MACHINE TOOL CONTROL DEVICE

Abstract

The purpose of the present invention is to provide a machine tool control device that can limit the amount of compressed air consumed.This machine tool control device 3 controls a machine tool M with a spindle 1 and a compressed air supply device 2 with respect to the supply of compressed air to the spindle 1, wherein the machine tool control device 3 comprises: a rotation status information acquisition unit 311 for acquiring rotation status information indicating a rotation status of the spindle 1; a supply condition determination unit 312 for determining a supply condition required for compressed air to be supplied to the interior of the spindle 1, based on the rotation status information acquired by the rotation status information acquisition unit 311; and a compressed air control unit 313 for controlling the compressed air supply device 2 based on the supply condition determined by the supply condition determination unit 312.

Description

TECHNICAL AREA

[0001] The present disclosure relates to a machine tool control device. STATE OF THE ART

[0002] Traditionally, a machine tool spindle includes a bearing to support high-speed rotation. From the perspective of the bearing's service life, it is necessary to prevent the ingress of foreign matter and fluids into the spindle's interior. However, due to the spindle's high-speed rotational capability, the use of a contact seal is not feasible. To address this, a technique is known in which a non-contact sealing structure, known as a labyrinth seal, is provided to the spindle, and clean air is introduced into the spindle's interior to maintain positive pressure (air purging), thereby preventing the ingress of foreign matter and fluids (Patent Document 1). List of references Patent document

[0003] Patent document 1: Unexamined Japanese patent application, publication no. H2-100851 DISCLOSURE OF INVENTION Technical tasks of the invention

[0004] Compressed air, which is introduced (supplied) to maintain positive pressure inside the spindle, is used under a specific, predetermined supply condition. However, since different operating conditions require different supply conditions, there is a risk of consuming more compressed air than necessary.

[0005] One objective of the present disclosure is to provide a machine tool control device that can reduce the consumption of compressed air. Means of solving the tasks

[0006] One aspect of the present disclosure relates to a machine tool control device for controlling a machine tool, comprising a spindle and a compressed air supply device which supplies compressed air to an interior of the spindle, wherein the machine tool control device comprises: a rotation status information acquisition unit which acquires rotation status information indicating a rotation status of the spindle; a supply condition determination unit which determines a supply condition required for compressed air to be supplied to the interior of the spindle, based on the rotation status information acquired by the rotation status information acquisition unit; and a compressed air control unit which controls the compressed air supply device based on the supply condition determined by the supply condition determination unit. BRIEF DESCRIPTION OF THE DRAWINGS Fig.Figure 1 is a schematic representation illustrating an example of the environment of a spindle of a machine tool according to one embodiment; Fig. Figure 2 is a block diagram illustrating a hardware configuration of a machine tool control device according to the embodiment; Fig. Figure 3 is a block diagram illustrating a functional configuration of the machine tool control device according to the embodiment; Fig. Figure 4 is a flowchart to illustrate an example of compressed air supply control by the machine tool control device according to the embodiment; Fig. Figure 5 is a block diagram illustrating a hardware configuration of a machine tool control device according to a modification; and Fig.Figure 6 is a block diagram illustrating a functional configuration of a machine tool control device according to the modification. PREFERRED METHOD OF IMPLEMENTATION <Machine tool>

[0007] A configuration of a machine tool M according to the present embodiment is described with reference to the Fig. 1 to 3 described. Fig. Figure 1 is a schematic representation illustrating an example of the environments of a spindle 1 of the machine tool M according to the present embodiment. Fig. Figure 2 is a block diagram illustrating a hardware configuration of a machine tool control device 3 according to the present embodiment. Fig. Figure 3 is a block diagram illustrating a functional configuration of the machine tool control device 3 according to the present embodiment. < Machine tool >

[0008] The machine tool M is a device comprising a spindle that rotates a tool mounted on it to perform machining. The machine tool M includes the spindle 1, a compressed air supply device 2, and a machine tool control device 3.

[0009] Spindle 1 is a rotating device that transmits energy to enable machine tool M to perform machining operations. Spindle 1 can be used in various machine tools. Details will be described later.

[0010] The compressed air supply device 2 is configured to supply compressed air to the interior of the spindle 1. According to the present embodiment, the compressed air supply device 2 supplies compressed air to the interior of the spindle 1 via a labyrinth seal 13 (to be described later), which functions as a non-contact sealing structure. The compressed air supply device 2 is, for example, a pump. It should be noted that the compressed air supply device 2 is not limited to a pump. It could, for example, be a conventional compressor for equipment installed in a factory.

[0011] The machine tool control device 3 is configured to control various operations of the machine tool M. The details will be described later. < Hardware configuration of the spindle environment >

[0012] The configuration of the spindle 1 contained in the machine tool M according to the present embodiment is described with reference to the Fig. 1 to 3 described. As in Fig. As illustrated in Figure 1, the spindle 1 comprises a spindle shaft 10, a plurality of bearings 11, a housing 12, and a labyrinth seal 13 as a non-contact sealing structure. Furthermore, the spindle 1 is equipped with a [missing information - likely a specific component or component] in the Fig. 2 and Fig. 3 illustrated spindle drive 14 provided.

[0013] The spindle shaft 10 is a solid cylindrical element for transmitting energy from a drive to a workpiece in the machine tool M. As in Fig.As illustrated in Figure 1, the spindle shaft 10 has a stop 10a attached to an outer circumferential surface. The stop 10a is configured to restrict movement of the spindle shaft 10 relative to the housing 12 in the axial direction. This axial movement is restricted by contact between the stop 10a and the bearing 11 positioned in the housing 12. The stop 10a can, for example, be an annular element shaped such that its inner circumferential surface is in contact with the outer circumferential surface of the spindle shaft 10. The shape of the stop 10a is not limited to an annular element.

