JP7441746B2 - Cooling water monitoring device for laser processing machines - Google Patents

Description

The present invention relates to a cooling water monitoring device for a laser processing machine.

The laser processing machine includes a cooling device that cools the heat generating part with cooling water. Patent Document 1 describes a cooling water supply system that supplies cooling water generated using pure water to a laser processing head.

Patent No. 6336163

Since pure water does not have residual chlorine like tap water, the interior of a cooling device in which pure water circulates tends to become an environment suitable for the growth of microorganisms such as algae, bacteria, and fungi.

An object of the present invention is to enable timely and continuous cooling of a laser processing machine with cooling water using pure water in which microorganisms can easily grow.

In order to achieve the above object, a cooling water monitoring device for a laser processing machine according to one aspect of the present invention includes:
A sensor that detects impurities present in the cooling water of the laser processing machine and outputs a detection signal,
a determination unit that determines whether or not to use the cooling water based on the detection signal while the laser processing machine is in operation;
a first acquisition unit that acquires environmental information regarding the temperature of the installation location of the laser processing machine during a period in which the determination by the determination unit is stopped due to the end of operation of the laser processing machine, when the laser processing machine resumes operation; and,
a first estimation unit that estimates the content of the change in water quality of the cooling water during the period based on the environmental information;
The determination unit determines whether or not the use of the cooling water is appropriate at the time of restarting the operation, taking into consideration the content of the water quality change estimated by the first estimation unit.

According to the present invention, it is possible to timely and continuously cool a laser processing machine with cooling water using pure water in which microorganisms easily grow.

FIG. 1 is an explanatory diagram showing a schematic configuration of a cooling water monitoring device according to an embodiment of the present invention that monitors cooling water supplied from a chiller device to cool a laser processing machine. 2 is an explanatory diagram showing the internal structure of the Y-type strainer of FIG. 1. FIG. FIG. 2B is an enlarged view of a main part of the filter member of FIG. 2A. FIG. 2 is a cross-sectional view showing state changes that occur over time inside the piping of the circulation path in FIG. 1. FIG. FIG. 2 is a cross-sectional view showing a state change that occurs over time inside a right-angled elbow existing in the piping of the circulation path in FIG. 1. FIG. FIG. 2 is an explanatory diagram of a case where a transmission type sensor for detecting impurities in cooling water for cooling the laser processing machine of FIG. 1 is arranged in a storage tank of a chiller device. FIG. 2 is an explanatory diagram of a case where a transmission type sensor for detecting impurities in the cooling water that cools the laser processing machine of FIG. 1 is arranged in a cooling water circulation path. 2 is a flowchart illustrating an example of a procedure related to a cooling water monitoring process executed by the controller in FIG. 1 based on a program. 2 is a flowchart illustrating an example of a procedure related to a process for estimating future changes in water quality of cooling water, which is executed by the controller in FIG. 1 based on a program. 3 is a flowchart illustrating another example of the procedure related to the process of estimating future changes in water quality of cooling water, which is executed by the controller in FIG. 1 based on a program.

[Embodiment]
Embodiments of the present invention will be described below with reference to the drawings. Identical or equivalent parts or constituent elements are designated by the same reference numerals throughout the drawings.

The embodiments described below exemplify devices and the like for embodying the technical idea of the present invention. The technical idea of this invention does not specify the material, shape, structure, arrangement, function, etc. of each component as described below.

A cooling water monitoring device 1 shown in FIG. 1 monitors the quality of cooling water. The cooling water is circulated between the chiller device 3 and the laser oscillation unit 7 of the laser beam machine 5, and between the chiller device 3 and the laser processing head 9 of the laser beam machine 5, respectively.

The chiller device 3 supplies cooling water at, for example, 25° C. to the laser oscillation unit 7 and the laser processing head 9. The cooling water monitoring device 1 can monitor the cooling water inside the chiller device 3 or in the cooling water circulation paths 11 and 13 provided outside the chiller device 3, for example, as described later.

A Y-shaped strainer 15 is provided on the outgoing path of each of the circulation paths 11 and 13, respectively. Cooling water heading toward the laser oscillation unit 7 and the laser processing head 9 passes through the outward paths of each of the circulation paths 11 and 13, respectively.

As shown in FIG. 2A, each Y-type strainer 15 includes a main body 17 connected to the middle of the circulation paths 11 and 13, and a filter member 19 provided within the main body 17.

The main body 17 has a main flow path 21 and a branch flow path 23 branched from an intermediate portion of the main flow path 21 . An inlet 25 is provided at one end of the main channel 21, and an outlet 27 is provided at the other end. A baffle plate 29 is provided in the middle of the main channel 21 to guide the fluid flowing through the main channel 21 from the inlet 25 to the outlet 27 to the branch channel 23 .

