JP2019002894A - Concentration detection device and machine tool system - Google Patents

Abstract

To provide a concentration detection device capable of accurately calculating concentration of the water-soluble cutting fluid stored in a fluid storage tank.SOLUTION: Liquid temperature detecting means 51 detects a liquid temperature Tg of the water-soluble cutting fluid WO stored in a fluid storage tank 26. Conductivity detecting means 52 detects an electric conductivity σg of the water-soluble cutting fluid WO stored in the fluid storage tank 26. Arithmetic control means 55 (controller 57) simultaneously inputs and acquires the liquid temperature Tg detected by the liquid temperature detecting means 51 and the electric conductivity σg detected by the conductivity detecting means 52. The controller 57 calculates concentration α of the water-soluble cutting fluid WO stored in the fluid storage tank 26 on the basis of a calibration formula F(Tg) of a linear function indicating the relationship between the concentration of the water-soluble cutting fluid and electric conductivity corresponding to the liquid temperature input from the liquid temperature detecting means 51 and the electric conductivity σg input from the conductivity detection means 52.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a concentration detection device that detects the concentration of stored water-soluble cutting fluid, and a machine tool system including the concentration detection device.

As a technique for detecting the concentration of water-soluble cutting oil, Patent Document 1 discloses an automatic management device for water-soluble cutting oil. The automatic management apparatus for water-soluble cutting oil includes a liquid storage tank (coolant tank) that stores the water-soluble cutting oil, and a concentration sensor that measures the electrical conductivity of the water-soluble cutting oil stored in the liquid storage tank.
Patent Document 1 stores a relational expression indicating the relationship between the concentration (dilution ratio) of water-soluble cutting oil and electrical conductivity, and based on the electrical conductivity measured by the concentration sensor and the stored relational expression, water-soluble cutting. The oil concentration is calculated.

Japanese Patent Laid-Open No. 9-85577

In Patent Document 1, the concentration of the water-soluble cutting oil is calculated from the electrical conductivity measured by the concentration sensor, but the water-soluble cutting oil is taken into account by taking into account the variation in the electrical conductivity due to the temperature change of the water-soluble cutting oil. It does not calculate the concentration of.
Therefore, in patent document 1, the density | concentration of the water-soluble cutting oil stored in the liquid storage tank cannot be calculated accurately.

  An object of the present invention is to provide a concentration detection device that can accurately calculate the concentration of stored water-soluble cutting fluid, and a machine tool system including the concentration detection device.

  A first aspect of the present invention is a concentration detection device for detecting the concentration of the stored water-soluble cutting fluid, the liquid temperature detecting means for detecting the liquid temperature of the stored water-soluble cutting fluid, and the stored water-soluble cutting fluid. The conductivity detection means for detecting the electrical conductivity of the stored water-soluble cutting fluid immersed in the liquid, the liquid temperature detected by the liquid temperature detection means, and the electrical conductivity detected by the conductivity detection means are simultaneously input. Calculation control means, wherein the calculation control means corresponds to the liquid temperature input from the liquid temperature detection means, a calibration curve indicating the relationship between the concentration of the water-soluble cutting fluid and electrical conductivity, and the conductivity detection The concentration detecting device calculates the concentration of the stored water-soluble cutting fluid based on the electrical conductivity input from the means.

  A second aspect of the present invention relates to a plurality of concentration data having different concentrations and the same component as the stored water-soluble cutting fluid, and the water-soluble cutting fluid of each concentration corresponding to each concentration data Storage means for storing a relationship between the liquid temperature of the water-soluble cutting fluid and the electrical conductivity corresponding to each concentration of water-soluble cutting fluid, and the arithmetic control means includes the concentration data and A linear function equation corresponding to each concentration of water-soluble cutting fluid is read from the storage unit, and based on a liquid temperature input from the liquid temperature detection unit and a linear function equation corresponding to each concentration of water-soluble cutting fluid. Calculating the electrical conductivity of the water-soluble cutting fluid of each concentration, and the liquid temperature input from the liquid temperature detecting means based on the concentration data and the electrical conductivity of the water-soluble cutting fluid of each concentration. Water-soluble cutting fluid corresponding to Calculate a calibration curve indicating the relationship between concentration and electrical conductivity, and calculate the concentration of the stored water-soluble cutting fluid based on the electrical conductivity input from the conductivity detection means and the calculated calibration curve. The concentration detection apparatus according to claim 1, wherein:

  A third aspect of the present invention includes storage means for storing a calibration curve indicating a relationship between the concentration of the water-soluble cutting fluid and the electrical conductivity corresponding to each of a plurality of liquid temperatures that can be detected by the liquid temperature detection means, The arithmetic control unit reads out a calibration curve corresponding to the liquid temperature from the storage unit based on the liquid temperature input from the liquid temperature detection unit, and the electrical conductivity input from the conductivity detection unit and the storage 2. The concentration detecting apparatus according to claim 1, wherein the concentration of the stored water-soluble cutting fluid is calculated based on the calibration curve read from the means.

  According to a fourth aspect of the present invention, there is provided a liquid storage tank storing a water-soluble cutting fluid, the water-soluble cutting fluid stored in the liquid storage tank is processed while being supplied to the workpiece, and the workpiece is processed. A machine tool that collects the supplied water-soluble cutting fluid in the liquid storage tank and a concentration detection device that detects the concentration of the water-soluble cutting fluid stored in the liquid storage tank, Liquid temperature detection means for detecting the liquid temperature of the water-soluble cutting fluid stored in the liquid storage tank, and the electricity of the water-soluble cutting liquid stored in the liquid storage tank that is immersed in the water-soluble cutting liquid stored in the liquid storage tank Conductivity detecting means for detecting conductivity, and arithmetic control means for simultaneously inputting the liquid temperature detected by the liquid temperature detecting means and the electric conductivity detected by the conductivity detecting means, and the arithmetic control means Is the liquid input from the liquid temperature detecting means The water-soluble cutting fluid stored in the liquid storage tank based on the calibration curve indicating the relationship between the concentration of the water-soluble cutting fluid and the electrical conductivity corresponding to the degree and the electrical conductivity input from the conductivity detecting means It is a machine tool system characterized by calculating the density | concentration of.

In claim 1 according to the present invention, the liquid temperature detecting means detects the liquid temperature of the stored water-soluble cutting fluid, and the conductivity detecting means detects the electrical conductivity of the stored water-soluble cutting fluid. The arithmetic control means inputs the liquid temperature detected by the liquid temperature detecting means and the electric conductivity detected by the conductivity detecting means at the same time, and the electric conductivity corresponding to the liquid temperature and the liquid temperature inputted from the liquid temperature detecting means. The rate (electric conductivity at liquid temperature) is acquired at the same time. The calculation control means is based on a calibration curve indicating the relationship between the concentration of the water-soluble cutting fluid and the electrical conductivity corresponding to the liquid temperature input from the liquid temperature detection means, and the electrical conductivity input from the conductivity detection means. The concentration of the stored water-soluble cutting fluid is calculated.
Accordingly, the concentration at the liquid temperature can be calculated for the stored water-soluble cutting fluid from the liquid temperature input from the liquid temperature detection means and the electric conductivity input from the conductivity detection means, and the water-soluble cutting fluid The concentration can be calculated with high accuracy.

According to the second aspect of the present invention, the electrical conductivity of the water-soluble cutting fluid of each concentration is calculated from the liquid temperature input from the liquid temperature detecting means and the linear function equation for the water-soluble cutting fluid of each concentration, and each concentration data And a calibration curve corresponding to the liquid temperature input from the liquid temperature detection means from the electrical conductivity of the water-soluble cutting fluid of each concentration, and the electrical conductivity input from the conductivity detection means and the calculated calibration curve. From this, the concentration of the stored water-soluble cutting fluid can be calculated.
In claim 2, before the detection of the stored water-soluble cutting fluid, the liquid temperature detection means is the same component as the stored water-soluble cutting fluid, and for each water-soluble cutting fluid of each concentration corresponding to each concentration data ,
The pre-measurement liquid temperature (sample liquid temperature) is detected, and the conductivity detecting means detects the pre-measurement electrical conductivity (sample electrical conductivity) for each of the water-soluble cutting fluids of the respective concentrations, and the calculation control means (control) Means) for each concentration of water-soluble cutting fluid, the pre-measurement liquid temperature detected by the liquid detection means and the pre-measurement electrical conductivity detected by the conductivity detection means are input at regular intervals, Acquire a plurality of liquid temperatures with different temperatures, and electrical conductivity corresponding to each liquid temperature, and input each of the water-soluble cutting fluids of each concentration from the liquid temperature detection means and the conductivity detection means before each measurement. Based on the liquid temperature and the pre-measurement electrical conductivity, a linear function equation indicating the relationship between the pre-measurement liquid temperature and the pre-measurement electrical conductivity of the water-soluble cutting fluid corresponding to each concentration of water-soluble cutting fluid is calculated. Primary corresponding to each calculated concentration of water-soluble cutting fluid Configured to store a formula in the storage means it can be employed.
Before detecting the liquid temperature (measured liquid temperature) and electrical conductivity (measured electrical conductivity) of the stored water-soluble cutting fluid, each component corresponding to each concentration data is the same component as the stored water-soluble cutting fluid. For each concentration of water-soluble cutting fluid, a plurality of pre-measurement liquid temperatures having different temperatures, and pre-measurement electrical conductivities corresponding to the respective pre-measurement liquid temperatures (pre-measurement electrical conductivity at the respective pre-measurement liquid temperatures ) And a linear function equation for each concentration of water-soluble cutting fluid can be calculated for each concentration of water-soluble cutting fluid based on the pre-measurement liquid temperature and each pre-measurement electrical conductivity.

According to a third aspect of the present invention, the calculation control means reads out a calibration curve corresponding to the liquid temperature from the storage means based on the liquid temperature input from the liquid temperature detection means, and reads the calibration curve and the conductivity detection. Based on the electrical conductivity input from the means, the concentration of the stored water-soluble cutting fluid can be calculated.
According to claim 3, for a plurality of temperatures in the temperature range that can be detected by the liquid temperature detecting means, a calibration curve indicating the relationship between the concentration of the water-soluble cutting fluid and the electrical conductivity corresponding to each temperature (a calibration function of a linear function) It is also possible to employ a configuration including storage means for storing.

According to a fourth aspect of the present invention, the liquid temperature detecting means detects the liquid temperature of the water-soluble cutting fluid stored in the liquid storage tank, and the conductivity detecting means is the electric power of the water-soluble cutting liquid stored in the liquid storage tank. Detect conductivity. The arithmetic control means inputs the liquid temperature detected by the liquid temperature detecting means and the electric conductivity detected by the conductivity detecting means at the same time, and the electric conductivity corresponding to the liquid temperature and the liquid temperature inputted from the liquid temperature detecting means. The rate (electric conductivity at liquid temperature) is acquired at the same time. The calculation control means is based on a calibration curve indicating the relationship between the concentration of the water-soluble cutting fluid and the electrical conductivity corresponding to the liquid temperature input from the liquid temperature detection means, and the electrical conductivity input from the conductivity detection means. The concentration of the stored water-soluble cutting fluid is calculated.
Thus, the concentration at the liquid temperature can be calculated for the water-soluble cutting fluid stored in the liquid storage tank from the liquid temperature input from the liquid temperature detection means and the electrical conductivity input from the conductivity detection means. The concentration of the neutral cutting fluid can be calculated with high accuracy.