[0014] The bearings 11 are configured to allow the spindle shaft 10 to rotate. Each bearing 11 comprises an outer ring, an inner ring, and a plurality of balls. The outer ring is fixed to the housing 12. The inner ring is mounted on the spindle shaft 10 to form a tight fit between them and rotates relative to the outer ring. The plurality of balls are arranged in a ring shape perpendicular to the axial direction and positioned between the outer and inner rings, allowing the inner ring to rotate relative to the outer ring. The bearings 11, configured in this way, support the spindle shaft 10 with respect to the housing 12 and allow the spindle shaft 10 to rotate with respect to the housing 12.

[0015] The spindle 1 according to the present embodiment comprises a total of four bearings 11, including two bearings 11 not shown, but this is a non-limiting example. For instance, the spindle 1 may comprise three or fewer bearings 11 or may comprise five or more bearings 11.

[0016] The housing 12 is a hollow cylindrical element that is open at opposite ends and can accommodate the spindle shaft 10 and other components. The housing 12 receives the spindle shaft 10 and the bearings 11, such that the spindle shaft 10 protrudes from the openings of its hollow cylindrical body. As shown in Fig.As illustrated in Figure 1, the housing 12 has a stop 12a attached to an inner circumferential surface. The stop 12a is configured to restrict movement of the bearings 11 relative to the housing 12 in the axial direction of the spindle shaft. The movement of the bearings 11 in the axial direction of the spindle shaft 10 is restricted by the contact of the bearing 11 with the stop 12a on the inner circumferential surface of the housing 12.

[0017] The labyrinth seal 13 is a non-contact sealing structure designed to prevent the ingress of foreign objects and liquids into the housing 12. Since the spindle 1 rotates at high speed, the labyrinth seal 13 is used in the machine tool M as a non-contact sealing structure for durability purposes. The labyrinth seal 13 is positioned to fill the space between each of the openings at opposite ends of the housing 12 and the spindle shaft 10. Fig.Figure 1 illustrates one of the opposite ends of the housing 12, each equipped with the labyrinth seal 13.

[0018] The labyrinth seal 13 comprises an annular inner seal 13a, which is attached to the spindle shaft 10, and an annular outer seal 13b, which is attached to the housing 12, facing the inner seal 13a, and which is arranged adjacent to the housing 12 and the outside of the inner seal 13a in a non-contact state.

[0019] The labyrinth seal 13 is configured to allow air purging to supply compressed air A to the interior of the spindle 1. Specifically, the labyrinth seal 13 has an air purge section 13b1 in the outer seal 13b, which is an airflow path through which the outer and inner surfaces of the labyrinth seal 13 are connected to supply the compressed air A to the inner surface of the labyrinth seal 13. The aforementioned compressed air supply device 2 supplies the compressed air A to the interior of the spindle 1 through the air purge section 13b1, thereby performing the air purging. The labyrinth seal 13 further includes a labyrinth passage 13c, which is a gap between the inner seal 13a and the outer seal 13b and serves as a flow path for air inside the spindle, allowing it to flow outwards. Consequently, the air inside the spindle 1 exits to the outside through the labyrinth passage 13c.By performing air purging, the interior of spindle 1 is maintained at a positive pressure relative to the outside air, which is present outside spindle 1 and contains cutting fluid mist. As a result, it is possible to cause the air inside spindle 1 to escape through the labyrinth passage 13c, which is the gap in the labyrinth seal 13, and to prevent foreign matter such as dust and liquid from penetrating through the gap.

[0020] The spindle drive 14 is configured to rotate the spindle shaft 10. The spindle drive 14 rotates the spindle shaft 10, for example, by a motor (not shown). < Hardware configuration of the machine tool control device >

[0021] The following is an example of a hardware configuration of the machine tool control device 3 according to an embodiment of the present invention with reference to Fig.2 described. As in Fig. As illustrated in Figure 2, the machine tool control device 3 comprises a processor 300, a read-only memory (ROM) 301, a random access memory (RAM) 302, a bus 303, an input / output interface 304, an input unit 305, an output unit 306, an additional memory unit 307, and a power supply 308.

[0022] The Processor 300 is a central component of a computer for performing processing such as calculations and control necessary for the operation of the machine tool M, and executes various calculations and processing tasks. The Processor 300 can be, for example, a central processing unit (CPU), a microprocessing unit (MPU), a system-on-a-chip (SoC), a digital signal processor (DSP), a graphics processing unit (GPU), an application-specific integrated circuit (ASIC), a programmable logic device (PLD), a field-programmable gate array (FPGA), or the like. Alternatively, the Processor 300 can be a combination of two or more of these components.Alternatively, the Processor 300 can be a combination of two or more of these components and a hardware accelerator or the like.

[0023] The Processor 300 controls the units to allow the machine tool control device to execute three different functions based on programs such as firmware, system software, and application software stored in ROM 301 or RAM 302. Furthermore, the Processor 300 performs processing based on these programs. It should be noted that some or all of the programs may be integrated into a single circuit of the Processor 300.

[0024] The processor 300, the ROM 301, and the RAM 302 are interconnected via bus 303. The input / output interface 304 is also connected to this bus 303. The input unit 305, the output unit 306, the additional memory unit 307, and the power supply 308 are connected to the input / output interface 304.