The inlet 25 is connected to the chiller device 3 side of the circulation paths 11 and 13. The outlet 27 is connected to the laser oscillation unit 7 side and the laser processing head 9 side of the circulation paths 11 and 13, respectively.

The filter member 19 is housed inside the branch channel 23 from the opening at its tip. The opening of the branch channel 23 in which the filter member 19 is accommodated is closed by a lid 31. The filter member 19 is fixed within the branch flow path 23 by this lid 31 .

The filter member 19 is formed into a cylindrical shape with both ends open. In this embodiment, the filter member 19 is configured of a mesh member made of stainless steel wire, as shown in FIG. 2B. For example, a mesh having 100 meshes per inch and a void ratio of 36.0% can be used.

Inside the Y-shaped strainer 15 interposed in the circulation paths 11 and 13, the cooling water that has flowed into the main flow path 21 from the inlet 25 flows into the filter member 19 of the branch flow path 23 through the baffle plate 29. The cooling water in the filter member 19 passes through the mesh of the mesh member and flows out from the branch flow path 23 to the outlet 27 side of the main flow path 21 . Impurities in the cooling water that cannot pass through the mesh remain in the filter member 19.

Pure water containing almost no impurities is used as the cooling water in the circulation paths 11 and 13 that cool the laser oscillation unit 7 and laser processing head 9 in FIG. Pure water is used as cooling water in order to prevent minerals in the water from precipitating in the heat exchange section (not shown) of the chiller device 3 and thereby reducing the heat exchange efficiency. However, since pure water does not have residual chlorine like tap water, cooling water using pure water tends to provide an environment suitable for the growth of microorganisms such as algae, bacteria, and fungi.

The microorganisms themselves and the viscous organic matter they secrete form slime in the cooling water. Slime can change its shape freely and can be separated into aggregations. Therefore, the slime in the cooling water passes through the mesh of the filter member 19 of the Y-shaped strainer 15 and flows into the circulation paths 11 and 13 on the side of the laser oscillation unit 7 and laser processing head 9 rather than the Y-shaped strainer 15. .

The slime in the cooling water flowing through the circulation paths 11 and 13 adheres to the inside of the piping of the circulation paths 11 and 13 to form a biofilm. As shown in FIG. 3A, the thickness of the biofilm 35 formed on the pipes 33 of the circulation paths 11 and 13 increases over time due to slime newly attached to the surface of the biofilm 35. In particular, when the right-angled elbow 37 shown in FIG. 3B exists in the piping 33, turbulent flow of cooling water occurs at the right-angled elbow 37 and slime tends to adhere, so the thickness of the biofilm 35 increases at a pace. tends to be faster.

When the film thickness of the biofilm 35 in the pipe 33 increases, the flow path cross-sectional area of the pipe 33 gradually narrows, and the amount of circulating cooling water in the circulation paths 11 and 13 decreases. When the circulating amount of cooling water decreases, the cooling efficiency of the laser oscillation unit 7 and the laser processing head 9 by the chiller device 3 decreases.

Therefore, in the cooling water monitoring device 1 of this embodiment, the state of impurities such as microorganisms present in the cooling water is added to the criteria for determining whether or not the cooling water needs to be replaced. In this embodiment, the controller 41 of the CNC device 39 shown in FIG. 1 determines whether or not the cooling water needs to be replaced.

The CNC device 39 controls the output of the laser beam from the laser oscillation unit 7 and the operation of the laser processing head 9 using NC (numerical control) based on the shape data of the workpiece to be processed by the laser processing machine 5. do. The controller 41 may also be used as a controller that controls the laser oscillation unit 7 and laser processing head 9 of the CNC device 39, or may be a dedicated controller that determines whether or not the cooling water needs to be replaced.

Detection signals from the conductivity meter 43 and transmission sensor 45 of the chiller device 3 are input to the controller 41 . The conductivity meter 43 and the transmission type sensor 45 can be provided, for example, in a cooling water storage tank (not shown) of the chiller device 3.

The conductivity meter 43 detects ions of the cooling water in the storage tank, measures conductivity, that is, electrical conductivity, and outputs a detection signal corresponding to the measured conductivity. The conductivity of cooling water increases as the amount of impurities (inorganic substances) in the pure water used for cooling water increases. Therefore, the controller 41 determines whether the impurities in the cooling water have increased due to continued use, based on the conductivity of the cooling water indicated by the detection signal of the conductivity meter 43.

