the bearing pockets 63, 66. More specifically, the bearing oil supplied from the tank is pressurized by the hydraulic pump 811, then reduced to a predetermined hydraulic pressure by the pressure reducing valve 812, and passed through the filter 813 before being supplied to each of the bearing pockets 63, 66. The second oil supply unit 96 also supplies bearing oil to each of the bearing pockets 71, 76 in a manner substantially similar to that described above.

[0037] The fluid control mechanism 150 provided in the braking device 140 shown in FIG. 1 is configured to be able to supply fluid pressure to the braking mechanism 141 of the braking device 140. The braking mechanism 141 is actuated by the fluid pressure supplied from the fluid control mechanism 150, and stops the rotation of the rotary table 52. In this embodiment, the fluid control mechanism 150 uses hydraulic oil as the fluid, and supplies hydraulic pressure as the fluid pressure to the braking mechanism 141. In addition, the braking mechanism 141 is actuated by the hydraulic pressure supplied from the fluid control mechanism 150.

[0038] FIG. 4 is a cross-sectional view for explaining the brake mechanism 141. The brake mechanism 141 in this embodiment has a plurality of hydraulic clamps 142 and a disk 55. The hydraulic clamp 142 is installed on a brake support base 146 placed on an installation surface. The disk 55 is a flat disk, and is fixed to the lower surface of the table body 53 of the rotary table 52 via a plurality of disk mounting members 56. The hydraulic clamp 142 incorporates a hydraulic cylinder 144 configured to advance by hydraulic pressure and retreat by spring force, and a pad 145 that advances by the hydraulic cylinder 144 and retreats by spring force. The hydraulic cylinder 144 advances by hydraulic pressure supplied from the fluid control mechanism 150, thereby applying a gripping force to the pads 145 arranged above and below the disk 55 to clamp and fix the disk 55. In this way, the brake mechanism 141 operates when hydraulic pressure is supplied to stop the rotation of the rotary table 52. Furthermore, when the supply of hydraulic pressure is stopped, more specifically, when the hydraulic pressure supplied to the hydraulic cylinder falls below a predetermined operating pressure, the hydraulic cylinder retracts due to the spring force of a spring incorporated in the hydraulic cylinder and the spring force of a spring that directly retracts the pad 145. As a result, the gripping of the disk 55 by the hydraulic clamp 142, that is, the braking of the rotary table 52, is released. Hereinafter, the state in which the brake mechanism 141 is operating is also referred to as the operating state, and the state in which the braking by the brake mechanism 141 is released is also referred to as the released state.

[0039] 5 is a diagram illustrating the fluid control mechanism 150. The fluid control mechanism 150 has a connection flow path 161, a supply flow path 162, a discharge flow path 163, a branch flow path 164, a bypass flow path 165, an accumulator 169, a first solenoid valve 171 (electromagnetic directional control valve), and a second solenoid valve 172 (electromagnetic on-off valve). Furthermore, the fluid control mechanism 150 in this embodiment has a third solenoid valve 173, a check valve 174, a pressure reducing valve 175, and variable throttle valves 176 and 177. The control of energization of the hydraulic pump 159, the first solenoid valve 171, the second solenoid valve 172, and the third solenoid valve 173 is executed by the PLC 902.

[0040] The connection flow passage 161 has one end connected to the brake mechanism 141 and the other end connected to a first solenoid valve (electromagnetic directional control valve) 171. The supply flow passage 162 is connected to the first solenoid valve (electromagnetic directional control valve) 171, and is supplied with hydraulic pressure generated by a hydraulic pump 159 serving as a fluid pressure generating unit that generates fluid pressure, and supplies the hydraulic pressure to the brake mechanism 141 via the connection flow passage 161. In this embodiment, the supply flow passage 162 is connected to the hydraulic pump 159 via a flow passage 166 for supplying hydraulic oil from a tank. The discharge flow passage 163 is connected to the first solenoid valve (electromagnetic directional control valve) 171, and discharges the hydraulic pressure from the brake mechanism 141 via the connection flow passage 161. In this embodiment, the end of the discharge flow passage 163 opposite to the first solenoid valve (electromagnetic directional control valve) 171 is connected to a flow passage 167 for discharging the hydraulic oil to the tank. The branch flow passage 164 has one end connected to the connection flow passage 161. An accumulator 169 is connected to the branch flow passage 164. The accumulator 169 is configured to be capable of holding a fluid pressure for operating the brake mechanism 141. Hereinafter, the maximum value of the fluid pressure that can be held by the accumulator 169 is also referred to as the reference internal pressure.