It is a front view which shows the machine tool of a machine tool system, and the density | concentration detection apparatus of 1st and 2nd embodiment. It is an AA arrow line view of FIG. It is BB sectional drawing of FIG. It is CC sectional drawing of FIG. It is DD sectional drawing of FIG. It is EE sectional drawing of FIG. It is a block diagram which shows the density | concentration detection apparatus of 1st and 2nd embodiment. It is a graph of the linear function formula which shows the relation between the water temperature before the measurement of the water-soluble cutting fluid and the electric conductivity before the measurement of the water-soluble cutting fluid with respect to the water-soluble cutting fluid of each concentration. It is a graph of a calibration curve (a calibration function of a linear function) showing the relationship between the concentration of the water-soluble cutting fluid and the calculated electrical conductivity of the water-soluble cutting fluid with respect to the liquid temperature input from the liquid temperature detecting means. It is a flowchart figure (the 1) which shows the measurement process 1 which the density | concentration detection apparatus of 1st Embodiment performs. It is a flowchart figure (the 2) which shows the measurement process 1 which the density | concentration detection apparatus of 1st Embodiment performs. It is a flowchart figure (the 3) which shows the measurement process 1 which the density | concentration detection apparatus of 1st Embodiment performs. It is a flowchart figure (the 1) which shows the measurement process 2 which the density | concentration detection apparatus of 2nd Embodiment performs. It is a flowchart figure (the 2) which shows the measurement process 2 which the density | concentration detection apparatus of 2nd Embodiment performs.

The machine tool system according to the present invention and the concentration detection apparatuses of the first and second embodiments will be described with reference to FIGS.
Hereinafter, an example in which the concentration detection devices of the first and second embodiments are applied to a machine tool system will be described.

<Machine tool system X>
1 to 7, the machine tool system X includes a machine tool Y and a darkness detection device Z.

<Machine tool Y>
In FIG. 1, the machine tool Y is, for example, a machining center (hereinafter referred to as “machining center Y”). The machine tool Y may be a lathe, a milling machine, an NC lathe (numerically controlled lathe), a grinder, and an NC grinder (numerically controlled grinder).

The machining center Y (machine tool) is a numerically controlled milling machine that processes the workpiece 1.
As shown in FIG. 1, the machining center Y includes a spindle head 2, a spindle 3, a blade tool 4, and a tool holder 5.

In the machining center Y, the spindle head 2 is disposed so as to be movable in the vertical direction A (feed direction) as shown in FIG.
As shown in FIG. 1, the spindle 3 is rotatably disposed on the spindle head 2. The main shaft 3 is connected to a drive motor 9 and is rotated by driving of the drive motor 9.

  The blade tool 4 is made of a carbide drill, a carbide end mill, or the like.

As shown in FIG. 1, the tool holder 5 includes a holder body 7 and a housing 8. The holder body 7 is externally fitted to the main shaft 3 with the axial center line coinciding with the axial center line of the main shaft 3. The holder body 7 is fixed to the spindle head 2.
The housing 8 is rotatably fitted to the holder body 7 and is held by the holder body 7. The housing 8 is coupled to the main shaft 3 such that the axis line coincides with the axis line of the main shaft 3.
Thereby, the tool holder 5 (the holder main body 7 and the housing 8) is moved in the vertical direction A (feeding direction) as the spindle head 2 moves.
In the tool holder 5, the housing 8 is rotated with the rotation of the main shaft 3.

  The housing 8 has a collet 10. The collet 10 has a chuck mechanism (not shown) that holds the blade tool 4 (a carbide drill, a carbide end mill, etc.).

As shown in FIG. 1, the tool holder 5 mounts the blade tool 4 in the collet 10 and fixes the blade tool 4 with the collet 10.
Thereby, the blade tool 4 (carbide drill) is fixed to the collet 10 (housing 8), and rotates with the rotation of the housing 8 (main shaft 3). The blade tool 4 is moved in the vertical direction A (feed direction) with the movement of the spindle head 2.

  As shown in FIG. 1, the machining center Y (machine tool Y) includes a plurality of injection nozzles 23 and 24, a processing table 25, a liquid storage tank 26, a liquid supply pipe 27, and a pump 28.

As shown in FIG. 1, each of the injection nozzles 23 and 24 is disposed outside the blade tool 4 (a carbide drill, a carbide end mill, etc.) and is opposed to the blade tool 4. Each injection nozzle 23, 24 is connected to a nozzle tube 23A, 24A. Each nozzle tube 23A, 24A is fixed to the spindle head 2.
Thereby, each injection nozzle 23 and 24 is moved to the up-down direction A (feeding direction) with the movement of the spindle head 2.

As shown in FIG. 1, the processing table 25 is arranged on the lower side in the up-down direction A with an interval from the blade tool 4 (each injection nozzle 23, 24). The processing table 25 is installed facing the blade tool 4.
The processing table 25 has a vise (not shown) that fixes the workpiece 1.

As shown in FIGS. 1 to 6, the liquid storage tank 26 stores a water-soluble cutting fluid (water-soluble cutting oil) WO.
The water-soluble cutting fluid WO is an alkaline fluid and is a water-soluble cutting fluid having a concentration α obtained by diluting a water-soluble cutting stock solution with water. The water-soluble cutting stock solution (water-soluble cutting fluid WO) is, for example, a component such as a rust preventive additive (containing an alkali component), a surfactant, a refined mineral oil (containing a sulfide), other components, and water. Become.
The concentration of the water-soluble cutting fluid means volume concentration (volume concentration) or weight concentration (mass concentration) in the relationship with the water-soluble cutting stock solution and water for diluting the water-soluble cutting stock solution (hereinafter the same).

The liquid storage tank 26 includes front and rear wall plates 26A and 26B, left and right wall plates 26C and 26D, and a bottom wall plate 26E, and is formed in a rectangular parallelepiped shape by the wall plates 26A to 26E.
The liquid storage tank 26 has a storage space 21 partitioned by the wall plates 26A to 26E, and the storage space 21 is opened upward.

As shown in FIGS. 1 and 2, the liquid storage tank 26 includes a partition plate 29 and front and rear cover plates 30 and 31.
In the liquid storage tank 26, the partition plate 29 is disposed in the storage space 21. The partition plate 29 is disposed on the front wall plate 26 </ b> A side of the liquid storage tank 26. In the front-rear direction B, the partition plate 29 is disposed parallel to the front wall plate 26A with a space therebetween, and is erected and fixed to the bottom wall plate 26E. The partition plate 29 is attached to the right wall plate 26D of the liquid storage tank 26 and extends to the left wall plate 26C side in the left-right direction C. As shown in FIG. 2, the partition plate 29 is arranged in the left-right direction C so as to form a gap δ in the left wall plate 26C.

  In the liquid storage tank 26, the front lid plate 30 is disposed on the front side of the liquid storage tank 26 as shown in FIGS. 1 and 2. The front lid plate 30 is disposed so as to extend between the front wall plate 26 </ b> A and the partition plate 29 in the front-rear direction B. The front lid plate 30 is disposed so as to extend between the left wall plate 26C and the right wall plate 26D in the left-right direction C. The front lid plate 30 covers the front side of the storage space 21 (a part of the storage space 21) and is placed on the front wall plate 26A, the partition plate 29, and the left and right wall plates 26C and 26D. The front lid plate 30 is attached to the front wall plate 26A, the partition plate 29, and the left and right wall plates 26C and 26D of the liquid storage tank 26. As shown in FIGS. 1 and 2, the front lid plate 30 has a liquid recovery port 32, and the liquid recovery port 32 is formed on the right wall plate 26 </ b> D side in the left-right direction C. In the vertical direction A, the liquid recovery port 32 penetrates the front lid plate 30 and communicates the storage space 21 to the outside.

In the liquid storage tank 26, the rear cover plate 31 is disposed on the rear side of the liquid storage tank 26 as shown in FIGS. 1 and 2. The rear cover plate 31 is disposed so as to extend between the left wall plate 26C and the right wall plate 26D in the left-right direction C. The rear cover plate 31 covers the rear side of the storage space 21 (a part of the storage space 21) and is placed on the rear wall plate 26B and the left and right wall plates 26C and 26D. The rear cover plate 31 is attached to the rear wall plate 26B and the left and right wall plates 26C and 26D of the liquid storage tank 26.
Thereby, in the liquid storage tank 26, the storage space 21 is opened upward between the front lid plate 30 and the rear lid plate 31.

  As shown in FIG. 1, the liquid storage tank 26 is disposed below the processing table 25 (workpiece 1). The liquid storage tank 26 is disposed with the liquid recovery port 32 facing the processing table 25 (workpiece 1). The liquid storage tank 26 is installed in the processing table 25 at intervals in the vertical direction A.

As shown in FIG. 1, the liquid supply pipe 27 is disposed between the injection nozzles 23 and 24 and the pump 28. One end of the liquid supply pipe 27 is connected to a pump 28. The other pipe end of the liquid supply pipe 27 is connected to the nozzle pipe 24 </ b> A of the injection nozzle 24. The liquid supply pipe 27 is connected to the nozzle pipe 23 </ b> A of the injection nozzle 23.
As a result, the liquid supply pipe 27 communicates with each of the injection nozzles 23 and 24 and the pump 28.

The pump 28 (electric pump) is arrange | positioned at the liquid storage tank 26, as shown in FIG.1, FIG2 and FIG.6. The pump 28 is disposed on the left wall plate 26C side in the left-right direction C as shown in FIGS. The pump 28 is mounted on the rear cover plate 31 of the liquid storage tank 26 and attached to the rear cover plate 31. The pump 28 is immersed in the water-soluble cutting fluid WO in the storage space 21. The pump 28 is connected to one end of the liquid supply pipe 27. The pump 28 communicates with the injection nozzles 23 and 24 through the liquid supply pipe 27 and the nozzle pipes 23A and 24A.
The pump 28 is connected to control means (not shown) of the machining center Y (machine tool), and is driven for suction / discharge based on a drive command (drive signal) of the control means.
The pump 28 sucks the water-soluble cutting fluid WO stored in the liquid storage tank 26 based on the drive command of the control means of the machining center Y, and discharges the water-soluble cutting fluid WO to the liquid supply pipe 27.
Thereby, each injection nozzle 23 and 24 injects the water-soluble cutting fluid WO to the blade tool 4 and the to-be-processed body 1, as shown in FIG.
The water-soluble cutting fluid WO sprayed from the spray nozzles 23 and 24 flows into the liquid storage tank 26 through the liquid recovery port 32 from the processing table 25 and is recovered.
As shown in FIG. 2, the water-soluble cutting fluid WO recovered in the liquid storage tank 26 is guided by the front wall plate 26A and the partition plate 29, flows from the liquid recovery port 32 to the left wall plate 26C, and the left wall plate. It flows out from the gap δ between 26C and the partition plate 29 to the pump 28 side of the storage space 21.