[0025] The input unit 305 and the output unit 306 are user interfaces that are electrically connected to the input / output interface 304 via a cable or wirelessly. For example, the input unit 305 includes operating buttons and inputs various information according to user commands. The output unit 306 includes a display for showing images and a speaker for adjusting the volume of sound, and outputs images and sound. It should be noted that, according to the present embodiment, the input unit 305 functions as an operating condition input device used by an operator of the machine tool M. Consequently, the machine tool M includes the input unit 305, into which an operator can input an operating condition.

[0026] Here, the term "operating condition" refers to information for controlling the rotation of spindle 1. For example, the operating condition is in the form of command information for rotating spindle 1 at a predetermined rotational speed. In the present embodiment, the operating conditions are defined for three rotational speeds, allowing selection from these three speeds. Specifically, the operating conditions for the three rotational speeds are defined in order from low to high: a low speed, a medium speed, and a high speed. It should be noted that the operating information is not limited to this.

[0027] The operating condition can be in the form of information that commands rotational acceleration if spindle 1 is to be accelerated until it rotates at a uniform speed, or rotational acceleration if spindle 1 is to be decelerated until it stops rotating. In this case, for example, spindle 1 is accelerated or decelerated so that it undergoes a rotational acceleration specified by the operating condition input device.

[0028] It should be noted that in the present embodiment, the input unit 305 also serves as the operating condition input device, but the present disclosure is not limited to this. The operating condition input device can be provided separately from the input unit 305. In the present embodiment, the operating condition is captured by an input from the operator into the input unit 305, but the present disclosure is not limited to this. For example, the operating condition for the machine tool M can be captured by an operating program that is stored in the additional storage unit 307 described later.

[0029] The additional storage unit 307 is an additional storage device, including a hard disk drive (HDD), a solid state drive (SSD), or the like. Various pieces of information, such as programs and settings related to different machining options, are stored on the additional storage unit 307. For example, the operating conditions (to be described later) entered by the operator of the machine tool M, information from the supply condition determination table (to be described later) relating to compressed air supply conditions associated with the operating conditions, various programs, and the like are stored on the additional storage unit 307.

[0030] Power supply unit 308 is connected to an external power source and is configured to supply power to the units of the machine tool control device 3. It should be noted that the configuration suitable for supplying power to the power supply unit is not limited to this and could, for example, also be a battery. < Functional configuration of the machine tool control device >

[0031] The following describes a functional configuration of the machine tool control device 3 with reference to Fig. 3 described. A control unit 310, which performs various controls for the machine tool control device 3, is implemented by the processor 300 (to be described later), which can perform arithmetic processing, execute programs stored in ROM 301, RAM 302 or in the additional memory unit 307, and the like.

[0032] The control unit 310 of the present embodiment comprises a rotation status information acquisition unit (function for acquiring rotation status information) 311, a supply condition determination unit (function for determining the supply condition) 312, a compressed air control unit (function for compressed air control) 313, a storage unit (storage function) 314 and a spindle control unit (function for spindle control) 315.

[0033] The rotation status information acquisition unit 311 acquires rotation status information that indicates the rotation status of the spindle 1. That is, the rotation status information is information that indicates the rotation status of the spindle 1. The rotation status information can, for example, include the status of the rotational speed of the spindle 1. Alternatively or additionally, the rotation status information can, for example, include the status of the rotational acceleration of the spindle 1. According to the present embodiment, the rotation status information constitutes the operating condition. That is, the rotation status information acquisition unit 311 functions as an operating condition acquisition unit. In the present embodiment, since the spindle 1 operates according to the operating condition, the operating condition can be used as rotation status information.

[0034] The supply condition determination unit 312 determines a supply condition based on the rotation status information acquired by the rotation status information acquisition unit 311. Specifically, the supply condition determination unit 312 of the present embodiment determines a supply condition required for compressed air to be supplied to the interior of the spindle 1, based on a rotation status of the spindle 1 specified by the operating condition acquired by the rotation status information acquisition unit 311.

[0035] The supply condition is information required regarding the compressed air to be supplied to the interior of spindle 1. According to the present embodiment, the supply condition is, for example, the pressure of the compressed air to be supplied to the interior of spindle 1. That is, the supply condition for compressed air determined by the supply condition determination unit 312 is the pressure of the compressed air.

[0036] It should be noted that the supply condition can, for example, be a flow rate of compressed air to be supplied to the interior of spindle 1. That is, the supply condition for compressed air determined by the supply condition determination unit 312 is a flow rate of compressed air.

[0037] In the present embodiment, different supply conditions are defined for different rotational states of the spindle 1. For example, the supply conditions, as shown in Table 1, which is a supply condition determination table and provides related information, are assigned to the operating conditions entered into the input unit 305. Table 1 is an example of the supply condition determination table, in which air pressures are defined as the supply conditions according to the operating conditions for the spindle. The pressure settings in Table 1 are given in five levels from "0", at which no pressure is applied, to "4", at which the pressure is maximum. It should be noted that the pressure settings are not limited to five levels and may be specified in four levels or fewer, or six levels or more. Furthermore, the pressure settings are not limited to those shown in Table 1. [Table 1] Condition Print setting The spindle is accelerated or decelerated. 4 Spindle is rotating (rotation speed: low). 4 Spindle is rotating (rotation speed: medium). 3 Spindle rotates (rotation speed: high). 2 The spindle comes to a complete stop immediately after being stopped. 1 The spindle remained stationary for a predetermined period after being stopped. 0

[0038] For example, the pressure for the operating condition under which spindle 1 is accelerated or decelerated is set to "4", which is the maximum pressure. This is because, during acceleration or deceleration of spindle 1, the internal pressure changes significantly due to the centrifugal force acting inside spindle 1, so there is a possibility that the internal pressure of spindle 1 will decrease and cannot be maintained at a positive pressure. If the internal pressure of spindle 1 decreases and cannot be maintained at a positive pressure, insufficient air will escape from the labyrinth passage 13c, which is a gap, and foreign matter and foreign liquids will penetrate.The above configuration increases the pressure of the compressed air to be supplied to the interior of spindle 1, thereby reducing the likelihood that the pressure inside spindle 1 will decrease and cannot be maintained at a positive pressure.