The transmission type sensor 45 has a pair of light projecting section 47 and light receiving section 49, as shown in FIG. 4A. In the transmission type sensor 45, the transmitted light 57 of the detection light 51 outputted by the light projecting section 47, which has passed through the cooling water 55 in the storage tank 53 of the chiller device 3, is transmitted to the light receiving section 49 which faces the storage tank 53 in between. receives light. Therefore, at least a portion of the storage tank 53 located on the optical path of the detection light 51 and the transmitted light 57 is formed of a material through which the detection light 51 and the transmitted light 57 can pass.

The transmission type sensor 45 outputs a detection signal according to the amount of transmitted light 57 received by the light receiving section 49 . The controller 41 can detect the number of impurities 59 in the cooling water 55 in the storage tank 53 located on the optical path of the detection light 51 from the detection signal of the transmission sensor 45 .

In addition, the transmission type sensor 45 is installed, for example, in a straight pipe section where the flow of the cooling water 55 in the circulation paths 11 and 13 is a clear stream, and a light projecting part 47 and a light receiving part with the pipe 33 in between, as shown in FIG. 4B. 49 may be arranged to face each other. The conductivity meter 43 may also be configured to be provided in the piping 33 in the circulation paths 11 and 13 to measure the conductivity of the internal cooling water 55, like a transmission type sensor 45 shown in FIG. 4B.

Further, the controller 41 adds up the time during which the CNC device 39 is operated by turning on the power.

While the CNC device 39 is in operation, the laser oscillation unit 7 and the laser processing head 9 can be operated under the control of the CNC device 39 to perform laser processing on the workpiece. Therefore, while the CNC device 39 is in operation, the laser oscillation unit 7 and the laser processing head 9 are cooled by the cooling water 55 that the chiller device 3 circulates through the circulation paths 11 and 13. Therefore, the time during which the cooling water 55 is used to cool the laser oscillation unit 7 and the laser processing head 9 can be determined using the cumulative value of the operating time of the CNC device 39 as a guide.

Therefore, the controller 41 determines whether or not it is time for periodic maintenance to replace the cooling water 55, based on the cumulative value of the operating hours of the CNC device 39.

Note that the controller 41 can obtain weather information from a web server (not shown) via the Internet 61 to which the CNC device 39 is connected. The web server can be, for example, a server operated by a service provider that provides past weather history and future weather forecasts as weather information.

The controller 41 uses the past weather history in the weather information of the district where the laser processing machine 5 is installed, out of the weather information acquired via the Internet 61, as environmental information regarding the temperature of the laser processing machine 5 installation location. . Using this environmental information, the controller 41 can estimate the content of the water quality change that occurred in the cooling water 55 while the CNC device 39 was stopped due to the power being turned off. The operation of the CNC device 39 is stopped by turning off the power, for example, when the laser processing machine 5 stops operating.

Further, the controller 41 uses the weather forecast after the present time in the acquired weather information to determine the future water quality that will occur in the cooling water 55 when the CNC device 39 is powered off and the operation of the laser processing machine 5 is terminated. The content of the change can be estimated. The content of future water quality changes may be, for example, how many days after the CNC device 39 is powered off, it will be time to replace the cooling water 55.

Here, the change in water quality of the cooling water 55 can be, for example, the generation of slime that becomes the source of the biofilm 35 inside the piping 33 described with reference to FIGS. 3A and 3B.

Next, an example of a procedure related to the monitoring process for the cooling water 55 executed by the controller 41 according to a program stored in a memory (not shown) will be described with reference to the flowchart in FIG. 5.

When the CNC device 39 is powered on (step S11), the controller 41 acquires information regarding the cooling water 55 (step S13). The acquired information includes information on the detection signals of the conductivity meter 43 and the transmission sensor 45, information on the cumulative operating time of the CNC device 39, and information on past weather history provided on the Internet 61. I'm here. The past weather history includes past temperatures in the area including the installation location of the laser processing machine 5.

The controller 41 can determine the number of impurities 59 present in the cooling water 55 on the optical path of the detection light 51 and the transmitted light 57 from the detection signal of the transmission type sensor 45 acquired in step S13. Then, the controller 41 compares the determined number of impurities 59 with an integrated value obtained by integrating the number of impurities 59 during the operating time of the CNC device 39 and a related threshold value (step S15).

If the number of impurities 59 in the cooling water 55 increases until the use of the cooling water 55 is determined to be inappropriate, that is, by comparison with the threshold value (NG in step S15), the process proceeds to step S25, which will be described later. Migrate processing. Further, if the impurities 59 have increased only to the extent that it is determined that the use is appropriate (OK in step S15), the controller 41 determines the timing of regular maintenance based on the integrated value of the operation time of the CNC device 39 acquired in step S13. It is confirmed whether or not it has arrived (step S17).