<Concentration Detection Device Z (Liquid State Measurement Device) of First Embodiment>
The concentration detection device Z of the first embodiment is a liquid state detection device that detects the liquid state of the water-soluble cutting fluid WO stored in the liquid storage tank 26 as shown in FIGS. The concentration of the water-soluble cutting fluid WO stored in 26 is calculated (calculated).
The concentration measuring device Z of the first embodiment detects the sulfide gas concentration (odor) of the water-soluble cutting fluid WO stored in the liquid storage tank 26 and the hydrogen ion concentration index (pH) of the water-soluble cutting fluid WO.

  As shown in FIGS. 1 to 5 and FIG. 7, the concentration measuring apparatus Z of the first embodiment includes a liquid temperature detecting means 51, a conductivity detecting means 52, an odor detecting means 53, a hydrogen ion concentration index detecting means 54, Arithmetic control means 55 and storage means 56 are provided.

The liquid temperature detection means 51 detects the liquid temperature Tg (° C.) of the stored water-soluble cutting fluid WO. The liquid temperature detecting means 51 is a contact temperature sensor (thermocouple, platinum measuring resistor, thermistor).
The liquid temperature detection means 51 is arrange | positioned at the rear cover plate 31 of the liquid storage tank 26, as shown in FIG. 1 thru | or FIG. The liquid temperature detection means 51 is disposed on the right wall plate 26D side in the left-right direction C with a space from the pump 28.
The liquid temperature detecting means 51 is fixed to the rear cover plate 31 of the liquid storage tank 26 and immersed in the water-soluble cutting liquid WO stored in the liquid storage tank 26.
The liquid temperature detection means 51 detects the liquid temperature Tg of the water-soluble cutting fluid WO stored in the liquid storage tank 26 [hereinafter referred to as “measured liquid temperature Tg (° C.)” and outputs it as the measured liquid temperature signal.
The liquid temperature detecting means 51 may be a non-contact temperature sensor (radiation thermometer, thermography). The non-contact temperature sensor is disposed so as to face the water-soluble cutting fluid WO from the opening of the liquid storage tank 26 (storage space 21).

The conductivity detection means 52 detects the electrical conductivity σg (micro Siemens per centimeter: μS / cm) of the stored water-soluble cutting fluid WO. The conductivity detector 52 is a conductivity sensor [electric conductivity sensor (two-electrode conductivity sensor or the like)]. Electrical conductivity is electrical conductivity.
The conductivity detecting means 52 is disposed on the rear cover plate 31 of the liquid storage tank 26 as shown in FIGS. The conductivity detecting means 52 is arranged on the right wall plate 26D side in the left-right direction C with a spacing from the pump 28.
As shown in FIGS. 1 to 5, the conductivity detecting means 52 is arranged in parallel with the liquid temperature detecting means 51 in the front-rear direction B, and is disposed between the liquid temperature detecting means 51 and the rear wall plate 26B.
The conductivity detecting means 52 is fixed to the rear cover plate 31 of the liquid storage tank 26 and is immersed in the water-soluble cutting fluid WO stored in the liquid storage tank 26.
The conductivity detecting means 52 detects the electrical conductivity σg of the water-soluble cutting fluid WO (alkali ions) stored in the liquid storage tank 26 (hereinafter referred to as “measured electrical conductivity σg (μS / cm)”), Output as measured electrical conductivity signal.

The odor detection means 53 detects the sulfide gas concentration γg emitted from the stored water-soluble cutting fluid WO. The odor detecting means 53 is a gas sensor (semiconductor gas sensor, organic semiconductor gas sensor, quartz pendulum gas sensor, fixed electrolyte gas sensor, etc.).
The odor detection means 53 is disposed on the rear cover plate 31 of the liquid storage tank 26 as shown in FIGS. The odor detection means 53 is arranged on the right wall plate 26D side in the left-right direction C with a space from the pump 28.
The odor detection means 53 is juxtaposed on the front wall plate 26 </ b> A side with an interval from the liquid temperature detection means 51 in the front-rear direction B, and is fixed to the rear cover plate 31 of the liquid storage tank 26.
The odor detection means 53 detects the sulfide gas concentration γg emitted from the water-soluble cutting fluid WO stored in the liquid storage tank 26 and outputs it as a sulfide gas concentration signal.

The hydrogen ion concentration index detecting means 54 detects the hydrogen ion concentration index εg (pH) of the stored water-soluble cutting fluid WO (hereinafter referred to as “pH detecting means 54”). The pH detection means 54 is a pH sensor.
The pH detection means 54 is disposed on the rear cover plate 31 of the liquid storage tank 26 as shown in FIGS. The pH detection means 54 is disposed on the right wall plate 26D side in the left-right direction C with a space from the pump 28.
The pH detection means 54 is juxtaposed with the odor detection means 53 at intervals in the left-right direction C. The pH detection means 54 is fixed to the rear cover plate 31 of the liquid storage tank 26 and is immersed in the water-soluble cutting fluid WO stored in the liquid storage tank 26.
The pH detection means 54 detects the hydrogen ion concentration index εg of the water-soluble cutting fluid WO stored in the liquid storage tank 26 and outputs it as a hydrogen ion concentration index signal.

The calculation control means 55 is connected to the liquid temperature detection means 51, the conductivity detection means 52, the odor detection means 53, and the pH detection means 54 as shown in FIG.
The arithmetic control unit 55 includes an actually measured liquid temperature Tg (measured liquid temperature signal) detected by the liquid temperature detecting unit 51, an actually measured electrical conductivity σg (measured electrical conductivity signal) detected by the conductivity detecting unit 52, and an odor detecting unit 53. And the hydrogen gas concentration index εg (hydrogen ion concentration index signal) detected by the pH detecting means 54 are simultaneously input.

As shown in FIG. 7, the arithmetic control means 55 includes a controller 57, an amplifier 58, and a timer 59 (timer).
The amplifier 58 is connected to the conductivity detecting means 52. The amplifier 58 receives the measured electrical conductivity σg (measured electrical conductivity signal) detected by the conductivity detector 52 and amplifies the measured electrical conductivity σg (measured electrical conductivity signal) (for example, the measured electrical conductivity signal). Is amplified 4 times) and output.

The controller 57 is, for example, a CPU (Central Processing Unit) and is connected to the amplifier 58 and the timer 59.
The controller 57 inputs the measured electrical conductivity σg (μS / cm) amplified by the amplifier 58. The controller 57 outputs a detection signal to the timer 59. The timer 59 measures the detection time t by inputting the detection signal.

The storage means 56 stores a plurality of density data αa1, αa2,..., Αan having different densities (where n = 1, 2, 3,..., I,..., N: natural numbers. Hereinafter, the same applies). ).
Each density data αa1, αa2,..., Αan is a value in the range of density 2% to 10%, for example.

  The storage unit 56 stores the density determination range value αx. The concentration determination range value αx is a range value indicating the concentration of the water-soluble cutting fluid WO, and is a value that takes a range value between the minimum concentration value αmin and the maximum concentration value αmax. In the density determination range value αx, the minimum density value αmin is, for example, 3% density, and the maximum density value αmax is, for example, 7% density.

  The storage means 56 stores the odor discrimination value γx. The odor discrimination value γx is a value indicating the sulfide gas concentration.

  The storage means 56 stores the hydrogen gas concentration index discrimination value εx. The hydrogen gas concentration index discrimination value εx is a value indicating the hydrogen gas concentration index of the water-soluble cutting fluid WO. The hydrogen gas concentration index discrimination value εx is, for example, εx = 8.9.

The storage means 56 is the same component as the water-soluble cutting fluid WO stored in the liquid storage tank 26, and is water-soluble cutting of each concentration α1, α2,..., Αn corresponding to each concentration data αa1, αa2,. For the liquids WO1, WO2,..., WOn, the linear function equations f1, f2,... Fn corresponding to the water-soluble cutting fluids WO1, WO2,.
The linear function equations f1, f2,..., Fn corresponding to the water-soluble cutting fluids WO1, WO2,. It is a functional equation showing the relationship between the liquid temperature (° C.) and the electric conductivity before measurement (μS / cm).
The linear function equations f1, f2,..., F3 corresponding to the water-soluble cutting fluids WO1, WO2,. And water-soluble cutting fluids WO1, WO2,..., WOn having the respective concentrations α1, α2,..., Αn indicating the electrical conductivity (electrical conductivity) before measurement of the water-soluble cutting fluids, f1, f2,. It is.
Each of the concentrations α1, α2,..., Αn is the same concentration as the respective concentration data αa1, αa2,..., Αan, and α1 = αa1, α2 = αa2,. Each concentration α1, α2,..., Αn is, for example, a value in the range of 2% to 10%.

  The concentration detector Z is a linear function equation corresponding to the water-soluble cutting fluids WO1, WO2,..., WOn of the respective concentrations a1, a2,. f1, f2,..., fn: f (i) = y (αi%) = Ax + B is calculated.

<Calculation of linear function equations f1, f2,..., Fn>
In the concentration detection device Z, the liquid temperature detection means 51 uses the liquid temperature (° C.) of the water-soluble cutting fluid for each of the water-soluble cutting fluids WO1, WO2,. The pre-measurement liquid temperature (sample liquid temperature) ”is detected.
The conductivity detecting means 52 determines the electrical conductivity (μS / cm) of the water-soluble cutting fluid for each of the water-soluble cutting fluids WO1, WO2,. Liquid temperature (sample electrical conductivity) ”.
The arithmetic control means 55 (controller 57) sets the pre-measurement liquid temperature (° C.) detected by the liquid temperature detection means 51 and the pre-measurement electrical conductivity (μS / cm) detected by the conductivity detection means 52 to a certain level. Input at every detection time (for example, every minute) to obtain a plurality (many) of pre-measurement liquid temperatures T having different temperatures and a plurality (many) of pre-measurement electrical conductivity.
As a result, the arithmetic control means 55 makes plural (many) pre-measurement liquid temperatures and plural (many) actual measurements for each of the water-soluble cutting fluids WO1, WO2,. Get the previous electrical conductivity. Each electric conductivity before measurement is electric conductivity corresponding to each liquid temperature before measurement (electric conductivity before measurement at each liquid temperature before measurement).
In the aqueous cutting fluid WO1 having the concentration α1, a plurality (large number) of pre-measurement liquid temperatures T11, T12,..., T1n and a plurality (multiple) pre-measurement electrical conductivities σ11, σ12,. , T2n and plural (many) pre-measurement electrical conductivities σ21, σ22,..., Σ2n are obtained. In the water-soluble cutting fluid WOn having the concentration αn, a plurality (large number) of pre-measurement liquid temperatures Tn1, Tn2,..., Tnn and a plurality (large number) of pre-measurement electrical conductivities σn1, σn2,.