[0039] For the operating condition where spindle 1 performs uniform rotation at high speed, the pressure is set to a lower value of "2". This is because, during uniform rotation of spindle 1 at high speed, even if the internal pressure is low, the air inside spindle 1 is forced outwards to the outside of spindle 1 by the effect of centrifugal force, and the air escapes sufficiently from the labyrinth passage 13c, which is the gap, thus preventing the ingress of foreign objects and foreign liquids.

[0040] On the other hand, the pressure for the operating condition where spindle 1 performs uniform rotation at low speed is set to a higher value of "4". This is because, during uniform rotation of spindle 1 at low speed, the influence of centrifugal force is low, and the force pushing the air inside spindle 1 outwards decreases. Consequently, when the internal pressure is low, insufficient air escapes from the labyrinth passage 13c, which is the gap, and foreign matter and liquids penetrate. The above configuration increases the pressure of the compressed air supplied to the interior of spindle 1, thereby reducing the likelihood of the internal pressure dropping and failing to maintain a positive pressure.Consequently, the setting is adjusted so that the internal pressure is higher when rotating at low speed than when rotating at high speed.

[0041] For the operating condition where spindle 1 performs a uniform rotation at medium speed, the pressure is set to "3", which is between the pressures set for high-speed and low-speed rotation. This is because, during uniform rotation of spindle 1 at medium speed, the influence of centrifugal force is approximately half that of high-speed and low-speed rotation. Setting the pressure to a higher value than that for low-speed rotation and a lower value than that for high-speed rotation is intended to reduce compressed air consumption while preventing the ingress of foreign particles and liquids.

[0042] For the operating condition where spindle 1 comes to a standstill immediately after stopping, the pressure is set to a lower value of "1". This is because, when spindle 1 comes to a standstill immediately after stopping, it is assumed that the machine tool M is not performing any machining operations. This means that the ambient air contains a small amount of foreign matter and liquids, and there is a low risk of foreign matter and liquids penetrating the interior of spindle 1.

[0043] For the operating condition where spindle 1 remains stationary for a predetermined period after being stopped, the pressure is set to "0". This means that if spindle 1 remains stationary for the predetermined period after being stopped, the air purge is stopped. This is because, when spindle 1 has been stationary for the predetermined period, the concentration of mist, including cutting fluid mist, in the ambient air decreases to a negligible level. The predetermined period is, for example, one minute. However, the predetermined period is not limited to one minute.

[0044] According to the supply condition determination table described above, the supply condition determination unit 312 determines a lower pressure as the supply condition when the rotational speed of spindle 1 increases, and a higher pressure as the supply condition when the rotational speed of spindle 1 decreases. The supply condition determination unit 312 determines an even lower pressure as the supply condition during the predetermined period immediately after the rotation of spindle 1 stops. The compressed air control unit 313 stops the operation of the compressed air supply device 2 immediately after the rotation of spindle 1 stops within the predetermined period.

[0045] It should be noted that in the present embodiment, the pressure of the compressed air to be supplied is defined as the supply condition associated with the operating condition, but the present disclosure is not limited to this. For example, the supply condition associated with the operating condition could be a flow rate of the compressed air to be supplied.

[0046] The compressed air control unit 313 controls the compressed air supply device 2 based on the supply condition determined by the supply condition determination unit 312. For example, the compressed air control unit 313 controls the compressed air supply device 2 and causes it to supply compressed air to the interior of the spindle 1 via the labyrinth seal 13 at a pressure specified in the supply condition.

[0047] In order for the supply condition determination unit 312 to determine the supply condition, the memory unit 314 reads from the additional memory unit 307 the information from the supply condition determination table shown in Table 1, as well as the associated information that maps the operating conditions to the supply conditions, and stores the read information in the processor 300, in the ROM 301, in the RAM 302, and the like. Furthermore, in order for the supply condition determination unit 312 to determine the supply condition, the memory unit 314 provides the supply condition determination unit 312 with the information from the supply condition determination table that maps the operating conditions to the supply conditions.

[0048] The spindle control unit 315 drives the spindle drive 14 while controlling the speed of the spindle 1. For example, the spindle control unit 315 drives the spindle drive 14 while controlling the speed of the spindle 1 in such a way that a rotational speed and rotational acceleration are achieved according to the operating condition detected by the rotational status information acquisition unit 311. < Control of compressed air supply >

[0049] The compressed air supply through the machine tool control device 3 according to the present embodiment is described below with reference to Fig. 4 described. Fig.Figure 4 is a flowchart illustrating an example of compressed air supply control by the machine tool control device according to the present embodiment. When the machine tool control device 3 of the present embodiment performs compressed air supply control, the rotation status information acquisition unit 311, the supply condition determination unit 312, the compressed air control unit 313, the storage unit 314, and the spindle control unit 315 in the processor 300 perform their respective functions. The compressed air supply control is started when an operating condition is entered into the input unit 305 by an operator of the machine tool M.