[0041] The first solenoid valve 171 connects the other end of the connection flow path 161 to the supply flow path 162 and the discharge flow path 163, and is configured to selectively switch between a supply state in which the connection flow path 161 and the supply flow path 162 are connected and a discharge state in which the connection flow path 161 and the discharge flow path 163 are connected. In this embodiment, the first solenoid valve 171 is configured as a solenoid switching valve that takes a discharge state when not energized and a supply state when energized. The second solenoid valve 172 is provided in a first portion P1 of the connection flow path 161, which is a portion between the first solenoid valve 171 and a connection position CP1 where the connection flow path 161 and the branch flow path 164 are connected. The second solenoid valve 172 is configured as a normally closed type shutoff solenoid valve that opens the connection flow path 161 by electromagnetic force when energized and closes the connection flow path 161 by spring force when not energized. The third solenoid valve 173 is provided in the branch flow path 164. The third solenoid valve 173 is configured as a normally open shutoff solenoid valve that closes the branch flow path 164 by electromagnetic force when energized and opens the branch flow path 164 by spring force when de-energized. In this embodiment, the speed at which the second solenoid valve 172 closes the connection flow path 161 is faster than the speed at which the third solenoid valve 173 opens the branch flow path 164. More specifically, the second solenoid valve 172 and the third solenoid valve 173 are configured such that, when the second solenoid valve 172 and the third solenoid valve 173 are simultaneously switched from an energized state to a de-energized state, the second solenoid valve 172 closes the connection flow path 161 faster than the third solenoid valve 173 opens the branch flow path 164.

[0042] The pressure reducing valve 175 is provided in the supply flow passage 162. In this embodiment, the pressure reducing valve 175 reduces the hydraulic pressure of the working oil to the same pressure as the reference internal pressure. The variable throttle valve 176 is provided in the second portion P2 of the connection flow passage 161, which is a portion between the second solenoid valve 172 and the connection position CP1. The variable throttle valve 177 is provided in the branch flow passage 164, which is a third portion P3, which is a portion between the accumulator 169 and the third solenoid valve 173.

[0043] The bypass flow path 165 connects the upstream and downstream of the third solenoid valve 173 in the branch flow path 164. The check valve 174 is provided in the bypass flow path 165. The check valve 174 regulates the supply of fluid pressure from the accumulator 169 to the connection flow path 161 in the bypass flow path 165, and allows the supply of fluid pressure from the connection flow path 161 to the accumulator 169. Therefore, in this embodiment, the fluid pressure of the accumulator 169 is supplied to the connection flow path 161 when the third solenoid valve 173 opens the branch flow path 164 while not energized.

[0044] FIG. 6 is an explanatory diagram showing the control pattern of the fluid control mechanism 150 in this embodiment. "OFF" shown in FIG. 6 indicates that each part (hydraulic pump 159 for braking and each solenoid valve) is in a non-energized state. "ON" indicates that each part is in a powered state. "Brake state" indicates whether the brake mechanism 141 is in an activated state or a released state. "Accumulator internal pressure" indicates the internal pressure of the accumulator 169.

