Control method and control device for cooling auxiliary equipment in machine tools

Abstract

To make it possible to perform processing with minimum energy over a shortest period of time by controlling an auxiliary machine for cooling according to a relatively simple method.SOLUTION: A control method of an auxiliary machine for cooling in a machine tool executes the steps: S-0 of preliminarily reading an NC program; S-1 of deriving a contact initiation position and contact termination position, based on model data on a tool, model data on a workpiece, and the NC program; S-2 of calculating a stableness distance L causing an arrival time T, which is required until movement to a contact position is completed, to be equal to or larger than a time t required until a motion of an auxiliary machine becomes stable; S-3 of delineating a region apart from each of contact position by the stableness distance L; S-4 of acquiring a position for entering the region; S-5 of moving to the contact initiation position; S-6 of issuing an auxiliary machine motion change command (motion control ON) at the position for entering the region; S-7 of moving to the contact termination position; S-8 of determining whether or not a next contact initiation position exists; S-9 of acquiring a position for exiting from the region when the next contact initiation position is determined not to exist; and S-10 of issuing an auxiliary machine motion change command (motion control OFF) at the position acquired at S-9.SELECTED DRAWING: Figure 2

Description

【Technical Field】 【0001】 The present disclosure relates to a control method and a control device for auxiliary equipment for cooling in a machine tool. Herein, the "auxiliary equipment for cooling" in the present disclosure refers to equipment or devices provided integrally or separately to a machine tool for supplying a cooling medium such as coolant, air, or oil mist to a predetermined machining site. 【Background Art】 【0002】 In a machine tool that performs cutting machining, by supplying a large amount of cooling media such as liquid coolant, air, or oil mist to the machining site, heat dissipation of the workpiece and the tool is performed, and auxiliary equipment for cooling is provided to prevent discharge of chips and welding to the tool. At that time, from the perspective of environmental protection, etc., it is a tendency to refrain from constantly using the auxiliary equipment for cooling. Conventionally, it has been activated and used according to the M code described in the machining program according to the timing of use, or according to the rotation and load of the spindle. For example, in Patent Document 1, an invention of a numerical control machine tool that finely controls the operation time of an auxiliary function is disclosed by starting the operation of the auxiliary function in advance based on the time required until a code for commanding the operation of the auxiliary function including the auxiliary equipment for cooling is executed. In Patent Document 2, an invention of a numerical control device that finely controls the operation time of an auxiliary function is disclosed by including a code for the operation command of the auxiliary function in the block of the contact position for performing the auxiliary operation including the auxiliary equipment for cooling in the program and pre-reading that block. 【Prior Art Documents】 【Patent Documents】 【0003】 【Patent Document 1】 Japanese Patent No. 5210070 【Patent Document 2】 Japanese Patent No. 6215872 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0004】 However, when the cooling auxiliary equipment is operated in advance according to a predetermined time, there is a problem that it may operate before the cooling auxiliary equipment is needed, depending on the machine's movement state and path, resulting in wasted operating time. In addition, precisely controlling the operation requires a large number of M codes and command positions, which can make the NC program complicated. 【0005】 Therefore, this disclosure was devised to solve the above-mentioned problems and aims to provide a control method and control device for a cooling auxiliary device in a machine tool that enables machining in the minimum time and with the minimum energy by controlling the cooling auxiliary device in a relatively simple manner. [Means for solving the problem] 【0006】 To achieve the above objective, the first configuration of this disclosure is a method for controlling a cooling auxiliary device provided in a machine tool for supplying a cooling medium to a predetermined machining area, A contact start / end position calculation step calculates, based on a machining program, tool model data, and workpiece model data, the contact start position where the tool contacts the workpiece on the tool's movement path, and the contact end position just before the tool leaves the workpiece on the movement path, respectively. A first operation switching step in which the cooling auxiliary device is operated at a predetermined position before the tool reaches the contact start position on the aforementioned movement path, A second operation switching step is performed, which involves stopping the operation of the cooling auxiliary equipment at a predetermined passing position after passing the contact termination position on the aforementioned movement path. Along with, In the first operation switching step, a stable distance is calculated based on the time it takes for the cooling auxiliary equipment to start operating and reach a stable state, and the feed speed of the tool