When the time for regular maintenance has arrived and it is determined that the use of the cooling water 55 is inappropriate (NG in step S17), the process moves to step S25. In addition, if the timing has not yet arrived and it is determined that the use of the cooling water 55 is appropriate (OK in step S17), the controller 41 determines that the use of the cooling water 55 is determined to be inappropriate. It is confirmed whether or not it has been detected from the cooling water 55 (step S19). At the time of this confirmation, the controller 41 detects the amount of ions in the cooling water 55 from the detection signal of the conductivity meter 43 acquired in step S13.

If ions are detected to the extent that it is determined that the use of the cooling water 55 is inappropriate (NG in step S19), the process moves to step S25. Further, if only enough ions are detected to determine that use is appropriate (OK in step S19), the controller 41 performs external environment integration (step S21).

In the external environment integration, the controller 41 determines the thickness of the biofilm 35 formed on the piping 33 of the circulation paths 11 and 13. The thickness of the biofilm 35 increases over time, reducing the amount of circulating cooling water 55 in the piping 33 of the circulation paths 11 and 13. Therefore, the controller 41 estimates the amount of biofilm 35 generated in the pipe 33 in the external environment integration in step S21. Then, the controller 41 calculates the film thickness of the biofilm 35 in the piping 33 by integrating the estimated generation amount, and determines whether the calculated film thickness has increased to the extent that the cooling efficiency is affected due to insufficient flow rate of the cooling water 55. Check whether or not.

During operation of the CNC device 39, the temperature of the cooling water 55 is maintained at, for example, 25° C. by the heat exchange section of the chiller device 3. Therefore, the amount of biofilm 35 generated during operation of the CNC device 39 can be estimated based on, for example, the operating time of the CNC device 39.

During the operation stop period of the CNC device 39, the temperature of the cooling water 55 is not maintained at 25° C. due to the stoppage of the chiller device 3, but changes under the influence of the external environment of the chiller device 3. Therefore, it is necessary to estimate the amount of biofilm 35 generated during the period when the CNC device 39 is not operating, taking into consideration the external environment of the chiller device 3, for example.

The cooling water 55 in the circulation paths 11 and 13 circulates through the installation location of the laser processing machine 5. Therefore, while the CNC device 39 is out of operation, the temperature of the cooling water 55 changes under the influence of the temperature at the location where the laser processing machine 5 is installed.

The amount of microorganisms that form the slime that forms the basis of the biofilm 35 is, for example, in pure water at 37°C to 40°C, which is the optimum temperature for the growth of microorganisms, compared to 25°C, which is the temperature of the cooling water 55. Exponentially increasing. The temperature of the cooling water 55 during the operation stop period of the CNC device 39 may rise to the optimum temperature for the growth of microorganisms depending on the temperature at the installation location of the laser processing machine 5 where the circulation paths 11 and 13 are present. Therefore, the estimated amount of biofilm 35 generated during the period when the CNC device 39 is out of operation needs to be calculated in consideration of the temperature at the location where the laser processing machine 5 is installed during the period when the CNC device 39 is out of operation.

Therefore, the controller 41 calculates the estimated amount of biofilm 35 generated during the period when the CNC device 39 is stopped, taking into account the temperature at the installation location of the laser processing machine 5 as the external environment of the chiller device 3. Specifically, the controller 41 calculates the estimated amount of biofilm 35 generated during the period when the CNC device 39 is not operating, using the temperature during the period when the CNC device 39 is not operating from among the past weather history acquired in step S13. calculate.

Specifically, the controller 41 corrects the temperature of the area including the installation location of the laser processing machine 5 in the weather history during the operation stop period of the CNC device 39 using a predetermined correction coefficient, and adjusts the temperature at the installation location of the laser processing machine 5. Find the temperature of Then, the controller 41 calculates the estimated amount of biofilm 35 generated for each time period during the operation stop period of the CNC device 39, using the temperature in each time period at the installation location of the laser processing machine 5.

The temperature correction coefficient described above can also be optimized using, for example, the difference between the corrected calculated temperature and the actually measured temperature at the location where the laser processing machine 5 is installed.

Further, the controller 41 determines the thickness of the biofilm 35 on the piping 33 that increased during the period when the CNC device 39 was out of operation, from the calculated estimated amount of biofilm 35 generated in each time period.