[0050] First, the rotation status information acquisition unit 311 captures information on the operating condition entered by the operator into the input unit 305, or information relating to an operating condition from an operating program stored in the additional control unit 307 or in the memory unit 314, which was entered together with the operator's input into the input unit 305, as rotation status information (step S10).

[0051] Then the supply condition determination unit 312 determines a supply condition necessary for compressed air to be supplied to the interior of the spindle 1, based on the information from the rotation status information acquisition unit 311 and the information from the supply condition determination table stored in the storage unit 314, and taking into account a plurality of supply conditions for compressed air in conjunction with operating conditions (step S11).

[0052] The compressed air control unit 313 then controls the compressed air supply device 2 based on the supply condition determined by the supply condition determination unit 312 (step S12). Specifically, the compressed air control unit 313 causes the compressed air supply device 2 to supply compressed air to the interior of the spindle 1 via the labyrinth seal 13 in accordance with the supply condition determined by the supply condition determination unit 312.

[0053] As described above, different pressures are required to prevent the ingress of foreign bodies and foreign liquids into the spindle 1 at different rotational states of the spindle shaft 10. In the machine tool M according to the present embodiment, the compressed air supplied to the spindle 1 can be set to a pressure appropriate for the rotational state of the spindle shaft 10.

[0054] The machine tool control device 3 according to the present embodiment described above performs the following effects. The spindle of the machine tool includes bearings to support high-speed rotation, and from the perspective of the bearings' service life, it is necessary to prevent the ingress of foreign objects and foreign fluids into the interior of the spindle.

[0055] However, due to the spindle's ability to rotate at high speed, the use of a contact seal is not feasible. To address this issue, the spindle is equipped with a non-contact sealing structure, known as a labyrinth seal, and the spindle's interior is maintained at positive pressure by an air purge that supplies clean air, thus preventing the ingress of foreign particles and liquids. Maintaining this positive pressure requires the use of compressed air, the generation of which necessitates a compressor.

[0056] The air purge is performed at a preset pressure regardless of operating conditions, and consequently, more air than necessary may be consumed depending on the operating conditions. High air consumption leads to increased energy consumption by the compressor.

[0057] According to the present embodiment, the air supplied to the interior of the spindle is controlled according to the spindle's rotation status. Consequently, air is consumed in the minimum quantity required for the spindle's rotation status, thereby reducing air consumption compared to the conventional case and thus lowering overall factory electricity consumption.

[0058] The machine tool control device 3 according to the present embodiment controls the machine tool M, which comprises the spindle 1, and the compressed air supply device 2, which supplies compressed air to the interior of the spindle 1. The machine tool control device 3 comprises: the rotation status information acquisition unit 311, which acquires rotation status information indicating a rotation status of the spindle 1; the supply condition determination unit 312, which determines a supply condition required for compressed air to be supplied to the interior of the spindle 1, based on the rotation status information acquired by the rotation status information acquisition unit 311; and the compressed air control unit 313, which controls the compressed air supply device 2 based on the supply condition determined by the supply condition determination unit 312.

[0059] This configuration makes it possible to reduce the consumption of compressed air supplied from inside spindle 1.

[0060] According to the machine tool control device 3 of the present embodiment, the machine tool M comprises the input unit 305, into which an operator can enter an operating condition, the rotation status information acquisition unit 311 acquires the operating condition entered by the operator as the rotation status information, and the supply condition determination unit 312 determines a supply condition necessary for compressed air to be supplied to the interior of the spindle 1, based on the rotation status of the spindle 1, specified by the operating condition acquired by the rotation status information acquisition unit 311.

[0061] Because of this configuration, the operating condition entered by the operator can be used as the rotation status information for spindle 1, making it possible to reduce the consumption of compressed air while simplifying control.

[0062] The machine tool control device 3 according to the present embodiment further comprises the storage unit 314, in which information from the supply condition determination table is stored, which assigns the operating conditions to supply conditions, and the supply condition determination unit 312 determines a supply condition based on the operating condition entered into the input unit 305 and the information from the supply condition determination table, which is stored in the storage unit 314.

[0063] Due to this configuration, the supply condition can be determined according to the table in which operating conditions and supply conditions are mapped to each other, making it possible to reduce the consumption of compressed air while simplifying control.

[0064] According to the machine tool control device 3 of the present embodiment, the rotation status of the spindle 1 includes a status of a rotation speed of the spindle 1.

[0065] Because of this configuration, information on the rotation speed can be used as the rotation status information, making it possible to reduce the consumption of compressed air while simplifying control.

[0066] According to the machine tool control device 3 of the present embodiment, the rotation status of the spindle 1 includes a status of rotational acceleration of the spindle 1.

[0067] Because of this configuration, information on rotational acceleration can be used as rotational status information, making it possible to reduce compressed air consumption while simplifying control.

[0068] According to the machine tool control device 3 of the present embodiment, the supply condition determined by the supply condition determination unit 312 is a pressure of the compressed air.

[0069] Because of this configuration, information specifying a supply pressure to which the compressed air is to be supplied by the compressed air supply device 2 can be used in the present form as the supply condition, making it possible to reduce the consumption of compressed air while simplifying control.

[0070] According to the machine tool control device 3 of the present embodiment, the supply condition determined by the supply condition determination unit 312 is a flow rate of the compressed air.