on the movement path, such that the stable distance is at least equal to the distance required for the stable operation of the cooling auxiliary equipment. The position that is at least equal to the stable distance from the contact start position is set as the front position. It is characterized by the following: Another aspect of the first configuration is, in the above configuration, when, in the contact start / end position calculation step, a plurality of contact start positions and contact end positions are calculated alternately, In the first operation switching step, at each of the contact start positions and each of the contact end positions, a region with a radius equal to the stabilization distance is set, During the operation of the cooling auxiliary equipment due to the execution of the first operation switching step, from the contact end position to the next contact start position The movement path is within the region. In this case, the second operation switching step is not performed. Another aspect of the first configuration is characterized in that, in the above configuration, the first operation switching step and the second operation switching step switch the operation control of the cooling auxiliary equipment to enable and disable it by a single block command, thereby causing the cooling auxiliary equipment to operate and stop. To achieve the above objective, a second configuration of this disclosure is a device for controlling a cooling auxiliary device provided in a machine tool for supplying a cooling medium to a predetermined machining area, A contact start / end position calculation means calculates, based on a machining program, tool model data, and workpiece model data, the contact start position where the tool contacts the workpiece on the movement path, and the contact end position just before the tool leaves the workpiece on the movement path, respectively. A first operation switching means for operating the cooling auxiliary device at a predetermined position before the tool reaches the contact start position on the aforementioned movement path, The system includes a second operation switching means for stopping the operation of the cooling auxiliary equipment at a predetermined passing position after passing the contact termination position on the aforementioned movement path. Along with, The first operation switching means calculates a stable distance that is at least the distance required for the stable operation of the cooling auxiliary equipment, based on the time it takes for the cooling auxiliary equipment to start operating and reach a stable state, and the feed speed of the tool on the movement path, and sets the position that is at least the stable distance away from the contact start position to the front position. It is characterized by the following: [Effects of the Invention] 【0007】 According to this disclosure, it becomes possible to control the cooling auxiliary equipment using a relatively simple method with a machining program and model data, thereby minimizing the operation of the cooling auxiliary equipment. As a result, machining can be performed in the shortest time and with the shortest energy. [Brief explanation of the drawing] 【0008】 [Figure 1] This is a block diagram illustrating the schematic configuration of a control device for a machine tool. [Figure 2] This is a flowchart showing the control method for the cooling auxiliary equipment. [Figure 3] It is an explanatory diagram showing an example of an area to be set as a contact position and an NC program. [Figure 4] It is a graph showing the change in flow rate from the operation command of the auxiliary machine for cooling to the stable operation. [Figure 5] It is an explanatory diagram showing an example when the movement path exits from the area. [Figure 6] It is an explanatory diagram showing an example when the movement path is within the area. [Figure 7] It is an explanatory diagram showing an example of an NC program for performing an operation switching command of the auxiliary machine for cooling. [Figure 8] It is an explanatory diagram showing an example of an NC program rewritten by the control method of the auxiliary machine for cooling. FIG. 8A shows the case where the movement path exits from the area, and FIG. 8B shows the case where the movement path is within the area. 【Mode for Carrying Out the Invention】 【0009】 Hereinafter, embodiments of the present disclosure will be described based on the drawings. FIG. 1 schematically shows an example of a control device according to the second configuration. The control device 10 shown in FIG. 1 is also a control device of a machine tool, and includes a storage unit 11, a program interpretation unit 12, a feed axis control unit 13, and an auxiliary machine control unit 14. The storage unit 11 stores non-temporarily a machining program, model data of tools and workpieces, etc. The program interpretation unit 12 interprets the machining program stored in the storage unit 11 and outputs it to the feed axis control unit 13 and the auxiliary machine control unit 14. The feed axis control unit 13 controls the feed axis 15 based on the interpreted machining program. The auxiliary machine control unit 14 controls the operation of a cooling auxiliary machine 16 that supplies coolant to a machining part based on the interpreted machining program. The control device 10 is configured to include a CPU and memory connected to the CPU, and controls the operation of predetermined machining and cooling auxiliary equipment 16 via the feed axis control unit 13 and the auxiliary equipment control unit 14. The control device 10 is an example of a contact start / end position calculation means, a first operation switching means, and a second operation switching means. 