If the process in step S21 is performed first after the CNC device 39 is powered on in step S11, the controller 41 determines the amount of biofilm 35 generated during the operation stop period of the CNC device 39 until the power is turned on. Estimate. Then, by integrating the estimated amount of biofilm 35 generated and the thickness of biofilm 35 calculated just before the CNC device 39 enters the shutdown period, the thickness of the biofilm 35 immediately after the CNC device 39 is powered on is calculated. is calculated as the current film thickness.

When performing the external environment integration process in step S21 immediately after the CNC device 39 is powered on, the controller 41 estimates the amount of biofilm 35 that has occurred after the process in the previous step S21. Then, the estimated biofilm 35 generation amount is multiplied by the biofilm 35 thickness calculated in the previous step S21 to calculate the current film thickness.

The estimated amount of biofilm 35 generated can be calculated using the information acquired in step S13 of FIG. The controller 41 checks whether the calculated current thickness of the biofilm 35 has increased to the extent that cooling efficiency is affected due to insufficient flow rate of the cooling water 55.

The controller 41 then compares the current thickness of the biofilm 35 with the relevant threshold value. This threshold value is used to check whether the thickness of the biofilm 35 in the pipe 33 has increased to the point where replacing the cooling water 55 is considered.

When the thickness of the biofilm 35 on the pipe 33 increases to the extent that the use of the cooling water 55 is determined to be inappropriate as a result of comparison with the threshold value (NG in step S21), the process moves to step S25. Further, if the film thickness has increased only to the extent that it is determined that the use is appropriate (OK in step S21), the controller 41 causes the chiller device 3 to continue the cooling operation of the laser oscillation unit 7 and the laser processing head 9. (Step S23), returning to step S13.

In step S25, the controller 41 comprehensively determines whether the quality of the cooling water 55 has deteriorated to a level that requires a warning to the user, based on the comparison or confirmation results in steps S15 to S21. Criteria for determining whether the warning level has been reached can be arbitrarily determined.

For example, in step S15, in order to determine whether or not the use of the cooling water 55 is appropriate, an integrated value obtained by integrating the number of impurities 59 in the cooling water 55 during the operating time of the CNC device 39 is compared with a threshold value. However, for example, in summer when the temperature of the cooling water 55 rises and a large amount of slime is generated, in step S25, the instantaneous value of the number of impurities 59 in the cooling water 55 determined from the detection signal of the transmission type sensor 45 is calculated. , may be compared with a threshold value for it.

As a result of the comprehensive judgment, if the condition has not deteriorated to the level that requires a warning (OK in step S25), the controller 41 continues the cooling operation of the chiller device 3 in step S23, and then returns to step S13. If the condition has deteriorated to a level that requires a warning (NG in step S25), the controller 41 issues a warning to the user regarding the quality of the cooling water 55 (step S27). This warning can be issued using, for example, a display unit 42 such as an indicator provided in the CNC device 39 and connected to the controller 41. After that, the controller 41 checks whether the laser processing machine 5 is busy, that is, is in operation (step S29).

Note that, for example, when the controller 41 determines OK in step S17 and determines NG in step S25, the period of regular maintenance in step S17 may be changed to a shorter period.

The controller 41 determines whether the laser processing machine 5 is busy or not based on, for example, the operating schedule of the laser processing machine 5, production management data such as products using the laser processing machine 5, whether it is currently daytime or nighttime. Judgment will be made taking into account the following. As a result, if the operating state is busy (BUSY in step S29), the controller 41 continues the cooling operation of the laser oscillation unit 7 and the laser processing head 9 by the chiller device 3 (step S23), and returns to step S13. Return.

Further, when the operating state of the laser processing machine 5 is not busy, that is, when the operation is stopped (SPARE in step S29), the controller 41 turns off the power of the chiller device 3 and the laser processing machine 5, and The cooling water 55 in 53 is drained (step S31). The drainage amount of the cooling water 55 may be the entire amount or may be a part of the amount. After draining, the controller 41 supplies new cooling water 55 in the same amount as the amount of drained water into the storage tank 53 (step S33). Then, the power of the CNC device 39 is turned off (step S35), and the series of processes ends.

As is clear from the above description, in this embodiment, the process of step S15 in the flowchart of FIG. 5 corresponds to the determination unit in the cooling water monitoring device. Moreover, in this embodiment, the process of step S21 in FIG. 5 is a process corresponding to the first acquisition unit and the first estimation unit in the cooling water monitoring device.

Furthermore, in this embodiment, the process of step S27 in FIG. 5 corresponds to the warning section in the cooling water monitoring device. Furthermore, in this embodiment, the processes in steps S31 and S33 in FIG. 5 correspond to the exchange section in the cooling water monitoring device.