The calculation control means 55 is provided with water-soluble cutting fluids WO1, WO2,..., Αn having respective concentrations α1, α2,. Linear function equations f1, f2,... Fn corresponding to WOn are calculated.
FIG. 8 shows “water temperature before measurement of water-soluble cutting fluid (° C.)” and “water-soluble cutting fluid” corresponding to the water-soluble cutting fluids WO1, WO2,. It is a graph of linear function formulas f1, f2,..., Fn showing the relationship of “electric conductivity before measurement (μS / cm)”.
In FIG. 8, the horizontal axis (x coordinate axis) represents “liquid temperature before measurement (° C.)”, and the vertical axis (y coordinate axis) represents “electric conductivity before measurement (μS / cm)”.
In FIG. 8, “liquid temperature before measurement (liquid temperature)” is “x coordinate value (xi)”, and “electric conductivity before measurement (electric conductivity)” is “y coordinate value (yi)”. In FIG. 8, the coordinate values are (x, y) = (liquid temperature before measurement, electrical conductivity before measurement).
In the water-soluble cutting fluid WO1 having a concentration α1, the coordinate value data number M is M = n, and the coordinate values are (x1, y1) = (T11, σ11), (x2, y2) = (T12, σ12), ..., (xn, xn) = (T1n, σ1n), and in the water-soluble cutting fluid WOn having a concentration αn, the number of coordinate value data is M = n, and each coordinate value is (x1, y1) = (Tn1, σn1) ), (X2, y2) = (Tn2, σn2),..., (Xn, xn) = (Tnn, σnn).
The arithmetic control means 55 (controller 57) uses, for example, a “least square method” to calculate a linear function equation f corresponding to the water-soluble cutting fluids WO1, WO2,. (I) = y (αi) = Ax + B is calculated.
According to the “least-squares method”, the number of coordinate value data M relating to “liquid temperature before measurement−electric conductivity before measurement”, i-th coordinate value (xi, yi) = (liquid temperature before measurement, electricity before measurement) (Conductivity), the “A value (gradient)” of the linear function formula f (i) = y (αi) = Ax + B is calculated by the formula (1).
The “B value (intercept)” of the linear function f (i) = y (αi) = Ax + B is calculated by the equation (2).

The calculation control means 55 determines the number of coordinate value data M = n and each coordinate value (xi, yi) = (before measurement) for each of the water-soluble cutting fluids WO1, WO2,. Substituting the liquid temperature and the electrical conductivity before measurement) into the equations (1) and (2), the linear functions corresponding to the water-soluble cutting fluids WO1, WO2,. “A value (slope)” and “B value” of the formula f (i) = y (αi) = Ax + B are calculated.
The arithmetic control means 55 stores the linear function equations f1, f2,..., Fn corresponding to the water-soluble cutting fluids WO1, WO2,.

The calculation control means 55 (controller 57) corresponds to the measured water temperature Tg (° C.) input from the liquid temperature detection means 51 in the detection of the water-soluble cutting liquid WO stored in the liquid storage tank 26. A calibration curve F (Tg) indicating the relationship between “liquid concentration α” and “calculated electrical conductivity (μS / cm)” is calculated.
The calibration curve F (Tg) is, for example, a linear function calibration formula F (Tg) = y (Tg) = Ax + B.

<Calculation of calibration curve F (Tg)>
The arithmetic control means 55 (controller 57) corresponds to the measured liquid temperature Tg (° C.) input from the liquid temperature detection means 51 and the water-soluble cutting fluids WO1, WO2,. .., Fn based on the linear function equations f1, f2,..., Fn, and the electric conductivity σb of each of the water-soluble cutting fluids WO1, WO2,. Calculated).
The calculation control means 55 (controller 57) uses the measured liquid temperature Tg (° C.) input from the liquid temperature detection means 51 as the linear function equations f1, f2,..., Fn of the water-soluble cutting fluids WO1, WO2,. .., Bn of the water-soluble cutting fluids WO1, WO2,..., WOn of the respective concentrations α1, α2,. .
The calculation control means 55 (controller 57) is configured to calculate the electrical conductivity σb1 of each concentration data αa1, αa2,..., Αan and the water-soluble cutting fluids WO1, WO2,. , Σb2,..., Σbn, a calibration curve F (T) [linear function calibration method F (T)] corresponding to the actually measured liquid temperature Tg (° C.) input from the liquid temperature detecting means 51 is calculated. .
FIG. 9 shows the relationship between “the concentration of the water-soluble cutting fluid” and “the calculated electrical conductivity (μS / cm) of the water-soluble cutting fluid” corresponding to the actually measured liquid temperature Tg (° C.) input from the liquid temperature detecting means 51. Is a graph of a calibration curve F (Tg) [a calibration function F (Tg) of a linear function].
In FIG. 9, the horizontal axis (x coordinate axis) represents “calculated electrical conductivity of water-soluble cutting fluid”, and the vertical axis (y coordinate axis) represents “concentration of water-soluble cutting fluid”.
In FIG. 9, “calculated electrical conductivity (electric conductivity) of water-soluble cutting fluid” is “x coordinate value”, and “water-soluble cutting fluid concentration” is “y coordinate value”. In FIG. 9, each coordinate value is (xi, yi) = (calculated electrical conductivity, concentration).
.., Αn water-soluble cutting fluids WO1, WO2,..., WOn calculated electrical conductivity σb1, σb2,..., Σbn and each concentration data αa1, αa2,. Coordinate value data number M = n regarding “calculated electrical conductivity”, each coordinate value is (x1, y1) = (σb1, αa1), (x2, y2) = (σb2, αa2),..., (Xn, yn) = (Σbn, αan).
The arithmetic control means 55 (controller 57) calculates the linear function calibration curve F (Tg) = y (Tg) = Ax + B using, for example, the “least square method”.
The calculation control means 55 has a coordinate value data number M = n regarding “concentration−calculated electrical conductivity”, each coordinate value (x1, y1) = (σb1, αa1), (x2, y2) = (σb2, αa2), .., (Xn, yn) = (σbn, αan) are substituted into the equation (1) to calculate the “A value (slope)” of the calibration curve F (Tg) = y (Tg) = Ax + B.
The arithmetic control means 55 (controller 57) is provided with the number of coordinate value data M = n, each coordinate value (x1, y1) = (σb1, αa1), (x2, y2) = (σb2, αa2),. , Yn) = (σbn, αan) is substituted into equation (2) to calculate the “B value (intercept)” of the calibration curve F (Tg) = y (Tg) = Ax + B.

Thereby, the calibration curve F (Tg) corresponding to the actually measured liquid temperature (Tg) input from the liquid temperature detecting means 51 is
y (Tg) = Ax + B ... Formula (3)
It becomes.
In equation (3), y (Tg) is the concentration α of the water-soluble cutting fluid WO at the measured liquid temperature (Tg), and x is the electric conduction before the measurement of the water-soluble cutting fluid WO at the measured liquid temperature (Tg). Rate (μS / cm).

  The calculation control means 55 (controller 57) is a calibration curve F (Tg) corresponding to the measured electrical conductivity σg (μS / cm) input (acquired) from the conductivity detection means 52 and the measured liquid temperature Tg (° C.). Based on the above, the concentration α of the water-soluble cutting fluid WO stored in the liquid storage tank 26 is calculated.

  The calculation control means 55 (controller 57) substitutes the measured electrical conductivity σg (μS / cm) input (acquired) from the conductivity detection means 52 for “x (x coordinate value)” in the equation (3). Thus, the concentration α of the water-soluble cutting fluid WO stored in the liquid storage tank 26 is calculated.

  As shown in FIG. 7, the concentration detection device Z of the first embodiment includes a display unit 65 and an alarm unit 66.

The display means 65 is, for example, a liquid crystal display. The display means 65 is connected to the controller 57.
The alarm means 66 is an alarm device for generating an alarm such as an alarm sound, and is connected to the controller 57.

In the machine tool system X, the machine tool Y processes the workpiece 1, and the concentration detection device Z according to the first embodiment detects the water-soluble cutting fluid WO stored in the liquid storage tank 26 as shown in FIG. The actual measurement process 1 shown in FIG. 12 is executed to detect the liquid state of the water-soluble cutting fluid WO (water-soluble cutting fluid WO whose concentration α is unknown) stored in the liquid storage tank 26, and the water-soluble cutting fluid WO The concentration α is calculated.
Hereinafter, processing of the workpiece 1 in the machine tool Y and measurement processing 1 of the concentration detection device Z of the first embodiment will be described with reference to FIGS. 1 to 12.

The machine tool Y (control means) drives the pump 28 for suction / discharge, as shown in FIG. The pump 28 sucks the water-soluble cutting fluid WO stored in the liquid storage tank 26 along with the suction / discharge driving, and discharges the water-soluble cutting fluid WO to the liquid supply pipe 27.
Thereby, the water-soluble cutting fluid WO discharged to the liquid supply pipe 27 is jetted from the jet nozzles 23 and 24 to the blade tool 4 and the workpiece 1 through the liquid feed pipe 27 and the nozzle pipes 23A and 24A ( Supply).

The machine tool Y drives the drive motor 9 to rotate the blade tool 4 (housing 8, collet 10) and move the spindle head 2 to send the blade tool 4 to the workpiece 1.
Thereby, the machine tool Y processes the workpiece 1 with the blade tool 4 while supplying the water-soluble cutting fluid WO stored in the liquid storage tank 26 to the blade tool 4 and the workpiece 1.
As shown in FIG. 1, the water-soluble cutting fluid WO sprayed (supplied) to the blade tool 4 and the workpiece 1 is recovered from the processing table 25 into the liquid storage tank 26 (storage space 21) through the liquid recovery port 32. The
In this way, the machine tool Y processes the workpiece 1 with the blade tool 4 while circulating the water-soluble cutting fluid WO between the blade tool 4 (workpiece 1) and the liquid storage tank 26.

<Measurement process 1>
In the detection of the water-soluble cutting fluid WO stored in the liquid storage tank 26, the controller 57 (calculation control means 55) detects the detection time of the timer 59 when the machine tool Y starts processing (circulation of the water-soluble cutting fluid WO). t is “zero set (t → 0)” (FIG. 10: ST01).

Subsequently, the controller 57 outputs a detection signal to the timer 59. The timer 59 measures the detection time t when the detection signal is input.
When the detection time t of the timer 59 reaches the time tk (detection time t = tk) (FIG. 10: ST02, Yes), the controller 57 detects the measured liquid temperature Tg (° C.) detected by the liquid temperature detection means 51, and the conductivity. The measured electrical conductivity σg (μS / cm) detected by the rate detecting means 52 is simultaneously input (acquired) (FIG. 10: ST03).
The measured electrical conductivity σg input by the controller 57 is an electrical conductivity corresponding to the measured liquid temperature Tg (° C.) [the electrical conductivity at the measured liquid temperature Tg (° C.)].
The controller 57 simultaneously inputs the sulfide gas concentration γg detected by the odor detecting means 53 and the hydrogen ion concentration index εg detected by the pH detecting means 54 (FIG. 10: ST03).
On the other hand, if the detection time t is not the time tk (FIG. 10: ST02, No) and the detection is not completed (FIG. 10: ST16, No), the controller 57 continues to count the timer 59.
When the detection is completed (FIG. 10: Yes, ST16), the controller 57 ends the detection of the measured liquid temperature Tg, the measured electrical conductivity Tg, the sulfide gas concentration γg, and the hydrogen ion concentration index εg, and is water-soluble. The calculation (calculation) of the concentration α of the cutting fluid WO is completed.

  In the arithmetic control means 55, the controller 57 inputs the measured liquid temperature Tg (° C.), the measured electrical conductivity σg (μS / cm), the sulfide gas concentration γg, and the hydrogen ion concentration index εg (FIG. 10: ST03). , Αan and the linear function equations f1, f2,..., Fn corresponding to the water-soluble cutting fluids WO1, WO2,. 56 is read out (FIG. 10: ST04).

