JP2004074380A - Control device of machine tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To automatically clean the filter of a coolant filtering device at an appropriate timing in machining operation of a machine tool. <P>SOLUTION: A CPU interprets the contents of a machining program for every one block, creates control instructions to a main spindle, X, Y and Z axes, and the coolant filtering device 5 constituting the machine tool 1 and executes the machining operation (S1). Then, the CPU determines the presence/absence of a code of commanding the execution of back washing (S2). When there is a code "M406" commanding the execution of the back washing (YES), the process is shifted to a subroutine of the back washing to perform the back washing (S3), when there is no code "M406" (NO), the CPU determines whether it is a code of commanding the completion of the program (S4). <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a machine tool control device that generates an operation command of a machine tool based on a machining condition specified by a machining program and controls the operation of each unit configuring the machine tool.
[0002]
[Problems to be solved by the invention]
Some machine tools include a coolant filtering device that collects used coolant discharged from the machine tool, removes chips and the like with a filter, and returns the chip to the machine tool.
[0003]
If the filter is clogged, the pump device for returning the coolant recovered from the machine tool to the machine tool is overloaded, so that the filter needs to be cleaned or replaced as appropriate. For this reason, the coolant filtration device is provided with a cleaning mechanism for cleaning the filtration filter.
[0004]
2. Description of the Related Art Conventionally, a control device of a machine tool controls the operation of each unit constituting a machine tool based on information about machining such as a tool type, machining coordinates, and machining speed recorded in a machining program called an NC program. . On the other hand, the cleaning operation of the filtration filter by the cleaning mechanism is performed, for example, when the operator operates the operation panel when the processing operation by the machine tool is completed or when the notification that the filtration filter is clogged is given. It was performed on the basis of giving a command from outside.
[0005]
Therefore, in the case of the above-described conventional configuration, it is necessary for the operator to be waiting near the machine tool. Further, when the filter is detected to be clogged in the middle of the machining operation by the machine tool, the machining cycle must be restarted from the beginning after the filter filter is cleaned. In other words, there is a problem that the processing operation performed by the machine tool is wasted until the clogging of the filtration filter is detected.
[0006]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a machine tool control device capable of automatically cleaning a filtration filter of a coolant filtration device at an appropriate timing of a machining operation of a machine tool. It is to be.
[0007]
[Means for Solving the Problems]
The control device for a machine tool according to claim 1 of the present invention collects the used coolant discharged from the machine tool, filters the collected coolant with a filter, and then returns the coolant to the machine tool and cleans the filter. The control means for controlling the operation of the machine tool including the coolant filtering device having the filter cleaning means is configured to cause the filter cleaning means to execute the cleaning operation of the filtration filter at a predetermined timing of the operation of the machine tool. It has features.
[0008]
According to the above configuration, even if the operator does not input an instruction to execute the cleaning operation of the filtration filter on the machine tool side, the cleaning unit automatically performs the cleaning operation.
[0009]
In this case, the control means is configured to control the operation of the machine tool based on a machining program in which information on machining such as a tool type used for machining, coordinates for machining, machining speed of the tool, etc. is recorded. The filter cleaning means may be configured to execute a cleaning operation of the filter every time the processing program is completed (the invention of claim 2).
[0010]
According to the above configuration, the cleaning operation of the filtration filter can be automatically executed without changing the description of the processing program.
[0011]
Further, the control means is configured to control the operation of the machine tool based on a machining program in which information relating to machining, such as a type of tool used for machining, coordinates for machining, and machining speed, is recorded. The program may have a configuration in which the control unit includes a record for causing the filter cleaning unit of the coolant filtration device to execute a filter filter cleaning operation (the invention according to claim 3).
[0012]
According to the above configuration, the cleaning operation can be performed at an arbitrary timing during the processing performed based on the processing program.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The machine tool according to the present embodiment integrally includes a control device. That is, in FIG. 1, a machine tool 1 includes an XY table 2 for mounting a workpiece (workpiece) (not shown), a spindle motor 3 for rotating a spindle (not shown), and a tool mounted on the spindle. 4 is provided with a tool magazine (not shown) and the like. The machine tool 1 includes a coolant filtering device 5 that collects used coolant discharged from the machine tool 1, removes chips and the like included in the coolant, and returns the coolant to the machine tool 1.
[0014]
The coolant supplied from the coolant filtering device 5 to the machine tool 1 is discharged from the tip of the tool 4 mounted on the spindle through a hole penetrating the inside of the spindle.