Next, an example of a procedure for estimating future water quality changes of the cooling water 55, which is executed by the controller 41 according to a program stored in a memory (not shown), will be described with reference to the flowchart of FIG.

The controller 41 can execute the estimation process according to the procedure of FIG. 6 as part of the external environment integration in step S21 in the monitoring process of FIG. That is, the controller 41 can periodically execute the estimation process shown in FIG. 6 while the CNC device 39 that executes the monitoring process shown in FIG. 5 is operating.

The controller 41 acquires weather forecast information for the area including the installation location of the laser processing machine 5, which is provided on the Internet 61 (step S43).

Then, the controller 41 determines the future temperature at the installation location of the laser processing machine 5 from the temperature of the area including the installation location of the laser processing machine 5 in the acquired weather forecast (step S45). The future temperature can be, for example, the temperature for a period obtained from a weather forecast. To determine the future temperature, for example, the correction coefficient used to determine the temperature at the location where the laser processing machine 5 is installed in step S21 of FIG. 5 can be used.

Next, as shown in FIG. 6, the controller 41 estimates the content of the change in water quality of the cooling water 55 that is expected to occur when the operation of the CNC device 39 is stopped from now on (step S47). The change in water quality of the cooling water 55 can be, for example, an increase in the thickness of the biofilm 35 on the piping 33 during a future shutdown of the CNC device 39. The amount of increase in the film thickness of the biofilm 35 during the future operation stop of the CNC device 39 can be calculated using, for example, the future temperature at the installation location of the laser processing machine 5 determined in step S45.

Next, the controller 41 estimates the thickness of the biofilm 35 on the pipe 33, which will increase when the operation of the CNC device 39 is stopped, for each elapsed time from the current time, based on the content estimated in step S47. Then, a warning time is predicted when the estimated thickness of the biofilm 35 reaches a thickness at which replacement of the cooling water 55 is considered (step S49). The warning time is determined by, for example, comparing the estimated thickness of the biofilm 35 for each elapsed time with the threshold value used in step S21 of FIG. 5 to check whether the thickness has increased to the point where replacing the cooling water 55 is considered. It can be predicted by this.

Further, the controller 41 outputs the warning time predicted in step S49 as a forecast of the expected replacement time of the cooling water 55 when the operation of the CNC device 39 is stopped from the current time (step S51). The forecast can be output using, for example, the above-mentioned display section 42 of the CNC device 39. This completes the series of processing.

As is clear from the above description, in this embodiment, the process of step S43 in the flowchart of FIG. 6 corresponds to the second acquisition unit in the cooling water monitoring device. Moreover, in this embodiment, the processes of step S45 and step S47 in FIG. 6 are processes corresponding to the second estimator in the cooling water monitoring device.

Furthermore, in this embodiment, the process of step S49 in FIG. 6 corresponds to the prediction unit in the cooling water monitoring device. Moreover, in this embodiment, the process of step S51 in FIG. 6 is a process corresponding to the forecast section in the cooling water monitoring device.

In the cooling water monitoring device 1 of the present embodiment described above, during the operation of the CNC device 39 in which the laser processing machine 5 is in operation, the controller 41 determines the number of impurities 59 in the cooling water 55 sent out by the chiller device 3. is determined from the detection signal of the transmission type sensor 45. When the calculated cumulative value of the number of impurities 59 increases to the point where it is determined that the use of the cooling water 55 is prohibited, that is, it is determined that the use of the cooling water 55 is inappropriate, the controller 41 notifies the user that the quality of the cooling water 55 has deteriorated. to warn.

For this reason, the number of impurities 59 generated in the cooling water 55 is reduced by cooling the laser processing machine 5 with the cooling water 55 using pure water, which tends to create an environment suitable for the growth of microorganisms that form the slime that becomes the impurities 59. This can be done in a restrained and appropriate state.

Furthermore, in this embodiment, the controller 41 estimates the temperature at the location where the laser processing machine 5 is installed during the period when the CNC device 39 is out of operation, based on past weather information on the Internet 61. Then, the controller 41 calculates the thickness of the biofilm 35 in the piping 33 of the circulation paths 11 and 13, which increased during the period when the CNC device 39 was stopped, from the estimated temperature. Furthermore, even if the controller 41 predicts that the thickness of the biofilm 35 in the piping 33 will increase to the point where it is determined that the use of the cooling water 55 is inappropriate during the period when the CNC device 39 is out of operation, the controller 41 controls the use of the cooling water. Warn the user of 55 water quality deterioration.