Subsequently, the controller 57 converts the measured liquid temperature Tg (° C.) input (acquired) from the liquid temperature detecting means 51 and the water-soluble cutting fluids WO1, WO2,. Based on the corresponding linear function equations f1, f2,..., Fn, the calculated electrical conductivity σb (μS / cm) of each water-soluble cutting fluid WO1, WO2,..., WOn is calculated (FIG. 10: ST05).
The controller 57 uses the measured liquid temperature Tg (° C.) input (acquired) from the liquid temperature detecting means 51 as the primary corresponding to the water-soluble cutting fluids WO1, WO2,. .., Fn: y (αi%) = Ax + B is substituted for “x (x coordinate value)”, and water-soluble cutting fluids WO1, WO2, WO3 having respective concentrations α1, α2,. ,..., WOn calculated electric conductivity σb (μS / cm) is calculated.

In the arithmetic control means 55, the controller 57 includes the calculated electrical conductivity of each concentration data αa1, αa2,..., Αan and the water-soluble cutting fluids WO1, WO2,. Based on σb (μS / cm), a calibration curve F (Tg) [calibration formula F (Tg) of a linear function] with respect to the actually measured liquid temperature Tg (° C.) is calculated (FIG. 10: ST06).
The controller 57 uses the calibration curve F (Tg) corresponding to the measured liquid temperature Tg (° C.) input (acquired) from the liquid temperature detection means 51 in the same manner as described above in <Calculation of calibration curve F (Tg)>. Is calculated.

Subsequently, the controller 57 inputs the measured electrical conductivity σg (μS / cm) input (acquired) from the conductivity detecting means 52 and the calibration curve F (Tg) corresponding to the calculated measured liquid temperature Tg (° C.). Based on the above, the concentration α of the water-soluble cutting fluid WO stored in the liquid storage tank 26 is calculated (FIG. 11: ST07).
The controller 57 substitutes the measured electrical conductivity σg input (acquired) from the conductivity detecting means 52 for “x (x coordinate value)” in the equation (3), and stores the water-soluble property stored in the liquid storage tank 26. The concentration α of the cutting fluid WO is calculated.

In the calculation control means 55, the controller 57 includes an actual liquid temperature Tg (actual liquid temperature signal), an actual electric conductivity σg (an actual electric conductivity signal), a calculated concentration α (concentration signal), and a sulfide gas concentration γg ( The sulfide gas concentration signal) and the hydrogen ion concentration index εg (hydrogen gas concentration index signal) are output to the display means 65 (FIG. 11: ST08).
Thereby, the display means 65 displays the measured liquid temperature Tg of the water-soluble cutting fluid WO, the measured electrical conductivity σg at the measured liquid temperature Tg, the concentration α of the water-soluble cutting fluid WO, and the sulfide gas concentration of the water-soluble cutting fluid WO. γg and the hydrogen ion concentration index εg of the water-soluble cutting fluid WO are displayed.

Subsequently, the controller 57 reads the concentration determination value αx from the storage means 56 (FIG. 11: ST09), and compares the concentration α of the water-soluble cutting fluid WO with the concentration determination value αx (αmin <α <αmax).
When the concentration α of the water-soluble cutting fluid WO is outside the concentration discrimination value αx (the concentration α is less than the minimum concentration value αmin or exceeds the maximum concentration value αmax) (FIG. 11: ST10, No), an alarm is issued. A signal is output to the alarm means 66 (FIG. 11: ST15).
Thereby, the alarm means 66 issues an alarm such as an alarm sound.

When the concentration α of the water-soluble cutting fluid WO is within the concentration determination value αx (FIG. 11: Yes at ST10), the controller 57 reads the odor determination value γx from the storage means 56 (FIG. 11: ST11).
The controller 57 compares the sulfide gas concentration γg and the odor discrimination value γx.
When the sulfide gas concentration γg exceeds the odor discrimination value γx (FIG. 11: Yes at ST12), the controller 57 outputs an alarm signal to the alarm means 66 (FIG. 11: ST15).
Thereby, the alarm means 66 issues an alarm such as an alarm sound.

If the sulfide gas concentration γg does not exceed the odor discrimination value γx (FIG. 11: ST12, No), the controller 57 reads the hydrogen ion concentration index discrimination value εx from the storage means 56 (FIG. 11: ST13).
The controller 57 compares the hydrogen ion concentration index εg and the hydrogen ion concentration index discrimination value εx.
When the hydrogen ion concentration index εg exceeds the hydrogen ion concentration index discrimination value εx (FIG. 11: Yes at ST14), the controller 57 outputs an alarm signal to the alarm means 66 (FIG. 11: ST15).
Thereby, the alarm means 66 issues an alarm such as an alarm sound.

In the calculation control means 55, the controller 57 does not exceed the hydrogen ion concentration index εg (FIG. 11: ST14, No) or outputs an alarm signal (FIG. 11: If it is not the end of detection (ST15) and ST17 (No in FIG. 12), ST01 to ST16 are repeatedly executed.
As a result, the controller 57 inputs (acquires) the measured liquid temperature Tg, the measured electrical conductivity σg, the sulfide gas concentration γg, and the hydrogen ion concentration index εg every fixed detection time tk (every unit time). In addition, the concentration α of the water-soluble cutting fluid WO is calculated every unit time.

  When the detection is completed (FIG. 12: ST17, Yes), the controller 57 ends the detection of the measured liquid temperature Tg, the measured electrical conductivity Tg, the sulfide gas concentration γg, and the hydrogen ion concentration index εg, and is water soluble. The calculation (calculation) of the concentration α of the cutting fluid WO is completed.

<Concentration Detection Device Z (Liquid State Measurement Device) of Second Embodiment>
The concentration detection device Z of the second embodiment is similar to that described with reference to FIGS. 1 to 7. The liquid temperature detection means 51, conductivity detection means 52, odor detection means 53, hydrogen ion concentration index detection means 54, calculation control Means 55, storage means 56, display means 65, and alarm means 66 are provided.

In the concentration detection device Z of the second embodiment, the storage means 56 is a calibration curve [linear function calibration corresponding to a plurality (large number) of liquid temperatures Tg1, Tg2,..., Tgn that can be detected by the liquid temperature detection means 51. Formula F (Tg)] F1, F2,..., Fn are stored.
The plurality of liquid temperatures that can be detected by the liquid temperature detection means 51 are a plurality of temperatures in a temperature range that can be detected by the liquid temperature detection means 51, and a calibration curve (Fg) corresponding to each temperature is stored in the storage means 56. To remember.
In the arithmetic control means 55, the controller 57 controls the liquid temperatures Tg1, Tg2, Tg3,..., Tgn to the respective concentrations α1, α2, α3 in the same manner as described above in <Calculation of calibration curve F (Tg)>. ,..., Αn water-soluble cutting fluids WO1, WO2, WO3,..., WOn are substituted into “x (x coordinate value)” of linear function equations f1, f2,. The calculated electrical conductivity σb of the water-soluble cutting fluids WO1, WO2,..., WOn of the respective concentrations α1, α2,.
As described in the above <Calculation of calibration curve F (T)>, the controller 57 sets each concentration data αa1, αa2,..., Αan and each water temperature corresponding to each liquid temperature Tg1, Tg2,. , Fn [calibration formula F of linear function corresponding to each liquid temperature Tg1, Tg2,..., Tg based on the calculated electrical conductivity σb of the cutting fluids WO1, WO2,. (Tg)] is calculated.
The controller 57 stores the calibration curves F1, F2,..., Fn corresponding to the liquid temperatures Tg1, Tg2,..., Tgn in the storage means 56 before detecting the water-soluble cutting fluid WO stored in the liquid storage tank 26. To do.

  In the detection of the water-soluble cutting fluid WO stored in the liquid storage tank 26, the concentration detection device Z of the second embodiment executes the actual measurement process 2 shown in FIGS. The liquid state of the water-soluble cutting fluid WO (water-soluble cutting fluid WO whose concentration α is unknown) is detected, and the concentration α of the water-soluble cutting fluid WO is calculated.

<Measurement process 2>
In the detection of the water-soluble cutting fluid WO stored in the liquid storage tank 26, the controller 57 (calculation control means 55) detects the detection time of the timer 59 when the machine tool Y starts processing (circulation of the water-soluble cutting fluid WO). t is “zero set (t → 0)” (FIG. 13: ST51).

Subsequently, the controller 57 outputs a detection signal to the timer 59. When the detection signal is input, the timer 59 measures the detection time tk.
When the detection time t of the timer 59 reaches time tk (detection time t = tk) (FIG. 13: Yes at ST52), the controller 57 detects the measured liquid temperature Tg (° C.) detected by the liquid temperature detection means 51 and the conductivity. The measured electrical conductivity σg (μS / cm) detected by the rate detecting means 52 is simultaneously input (acquired) (FIG. 13: ST53).
The controller 57 simultaneously inputs the sulfide gas concentration γg detected by the odor detecting means 53 and the hydrogen ion concentration index εg detected by the pH detecting means 54 (FIG. 13: ST53).
On the other hand, if the detection time t is not the time tk (FIG. 13: ST52, No) and the detection is not completed (FIG. 13: ST64, No), the controller 57 continues to count the timer 59.
When the detection is finished (FIG. 13: ST64, Yes), the controller 57 finishes the detection of the measured liquid temperature Tg, the measured electrical conductivity σg, the sulfide gas concentration γg, and the hydrogen ion concentration index εg, and is water-soluble. The calculation (calculation) of the concentration α of the cutting fluid WO is completed.

  Based on the measured liquid temperature Tg input (acquired) from the liquid temperature detecting means 51, the controller 57 reads a calibration curve F (Tg) corresponding to the measured liquid temperature Tg from the storage means 56 (FIG. 13: ST54). ).

Subsequently, the controller 57 sets the calibration curve F (Tg) for the measured electrical conductivity σg (μS / cm) input (acquired) from the conductivity detecting means 52 and the measured liquid temperature Tg (° C.) read from the storage means 56. ), The concentration α of the water-soluble cutting fluid WO stored in the liquid storage tank 26 is calculated (FIG. 13: ST55).
The controller 57 substitutes the measured electrical conductivity σg input (acquired) from the conductivity detecting means 52 for “x (x coordinate value)” in the equation (3), and stores the water-soluble property stored in the liquid storage tank 26. The concentration α of the cutting fluid WO is calculated.

In the calculation control means 55, the controller 57 includes an actual liquid temperature Tg (actual liquid temperature signal), an actual electric conductivity σg (an actual electric conductivity signal), a calculated concentration α (concentration signal), and a sulfide gas concentration γg ( The sulfide gas concentration signal) and the hydrogen ion concentration index εg (hydrogen gas concentration index signal) are output to the display means 65 (FIG. 13: ST56).
Thereby, the display means 65 displays the measured liquid temperature Tg and measured electrical conductivity σg of the water-soluble cutting fluid WO, the concentration α of the water-soluble cutting fluid WO, the sulfide gas concentration γg of the water-soluble cutting fluid WO, and the water-soluble cutting. The hydrogen ion concentration index εg of the liquid WO is displayed.

