JP6239489B2 - Reduction potential generator for water-soluble cutting and grinding fluid generation - Google Patents

Description

The present invention is a water-soluble cutting and grinding fluid used during grinding machining, relates originating NamaSo location of the reduction potential for efficiently producing or reproducing, and more particularly, water is electrolyzed treated reduced water with the sterilization, is held excellent machining performance, further, it relates originating NamaSo location of the water-soluble cutting and grinding fluid for generating the reduction potential for regenerating spent water-soluble cutting and grinding fluid It is.

In cutting and grinding machining, a cutting / grinding fluid is used for the purpose of cooling, lubrication, chip flow and the like.
This cutting / grinding fluid is roughly classified into oily and water-soluble. Oily liquid is mineral oil and has excellent lubricity, but there are fires, environmental pollution problems during disposal, and stickiness during use. On the other hand, most of the water-soluble liquids are water, which is advantageous with few oily problems.
However, water-soluble liquids have a certain level of stickiness, which can contaminate processing machines, cause bacteria to develop due to use for a certain period of time, cause skin irritation, and rot to produce a strange odor. There is also a negative impact on the environment at the time of disposal.

In order to make water-soluble cutting / grinding fluid with excellent properties, tap water, industrial water (groundwater) or their softened water or used liquid is subjected to electrolysis treatment to reduce water. Prevents corruption and improves processability.
A comparison of reduced water and mineral oil is as follows.
1. Heat of vaporization: reduced water 586 cal / g, mineral oil 90 cal / g or less, ethanol 93 cal / g, and reduced water is far superior.
2. Specific heat: 1.00 cal / g · deg of reduced water, 0.44 cal / g · deg of mineral oil, and 0.57 cal / g · deg of ethanol, the reduced water is most difficult to warm and hard to cool.
3. Thermal conductivity: Reduced water 0.51 W / m / K, mineral oil 0.12 W / m / K, ethanol 0.18 W / m / K, and reduced water is most easily transferred.
As described above, the reduced water has a larger value than mineral oil in any of heat of vaporization, specific heat, and thermal conductivity, and has excellent properties as a cutting / grinding fluid.

  As a method for obtaining reduced water by electrolysis, a method shown in Patent Document 1 is known. According to the method described in Patent Document 1, a pair of AC electrode plates and two ground electrode plates are inserted into a target aqueous grinding / cutting fluid, and an AC power supply is passed through the AC electrodes to generate high frequency AC. When performing electrolysis, FM modulation with a fluctuation range of ± 3 to 5 KHz is applied around an oscillation frequency of about 5 to 100 KHz, and a random signal generator is built in. Water-based grinding / cutting fluid characterized by generating electric field interference by generating a part that changes up and down, creating shock waves, increasing the amount of hydrogen generated by the electrolysis and generating oxygen reduced to nanobubbles This is an electrolysis method.

When the inventors of the present invention applied a conventional pulse voltage and measured the change over time of the oxidation-reduction potential under the following conditions, the result shown by the characteristic curve O in FIG. 5 was obtained. Note that the application of a pulse voltage adds permeability and affinity to water.
Conditions / Container: Alkaline water production device / Water: Soft water / Water volume: 160 liters / Room temperature: 25 ° C.
・ Pulse wave: 10kHz, 15V, 5A
As is apparent from this characteristic curve O, it became about −200 mV in 120 minutes, and it substantially converged at this value, and hardly decreased even if it took more time.
As described above, there is a problem that it takes a long time to obtain a predetermined reduction potential in order to sterilize the water-soluble cutting / grinding fluid by electrolysis and to generate the original processing performance.

JP 2013-46936 A

The present inventor has made various studies and obtained the knowledge that it is desirable to use a water-soluble cutting / grinding fluid obtained by electrolyzing water at a reduction potential of −150 mV to −300 mV.
The problem to be solved is to generate water-soluble cutting / grinding fluid from water, and to reduce the water by electrolysis for reducing sterilization, anti-corruption and improving workability. In the method in which only 150 μm is applied, it takes 90 minutes or more to obtain −150 mV, 120 minutes or more to obtain −200 mV, and an extremely long time is required from −250 to −300 mV.
The present invention seeks to provide a can Ru equipment of obtaining a predetermined reduction potential in the shortest possible time.

In the present invention, tap water, industrial water (ground water) or softened water thereof or used water-soluble cutting / grinding fluid is placed in the reduction tank 18 and a reduction potential is applied to the reduction electrode 19 to perform electrolysis treatment. In the reducing potential generator for water-soluble cutting / grinding fluid generation to be reduced water,
A PWM oscillation circuit 10 for oscillating a pulse signal for obtaining a pulse voltage to be applied to the reduction electrode 19;
A waveform shaping circuit 11 for shaping a waveform in order to apply the pulse signal generated by the PWM oscillation circuit 10 to the paired reduction electrodes 19;
A driving DC power supply 14 for controlling the peak value of the pulse voltage;
A superimposed DC power supply 13 for obtaining a flat DC voltage superimposed on the pulse voltage;
And a drive circuit 12 for applying a substantially flat DC voltage to the pulse voltage and applying it to the reduction electrode 19.