Therefore, even if it is predicted that the cooling water 55 will be in an environment suitable for the growth of microorganisms during the period when the CNC device 39 is out of operation, the insufficient flow rate of the cooling water 55 due to the increase in the film thickness of the piping 33 will cause the CNC device 39 to It is possible to prompt for replacement of the cooling water 55 in advance so that this does not occur when the operation is restarted. If the cooling water 55 is replaced in response to the warning, when the CNC device 39 resumes operation, the cooling water 55 is replaced in an appropriate state where the flow rate of the cooling water 55 is not insufficient due to an increase in the film thickness of the piping 33. The laser processing machine 5 can be appropriately cooled.

Furthermore, in this embodiment, when a change in water quality of the cooling water 55 is warned, if the laser processing machine 5 is not in operation, the controller 41 replaces the cooling water 55 in the storage tank of the chiller device 3 with new cooling water 55. It can be exchanged. Therefore, if deterioration in water quality is predicted, the cooling water 55 can be automatically replaced.

Note that the temperature at the installation location of the laser processing machine 5 during the period when the CNC device 39 is out of operation does not have to be estimated based on past weather information as in the above example; The temperature may be actually measured at the location where the laser processing machine 5 is installed.

Further, in this embodiment, the controller 41 estimates the future temperature at the location where the laser processing machine 5 is installed based on the weather forecast on the Internet 61. Based on the estimated future temperature, the controller 41 predicts a warning period when the thickness of the biofilm 35 in the piping 33 will increase until it is necessary to consider replacing the cooling water 55 when the CNC device 39 stops operating. , is output to the user as a forecast of the expected replacement time.

Therefore, when there is a plan to stop the operation of the CNC device 39, it is possible to estimate when the quality of the cooling water 55 will deteriorate enough to consider replacing it after the operation is stopped, and to operate the CNC device 39 as planned. You can have the user confirm in advance whether it is safe to stop the service.

In order to output the above-mentioned forecast, in this embodiment, the controller 41 periodically executes the estimation process shown in FIG. 6 . However, the estimation process shown in FIG. 6 may be caused to be executed by the controller 41 when a triggering event occurs. The event that triggers the estimation process can be generated, for example, by the user's operation of a button (not shown) that is detectable by the controller 41 and requests execution of the estimation process.

When the controller 41 executes the estimation process of FIG. 6 when an event occurs, a step of checking whether an event has occurred is added before step S43 of FIG. The flowchart in FIG. 7 shows the procedure of the estimation process with this step added.

In the estimation process according to the procedure of FIG. 7, the controller 41 checks whether an event has occurred (step S41). If no event has occurred (NO in step S41), the series of processes ends. If an event has occurred (YES in step S41), the controller 41 moves to the processing from step S43 onward in FIG.

When the controller 41 executes the estimation process according to the procedure shown in FIG. The prediction results are output as a forecast. Therefore, if the user does not perform an operation to generate an event because, for example, there is no plan to stop the CNC device 39, the forecast of the expected replacement time of the cooling water 55 will be output unnecessarily. It can be avoided.

Note that, when an event such as a user's operation occurs, the configuration that predicts the warning timing of the cooling water 55 in case the CNC device 39 stops operating in the future and outputs a forecast may be omitted. Additionally, the amount by which the film thickness of the biofilm 35 in the piping 33 increases during the period when the CNC device 39 is out of operation is estimated, and a warning regarding the quality of the cooling water 55 is output to the user depending on the estimated amount of increase in film thickness. The configuration may be omitted.

Furthermore, after outputting a warning regarding the water quality of the cooling water 55 to the user, if the operating state of the laser processing machine 5 is not busy, some or all of the cooling water 55 in the storage tank of the chiller device 3 is replaced with new cooling water 55. The configuration for exchanging it may be omitted.

Further, in this embodiment, the controller 41 detects the number of impurities 59 in the cooling water 55 in the storage tank 53 located on the optical path of the detection light 51 from the detection signal of the transmission type sensor 45. However, the controller 41 may determine the light transmittance based on the detection signal of the transmission type sensor 45 according to the presence rate of the impurity 59 in the cooling water 55 on the optical path of the detection light 51 and the transmitted light 57. In that case, the controller 41 compares the determined instantaneous value or integrated value of the light transmittance with the related threshold value, for example in step S15 of FIG.

[Inventions disclosed by embodiments and their effects]
The embodiments and their modifications described above disclose the following aspects of the invention.

First, as the invention according to the first aspect,
A sensor that detects impurities present in the cooling water of the laser processing machine and outputs a detection signal,
a determination unit that determines whether or not to use the cooling water based on the detection signal while the laser processing machine is in operation;
A cooling water monitoring device for a laser processing machine is disclosed.