Subsequently, the controller 57 reads the concentration determination value αx from the storage means 56 (FIG. 13: ST57), and compares the concentration α of the water-soluble cutting fluid WO with the concentration determination value αx (αmin <α <αmax).
When the concentration α of the water-soluble cutting fluid WO is outside the concentration discrimination value αx (the concentration α is less than the minimum concentration value αmin or exceeds the maximum concentration value αmax) (FIG. 14: ST58, No), the controller 57 issues an alarm. A signal is output to the alarm means 66 (FIG. 14: ST63).
Thereby, the alarm means 66 issues an alarm such as an alarm sound.

When the concentration α of the water-soluble cutting fluid WO is within the concentration determination value αx (FIG. 14: Yes at ST58), the controller 57 reads the odor determination value γx from the storage means 56 (FIG. 14: ST59).
The controller 57 compares the sulfide gas concentration γg and the odor discrimination value γx.
When the sulfide gas concentration γg exceeds the odor discrimination value γx (FIG. 14: Yes at ST60), the controller 57 outputs an alarm signal to the alarm means 66 (FIG. 14: ST63).
Thereby, the alarm means 66 issues an alarm such as an alarm sound.

If the sulfide gas concentration γg does not exceed the odor discrimination value γx (FIG. 14: ST60, No), the controller 57 reads the hydrogen ion concentration index discrimination value εx from the storage means 56 (FIG. 14: ST61).
The controller 57 compares the hydrogen ion concentration index εg and the hydrogen ion concentration index discrimination value εx.
When the hydrogen ion concentration index εg exceeds the hydrogen ion concentration index discriminating value εx (FIG. 14: Yes at ST62), the controller 57 outputs an alarm signal to the alarm means 66 (FIG. 14: ST63).
Thereby, the alarm means 66 issues an alarm such as an alarm sound.

In the calculation control means 55, the controller 57 does not exceed the hydrogen ion concentration index εg (FIG. 14: ST62, No) or outputs an alarm signal (FIG. 14: If the detection is not finished (ST63) (FIG. 14: ST65, No), ST51 to ST64 are repeated.
As a result, the controller 57 inputs (acquires) the measured liquid temperature Tg, the measured electrical conductivity σg, the sulfide gas concentration γg, and the hydrogen ion concentration index εg every fixed detection time tk (every unit time). In addition, the concentration α of the water-soluble cutting fluid WO is calculated every unit time.

  When the detection is completed (FIG. 14: ST65, Yes), the controller 57 ends the detection of the measured liquid temperature Tg, the measured electrical conductivity Tg, the sulfide gas concentration γg, and the hydrogen ion concentration index εg, and is water-soluble. The calculation (calculation) of the concentration α of the cutting fluid WO is completed.

  In the concentration detection device Z of the first and second embodiments, the example applied to the machine tool system X (machine tool Y) has been described, but the present invention is not limited to this.

Next, before detecting the measured liquid temperature Tg (° C.) and the measured electrical conductivity σg (μS / cm) of the water-soluble cutting fluid WO stored in the liquid storage tank 26, a plurality of water-soluble cuttings having different concentrations are detected. A detection test (liquid temperature-electric conductivity detection test) for detecting the liquid temperature and electrical conductivity of the water-soluble cutting fluid will be described for the liquid (water-soluble cutting fluid having a known concentration).
Further, from the detection result of the liquid temperature-electric conductivity detection test, a linear function formula f (i) corresponding to each concentration of water-soluble cutting fluid is calculated, and a calibration curve F (Tg) [linear function calibration formula F (Tg)] is calculated (calculated).

1: Liquid temperature-electric conductivity detection test The liquid temperature-electric conductivity detection test was implemented about "Example 1", "Example 2", and "Example 3".

<Water-soluble cutting fluid>
In the liquid temperature-electric conductivity test, water-soluble cutting fluids WO1, WO2, and WO3 having the same components as the water-soluble cutting fluid stored in the liquid storage tank and having concentrations of 2%, 5%, and 10% were used.
Each of the water-soluble cutting fluids WO1 to WO3 was an alkaline fluid, and the concentration was adjusted by diluting the water-soluble cutting stock solution with water, so that the total volume (capacity) of the liquid was 100 milliliters (mL).
As the water-soluble cutting stock solution, “SX-557S” manufactured by Taiyu Co., Ltd. was used.
The ingredients of Taiyu Co., Ltd. “SX-557S (water-soluble cutting stock solution)” are 20% or less rust preventive additive (containing alkali component), 40% or less surfactant, and 20% content. The following refined mineral oil, water with a content of 60% or less, and other components with a content of 1% or less are contained, and the content of each component is adjusted so that the total concentration of the stock solution is 100%.
Example 1
Example 1 used a water-soluble cutting fluid WO1 having a concentration of 2% (volume concentration of 2%) (when water: 98 mL, water-soluble cutting stock solution: 2 mL, the volume concentration α = 2/100 = 2%) .
(Example 2)
Example 2 used a water-soluble cutting fluid WO2 having a concentration of 5% (volume concentration 5%) (water: 95 mL, water-soluble cutting stock solution; assuming 5 mL, the volume concentration α = 5/100 = 5%) .
Example 3
In Example 3, a water-soluble cutting fluid WO3 having a concentration of 10% (volume concentration of 10%) was used (when water: 90 mL, water-soluble cutting stock solution: 10 mL, the volume concentration α = 10/100 = 10%). .

<Liquid temperature detection means>
As the liquid temperature detecting means, a thermocouple temperature sensor (general-purpose product) was used.

<Conductivity detection means>
As the conductivity detection means, a two-electrode conductivity sensor (general-purpose product) was used.

<Detection conditions>
(1) The water-soluble cutting fluids WO1 to WO3 of Examples 1 to 3 were put in separate containers (beakers).
(2) The water-soluble cutting fluids WO1 to WO3 of Examples 1 to 3 were placed in a room temperature after being cooled in a freezer together with the container.
In Examples 1 to 3, the water-soluble cutting fluids WO1 to WO3 were naturally raised at room temperature.
(3) Example 1 to Example 3 For each water-soluble cutting fluid WO1 to WO3, a thermocouple temperature sensor and a two-electrode conductivity sensor are immersed, and each water-soluble cutting fluid WO1, using a thermocouple temperature sensor. The liquid temperature before measurement of WO2 and WO3 (sample liquid temperature) T1, T2 and T3 (° C.) is detected, and the electrical conductivity before measurement of each water-soluble cutting fluid WO1, WO2 and WO3 is detected by a two-electrode conductivity sensor. (Sample electrical conductivity) σ1, σ2, and σ3 (μS / cm) were detected.
(4) In Examples 1 to 3, the liquid temperatures T1, T2, and T3 (° C.) before the measurement of the water-soluble cutting fluids WO1, WO2, and WO3 and the electricity before the measurement of the water-soluble cutting fluids WO1, WO2, and WO3 Conductivities σ1, σ2, and σ3 (μS / cm) were detected at the same time, and a plurality of detections (a large number of detections) were made every constant detection time: 1 minute.
For each of the water-soluble cutting fluids WO1 to WO3, the pre-measurement liquid temperatures T1 to T3 detected by the thermocouple temperature sensor and the pre-measurement electrical conductivities σ1 to σ3 detected by the two-electrode conductivity sensor are set at regular detection times. (Every minute), a plurality of (many) pre-measurement liquid temperatures (° C.) with different temperatures, and a plurality (many) pre-measurement electrical conductivities at each pre-measurement liquid temperature (° C.) μS / cm) was obtained.

<Detection result>
Example 1
As the detection results of Example 1, the pre-measurement liquid temperature T1 (° C.) and the pre-measurement electrical conductivity σ1 (μS / cm) of the water-soluble cutting fluid WO1 having a concentration of 2% are shown in “Table 1” to “Table 11”. .
The number of detected data in Example 1 is 642 (detection No. 1 to detection No. 642).
The detection numbers of “Table 1” to “Table 11”. 1 to detection No. 1 642 indicates a pre-measurement electric conductivity σ1 (μS / cm) corresponding to the pre-measurement liquid temperature T1 (° C.). 1, the pre-measurement electrical conductivity σ1 at the pre-measurement liquid temperature T1: 6.0000 (° C.) is σ1 = 708.156 (μS / cm).
The detection No. 1 to detection No. 1 The pre-measurement electric conductivity σ1 of 642 is a value obtained by amplifying the detection value detected by the two-electrode conductivity sensor four times (hereinafter, the same applies to the second and third embodiments).

(Example 2)
Regarding the detection results of Example 2, the pre-measurement liquid temperature T2 (° C.) and the pre-measurement electrical conductivity σ2 (μS / cm) of the water-soluble cutting fluid WO2 (concentration 5%) are shown in “Table 12” to “Table 28”. Show.
The number of detected data in Example 2 is 1019 (detection No. 1 to detection No. 1019).
The detection numbers of “Table 12” to “Table 28”. 1 to detection No. 1 Reference numeral 1019 denotes a pre-measurement electric conductivity σ2 (μS / cm) corresponding to the pre-measurement liquid temperature T2 (° C.). 18, the electric conductivity σ2 before the measurement when the liquid temperature T2 before the measurement is 7.1875 (° C.) is σ2 = 830.6390 (μS / cm).

Example 3
Regarding the detection results of Example 3, the liquid temperature T3 (° C.) before measurement and the electric conductivity σ3 (μS / cm) before measurement of the water-soluble cutting fluid WO3 (concentration 10%) are shown in “Table 29” to “Table 62”. Show.
The number of detected data in Example 3 is 2027 (detection No. 1 to detection No. 2027).
The detection numbers of “Table 29” to “Table 62”. 1 to detection No. Reference numeral 2027 denotes a pre-measurement electric conductivity σ3 (μS / cm) corresponding to the pre-measurement liquid temperature T3 (° C.). In 121, the electrical conductivity before measurement σ3 at the time of liquid temperature T3 before measurement: 11.8750 (° C.) is σ3 = 11788.8634 (μS / cm).

  As shown in "Table 1" to "Table 62", Examples 1 to 3 show that each water-soluble cutting fluid WO1 to WO3 increases in water temperature T1 to T3 (° C.) before the measurement, It can be said that the electrical conductivity σ1 to σ3 (μS / cm) before actual measurement of the neutral cutting fluids WO1 to WO3 also rises to a high value.