[0045] In the "normal power off" shown in FIG. 6, the hydraulic pump 159 and each solenoid valve are OFF, the brake mechanism 141 is in an operating state, and the internal pressure of the accumulator 169 is the reference internal pressure. In the present embodiment, the "normal power off" refers to a state in which the power of the machine tool 10, which was in an operating state immediately before, is turned off, and the power of the fluid control mechanism 150 is turned off accordingly. The "operation preparation" is a state in which the power of the machine tool 10 is turned on from the "normal power off" state, the operation preparation button is turned on, and electricity is supplied to each part of the machine tool 10. The operation preparation button 962 is turned on when starting the hydraulic pump, etc., or when restarting the hydraulic pump, etc. after a power outage, which will be described later. In the "operation preparation", the hydraulic pump 159 is changed to ON, and the second solenoid valve 172 is changed to ON by energization. The first solenoid valve 171 is maintained in the immediately previous state. The third solenoid valve 173 is maintained ON if it was ON immediately before, and is changed to ON by energization if it was OFF immediately before. Here, ON refers to a state in which the hydraulic pump 159, the first solenoid valve 171, and the second solenoid valve 172 supply pressurized oil to the brake mechanism 141, and the third solenoid valve 173 does not supply pressurized oil from the accumulator 169 to the brake mechanism 141, and OFF refers to a state in which the hydraulic pump 159, the first solenoid valve 171, and the second solenoid valve 172 do not supply pressurized oil to the brake mechanism 141, and the third solenoid valve 173 supplies pressurized oil from the accumulator 169 to the brake mechanism 141.

[0046] "Brake application" and "brake release" are each executed according to the machining contents described in the machining program when "operation preparation" is completed. In "brake application", the first solenoid valve 171 is controlled to be ON by energization, that is, the first solenoid valve 171 is in a supply state, and the brake mechanism 141 is in an operating state. More specifically, when the first solenoid valve 171 is in a supply state, the hydraulic oil is supplied to the brake mechanism 141 via the supply flow path 162 and the connection flow path 161. At this time, the hydraulic oil is pressurized by the hydraulic pump 159, and then adjusted to a predetermined pressure by the pressure reducing valve 175, and the operating speed of the brake mechanism 141 is adjusted by the variable throttle valve 176, and then supplied to the brake mechanism 141. At this time, the hydraulic oil can also be supplied to the accumulator 169 via the connection flow path 161, the branch flow path 164, and the bypass flow path 165. Therefore, as described below, when the internal pressure of the accumulator 169 is lower than the reference internal pressure, the internal pressure of the accumulator 169 increases toward the reference internal pressure.

[0047] On the other hand, in "brake release", the first solenoid valve 171 is controlled to be OFF by cutting off the current to the first solenoid valve 171, that is, the first solenoid valve 171 puts the pressure oil of the brake mechanism 141 in a discharge state, thereby putting the brake mechanism 141 in a released state. More specifically, when the first solenoid valve 171 takes the discharge state, the discharge flow path 163 and the connection flow path 161 are in communication, so that the supply of hydraulic oil to the brake mechanism 141 is stopped and hydraulic pressure is discharged from the brake mechanism 141 to the tank via the connection flow path 161, the discharge flow path 163, and the flow path 167.

[0048] "Power outage in the operating state" refers to a power outage causing the power supply to machine tool 10 to be cut off in the operating state. Accordingly, the power supply to fluid control mechanism 150 is also cut off. "Power outage in the released state" refers to a power outage causing the power supply to fluid control mechanism 150 to be cut off in the released state. In this case, the power supply to each component of fluid control mechanism 150 is cut off, so that hydraulic pump 159 and each solenoid valve are turned OFF. Furthermore, in this state, hydraulic pump 811 in second oil supply unit 96 also stops due to the cut off of the power supply.

[0049] When the power supply to the fluid control mechanism 150 is cut off due to a power outage, the second solenoid valve 172 closes the connecting flow path 161, and the third solenoid valve 173 opens the branch flow path 164. Therefore, in this state, the fluid pressure held by the accumulator 169 is supplied to the brake mechanism 141 via the branch flow path 164 and the connecting flow path 161, and the fluid pressure supplied to the brake mechanism 141 is prevented from being discharged via the connecting flow path 161 and the discharge flow path 163. When the power supply to the fluid control mechanism 150 is cut off in the operating state, the internal pressure of the accumulator 169 is maintained at the reference internal pressure because the fluid pressure from the first oil supply unit 94 is supplied to the brake mechanism 141 immediately before the power supply is cut off. On the other hand, when the power supply to the fluid control mechanism 150 is cut off in the released state, the internal pressure of the accumulator 169 drops below the reference internal pressure by the amount of operation of the brake mechanism 141 without the fluid pressure from the first oil supply unit 94 being supplied to the brake mechanism 141 immediately before the power supply is cut off. Therefore, the reference internal pressure of the accumulator 169 is set to a pressure that allows the brake mechanism 141 to operate not only when the power supply to the fluid control mechanism 150 is cut off in the operating state, but also when the power supply to the fluid control mechanism 150 is cut off in the released state. The variable throttle valve 177 adjusts the operating speed of the brake mechanism 141 when the brake mechanism 141 is operated by the internal pressure of the accumulator 169, and the internal pressure of the accumulator 169 is supplied to the brake mechanism 141 with the operating speed adjusted by the variable throttle valve 177.