【0010】 The control method for the cooling auxiliary equipment (hereinafter simply referred to as "auxiliary equipment") 16 related to the first configuration by the control device 10 will be explained below based on the flowchart in Figure 2. Here, an NC program that performs machining on the X and Y planes will be used as an example of the machining program. First, the NC program is pre-read using S-0. Next, in S-1, as shown in Figure 3, based on the pre-set model data of tool 1, model data of workpiece 2, and NC program, the contact start position p1 and contact end position q1 are derived from the point where the movement path connecting command positions a2 and a3 intersects with the model data of workpiece 2, and the contact start position p2 and contact end position q2 are derived from the point where the movement path connecting command positions a4 and a5 intersects with the model data of workpiece 2 (contact start / end position calculation step). Next, in S-2, the distance (stable distance) L at which the time T to reach the contact position, calculated from the quotient of the distance L to the contact position derived in S-1 and the maximum feed rate Fmax of the machine, is equal to or greater than the time t until the auxiliary machine 16 stabilizes, is calculated using the following equation 2. Time t is the time from the operation command t1 to t2, when the auxiliary machine 16 stabilizes with a constant coolant flow rate, as shown in Figure 4, and is calculated using the following equation 1. Note that in the case where the feed rate is constant as in this example, the stable distance L may be calculated using the feed rate FF as shown in the following equation 3. Here, the feed rate FF is the one described in the NC program, but it may be changed within the scope of this disclosure, such as by using a calculated value of the feed rate that takes into account acceleration / deceleration and feed rate override. 【0011】 t=t2-t1 (formula 1) L=Fmax×T (t≦T) (Formula 2) L=FF×T (t≦T) (Formula 3) 【0012】 Next, in S-3, the region r1 to r4 of the stable distance L is set from the contact positions p1 and p2 and contact end positions q1 and q2 derived in S-1. The following describes the case where the movement path from the contact end position q1 to the contact start position p2 exits the region, as shown in Figure 5. First, in S-4, the movement path connecting command positions a2 and a3, and position b1, which enters the region that intersects with region r1 before passing contact start position p1, are obtained. This position b1 is an example of a predetermined pre-position. Next, in S-5, move to the contact start position p1. Next, in S-6, a command to switch the operation of the auxiliary device 16 (in this case, operation control ON) is issued at position b1 where the acquired area is entered (S-2 to S-6: First operation switching step). Next, in S-7, move to the contact end position q1. 【0013】 Next, in S-8, it is determined whether there is a next contact start position. Here, there is a next contact start position p2, so in S-11, it is determined whether the movement path to the next contact start position p2 goes inside or outside the region. Here, since the movement to the contact start position p2 exits the regions r2 and r3 set from the contact end position q1 and the contact start position p2, in S-12, the position c1 is obtained, which is the exit point from the region where the movement path connecting command positions a2 and a3 intersects with region r2 after passing the contact end position q1. This position c1 is an example of a predetermined passing position. Next, in S-13, move outside the area. Next, in S-14, a command to switch the operation of the auxiliary equipment 16 (in this case, operation control OFF) is issued at position c1 acquired in S-12 (S-7 to S-14: Second operation switching step). Next, in S-4, the movement path connecting command positions a4 and a5, and position b2, which enters the region where it intersects with region r3 before passing contact start position p2, are obtained. This position b2 is an example of a predetermined pre-position. Next, at S-5, the system moves to the contact start position p2. Next, in S-6, a command to switch the operation of the auxiliary equipment 16 (in this case, operation control ON) is issued at position b2, which is the location of the area acquired in S-4 (S-4 to S-6: First operation switching step). 【0014】 Next, in S-7, move to the contact end position q2. Next, in S-8, it is determined whether or not there is a next contact start position. Since there is no next contact start position at command position a5, in S-9, the movement path connecting command positions a4 and a5 is obtained, and the position c2 is obtained when exiting the region that intersects with region r4 after passing contact end position q2. This position c2 is an example of a predetermined passage position. Next, in S-10, a command to switch the operation of the auxiliary equipment 16 (in this case, operation control OFF) is issued at position c2 acquired in S-9 (S-7~S-10: Second operation switching step). In this example, the operation control of the auxiliary device 16 was turned OFF at position c2, which was obtained in the stable distance L region r4. However, any position that has passed the contact termination position q2 may be before position c2. 