[0071] Because of this configuration, the information specifying a supply flow rate to which the compressed air is to be supplied by the compressed air supply device 2 can be used in its present form as the supply condition, making it possible to reduce the consumption of compressed air more easily.

[0072] According to the machine tool control device 3 of the present embodiment, the supply condition determination unit 312 determines a higher pressure as a supply condition when the rotational speed of the spindle 1 decreases, and determines a lower pressure as a supply condition when the rotational speed of the spindle 1 increases.

[0073] Because of this configuration, the pressure of the compressed air can be reduced by the order of magnitude of a pressure that becomes unnecessary due to the centrifugal force applied to the air inside the spindle 1 by rotation of the spindle 1, thus making it possible to further reduce the consumption of compressed air without any problems.

[0074] According to the machine tool control device 3 of the present embodiment, the supply condition determination unit 312 determines a lower pressure as the supply condition for a predetermined period immediately after the rotation of the spindle 1 has stopped, and the compressed air control unit 313 stops the operation of the compressed air supply device 2 after a predetermined period has elapsed immediately after the rotation of the spindle 1 has stopped.

[0075] This configuration prevents unnecessary compressed air consumption in cases where no machining is performed immediately after spindle 1 stops and the ambient air contains a small amount of foreign matter and liquids. Furthermore, it prevents unnecessary compressed air consumption if spindle 1 remains stationary for the predetermined period after stopping and the concentration of mist, including cutting fluid mist, in the ambient air drops to a negligible level. Consequently, compressed air consumption can be more easily reduced. <Modification>

[0076] In the embodiment described above, the supply condition determination unit 312 determines the supply condition necessary for the compressed air to be supplied to the interior of the spindle 1, based on the operating condition entered into the input unit 305 by the operator of the machine tool M as the rotation status information for the spindle 1. However, this is a non-limiting example. For instance, in a case where the machine tool M further comprises measuring equipment 15 (to be described later) that can measure the rotation status of the spindle 1, the rotation status information acquisition unit 311 can acquire measurement result information that indicates the rotation status of the spindle 1, as measured by the measuring equipment 15, as the rotation status information for the spindle 1.The supply condition determination unit 312 can determine the supply condition required for the compressed air to be supplied to the interior of the spindle 1, based on the measurement result information acquired by the rotation status information acquisition unit 311.

[0077] The following describes a machine tool M according to the above modification with reference to Fig. 1 and the Fig. 4 to 6 described. Fig. Figure 5 is a block diagram illustrating a hardware configuration of a machine tool control device 3 according to the modification. Fig. Figure 6 is a block diagram illustrating a functional configuration of the machine tool control device 3 according to the modification. Components similar to those described in the preceding embodiment are identified by the same reference numerals, and their detailed description is omitted. < Machine tool >

[0078] The machine tool M is a device comprising a spindle that rotates a tool mounted on it to perform machining operations. The machine tool M includes the spindle 1, a compressed air supply device 2, and a machine tool control device 3. < Hardware configuration of the spindle environment >

[0079] As in Fig. As illustrated in Figure 1, the spindle 1 comprises a spindle shaft 10, a plurality of bearings 11, a housing 12, and a labyrinth seal 13 as a non-contact sealing structure. Furthermore, the spindle 1 is equipped with a spindle drive 14 and measuring equipment 15, as illustrated in the Fig. 5 and Fig. 6, provided.

[0080] The measuring equipment 15 is configured to measure the rotational status of the spindle shaft 10. In other words, the machine tool M also includes measuring equipment 15, which can measure the rotational status of the spindle 1. The measuring equipment 15 consists, for example, of a rotary encoder that can measure rotational speed and the rotational velocity of the spindle shaft 10. The measuring equipment 15 can also be suitable for measuring acceleration based on the rotational speed of the spindle shaft 10. < Hardware configuration of the machine tool control device >

[0081] The following is an example of a hardware configuration of the machine tool control device 3 according to the present modification, with reference to Fig. 5 described. As in Fig.As illustrated in Figure 5, the machine tool control device 3 comprises a processor 300, a ROM 301, a RAM 302, a bus 303, an input / output interface 304, an input unit 305, an output unit 306, an additional storage unit 307 and a power supply 308. < Functional configuration of the machine tool control device >

[0082] The functional configuration of the machine tool control device 3 is described below with reference to Fig.6 described. The control unit 310 of the present modification comprises a rotation status information acquisition unit (function for acquiring rotation status information) 311, a supply condition determination unit (function for determining the supply condition) 312, a compressed air control unit (function for compressed air control) 313, a storage unit (storage function) 314 and a spindle control unit (function for spindle control) 315.

[0083] The rotation status information acquisition unit 311 acquires rotation status information indicating the rotation status of spindle 1. For example, according to the present modification, the rotation status information acquisition unit 311 acquires measurement result information indicating the rotation status of spindle 1 as measured by the measuring equipment 15.

[0084] The supply condition determination unit 312 determines a supply condition based on the rotation status information acquired by the rotation status information acquisition unit 311. For example, according to the present modification, the supply condition determination unit 312 determines a supply condition required for the compressed air to be supplied to the interior of the spindle 1, based on the measurement result information acquired by the rotation status information acquisition unit 311.