[0050] An "emergency stop in an activated state" refers to an emergency stop being executed in an activated state. An "emergency stop in a released state" refers to an emergency stop being executed in a released state. An emergency stop is executed, for example, by pressing an emergency stop button 961 provided on the CNC device 901 of the machine tool 10. Unlike a power outage, an emergency stop does not cut off the power supply to the machine tool 10, the brake device 140, etc. When an emergency stop is executed, the PLC 902 changes the hydraulic pump 159 to OFF, changes the second solenoid valve 172 to OFF, and maintains the third solenoid valve 173 ON. Also, the first solenoid valve 171 is maintained in the immediately preceding state. Therefore, in this case, the brake state is maintained in the immediately preceding state.

[0051] 7 is a flowchart of the machining process for realizing the machining process of the workpiece 120 in this embodiment. The processor 91 of the control device 90 executes the machining program stored in the memory 92, triggered by, for example, a predetermined start operation on the control device 90 by the user, thereby executing the machining process.

[0052] In step S110, the control device 90 determines whether or not to execute drilling by, for example, referring to the machining program. If it is determined that drilling is to be executed, in step S120, the control device 90 controls the fluid control mechanism 150 to activate the brake mechanism 141. More specifically, in step S120, the control device 90 executes the "brake operation" shown in FIG. 6 to supply fluid pressure to the brake mechanism 141 and regulate the rotation of the rotary table 52. In step S130, the control device 90 uses a drill as the first processing tool 35 to drill the workpiece 120 while the rotation of the rotary table 52 is regulated.

[0053] If it is determined in step S110 that the drilling process is not to be performed, in step S140, the control device 90 releases the brake applied by the brake mechanism 141 by controlling the fluid control mechanism 150. More specifically, in step S140, the control device 90 executes the "brake release" shown in FIG. 6 to stop the supply of fluid pressure to the brake mechanism 141 and permit the rotation of the rotary table 52. In step S150, the control device 90 performs lathe machining of the workpiece 120 using a cutting tool as the first processing tool 35 while appropriately rotating the rotary table 52 by controlling the rotary drive device 130. Note that the control device 90 may execute special shape machining by the second gripping mechanism 40, for example, before or after the drilling process or the lathe process.

[0054] According to the rotary table device 50 in the present embodiment described above, the second solenoid valve 172 is provided in a portion of the connecting flow passage 161 connected to the brake mechanism 141 between the connection position CP1 to which the accumulator 169 is connected via the branch flow passage 164 and the first solenoid valve 171. The second solenoid valve 172 is configured to open the connecting flow passage 161 by electromagnetic force when energized and close the connecting flow passage 161 by spring force when de-energized. In this manner, for example, when the power supply to the rotary table device 50 or the fluid control mechanism 150 is cut off due to a power outage, the connecting flow passage 161 is closed by the second solenoid valve 172 provided in the connecting flow passage 161 between the connection position CP and the first solenoid valve 171. Therefore, even if the power supply is cut off in either the supply state or the discharge state, the brake mechanism 141 can be operated by the fluid pressure of the accumulator 169 to regulate the rotation of the rotary table 52. Furthermore, since the second solenoid valve 172 is an on-off valve, it can close the connection flow path 161 more quickly than a directional control valve such as the first solenoid valve 171 when the power supply is interrupted.