【0015】 Next, we will explain the case where the movement path from the contact end position q1 to the contact start position p2 is within the region, as shown in Figure 6. Since S-0 to S-3 are the same as in the previous case, the explanation will be omitted. Next, in S-4, the movement path connecting command positions a2 and a3, and position b1, which enters the region that intersects with region r1 before passing contact start position p1, are obtained. Next, in S-5, move to the contact start position p1. Next, in S-6, an operation switching command (operation control ON) is issued for the auxiliary equipment 16 at position b1, which is the position to enter the acquired area (first operation switching step). Next, in S-7, move to the contact end position q1. 【0016】 Next, in S-8, it is determined whether there is a next contact start position. Here, there is a next contact start position p2, so in S-11, it is determined whether the movement path to the next contact start position p2 is within or outside the region. Here, the movement to the contact start position p2 is within the regions r2 and r3 set from the contact end position q1 and the contact start position p2, so in S-15, the movement to the contact start position p2 is performed. Next, in S-7, move to the contact end position q2. Next, in S-8, it is determined whether or not there is a next contact start position. Since there is no next contact start position at command position a5, in S-9, the movement path connecting command positions a4 and a5 and the position c2 at which the system exits the region that intersects with region r4 after passing contact end position q2 are obtained. Next, in S-10, a command to switch the operation of the auxiliary equipment 16 (operation control OFF) is issued at position c2 acquired in S-9 (second operation switching step). 【0017】 Figure 7 shows an example of an NC program that issues commands for switching the operation of the auxiliary device 16. In the control method described above, the operation of the auxiliary machine 16 is switched simply by issuing the command M800 to turn the operation control of the auxiliary machine 16 ON and M801 to turn the operation control of the auxiliary machine 16 OFF, without writing any code for the operation switching command of the auxiliary machine 16. In this example, the operation of the auxiliary machine 16 is enabled by issuing the command M800 in the NC program, but the operation of the auxiliary machine 16 could also be switched by, for example, switching the enable or disable of a parameter set on the machine tool. 【0018】 Figure 8 shows an example of an NC program rewritten using the control method described above. In this example, the program is explained using a program in which the operation switching commands for the auxiliary equipment 16 are performed by the auxiliary equipment 16 operation start command M08 and the auxiliary equipment 16 operation stop command M09. Figure 8A shows an example program where the movement path from the contact end position q1 to the contact start position p2 exits the region, as shown in Figure 5. In Figure 5, the movement path connecting command positions a2 and a3 includes a position b1 for entering the area and a position c1 for exiting the area. Therefore, in one block between command positions a2 and a3, there is a command position b for switching the operation of the auxiliary device 16. 1x The auxiliary equipment 16 operation start command M08 is added, and the auxiliary equipment 16 operation switching command position c is added to the next block as described above. 1x Add the instruction M09 to stop the operation of auxiliary equipment 16. Furthermore, in the movement path connecting command positions a4 and a5, there is a position b2 for entering the area and a position c2 for exiting the area. Therefore, in one block between command positions a4 and a5, there is an operation switching command position b of the auxiliary device 16. 2x The auxiliary equipment 16 operation start command M08 is added, and the auxiliary equipment 16 operation switching command position c is added to the next block as described above. 2x Add the instruction M09 to stop the operation of auxiliary equipment 16. 【0019】 Figure 8B shows an example program where the movement path from the contact end position q1 to the contact start position p2 is within the region, as shown in Figure 6. In Figure 6, there is a position b1 that enters the area along the movement path connecting command positions a2 and a3. Therefore, in one block between command positions a2 and a3, there is a command position b for switching the operation of the auxiliary device 16. 1x Add the instruction M08 to start operation of auxiliary equipment 16. Furthermore, in the movement path connecting command positions a4 and a5, there is a position c2 where the unit exits the area. Therefore, in one block between command positions a4 and a5, there is a command position c for switching the operation of the auxiliary unit 16. 2x Add the instruction M09 to stop the operation of auxiliary equipment 16. 【0020】 In this manner, the control method and control device 10 for the auxiliary equipment 16 in the machine tool of the above configuration calculate, based on the NC program, the model data of the tool 1, and the model data of the workpiece 2, the contact start position where the tool 1 makes contact with the workpiece 2 on the movement path 3 of the tool 1, and the contact end position just before the tool 1 leaves the workpiece 2 on the movement path 3. The auxiliary equipment 16 is operated at a predetermined position before the tool 1 reaches the contact start position on the movement path 3, and the operation of the auxiliary equipment 16 is stopped at a predetermined position after passing the contact end position on the movement path 3. This configuration allows for the control of the auxiliary equipment 16 using a relatively simple method involving NC programs and model data, minimizing the operation of the auxiliary equipment 16. Therefore, machining can be performed in the shortest possible time and with the least amount of energy. 