[0015]
The coolant filtering device 5 collects and stores a used coolant discharged from the machine tool 1 through a collecting tank (not shown), a coolant tank 6, and a medium-pressure pump 7 (discharge) that sucks up the coolant in the coolant tank 6. A pressure of 1.5 to 7.0 MPa), a first return pipe 8 connected to a discharge port 7a of the intermediate pressure pump 7, and a second return pipe 8 connected to the first return pipe 8 via a filter device 9. A reflux pipe 10 is provided.
[0016]
The pipe 11 connected to the suction port 7b of the intermediate pressure pump 7 extends to the inside of the coolant tank 6. A cylindrical suction filter 12 is connected to a lower end of the pipe 11.
[0017]
The filter device 9 includes a housing 13 having a liquid inlet 13a, a liquid outlet 13b, and a liquid outlet 13c, and a hollow cylindrical filtration filter 14 housed in the housing 13. A space is formed between the outer peripheral surface of the filtration filter 14 and the housing 13, a liquid inlet 13 a and a liquid outlet 13 c communicate with the space, and a liquid outlet 13 b communicates with the inside of the filtration filter 14. I have.
[0018]
The first and second reflux pipes 8 and 10 are connected to a liquid inlet 13a and a liquid outlet 13b of the housing 13, respectively. The first and second return pipes 8 and 10 are connected to a differential pressure switch 15 for detecting clogging of the filtration filter 14 based on the pressure of both. The end of the second return pipe 10 is connected to a through hole of the main shaft via a rotary joint 16 at an upper portion of the motor 3. A valve A is attached to the second recirculation pipe 10 in front of the rotary joint 16, and an air source 17 is connected to the vicinity of the filter device 9 via a valve B.
[0019]
On the other hand, a liquid discharge pipe 18 (corresponding to a discharge path) is connected to the liquid discharge port 13c of the housing 13. A valve C is mounted in the middle of the drainage pipe 18. The lower end of the drainage pipe 18 is disposed inside the coolant tank 6.
[0020]
Each of the valves A to C is a normally closed type, and is closed in an off state and opened in an on state. In this embodiment, the coolant tank 6, the medium pressure pump 7, the first and second reflux pipes 8, 10, the filter device 9, and the like constitute a coolant reflux means. The filter cleaning means is constituted by the medium pressure pump 7, the air source 17, valves A to C, and the like.
[0021]
FIG. 2 is a diagram schematically illustrating an electrical configuration of the machine tool 1. In FIG. 2, a ROM 22, a RAM 23, an operation panel 24, a display 25, and a buzzer 26 are connected to an input / output bus 21 connected to a CPU 20 constituting a control unit.
[0022]
The operation panel 30 includes various keys for giving commands to the machine tool 1 and performing various settings. The display 31 displays the operating status of the machine tool 1 and the like. The ROM 22 stores in advance basic programs to be decoded and executed by the CPU 20. The RAM 23 stores a machining program, a backwash condition table (all of which will be described later in detail), and the like.
[0023]
The I / O bus 21 is connected to the intermediate pressure pump 7, the differential pressure switch 15, and the valves A, B, and C via an I / O interface 27. Further, a spindle motor amplifier 28 and X, Y, and Z axis motor amplifiers 29 are connected to the input / output bus 21. The spindle motor 3 and the X, Y, and Z axis motors 30 are connected to the motor amplifiers 28 and 29, respectively. Although not shown, the input / output bus 21 is connected to a motor amplifier for rotating a tool magazine and the like in addition to the motor amplifiers 28 and 29 for the respective axes.
[0024]
The CPU 20 controls the display 25, the buzzer 26, the medium pressure pump 7, the valves A, B, C, and the like based on input signals from the operation panel 24 and the differential pressure switch 15, programs stored in the ROM 22 and the RAM 23, and various data. The entire machine tool 1 such as the shaft motors 3 and 30 is controlled.
[0025]
Next, a machining program will be described with reference to FIGS. FIG. 4A is a machining program for performing a drilling process for drilling three holes H1 to H3 on a work (workpiece) 31 as shown in FIG. 3, and FIG. The specific execution contents are described for each block.
[0026]
In the machining program, information necessary for machining, such as a code indicating the machining content, the type of tool to be used, the number of revolutions of the spindle, the feed speed of the Z-axis (movement speed of the tool), the coordinates for machining, and the like are described in the machining order. ing. At the end of the machining program, a code "M30" indicating the end of the program is described. The CPU 20 drives each part of the machine tool 1 and processes the work by interpreting the contents of the processing program one block at a time.
[0027]
On the other hand, FIG. 5 shows a machining program for performing a drilling operation for drilling three holes in the work 31 shown in FIG. 3 in the same manner as FIG. Specifies that the backwashing of the filtration filter 14 of the coolant filtration device 5 is performed (code “M406”).