[0055] In this embodiment, the branch flow path 164 is provided with a third solenoid valve 173 that closes the branch flow path 164 by electromagnetic force when energized and opens the branch flow path 164 by spring force when de-energized. In this manner, the branch flow path 164 is closed by the third solenoid valve 173, so that the fluid pressure of the accumulator 169 can be prevented from decreasing. In addition, when the power supply to the rotary table device 50 or the fluid control mechanism 150 is cut off due to a power outage, the branch flow path 164 is opened by the third solenoid valve 173, so that the brake mechanism 141 can be operated by the fluid pressure of the accumulator 169. Furthermore, since the third solenoid valve 173 is an opening / closing valve, the branch flow path 164 can be quickly opened when the power supply is cut off.

[0056] Moreover, in this embodiment, a check valve 174 is provided in the bypass flow path 165 that connects the upstream and downstream of the third solenoid valve 173 in the branch flow path 164. This check valve 174 regulates the supply of fluid pressure from the accumulator 169 to the connecting flow path 161 and allows the supply of fluid pressure from the connecting flow path 161 to the accumulator 169. In this way, in the supply state, by closing the branch flow path 164 with the third solenoid valve 173, the fluid pressure generated by the hydraulic pump 159 can be supplied to the accumulator 169 via the bypass flow path 165. Therefore, the fluid pressure in the accumulator 169 can be effectively maintained.

[0057] In addition, in this embodiment, the speed at which the second solenoid valve 172 closes the connection flow path 161 is faster than the speed at which the third solenoid valve 173 opens the branch flow path 164. In this way, when the power supply to the rotary table device 50 is cut off, the second solenoid valve 172 closes the connection flow path 161 before the third solenoid valve 173 opens the branch flow path 164. Therefore, when the power supply to the rotary table device 50 or the fluid control mechanism 150 is cut off, the fluid pressure of the accumulator 169 can be supplied to the brake mechanism 141 more efficiently, as compared to a mode in which the speed at which the second solenoid valve 172 closes the connection flow path 161 is equal to or faster than the speed at which the third solenoid valve 173 opens the branch flow path 164.

[0058] In this embodiment, the support mechanism 60 is a hydrostatic bearing. Therefore, the rotary table 52 can be rotatably supported by the hydrostatic bearing. Furthermore, even if the power supply is interrupted in either the supply state or the discharge state, the rotation of the rotary table 52 is restricted. As a result, even if the support mechanism 60 and the rotary table 52 come into direct contact without the bearing oil between them due to the interruption of the supply of bearing oil to the support mechanism 60, which is a hydrostatic bearing, during a power outage, the rotary table 52 does not rotate, so that wear and damage to the support mechanism 60 and the rotary table 52 can be suppressed.

[0059] Furthermore, in this embodiment, machine tool 10 includes a rotary table device 50 and a spindle device 34 to which a bit and a drill as first processing tool 35 are interchangeably attached. Therefore, by allowing rotation of rotary table 52 when turning workpiece 120 using a bit and restricting rotation of rotary table 52 when drilling workpiece 120 using a drill, machine tool 10 can appropriately turn and drill workpiece 120.

[0060] Furthermore, in this embodiment, the control device 90 controls the fluid control mechanism 150 so that when the workpiece 120 is machined with a cutting tool, fluid pressure is not supplied to the brake mechanism 141 to allow rotation of the rotary table 52, and when the workpiece 120 is machined with a drill, fluid pressure is supplied to the brake mechanism 141 to restrict rotation of the rotary table 52. In this way, the workpiece 120 can be appropriately cut and drilled under the control of the control device 90.

[0061] B. Other embodiments: (B-1) In the above embodiment, the third solenoid valve 173 is provided in the branch flow path 164. In contrast to this, for example, when the reference internal pressure of the accumulator 169 is set high enough to operate the brake mechanism 141 even if the third solenoid valve 173 is not provided, the third solenoid valve 173 may not be provided.

[0062] (B-2) In the above embodiment, the check valve 174 is provided in the bypass flow path 165, but the bypass flow path 165 and the check valve 174 do not necessarily have to be provided.