Detection No. of Example 1 201, as shown in “Table 4”, the measured liquid temperature T1: 14.1875 (° C.) of the water-soluble cutting fluid WO1 and the electrical conductivity σ1: 758.0074 (μS / cm).
Detection No. of Example 1 285, as shown in “Table 5”, the pre-measurement liquid temperature T1: 16.5000 (° C.) of the water-soluble cutting fluid WO1 and the pre-measurement electrical conductivity σ1: 769.5470 (μS of the water-soluble cutting fluid WO1. / Cm).
Detection No. of Example 2 211, as shown in “Table 15”, the liquid temperature T2 before measurement of the water-soluble cutting fluid WO2: 14.1875 (° C.) and the electric conductivity before measurement of the water-soluble cutting fluid WO2 σ2: 901.2342 (μS / Cm).
Detection No. of Example 2 299, as shown in “Table 16”, the liquid temperature T2 before measurement of the water-soluble cutting fluid WO2: 16.5000 (° C.) and the electric conductivity before measurement of the water-soluble cutting fluid WO2 σ2: 1959.5618 (μS / Cm).
Detection No. in Example 3 189, as shown in “Table 32”, the liquid temperature T3 before measurement of the water-soluble cutting fluid WO3: 14.1875 (° C.) and the electric conductivity before measurement of the water-soluble cutting fluid WO3 σ3: 1226.0400 (μS). / Cm).
Detection No. in Example 3 273, as shown in “Table 33”, the liquid temperature T3 before measurement of the water-soluble cutting fluid WO3: 16.5000 (° C.), and the electric conductivity before measurement of the water-soluble cutting fluid WO3 σ3: 1271.5196 (μS). / Cm).
Thereby, in Example 1 thru | or Example 3, before-measurement electric conductivity (sigma) 1- (sigma) 3 corresponding to the liquid temperature T1-T3 before measurement of the same temperature is water-soluble cutting fluid WO1 (Example 1) <2% of density | concentration < The relationship is 5% water-soluble cutting fluid WO2 (Example 2) <10% water-soluble cutting fluid WO3 (Example 3).
As described above, in each of the water-soluble cutting fluids WO1 to WO3 having a concentration of 2%, 5%, and 10%, the water-soluble cutting fluid increases as the concentration of the water-soluble cutting fluid increases at the same liquid temperature (liquid temperature) before the measurement. The electrical conductivity (electrical conductivity) before actual measurement of the cutting fluid becomes a high value.

2: Calculation of linear function formula (calculation)
From the detection results of the liquid temperature-electric conductivity detection test (detection results of Examples 1 to 3), linear functions corresponding to the water-soluble cutting fluids WO1, WO2, and WO3 having concentrations of 2%, 5%, and 10%, respectively. Formulas f1, f2, and f3 are calculated.

(1) Graph (Figure 8)
FIG. 8 shows the “liquid temperature before measurement of water-soluble cutting fluid (° C.)” and “measurement of water-soluble cutting fluid” corresponding to the water-soluble cutting fluids WO1, WO2, and WO3 having concentrations of 2%, 5%, and 10%, respectively. It is a graph of linear function formula f1, f2, f3 which shows the relationship (relevance) of "pre-electrical conductivity (microS / cm)".
In FIG. 8, the horizontal axis (x coordinate axis) is “liquid temperature before measurement (° C.)” and the vertical axis (y coordinate axis) is “electric conductivity before measurement (μS / cm)”.
In FIG. 8, “liquid temperature before measurement (liquid temperature)” is “x coordinate value (xi)”, and “electric conductivity before measurement (electric conductivity)” is “y coordinate value (yi)”.
In FIG. 8, the coordinate values are (xi, yi) = (liquid temperature before actual measurement, electrical conductivity before actual measurement).

Example 1
In Example 1, based on the plurality of pre-measurement liquid temperatures T1 (° C.) acquired from the thermocouple temperature sensor and the plurality of pre-measurement electrical conductivities σ1 (μS / cm) acquired from the two-electrode conductivity sensor, A linear function formula f1 for a water-soluble cutting fluid WO1 having a concentration of 2% was calculated.
For the linear function formula f1 corresponding to the water-soluble cutting fluid WO1 having a concentration of 2%, for example, “(2%) = Ax + B” was calculated using the “least square method”.
According to the “least square method”, when the number of data M (the number of detected data) and the i-th coordinate value (xi, yi) = (liquid temperature before measurement, electrical conductivity before measurement), the linear function formula f1: y The “A value (slope)” of (2%) = Ax + B is calculated by the equation (1).
The “B value (intercept)” of the linear function formula f1: y (2%) = Ax + B is calculated by the formula (2).

In “Example 1”, the detection numbers “Table 1” to “Table 11”. 1 to detection No. 1 For 642, the coordinate value data number M (detection data number) = 642, and each coordinate value (x1, y1) = (6.0000, 708.1156), (x2, y2) = (6.0625, 708.7944),..., (X383, y383 ) = (18.6250, 780.4078),... (X641, y641) = (22.0625, 794.6626), (x642, y642) = (22.0625, 795.0020).
The coordinate value data number M = 642 of “Example 1”, and each coordinate value (x1, y1) = (6.0000, 708.1156), (x2, y2) = (6.0625, 708.7944),..., (X383, y383) = (18.6250, 780.4078), ..., (x641, y641) = (22.0625, 794.6626), (x642, y642) = (22.0625, 795.0020) are substituted into the equations (1) and (2), and the linear function equation f1 : “A value (slope)” and “B value (intercept)” of y (2%) = Ax + B are calculated.
The “A value (slope)” of the linear function equation f1 is A = 5.0979 according to the equation (1), and the “B value (intercept)” of the linear function equation f1 is B = 684.17.

Thus, the linear function formula f1 is
y (2%) = 5.0979x + 684.17 Formula (4)
It becomes.
In equation (4), “y (2%)” is the electrical conductivity before measurement σ1 (μS / cm), and “x” is the liquid temperature T1 (° C.) before measurement.

(Example 2)
In Example 2, based on the plurality of pre-measurement liquid temperatures T2 (° C.) acquired from the thermocouple temperature sensor and the plurality of pre-measurement electrical conductivities σ2 (μS / cm) acquired from the two-electrode conductivity sensor, A linear function formula f2 corresponding to a water-soluble cutting fluid WO2 having a concentration of 5% was calculated.
As for the linear function equation f2 corresponding to the water-soluble cutting fluid WO2 having a concentration of 5%, y (5%) = Ax + B was calculated using the “least square method” in the same manner as in Example 1 (linear function equation f1). .
In “Example 2”, the detection numbers of “Table 12” to “Table 28”. 1 to detection No. 1 For 1019, the coordinate values are (x1, y1) = (6.5000,819.7782), (x2, y2) = (6.5625,820.7964),..., (X556, y556) = (20.81250,965,0414),. x1018, y1018) = (24.1250, 1001.3572), (x1019, y1019) = (24.1250, 1001.0178).
Coordinate value data number M (detection data number) = 1019 and coordinate values (x1, y1) = (6.5000,819.7782), (x2, y2) = (6.5625,820.7964),. x556, y556) = (20.81250,965,0414),..., (x1018, y1018) = (24.1250,1001.3572), (x1019, y1019) = (24.1250,1001.0178) are substituted into equations (1) and (2) Then, “A (slope)” and “B value (intercept)” of the linear function formula f2: y (5%) = Ax + B are calculated.
The “A value (slope)” of the linear function equation f2 is A = 10.003 by the equation (1), and the “B value (intercept)” of the linear function equation f2 is B = 757.33.

The linear function formula f2 is
y (5%) = 10.003x + 757.33 (5)
It becomes.
In the equation (5), “y (5%)” is the electric conductivity before measurement σ2 (μS / cm), and “x” is the liquid temperature T2 (° C.) before measurement.

Example 3
In Example 3, based on the plurality of pre-measurement liquid temperatures T3 (° C.) obtained from the thermocouple temperature sensor and the plurality of pre-measurement electrical conductivities σ3 (μS / cm) obtained from the two-electrode conductivity sensor. The linear function formula f3 corresponding to the water-soluble cutting fluid WO3 having a concentration of 10% was calculated.
As for the linear function formula f3 corresponding to the water-soluble cutting fluid WO3 having a concentration of 10%, y (10%) = Ax + B was calculated using the “least square method” in the same manner as in Example 1 (linear function formula f1). .
In “Example 3”, the detection numbers of “Table 29” to “Table 62”. 1 to detection No. 1 For 2027, the coordinate values are (x1, y1) = (7.1875,1052.6066), (x2, y2) = (7.2500,1054.3036), ..., (x1005, y1005) = (24.0625,1402.8674), ..., (x2025, y2025) = (25.1250, 1424.9284), (x2027, y2027) = (25.1250, 1424.2496).
The coordinate value data number M (detection data number) = 2027 and coordinate values (x1, y1) = (7.1875,1052.6066), (x2, y2) = (7.2500,1054.3036),. x1005, y1005) = (24.0625,1402.8674), ..., (x2025, y2025) = (25.1250,1424.9284), (x2027, y2027) = (25.1250,1424.2496) are substituted into formula (1) and formula (2) , “A value (slope)” and “B value (intercept)” of linear function formula f3: y (10%) = Ax + B are calculated.
The “A value (slope)” of the linear function equation f3 is A = 18.973 by the equation (1), and the “B value (intercept)” of the linear function equation f3 is B = 949.48.

The linear function formula f3 is
y (10%) = 18.973x + 949.48 (6)
It becomes.
In equation (6), “y (10%)” is the electrical conductivity before measurement σ3 (μS / cm), and “x” is the liquid temperature T3 (° C.) before measurement.

Thus, before detecting the measured liquid temperature Tg (° C.) and the measured electrical conductivity σg (μS / cm) of the water-soluble cutting fluid WO (water-soluble cutting fluid whose concentration is unknown) stored in the liquid storage tank 26. The same components as the water-soluble cutting fluid WO stored in the liquid storage tank 26 are used, and the water-soluble cutting fluids WO1 to WO3 (water-soluble cutting fluids having known concentrations) having concentrations of 2%, 5%, and 10% are used. Then, a liquid temperature-electric conductivity test was performed.
In the liquid temperature-electric conductivity test, a thermocouple temperature sensor and a two-electrode conductivity sensor are immersed in water-soluble cutting fluids WO1 to WO3 having concentrations of 2%, 5%, and 10%, respectively. The liquid temperatures T1 to T3 (° C.) before measurement and the electrical conductivity σ1 to σ3 (μS / cm) before measurement of WO1 to WO3 were detected (see “Table 1” to “Table 62”).
The linear function equations f1 to f3 corresponding to the water-soluble cutting fluids WO1 to WO3 having a concentration of 2%, 5%, and 10% are based on the pre-measurement liquid temperatures T1 to T3 and the pre-measurement electrical conductivities σ1 to σ3, respectively. For example, the calculation (calculation) was performed using the “least square method”.
As shown in FIG. 8, the linear function equations f1, f2, and f3 corresponding to the water-soluble cutting fluids WO1 to WO3 having a concentration of 2%, 5%, and 10% are represented by coordinate values (xi, yi) = (before measurement). It can be said that this is a linear function that matches or approximates (liquid temperature, electrical conductivity before measurement).
Thus, for each concentration of water-soluble cutting fluid (water-soluble cutting fluid having a known concentration), a plurality (many) of pre-measurement liquid temperatures (° C.) and a plurality (many) of pre-measurement electrical conductivity (μS / cm), and based on each pre-measurement liquid temperature (° C.) and each measured electrical conductivity (μS / cm), a linear function formula f (i): y (α%) of each concentration of water-soluble cutting fluid ) = Ax + B, the linear function equation f (i) can be obtained as a linear function that matches or approximates each pre-measurement liquid temperature (x coordinate value) and each pre-measurement electrical conductivity (y coordinate value). it can.

