JP-2026075425-A - Machine tool, control method, and control program

JP2026075425AJP 2026075425 AJP2026075425 AJP 2026075425AJP-2026075425-A

Abstract

[Problem] To provide a technique for accurately estimating characteristic values that correlate with the flow resistance of coolant within a tool. [Solution] The machine tool comprises a spindle having a second passage connected to a first passage of the tool when the tool is mounted, a pump that pumps coolant into a main passage connected to the second passage, an adjustment mechanism that adjusts the flow rate of coolant in the main passage or its branch passages, a pressure sensor that detects the discharge pressure of coolant from the tool, a flow sensor that detects the discharge amount, and a control unit. The control unit performs the following processes: acquiring information that defines the relationship between the discharge pressure of coolant from the tool's discharge port, the discharge amount of coolant from the discharge port, and a characteristic value that correlates with the flow resistance of the coolant within the tool; and estimating a characteristic value that correlates with the flow resistance of the coolant within the machining tool based on the above information, the detected discharge pressure, and the detected discharge amount. [Selection Diagram] Figure 3

Inventors

船越元気
神田悟
月脚博文

Assignees

ＤＭＧ森精機株式会社

Dates

Publication Date: 20260508
Application Date: 20241022

Claims (9)

A machine tool capable of machining a workpiece using a machining tool in which a first coolant passage is formed inside, A spindle is configured to be able to mount the aforementioned machining tool, and has a second passage that is connected to the first passage when the machining tool is mounted, A pump for pressurizing and supplying coolant to the main flow path connected to the second passage, One or more branch channels branching off from the main channel, or an adjustment mechanism capable of adjusting the flow rate of coolant in the main channel, A pressure sensor for detecting the discharge pressure of coolant from the aforementioned machining tool, A flow sensor for detecting the amount of coolant discharged from the machining tool, It includes a control unit, The control unit, A process for acquiring information that defines the relationship between the coolant discharge pressure from the tool's discharge port, the amount of coolant discharged from the said discharge port, and a characteristic value that correlates with the flow resistance of the coolant within the tool, A machine tool that performs a process of estimating a characteristic value correlated with the flow resistance of the coolant within the machining tool, based on the aforementioned information, the discharge pressure detected by the pressure sensor, and the discharge amount detected by the flow sensor.
The characteristic value relating to the tool specified in the aforementioned information is the size of the tool's discharge port. The machine tool according to claim 1, wherein the characteristic value related to the machining tool estimated in the estimation process is the size of the discharge port of the machining tool.
The control unit further, A process to control the adjustment mechanism according to the estimated size, The machine tool according to claim 2, wherein after the execution of the control process, a process for controlling the pump is performed.
The branch channel from the main channel includes a first branch channel and a second branch channel. The adjustment mechanism is, A first valve provided in the first branch channel, The system includes a second valve provided in the second branch channel, The first valve is configured to at least switch whether or not to allow the coolant in the main passage to flow into the first branch passage by opening and closing the first valve, The second valve is configured to at least switch whether or not to allow the coolant in the main passage to flow into the second branch passage by opening and closing the second valve, The machine tool according to claim 3, wherein the process for controlling the adjustment mechanism controls the opening and closing of the first valve and the opening and closing of the second valve.
The maximum flow rate of the first branch passage when the first valve is open is less than the maximum flow rate of the coolant in the second branch passage when the second valve is open. In the process of controlling the adjustment mechanism, If the estimated size is smaller than the first threshold, the first valve is closed and the second valve is opened. If the estimated size is greater than or equal to the first threshold and less than the second threshold, the first valve is opened and the second valve is closed. If the estimated size is greater than or equal to the second threshold, both the first valve and the second valve are closed. The machine tool according to claim 4, wherein the first threshold is smaller than the second threshold.
The process for controlling the pump is as follows: Feedforward control that controls the pump without relying on the discharge pressure detected by the pressure sensor and the discharge amount detected by the flow sensor, The system includes feedback control that controls the pump so that the discharge pressure detected by the pressure sensor or the discharge amount detected by the flow sensor approaches a target value, In the process of controlling the pump, If the target value is smaller than a predetermined threshold, the feedback control is started after the feedforward control is executed. The machine tool according to any one of claims 3 to 5, wherein if the target value is greater than or equal to the predetermined threshold, the feedforward control is not performed and the feedback control is started.
The control unit, A first control device capable of controlling the pump, The system comprises a second control device different from the first control device, The machine tool according to any one of claims 1 to 5, wherein the estimation process is performed by the second control device.
A control method for a machine tool capable of machining a workpiece using a machining tool having a first coolant passage formed inside, The aforementioned machine tool is A spindle is configured to be able to mount the aforementioned machining tool, and has a second passage that is connected to the first passage when the machining tool is mounted, A pump for pressurizing and supplying coolant to the main flow path connected to the second passage, One or more branch channels branching off from the main channel, or an adjustment mechanism capable of adjusting the flow rate of coolant in the main channel, A pressure sensor for detecting the discharge pressure of coolant from the aforementioned machining tool, The system includes a flow sensor for detecting the amount of coolant discharged from the machining tool, The control method described above is A step of obtaining information that defines the relationship between the discharge pressure of coolant from the tool's discharge port, the discharge volume of coolant from said discharge port, and a characteristic value that correlates with the flow resistance of the coolant within the tool, A control method comprising the steps of estimating a characteristic value that correlates with the flow resistance of the coolant in the machining tool, based on the aforementioned information, the discharge pressure detected by the pressure sensor, and the discharge amount detected by the flow sensor.
A control program for a machine tool capable of machining a workpiece using a machining tool having a first coolant passage formed inside, The aforementioned machine tool is A spindle is configured to be able to mount the aforementioned machining tool, and has a second passage that is connected to the first passage when the machining tool is mounted, A pump for pressurizing and supplying coolant to the main flow path connected to the second passage, One or more branch channels branching off from the main channel, or an adjustment mechanism capable of adjusting the flow rate of coolant in the main channel, A pressure sensor for detecting the discharge pressure of coolant from the aforementioned machining tool, The system includes a flow sensor for detecting the amount of coolant discharged from the machining tool, The control program is provided to the machine tool. A process for acquiring information that defines the relationship between the coolant discharge pressure from the tool's discharge port, the amount of coolant discharged from the said discharge port, and a characteristic value that correlates with the flow resistance of the coolant within the tool, A control program that performs a process to estimate characteristic values correlated with the flow resistance of the coolant within the machining tool, based on the aforementioned information, the discharge pressure detected by the pressure sensor, and the discharge amount detected by the flow rate sensor.