[0063] (B-3) In the above embodiment, the second solenoid valve 172 and the third solenoid valve 173 are configured so that the speed at which the second solenoid valve 172 closes the connecting flow path 161 is faster than the speed at which the third solenoid valve 173 opens the branch flow path 164. In contrast to this, the speed at which the second solenoid valve 172 closes the connecting flow path 161 may be equal to or slower than the speed at which the third solenoid valve 173 opens the branch flow path 164.

[0064] (B-4) In the above embodiment, the support mechanism 60 rotatably supports the turntable 52 relative to the base 110 by a hydrostatic bearing, but this is not necessarily the case. For example, the support mechanism 60 may rotatably support the turntable 52 by a sliding bearing different from a hydrostatic bearing such as a dynamic bearing, or may rotatably support the turntable 52 by a rolling bearing.

[0065] The present disclosure is not limited to the above-mentioned embodiment, and can be realized in various configurations without departing from the spirit of the present disclosure. For example, the technical features in each embodiment corresponding to the technical features in the form described in the Summary of the Invention column can be appropriately replaced or combined in order to solve some or all of the above-mentioned problems or to achieve some or all of the above-mentioned effects. Furthermore, if the technical feature is not described as essential in this specification, it can be appropriately deleted. [Explanation of symbols]

[0066] 10...machine tool, 12...column, 13...column, 14...column, 20...crossbeam, 21...first horizontal feed device, 22...second horizontal feed device, 30...first gripping mechanism, 31...first guide table, 32...first vertical feed device, 34...spindle device, 35...first processing tool, 36...first horizontal slider, 38...vertical guide table, 40...second gripping mechanism, 41...second guide table, 42...second vertical feed device, 44...grindstone head, 45...second processing tool, 46...first 2 horizontal slider, 47... rotating shaft portion, 48... upper and lower guide table, 50... rotating table device, 52... rotating table, 53... table body, 54... chuck, 55... disk, 56... disk mounting member, 60... support mechanism, 62... member body, 63, 66... ​​bearing pocket, 69... thrust bearing, 70... bearing member, 71... bearing pocket, 75... radial bearing, 76... bearing pocket, 79... thrust bearing, 90... control device , 91 ... processor, 92 ... memory, 93 ... external interface, 94 ... first oil supply unit, 96 ... second oil supply unit, 97 ... display unit, 98 ... operation panel, 99 ... interface, 110 ... base, 120 ... work, 130 ... rotation drive device, 131 ... servo motor, 132 ... drive circuit, 133 ... reduction mechanism, 134 ... final gear, 139 ... table side gear, 140 ... brake device, 141 ... brake mechanism, 14 2...hydraulic clamp, 144...hydraulic cylinder, 145...pad, 146...brake support stand, 150...fluid control mechanism, 159...hydraulic pump, 161...connection flow path, 162...supply flow path, 163...discharge flow path, 164...branch flow path, 165...bypass flow path, 166, 167...flow path, 169...accumulator, 171...first solenoid valve, 172...second solenoid valve, 173...third solenoid valve, 174...check valve, 175...pressure reducing valve, 176,177...variable throttle valve, 180...rotating shaft, 181...upper end portion, 183...middle portion, 184...flange-shaped portion, 201...LM guide, 211...ball screw, 212...servo motor, 213...drive circuit, 221...ball screw, 222...servo motor, 223...drive circuit, 311...LM guide, 321...ball screw, 322...servo motor, 323...drive circuit, 331...servo motor, 332...drive circuit, 341...servo motor, 342...Drive circuit, 343...Main shaft, 411...LM guide, 421...Ball screw, 422...Servomotor, 423...Drive circuit, 431...Servomotor, 432...Drive circuit, 471...Grinding wheel drive motor, 472...Drive circuit, 473...Pulley, 481...Upper and lower feed table, 811...Hydraulic pump, 812...Pressure reducing valve, 813...Filter, 901...CNC device, 902...PLC, 961...Emergency stop button, 962...Operation preparation button,