3: Calculation of calibration curve (calibration formula of linear function) The controller 57 of the concentration detector Z detects the water-soluble cutting fluid WO (water-soluble cutting fluid whose concentration α is unknown) stored in the liquid storage tank 26. Measured liquid temperature Tg (° C.) input (acquired) from the liquid temperature detecting means 51, concentration data 2%, 5%, 10%, and linear function equations f1 to f3 corresponding to the water-soluble cutting fluids WO1 to WO3. Based on this, a calibration curve F (Tg) [a calibration function F (Tg) of a linear function] corresponding to the actually measured liquid temperature Tg (° C.) input (acquired) from the liquid temperature detection means 51 is calculated (calculated).
Hereinafter, calculation (calculation) of the calibration curve F (Tg) [calibration formula F (Tg) of a linear function] will be described.

<1> Calculation of Calculated Electrical Conductivity (μS / cm) of Water-soluble Cutting Fluids with Different Concentrations Controller 57 inputs measured liquid temperature Tg (° C.) input (acquired) from liquid temperature detecting means 51. The measured liquid temperature Tg (° C.) input (acquired) from the liquid temperature detecting means 51 by substituting it into “x (x coordinate value)” of the linear function expressions f1, f2, and f3 of Expressions (4) to (6). The calculated electrical conductivities σb1, σb2, and σb3 of the water-soluble cutting fluids WO1 to WO3 corresponding to the above are calculated.
For example, the measured liquid temperature Tg = 20 (° C.) input (acquired) from the liquid temperature detection means 51 is substituted into “x (x coordinate value)” of each of the linear function equations f1 to f3. The calculated electrical conductivity σb1 of the water-soluble cutting fluid WO1 having a concentration of 2% is σb1 = 786.128 (μS / cm) according to the equation (4). The calculated electrical conductivity σb2 of the water-soluble cutting fluid WO2 having a concentration of 5% is σb2 = 957.390 (μS / cm) according to the equation (5), and the calculated electrical conductivity σb3 of the water-soluble cutting fluid WO3 having a concentration of 10% is obtained. Is σb3 = 1328.940 (μS / cm) from Equation (6).
Calculated electrical conductivity σb1 = 786.128 (μS / cm) of water-soluble cutting fluid WO1 having a concentration of 2%, calculated electrical conductivity σb2 = 957.390 (μS / cm) of water-soluble cutting fluid WO2 having a concentration of 5%, and The calculated electric conductivity σb3 = 1328.940 (μS / cm) of the water-soluble cutting fluid WO3 having a concentration of 10% is an electric conductivity corresponding to the actually measured liquid temperature T = 20 (° C.) at the same temperature.

<2> Calibration curve F (Tg) [Calibration formula F (Tg) of linear function]
FIG. 9 shows a relationship between “concentration (%) of water-soluble cutting fluid” and “calculated electrical conductivity (μS / cm) of water-soluble cutting fluid” corresponding to the actually measured liquid temperature Tg input from the liquid temperature detecting means 51 ( It is a graph of a calibration curve F (Tg) showing (related).
FIG. 9 shows “calculated electrical conductivity of water-soluble cutting fluid (μS / cm)” on the horizontal axis (x coordinate axis) and “concentration (%) of water-soluble cutting fluid” on the vertical axis (y coordinate axis). .
In FIG. 9, “calculated electrical conductivity (electric conductivity) of water-soluble cutting fluid” is “x coordinate value (xi)”, and “water-soluble cutting fluid concentration (%)” is “y coordinate value (yi). ) ”. In FIG. 9, the coordinate values are (xi, yi) = (calculated electrical conductivity, concentration).

For the calculated electrical conductivities σb1 to σb3 of the water-soluble cutting fluids WO1 to WO3 having concentrations of 2%, 5%, and 10% and the concentration data of 2%, 5%, and 10%, the coordinate values are (x1, y1) = (Σb1, 0.02), (x2, y2) = (σb2, 0.05), (x3, y3) = (σb3, 0.10).
For example, for the measured liquid temperature Tg = 20 (° C.) of the water-soluble cutting fluid WO, the coordinate values are (x1, y1) = (786.128, 0.02), (x2, y2) = (957.390, 0.05), (x3, y3) = (1328.940, 0.10).
The calibration curve F (Tg) corresponding to the actually measured liquid temperature Tg input from the liquid temperature detection means 51 is, for example, a linear function equation (linear function calibration equation), and uses the “least square method” to calculate the calibration curve. F (Tg): y (Tg) = Ax + B was calculated.
The number of coordinate value data M = 3 and the coordinate values (x1, y1) = (σb1, 0.02), (x2, y2) = (σb2, 0.05), (x3, y3) = (σb3, 0.10) ) And Equation (2), the “A value (slope)” and “B value (intercept)” of the calibration curve F (Tg): y (Tg) = Ax + B of the linear function are calculated.

A calibration curve F (Tg) corresponding to the actually measured liquid temperature Tg input (acquired) from the liquid temperature detecting means 51 is:
y (Tg) = Ax + B (7)
It becomes.
In equation (7), “(Tg)” is the concentration α of the water-soluble cutting fluid WO at the measured liquid temperature Tg, and “x” is the measured electrical conductivity σg of the water-soluble cutting fluid WO at the measured liquid temperature Tg. .

  For example, at the measured liquid temperature Tg = 20 (° C.) input (acquired) from the liquid temperature detecting means 51, the number of coordinate value data M = 3, the coordinate value (x1, y1) = (786.128, 0.02), (x2, y2) ) = (957.390,0.05) and (x3, y3) = (1328.940,0.10) are substituted into the equations (1) and (2), the “A value (slope)” of the calibration curve F (20) is According to (1), A = 0.000145, and the “B value (intercept)” of the calibration curve F (30) is B = −0.09216 from the equation (2).

The calibration curve F (20) for the measured liquid temperature Tg = 20 (° C.) input (acquired) from the liquid temperature detecting means 51 is:
y (20) = 0.000145x-0.09216 ... Formula (8)
It becomes.

Thus, the controller 57 inputs (acquires) the measured liquid temperature Tg (° C.) from the liquid temperature detection means 51 for the water-soluble cutting liquid WO (water-soluble cutting liquid with an unknown concentration) stored in the liquid storage tank 26. The measured liquid temperature Tg is substituted into the linear function equations f1 to f3 of the equations (4) to (6), and the water-soluble cutting fluids WO1 to WO3 having the respective concentrations of 2%, 5%, and 10%. Calculate electric conductivity σb1 to σb3.
A calibration curve F (Tg) [a calibration function F (Tg) of a linear function] corresponding to the actually measured liquid temperature Tg (° C.) input (acquired) from the liquid temperature detecting means 51 is the concentration data 2%, 5%, 10 % And the calculated electrical conductivities σb1, σb2, and σb3 of the water-soluble cutting fluids WO1 to WO3 having concentrations of 2%, 5%, and 10%.
In the calculation control means 55 (controller 57) of the concentration measuring apparatus Z, the measured electrical conductivity of the water-soluble cutting fluid WO (water-soluble cutting fluid whose concentration is unknown) stored in the liquid storage tank 26 is measured from the conductivity detecting means 52. σg is input (acquired), and the measured electrical conductivity σg input (acquired) from the conductivity detection means 52 is expressed by the calibration curve F (Tg) of the equation (7) [calibration formula F (Tg) of the linear function]. By substituting for “x (x coordinate value)”, an unknown concentration of the water-soluble cutting fluid WO stored in the liquid storage tank 26 is calculated.

  The present invention is optimal for detecting the concentration of stored water-soluble cutting fluid.

X machine tool system Y machine tool Z concentration detector (concentration detector of the first and second embodiments)
F (Tg) calibration curve (calibration formula of linear function)
f (i) Linear function equation Tg Measured liquid temperature (liquid temperature)
σg Measured electrical conductivity (electrical conductivity)
26 Liquid storage tank 51 Liquid temperature detection means 52 Conductivity detection means 55 Calculation control means (farming degree calculation control means)
56 Memory means

Claims (4)

A concentration detection device for detecting the concentration of stored water-soluble cutting fluid,
Liquid temperature detecting means for detecting the liquid temperature of the stored water-soluble cutting fluid;
A conductivity detecting means for detecting electrical conductivity of the stored water-soluble cutting fluid, immersed in the stored water-soluble cutting fluid;
Calculation control means for simultaneously inputting the liquid temperature detected by the liquid temperature detection means and the electrical conductivity detected by the conductivity detection means;
With
The arithmetic control means includes
A calibration curve indicating the relationship between the concentration of the water-soluble cutting fluid and the electrical conductivity corresponding to the liquid temperature input from the liquid temperature detecting means;
A concentration detection apparatus that calculates the concentration of the stored water-soluble cutting fluid based on the electrical conductivity input from the conductivity detection means. Multiple concentration data with different concentrations,
For the water-soluble cutting fluid having the same components as the stored water-soluble cutting fluid and corresponding to the concentration data, the liquid temperature and the electric power of the water-soluble cutting fluid corresponding to the water-soluble cutting fluid of the respective concentrations A storage unit for storing a linear function equation indicating a relationship of conductivity;
The arithmetic control means includes
Read each concentration data and a linear function expression corresponding to the water-soluble cutting fluid of each concentration from the storage means,
Based on the liquid temperature input from the liquid temperature detecting means and a linear function equation corresponding to the water soluble cutting fluid of each concentration, the electrical conductivity of the water soluble cutting fluid of each concentration is calculated,
Based on the concentration data and the electrical conductivity of the water-soluble cutting fluid at each concentration, the relationship between the concentration of the water-soluble cutting fluid and the electrical conductivity corresponding to the liquid temperature input from the liquid temperature detecting means is shown. Calculate the calibration curve,
The concentration detection apparatus according to claim 1, wherein the concentration of the stored water-soluble cutting fluid is calculated based on the electrical conductivity input from the conductivity detection means and the calculated calibration curve. Storage means for storing a calibration curve indicating the relationship between the concentration of water-soluble cutting fluid and electrical conductivity corresponding to each of a plurality of liquid temperatures that can be detected by the liquid temperature detection means;
The arithmetic control means includes
Based on the liquid temperature input from the liquid temperature detection means, a calibration curve corresponding to the liquid temperature is read from the storage means,
2. The concentration according to claim 1, wherein the concentration of the stored water-soluble cutting fluid is calculated based on the electrical conductivity input from the conductivity detection unit and the calibration curve read from the storage unit. Detection device. A liquid storage tank storing water-soluble cutting fluid; processing while supplying the water-soluble cutting fluid stored in the liquid storage tank to the workpiece; and supplying the water-soluble cutting fluid supplied to the workpiece A machine tool to be collected in the liquid storage tank;
A concentration detector for detecting the concentration of the water-soluble cutting fluid stored in the liquid storage tank;
Comprising
The concentration detector is
Liquid temperature detecting means for detecting the liquid temperature of the water-soluble cutting fluid stored in the liquid storage tank;
Conductivity detection means for detecting the electrical conductivity of the water-soluble cutting fluid stored in the liquid storage tank, immersed in the water-soluble cutting liquid stored in the liquid storage tank;
Calculation control means for simultaneously inputting the liquid temperature detected by the liquid temperature detection means and the electrical conductivity detected by the conductivity detection means;
With
The arithmetic control means includes
A calibration curve indicating the relationship between the concentration of the water-soluble cutting fluid and the electrical conductivity corresponding to the liquid temperature input from the liquid temperature detecting means;
A machine tool system, wherein the concentration of the water-soluble cutting fluid stored in the liquid storage tank is calculated based on the electrical conductivity input from the conductivity detection means.

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