[0028]
In the machine tool 1 according to the present embodiment, the CPU 20 sends the filter 12 to the filter cleaning means based on the code “M406” designating that the backwashing process of the filter 14 is performed or the code “M30” designating the end of the program. Is performed. At this time, the CPU 20 refers to the backwash condition table held in the RAM 23 and acquires the set values of the air inflow time and the filter cleaning time in the backwash process. The backwash condition table is a database in which parameters such as an air inflow time and a filter cleaning time in the backwash process are stored for each tool type. The air inflow time and the filter cleaning time can be arbitrarily set by the operator by operating keys on the operation panel 24.
[0029]
Next, the processing performed by the CPU 20 by interpreting the processing program shown in FIG. 4A or 5 will be described with reference to FIGS. Here, detailed description of the contents of the processing is omitted. That is, when this processing is started, first, in step S1, the CPU 20 interprets the contents of the machining program one block at a time, and issues control commands for the main spindle, the XYZ axes, the coolant filtration device 5, etc., which constitute the machine tool 1. Generate and execute machining operation.
[0030]
In step S2, it is determined whether or not the code specifies execution of the backwash process. If the code is "M406" designating the execution of the backwashing process (YES), the process proceeds to the subroutine of the backwashing process of step S3, and if not (NO), the process proceeds to step S4. .
[0031]
Here, the backwash process will be described with reference to the flowchart of FIG. In the backwashing process routine, first, in step T1, the air inflow time t1 and the filter cleaning time t2 in the backwashing process are obtained from the backwashing condition table. Here, it is assumed that “0.3 seconds” is obtained as the air inflow time t1 and “1.7 seconds” is obtained as the in-filter cleaning time t2.
[0032]
In step T2, the intermediate pressure pump 7 is turned off and the valves B and C are turned on. Then, the valves B and C are opened while the valve A is closed. Thereby, pressurized air (pressure 0.4 to 0.6 MPa) from the air source 17 flows into the casing 13 through the liquid outlet 13b. Due to this air pressure, the coolant in the filtration filter 14 blows out of the filtration filter 14 from inside to outside. As a result, chips and the like adhering to the filtration filter 14 are peeled off and dropped into the space between the filtration filter 14 and the housing 13.
[0033]
When the air inflow time (0.3 seconds) obtained in step T1 elapses, the process proceeds to step T3, where the valve B is turned off, and then the intermediate pressure pump 3 is turned on. As a result, the valve B is closed, the supply of pressurized air from the air source 17 is stopped, and the coolant in the coolant tank 6 is supplied to the filter device 9 again. As a result, chips and the like dropped into the housing 13 are discharged together with the coolant from the liquid discharge port 13c through the drainage pipe 18 to the coolant tank 6.
[0034]
After the elapse of the filter cleaning time (1.7 seconds) obtained in step T1, the process proceeds to step T4, where the valve C is turned off and the intermediate pressure pump 7 is turned off. As a result, the valve C is closed. Further, the supply of the coolant from the coolant tank 6 to the filter device 9 is stopped. Thus, the backwashing process is completed.
[0035]
The CPU 20 returns to step S1 and executes the next process as soon as the CPU 20 reads the command for executing the backwashing process. In the machining program shown in FIG. 5, execution of the tool change process is specified (G100). Since no coolant is used during the tool change, the backwash process and the tool change process are performed in parallel. At this time, if the tool exchange processing time is shorter than the backwash processing time, after the tool is exchanged, after waiting until the backwash processing is completed, the next processing (in the machining program shown in FIG. Processing shifts to "M3").
[0036]
In step S4, it is determined whether or not the code (M30) specifies the end of the program. If the code is for designating the end of the program, the machining operation is stopped (step S5). If the code is not for designating the end, the process returns to step S1 and proceeds to the next block.
[0037]
In step S6, parameters relating to the backwash process corresponding to the type of tool mounted on the spindle are acquired from the backwash condition table, and it is determined whether or not to execute the backwash process at the end of the program based on the parameters. Here, if the air inflow time t1 and the filter cleaning time t2 as parameters are both zero (NO in step S6), the processing process ends without executing the backwash process.
[0038]
When the set value of the air inflow time and the set value of the cleaning time in the filter are not zero (YES in step S6), it is determined that the backwashing process is to be performed, and the process proceeds to step S7 to perform the backwashing process. Then, the processing is terminated. The backwashing process in step S7 is substantially the same as the backwashing process in step S3, and a description thereof will not be repeated.