As the invention according to the second aspect, regarding the invention according to the first aspect,
a first acquisition unit that acquires environmental information regarding the temperature of the installation location of the laser processing machine during a period in which the determination by the determination unit is stopped due to the end of operation of the laser processing machine, when the laser processing machine resumes operation; and,
further comprising: a first estimating unit that estimates the content of the change in water quality of the cooling water during the period based on the environmental information;
The determination unit determines whether or not the use of the cooling water is appropriate in consideration of the content of the water quality change estimated by the first estimation unit at the time of restarting the operation. A cooling water monitoring device for a laser processing machine is disclosed. .

As the invention according to a third aspect, in the invention according to the first or second aspect, there is provided a warning unit that outputs a warning regarding the quality of the cooling water when the determination unit determines that the cooling water is not to be used. A cooling water monitoring device for a laser processing machine is disclosed, further comprising:

As the invention according to a fourth aspect, in the invention according to any one of the first to third aspects, when the determination unit determines that the cooling water is not to be used, A cooling water monitoring device for a laser processing machine is disclosed, further comprising an exchange unit for exchanging the cooling water in the storage tank.

As the invention according to the fifth aspect, regarding the invention according to any one of the first to fourth aspects,
a second acquisition unit that acquires weather forecast information for the area where the laser processing machine is installed;
a second estimator that estimates future changes in water quality that will occur in the cooling water when the operation of the laser processing machine is terminated, based on the future temperature of the installation location obtained from the weather forecast information; and,
A cooling water monitoring device for a laser processing machine, further comprising: a prediction unit that predicts a future time when the cooling water will not be used, based on the content of the future water quality change estimated by the second estimation unit. be disclosed.

As an invention according to a sixth aspect, regarding the invention according to the fifth aspect, the laser further includes a forecasting section that outputs a forecast regarding the future water quality of the cooling water based on the future time predicted by the forecasting section. A cooling water monitoring device for a processing machine is disclosed.

According to the cooling water monitoring device for a laser processing machine of the invention according to the first to sixth aspects, the laser processing machine can be continuously cooled in a timely manner using cooling water that uses pure water in which microorganisms can easily grow. can do.

1 Cooling water monitoring device 3 Chiller device 5 Laser processing machine 7 Laser oscillation unit 9 Laser processing head 11, 13 Circulation path 15 Y-shaped strainer 17 Main body 19 Filter member 21 Main channel 23 Branch channel 25 Inlet 27 Outlet 29 Rectifier plate 31 Lid 33 Piping 35 Biofilm 37 Right-angled elbow 39 CNC device 41 Controller 42 Display unit 43 Conductivity meter 45 Transmissive sensor 47 Light emitter 49 Light receiver 51 Detection light 53 Storage tank 55 Cooling water 57 Transmitted light 59 Impurities 61 Internet

Claims (5)

A sensor that detects impurities present in the cooling water of the laser processing machine and outputs a detection signal,
a determination unit that determines whether or not to use the cooling water based on the detection signal while the laser processing machine is in operation;
a first acquisition unit that acquires environmental information regarding the temperature of the installation location of the laser processing machine during a period in which the determination by the determination unit is stopped due to the end of operation of the laser processing machine, when the laser processing machine resumes operation; and,
a first estimation unit that estimates the content of the change in water quality of the cooling water during the period based on the environmental information;
The determination unit determines whether or not the use of the cooling water is appropriate in consideration of the content of the water quality change estimated by the first estimating unit at the time of restarting the operation. The cooling water monitoring device for a laser processing machine according to claim 1, further comprising a warning unit that outputs a warning regarding the quality of the cooling water when the determination unit determines that the cooling water should not be used. The laser processing according to claim 1 or 2, further comprising a replacement part that replaces the cooling water in the storage tank while the laser processing machine is stopped when the determination part determines that the cooling water should not be used. Machine cooling water monitoring device. a second acquisition unit that acquires weather forecast information for the area where the laser processing machine is installed;
a second estimation unit that estimates future changes in water quality that will occur in the cooling water when the operation of the laser processing machine is terminated, based on the future temperature of the installation location obtained from the weather forecast information; and,
Any one of claims 1 to 3, further comprising: a prediction unit that predicts a future time when the cooling water will not be used based on the content of the future water quality change estimated by the second estimation unit. A cooling water monitoring device for a laser processing machine as described in 2. 5. The cooling water monitoring device for a laser processing machine according to claim 4, further comprising a forecasting unit that outputs a forecast of future water quality of the cooling water based on the future time predicted by the forecasting unit.

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