[0085] For example, for the information described above from the supply condition determination table in Table 1, threshold values ​​for low speed, medium speed, and high speed can be predefined and stored in the additional storage unit 307 or the storage unit 314. The supply condition determination unit 312 can compare the rotational speed measured by the measuring equipment 15 with the stored threshold values ​​to determine the operating condition and determine a supply condition based on the determined operating condition and the information from the supply condition determination table. The supply condition determination unit 312 can also calculate and determine a supply condition based on the measured rotational speed.The specified supply condition may, for example, include a pressure setting or a flow rate setting that is inversely proportional to the measured rotational speed. < Control of compressed air supply >

[0086] The compressed air supply is subsequently described by the machine tool control device 3 according to the present modification with reference to Fig.4 described. When the machine tool control device 3 performs the compressed air supply control according to the present modification, the rotation status information acquisition unit 311, the supply condition determination unit 312, the compressed air control unit 313, the storage unit 314, and the spindle control unit 315 in the processor 300 perform the corresponding functions. The compressed air supply control is started when an operating condition is entered into the input unit 305 by an operator of the machine tool M.

[0087] First, the rotation status information acquisition unit 311 records the measurement result information measured by the measuring equipment 15 as the rotation status information for spindle 1 (step S10).

[0088] Then the supply condition determination unit 312 determines the supply condition required for the compressed air to be supplied to the interior of the spindle 1, based on the measurement result information acquired by the rotation status information acquisition unit 311 (step S11).

[0089] The compressed air control unit 313 then controls the compressed air supply device 2 based on the supply condition determined by the supply condition determination unit 312 (step S12). Specifically, the compressed air control unit 313 causes the compressed air supply device 2 to supply compressed air to the interior of the spindle 1 via the labyrinth seal 13 in accordance with the supply condition determined by the supply condition determination unit 312.

[0090] As described above, different pressures are required to prevent the ingress of foreign bodies and foreign liquids into the spindle 1 at different rotational states of the spindle shaft 10. In the machine tool M according to the present embodiment, the compressed air supplied to the spindle 1 can be set to a pressure appropriate for the rotational state of the spindle shaft 10.

[0091] The machine tool control device 3, according to the modification described above, performs the following functions. According to the machine tool control device 3 of this modification, the machine tool M further comprises measuring equipment 15, which can measure the rotation status of the spindle 1. The rotation status information acquisition unit 311 acquires measurement result information indicating the rotation status of the spindle 1, as measured by the measuring equipment 15, and the supply condition determination unit 312 determines a supply condition required for the compressed air to be supplied to the interior of the spindle 1, based on the measurement result information acquired by the rotation status information acquisition unit 311.

[0092] Due to this configuration, supply information necessary for the compressed air to be supplied to the interior of spindle 1 can be determined for a more detailed rotation status of spindle 1 based on the measurement result, making it possible to further reduce the consumption of compressed air.

[0093] The series of processing operations according to the procedure described above can be performed by hardware or by software. In other words, the operations performed in the Fig. 3 and Fig. The six illustrated functional configurations are merely examples, and no particular restrictions apply. Specifically, it is simply necessary to have a function to perform the series of processes described above as a whole, and the functional blocks used to fulfill this function are not specifically limited to those shown in the Fig. 3 and Fig. Limited to 6 illustrated examples.

[0094] A functional block can be formed by hardware alone, by software alone, or by a combination of both. The functional configuration of the present embodiment is implemented by a processor that performs arithmetic processing, and examples of the processor that can be used in the present embodiment include a processor formed solely from one of several processing devices, for example, a single processor, a multiprocessor, and a multi-core processor, as well as a processor in which one or more different processing devices are combined with a processing circuit, for example, an application-specific integrated circuit (ASIC) or a field-programmable gate array (FPGA).

[0095] In a case where the processing sequence is executed by software, a program constituting the software is installed on a computer or similar device from a network or storage medium. The computer can be a computer integrated into dedicated hardware. Alternatively, the computer can be a computer capable of performing various functions by installing different programs, for example, a general-purpose personal computer.

[0096] Examples of a storage medium containing such a program include not only a removable medium distributed separately from the device body to provide the program to a user, but also a storage medium or the like that is pre-integrated into the device body and provided to a user. Examples of a removable medium include a magnetic disk (including a floppy disk), an optical disk, a magneto-optical disk, and the like. Examples of optical disks include a compact disk-read-only memory (CD-ROM), a digital versatile disk (DVD), a Blu-ray disc (registered trademark), and the like. Examples of magneto-optical disks include a MiniDisc (MD) and the like.Examples of the capture medium that is pre-integrated into a device body and made available to a user include the ROM on which a program is captured and which is stored in the . Fig. 2 and Fig. Figure 5 illustrates a hard drive that is in the Fig. 2 and Fig. 5 illustrated additional storage units are included, and the like.

[0097] It should be noted that in the present description, steps for describing a program to be recorded on a storage medium include not only processes that are to be executed sequentially, but also processes that are to be executed in parallel or individually and not necessarily sequentially.

[0098] Although some embodiments of the present invention have been described above, these embodiments are merely examples and are not intended to limit the technical scope of protection of the present invention. The present invention can be implemented in various other embodiments, and furthermore, various modifications such as omissions and substitutions can be made without departing from the essence of the present invention. These embodiments and modifications are included in the scope of protection and the essence of the invention as described in this description and other related documents, and are included in the invention as described in the claims and equivalents thereof.