【0021】 This disclosure is not limited to the examples of embodiments described above, and can be implemented in various forms by making appropriate modifications. The cooling medium is not limited to coolant; it may also be air, oil mist, or other similar substances. The movement path is not limited to the above configuration and can be changed as appropriate. The number of contact start and end points can also be increased or decreased as appropriate according to the movement path. In the above configuration, the control device for the auxiliary equipment is provided in the control device for the machine tool, but the control device for the auxiliary equipment may be provided separately from the control device for the machine tool. [Explanation of symbols] 【0022】 1. Tool, 2. Workpiece, 3. Movement path, 10. Control device, 11. Memory unit, 12. Program interpretation unit, 13. Feed axis control unit, 14. Auxiliary equipment control unit, 15. Feed axis, 16. Cooling auxiliary equipment.

Claims

[Claim 1] A method for controlling a cooling auxiliary device installed in a machine tool to supply a cooling medium to a predetermined machining area, A contact start / end position calculation step calculates, based on a machining program, tool model data, and workpiece model data, the contact start position where the tool contacts the workpiece on the tool's movement path, and the contact end position just before the tool leaves the workpiece on the movement path, respectively. A first operation switching step in which the cooling auxiliary device is operated at a predetermined position before the tool reaches the contact start position on the aforementioned movement path, A second operation switching step which stops the operation of the cooling auxiliary equipment at a predetermined passing position after passing the contact termination position on the aforementioned movement path, Execute the following: A method for controlling a cooling auxiliary device in a machine tool, characterized in that, in the first operation switching step, a stable distance is calculated based on the time it takes for the cooling auxiliary device to start operating and reach a stable state, and the feed speed of the tool on the movement path, and the position that is at least the distance required for the stable operation of the cooling auxiliary device is set to the front position, which is at least the distance from the contact start position to the stable distance. [Claim 2] In the step of calculating the contact start and end positions, if multiple contact start positions and contact end positions are calculated alternately, In the first operation switching step, at each of the contact start positions and each of the contact end positions, a region with a radius equal to the stabilization distance is set, A method for controlling a cooling auxiliary device in a machine tool according to claim 1, characterized in that, during the operation of the cooling auxiliary device by the execution of the first operation switching step, if the movement path from the contact end position to the next contact start position is within the area, the second operation switching step is not executed. [Claim 3] The method for controlling a cooling auxiliary device in a machine tool according to claim 1 or 2, characterized in that in the first operation switching step and the second operation switching step, the operation and stopping of the cooling auxiliary device are controlled by switching the operation control of the cooling auxiliary device to enabled and disabled by a single block command. [Claim 4] A device for controlling a cooling auxiliary machine installed in a machine tool to supply a cooling medium to a predetermined machining area, A contact start / end position calculation means calculates, based on a machining program, tool model data, and workpiece model data, the contact start position where the tool contacts the workpiece on the movement path, and the contact end position just before the tool leaves the workpiece on the movement path, respectively. A first operation switching means for operating the cooling auxiliary device at a predetermined position before the tool reaches the contact start position on the aforementioned movement path, A second operation switching means for stopping the operation of the cooling auxiliary equipment at a predetermined passing position after passing the contact termination position on the aforementioned movement path, It is equipped with, The control device for a cooling auxiliary device in a machine tool is characterized in that the first operation switching means calculates a stable distance that is at least the distance required for the stable operation of the cooling auxiliary device, based on the time it takes for the cooling auxiliary device to start operating and reach a stable state and the feed speed of the tool on the movement path, and sets the position that is at least the distance from the contact start position to the stable distance to be set as the front position.

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