Description

This disclosure relates to machine tools, control methods, and control programs. Japanese Patent Publication No. 2016-64462 (Patent Document 1) discloses a machine tool capable of machining a workpiece while discharging coolant from the tip of the tool. A spindle capable of mounting such a tool is called a coolant-through spindle. Japanese Patent Publication No. 2016-64462 This is a diagram showing the external appearance of a machine tool.This figure shows an example of a coolant supply mechanism.This diagram schematically illustrates the process that estimates the aperture size.This diagram shows a flowchart related to the calibration phase.This diagram shows a flowchart related to the calibration phase.This figure shows an example of a tool database.This diagram shows a flowchart related to the processing phase.This figure shows a flowchart relating to the process in step S300, as shown in Figure 7.This is a diagram illustrating the second driving mode.This figure shows a flowchart relating to the process in step S400, as shown in Figure 7.This figure shows an example of threshold information.This figure shows a flowchart relating to the process in step S500, as shown in Figure 7.This figure shows an example of the hardware configuration of a CPU (Central Processing Unit) unit.This figure shows an example of the hardware configuration of a CNC (Computer Numerical Control) unit.This figure shows an example of the hardware configuration of a control panel.This figure shows an example of an implementation configuration for a calibration program and a dispensing program.This diagram shows a coolant supply mechanism according to a modified example. The following describes various embodiments of the present invention with reference to the drawings. In the following description, identical parts and components are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed descriptions of these will not be repeated. The embodiments and modifications described below may be combined selectively as appropriate. <A. Machine tools 100> First, a machine tool 100 according to an embodiment will be described with reference to Figure 1. Figure 1 is a diagram showing the external appearance of the machine tool 100. In this specification, "machine tool" is a concept that encompasses various devices equipped with the function of processing a workpiece. Machine tool 100 may be a horizontal machining center or a vertical machining center. Alternatively, machine tool 100 may be a lathe, or other cutting machine, grinding machine, multi-tasking machine, 5-axis machining center, etc. Furthermore, machine tool 100 is not limited to performing only subtractive machining. Machine tool 100 may perform additive machining in addition to subtractive machining. The machine tool 100 has a tool storage section 40A and a machine tool body 40B. Each of the tool storage section 40A and the machine tool body 40B is partitioned by a cover. The tool storage section 40A is equipped with a magazine 150 and an ATC (Automatic Tool Changer) 160. The machine tool body 40B is equipped with a spindle head 170. The spindle head 170 includes a spindle cylinder 175 and a spindle 180. The spindle 180 is rotatably supported in the spindle cylinder 175, with its axial direction as the center of rotation. The rotation of the spindle 180 is achieved, for example, by a drive mechanism such as a motor. A tool selected from the magazine 150 is mounted on the spindle 180. More specifically, the machine tool 100 drives the magazine 150 to move a tool (hereinafter also referred to as the "machining tool") corresponding to the machining process to the first tool change position. The machine tool 100 also drives the spindle head 170 to move the tool mounted on the spindle 180 (hereinafter also referred to as the "used tool") to the second tool change position. Subsequently, the ATC 160 exchanges the machining tool waiting at the first tool change position with the used tool waiting at the second tool change position. The tool exchange is performed via a door D located in the partition between the machine tool body 40B and the tool storage section 40A. The door D is a sliding door and is opened and closed by a drive source such as a motor. Afterward, the machine tool 100 processes the workpiece using the machining tool mounted on the spindle 180. Furthermore, the machine tool 100 is equipped with an operation panel 400. The operation panel 400 includes a display 405 for displaying various information related to machining, and operation keys 406 for receiving various operations on the machine tool 100. <B. Coolant Supply Mechanism> Next, the coolant supply mechanism in the machine tool 100 will be described with reference to Figure 2. Figure 2 shows an example of a coolant supply mechanism. The machine tool 100 includes a control unit 50, a coolant tank 52, a motor driver 54, a motor 55, a pump 56, an adjustment mechanism 58,