[0039]
As described above, according to the present embodiment, since the machining program including the code for designating the execution of the backwashing process is provided during the machining, the backwashing process of the filtration filter 14 is automatically executed at an appropriate timing during the machining. Can be done. Therefore, it is not necessary for the operator to give a command to execute the backwash process to the machine tool 1 side.
[0040]
In particular, when the tool change processing without using the coolant and the backwash processing are configured to be performed in parallel as in the processing program shown in FIG. 5, the processing time by performing the backwash processing of the filtration filter 14 during the processing is reduced. Extension can be minimized.
[0041]
Further, since the backwashing process can be performed during the processing, it is possible to avoid a problem that the filtering filter 14 is clogged during the processing and the processing is forcibly stopped. Such a configuration is particularly effective when the processing cycle is long.
[0042]
Further, in the present embodiment, when performing the backwashing process, the air inflow time and the filter cleaning time are acquired by referring to the backwashing condition table. Therefore, the backwashing process is automatically executed for a time suitable for the type of tool mounted on the spindle.
[0043]
Furthermore, at the end of the processing program, the air inflow time and the filter cleaning time are obtained by referring to the backwash condition table, and it is determined whether or not to execute the backwash process based on these times. did. Therefore, by setting the air inflow time and the filter cleaning time to predetermined values in advance, the cleaning process can be automatically executed even when the processing program ends.
[0044]
It should be noted that the present invention is not limited to the above-described embodiments, but can be modified or expanded as follows.
The description designating the execution of the backwash process may be included twice or more in the machining program. Further, it may be described not only during the processing but also immediately before the end of the processing, that is, before the code indicating the end of the program. In such a configuration, it is possible to omit the determination as to whether or not to execute the backwashing process at the end of the machining program.
[0045]
A parameter for determining whether or not to execute the backwash process at the end of the machining program may be provided independently. Further, the control means may be configured to always execute the backwashing process every time the machining program ends, irrespective of the type of tool mounted on the spindle.
[0046]
The filter cleaning means for cleaning the filtration filter is not limited to the above-described backwashing method using pressurized air. For example, a method of rotating the filtration filter to shake off dust, or a method of scraping the outer periphery of the filter with a scraper A method of rubbing off may be used.
A control device for controlling the operation of the machine tool may be configured separately from the machine tool.
[0047]
【The invention's effect】
As is clear from the above description, according to the present invention, the control unit for controlling the operation of the machine tool automatically performs the cleaning operation of the filtration filter of the coolant filtration device at an appropriate timing. Even if the operator is not on the side of the machine tool, it is possible to avoid a situation in which the filtration filter is clogged and stops operating during the processing.
[Brief description of the drawings]
FIG. 1 is a diagram schematically showing an overall configuration of a machine tool according to an embodiment of the present invention; FIG. 2 is a diagram showing an electrical configuration; FIG. 3 is a diagram showing an example of drilling; FIG. (A) showing an example of a machining program corresponding to the machining content shown in FIG.
FIG. 5 is a diagram showing an example of a machining program including a description corresponding to a backwashing process step. FIG. 6 is a flowchart showing the contents of processing of the machining program. FIG. 7 is a flowchart showing the contents of a subroutine of the backwashing process. Description]
In the figure, 1 is a machine tool, 5 is a coolant filtration device, 6 is a coolant tank (coolant recirculation means), 7 is a medium pressure pump (coolant recirculation means, filter cleaning means), 8 is a first recirculation pipe (coolant recirculation means) ), 9 are filter devices (coolant recirculation means), 10 is a second recirculation pipe (coolant recirculation means), 14 is a filter, 17 is an air source (filter cleaning means), and 20 is a CPU (control means).

Claims (3)

In a machine tool control device having control means for controlling the operation of a machine tool that performs machining such as cutting,
The machine tool collects used coolant discharged from the machine tool, filters the filtered coolant with a filter, and then returns the coolant to the machine tool. The coolant filtering device includes a filter cleaning unit that cleans the filter. With
The control device for a machine tool, wherein the control means causes the filter cleaning means to execute the cleaning operation of the filtration filter at a predetermined timing of the operation of the machine tool. The control means is configured to control the operation of the machine tool based on a machining program in which information on machining such as a tool type used for machining, coordinates for machining, machining speed of the tool, etc. is recorded, and 2. The control device for a machine tool according to claim 1, wherein each time the machining program is completed, the filter cleaning means executes a cleaning operation of the filter. The control means is configured to control the operation of the machine tool based on a machining program in which information on machining such as a tool type used for machining, coordinates for machining, and machining speed is recorded,
The machine tool control device according to claim 1, wherein the processing program includes a record for causing the control unit to execute a filter filter cleaning operation by a filter cleaning unit of the coolant filtration device.

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