Claims

1. With the base, A rotating table and a support mechanism that supports the rotary table relative to the base so as to be rotatable about an axis along a vertical direction; a rotary drive device that rotates the rotary table; a brake device configured to regulate the rotation of the rotary table, the brake device includes a brake mechanism that is actuated by a supply of fluid pressure to stop rotation of the turntable, and a fluid control mechanism configured to be able to supply fluid pressure to the brake mechanism, The fluid control mechanism includes: a connecting passage having one end connected to the brake mechanism; a supply flow passage connected to a fluid pressure generating unit that generates a fluid pressure, and that supplies the fluid pressure to the brake mechanism via the connection flow passage; a discharge passage for discharging fluid pressure from the brake mechanism via the connecting passage; a first solenoid valve that connects the other end of the connection flow path to the supply flow path and the discharge flow path, and is configured to selectively switch between a supply state in which the connection flow path and the supply flow path are in communication with each other and a discharge state in which the connection flow path and the discharge flow path are in communication with each other; a branch flow path connected to the connection flow path and having an accumulator connected thereto, the accumulator being configured to be capable of holding a fluid pressure for actuating the brake mechanism; a second solenoid valve provided in a portion of the connection flow path between a connection position where the connection flow path and the branch flow path are connected and the first solenoid valve, the second solenoid valve being configured to open the connection flow path by an electromagnetic force when energized and to close the connection flow path by a spring force when deenergized; Rotating table device.

2. 2. The rotary table device according to claim 1, The fluid control mechanism includes a third solenoid valve that is provided in the branch flow path and closes the branch flow path by electromagnetic force when energized and opens the branch flow path by spring force when de-energized.

3. 3. The rotary table device according to claim 2, a bypass flow path connecting the upstream and downstream of the third solenoid valve in the branch flow path; a check valve provided in the bypass flow path for regulating the supply of fluid pressure from the accumulator to the connecting flow path and for allowing the supply of fluid pressure from the connecting flow path to the accumulator.

4. 3. The rotary table device according to claim 2, A rotary table device, wherein the second solenoid valve closes the connecting passage faster than the third solenoid valve opens the branch passage.

5. 2. The rotary table device according to claim 1, The support mechanism is a hydrostatic bearing.

6. A rotary table device according to any one of claims 1 to 5, a spindle device to which a bit for turning a work supported by the rotary table device and a drill for drilling a hole in the work are interchangeably attached; a guide table that supports the spindle device and guides the spindle device in a guide direction that intersects a horizontal plane; a vertical feed device that feeds the spindle device in the guide direction relative to the guide table; A cross beam that guides the guide table in a horizontal direction; a horizontal feed device that feeds the guide table horizontally relative to the crossbeam; a control device that controls the rotation drive device, the fluid control mechanism, the vertical feed device, and the horizontal feed device.

7. 7. The machine tool according to claim 6, The control device controls the fluid control mechanism to When the workpiece is machined by the cutting tool, the fluid pressure is not supplied to the brake mechanism to allow the rotation of the rotary table; When the workpiece is machined by the drill, the fluid pressure is supplied to the brake mechanism to regulate the rotation of the rotary table. Machine tools.

8. a brake mechanism that is actuated by the supply of fluid pressure to stop the rotation of the rotary table; a fluid control mechanism configured to supply fluid pressure to the brake mechanism, The fluid control mechanism includes: a connecting passage having one end connected to the brake mechanism; a supply flow passage connected to a fluid pressure generating unit that generates a fluid pressure, and that supplies the fluid pressure to the brake mechanism via the connection flow passage; a discharge passage for discharging fluid pressure from the brake mechanism via the connecting passage; a first solenoid valve that connects the other end of the connection flow path to the supply flow path and the discharge flow path, and is configured to selectively switch between a supply state in which the connection flow path and the supply flow path are in communication with each other and a discharge state in which the connection flow path and the discharge flow path are in communication with each other; a branch flow path connected to the connection flow path and having an accumulator connected thereto, the accumulator being configured to be capable of holding a fluid pressure for actuating the brake mechanism; a second solenoid valve provided in a portion of the connection flow path between a connection position where the connection flow path and the branch flow path are connected and the first solenoid valve, the second solenoid valve being configured to open the connection flow path by an electromagnetic force when energized and to close the connection flow path by a spring force when deenergized; Brake device.

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