[0099] Further remarks on the above embodiments and modifications are disclosed below. (Additional remark 1)

[0100] A machine tool control device for controlling a machine tool, comprising a spindle and a compressed air supply device that supplies compressed air to an interior of the spindle, wherein the machine tool control device includes the following: a rotation status information acquisition unit that acquires rotation status information indicating the rotation status of the spindle; a supply condition determination unit that determines a supply condition required for compressed air to be supplied to the interior of the spindle, based on the rotation status information acquired by the rotation status information acquisition unit; and a compressed air control unit that controls the compressed air supply device based on the supply condition determined by the supply condition determination unit. (Additional remark 2)

[0101] According to the machine tool control device of supplementary remark 1, the machine tool includes an operating input unit into which an operator can enter an operating condition, The rotation status information acquisition unit captures the operating condition entered by the operator as the rotation status information, and The supply condition determination unit determines the supply condition required for compressed air to be supplied to the interior of the spindle, based on a spindle rotation status specified by the operating condition detected by the rotation status information acquisition unit. (Additional remark 3)

[0102] The machine tool control device according to supplementary note 2 further comprises a storage unit in which assignment information is stored that assigns the operating condition to the supply condition, and the supply condition determination unit determines the supply condition based on the operating condition entered into the operating input unit and the assignment information stored in the storage unit. (Additional remark 4)

[0103] According to the machine tool control device of supplementary remark 1, the machine tool further includes measuring equipment that can measure a rotation status of the spindle, The rotation status information acquisition unit captures measurement result information that indicates the rotation status of the spindle, measured by the measuring equipment as rotation status information, and The supply condition determination unit determines the supply condition required for compressed air to be supplied to the interior of the spindle, based on the measurement result information acquired by the rotation status information acquisition unit. (Additional remark 5)

[0104] According to the machine tool control device, as per one of the additional remarks 1 to 4, the rotation status of the spindle includes a status of the rotation speed of the spindle. (Additional remark 6)

[0105] According to the machine tool control device, as per one of the additional remarks 1 to 5, the rotation status of the spindle includes a status of rotational acceleration of the spindle. (Additional note 7)

[0106] According to the machine tool control device, as per one of the additional remarks 1 to 6, the supply condition for compressed air determined by the supply condition determination unit is a pressure of compressed air. (Additional remark 8)

[0107] According to the machine tool control device, as per one of the additional remarks 1 to 7, the supply condition for compressed air determined by the supply condition determination unit is a flow rate of compressed air. (Additional remark 9)

[0108] According to the machine tool control device, as per one of the supplementary remarks 5 to 7, the supply condition determination unit determines a lower pressure as the supply condition when the rotational speed of the spindle increases, and determines a higher pressure as the supply condition when the rotational speed of the spindle decreases. (Additional note 10)

[0109] According to the machine tool control device of supplementary note 9, the supply condition determination unit determines a lower pressure as the supply condition for a predetermined period immediately after the spindle rotation has stopped, and The compressed air control unit stops the operation of the compressed air supply device immediately after the predetermined period has elapsed and the spindle rotation has stopped. M machine tool 1 spindle 2 Compressed air supply device 3 machine tool control device 311 Rotation status information acquisition unit 312 Supply Conditions Determination Unit 313 Compressed air control unit

Claims

[1] Machine tool control device for controlling a machine tool, comprising a spindle and a compressed air supply device which supplies compressed air to an interior of the spindle, wherein the machine tool control device comprises: a rotation status information acquisition unit that acquires rotation status information indicating the rotation status of the spindle; a supply condition determination unit that determines a supply condition required for compressed air to be supplied to the interior of the spindle, based on the rotation status information acquired by the rotation status information acquisition unit; and a compressed air control unit that controls the compressed air supply device based on the supply condition determined by the supply condition determination unit. [2] Machine tool control device according to claim 1, wherein the machine tool includes an operating input unit into which an operator can enter an operating condition, The rotation status information acquisition unit captures the operating condition entered by the operator as the rotation status information, and The supply condition determination unit determines the supply condition required for compressed air to be supplied to the interior of the spindle, based on a spindle rotation status indicated by the operating condition detected by the rotation status information acquisition unit. [3] Machine tool control device according to claim 2, further comprising: a storage unit that stores mapping information that maps the operating condition to the supply condition, wherein The supply condition determination unit determines the supply condition based on the operating condition entered into the operating input unit and the allocation information stored in the storage unit. [4] Machine tool control device according to claim 1, wherein The machine tool also includes measuring equipment that can measure the rotation status of the spindle, The rotation status information acquisition unit acquires measurement result information that indicates the rotation status of the spindle, measured by the measuring equipment as rotation status information, and The supply condition determination unit determines the supply condition required for compressed air to be supplied to the interior of the spindle, based on the measurement result information acquired by the rotation status information acquisition unit. [5] Machine tool control device according to claim 1 or 2, wherein the rotation status of the spindle includes a status of a rotation speed of the spindle. [6] Machine tool control device according to claim 1 or 2, wherein the rotation status of the spindle includes a status of rotation acceleration of the spindle. [7] Machine tool control device according to claim 1 or 2, wherein the supply condition for compressed air determined by the supply condition determination unit is a pressure of compressed air. [8] Machine tool control device according to claim 1 or 2, wherein the supply condition for compressed air determined by the supply condition determination unit is a flow rate of compressed air. [9] Machine tool control device according to claim 5, wherein the supply condition determination unit determines a lower pressure as the supply condition when the rotational speed of the spindle increases, and determines a higher pressure as the supply condition when the rotational speed of the spindle decreases. [10] Machine tool control device according to claim 9, wherein The supply condition determination unit determines a lower pressure as a supply condition for a predetermined period immediately after the spindle rotation stops, and The compressed air control unit stops the operation of the compressed air supply device immediately after the predetermined period has elapsed and the spindle rotation has stopped.

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