In addition to the reduction electrode 19, a common electrode 20 is provided in the reduction tank 18, a current detection circuit 15 is connected between the common electrode 20 and the common terminal of the drive circuit 12, and an amplifier circuit 16 is connected to both ends of the current detection circuit 15. The switching circuit 17 connects the PWM oscillation circuit 10, the drive DC power supply 14, and the superimposed DC power supply 13 to the amplifier circuit 16 selectively.
The switching circuit 17 is a selection of any one of the PWM oscillation circuit 10, the superimposed DC power supply 13 and the driving DC power supply 14, or a combination of any two or more of the PWM oscillation circuit 10, the superimposed DC power supply 13 and the driving DC power supply 14. It can be configured to make a selection.

According to invention of Claim 1 ,
In an apparatus for generating a reduction potential for water-soluble cutting / grinding fluid generation by applying water to a reduction tank, applying a reduction potential to the reduction electrode, and electrolyzing it into reduced water,
A PWM oscillation circuit for oscillating a pulse signal for obtaining a pulse voltage to be applied to the reduction electrode;
A waveform shaping circuit for shaping a waveform in order to apply the pulse signal generated by the PWM oscillation circuit to the paired reduction electrodes;
A driving DC power supply for controlling the peak value of the pulse voltage;
A superimposed DC power source for obtaining a substantially flat DC voltage superimposed on the pulse voltage;
And a drive circuit for applying a substantially flat DC voltage to the pulse voltage and applying it to the reduction electrode. Therefore, a reduction potential generator for water-soluble cutting / grinding fluid generation can be easily and easily provided. Can be obtained.

According to invention of Claim 2 ,
In addition to the reduction electrode, a common electrode is provided in the reduction tank, a current detection circuit is connected between the common electrode and the common terminal of the drive circuit, and both ends of the current detection circuit are connected to a switching circuit via an amplifier circuit. Since the switching circuit selectively connects the PWM oscillation circuit, the drive DC power source, and the superimposed DC power source to the amplifier circuit, when the current flowing through the reduction electrode increases or decreases, By selectively controlling any one of the duty ratio, the superimposed substantially flat DC voltage, and the peak value of the drive voltage, the drive current of the reduction electrode can be held at a constant value.

According to invention of Claim 3 ,
Since the switching circuit is configured to select any one of the PWM oscillation circuit, the superimposed DC power supply, and the driving DC power supply, or to select any combination of two or more of the PWM oscillation circuit, the superimposed DC power supply, and the driving DC power supply. The selective combination can be changed according to the properties of the water-soluble cutting / grinding fluid to be used, the length of time until the desired reduction potential is obtained, and the like.

Example 1 of the origination NamaSo location of the water-soluble cutting and grinding fluid for generating reduction potential according to the present invention is an electrical circuit block diagram showing. FIG. 1 is an output waveform diagram of each part when the pulse width is controlled by the PWM oscillation circuit 10 in FIG. In FIG. 1, it is an output waveform diagram of each part when the superimposed voltage v2 is controlled by the superimposed DC power supply 13. In FIG. 1, it is an output waveform diagram of each part when the drive voltage v1 is controlled by the drive DC power supply 14. A characteristic curve P by the originating NamaSo location of the water-soluble cutting and grinding fluid for generating reduction potential of the present invention, is a comparison diagram of the characteristic curve O by conventional methods.

The present invention
In the method of generating a reduction potential for water-soluble cutting / grinding fluid generation by applying water to the reduction tank 18 and applying a reduction potential to the reduction electrode 19 and electrolyzing it into reduced water, a pulse voltage is applied to the reduction electrode 19. A DC voltage is superimposed on and applied.
As a specific example, the pulse voltage has a frequency of 5 kHz to 30 kHz, a duty ratio of 30 to 80%, the substantially flat DC voltage to be superimposed is 10 to 30 V, and the driving voltage peak is 50 V or less.

The present invention
In an apparatus for generating a reduction potential for producing a water-soluble cutting / grinding fluid by putting a water-soluble cutting / grinding fluid in a reduction tank 18 and applying a reduction potential to the reduction electrode 19 to electrolyze it into reduced water,
A PWM oscillation circuit 10 for oscillating a pulse signal for obtaining a pulse voltage to be applied to the reduction electrode 19;
A waveform shaping circuit 11 for shaping a waveform in order to apply the pulse signal generated by the PWM oscillation circuit 10 to the paired reduction electrodes 19;
A driving DC power supply 14 for controlling the peak value of the pulse voltage;
A superimposed DC power supply 13 for obtaining a substantially flat DC voltage superimposed on the pulse voltage;
And a drive circuit 12 for applying a substantially flat DC voltage to the pulse voltage and applying it to the reduction electrode 19.

In addition to the reduction electrode 19, a common electrode 20 is provided in the reduction tank 18, a current detection circuit 15 is connected between the common electrode 20 and the common terminal of the drive circuit 12, and amplifier circuits 16 are connected to both ends of the current detection circuit 15. The switching circuit 17 connects the PWM oscillation circuit 10, the drive DC power supply 14, and the superimposed DC power supply 13 to the amplifier circuit 16 selectively.
The switching circuit 17 selects any one of the PWM oscillation circuit 10, the superimposed DC power supply 13 and the driving DC power supply 14, or any two or more of the PWM oscillation circuit 10, the superimposed DC power supply 13 and the driving DC power supply 14. Configure to select combinations.

In Figure 1, originating NamaSo location of the water-soluble cutting and grinding fluid for generating reduction potential of the present invention includes a PWM (pulse width control) oscillator circuit 10, a waveform shaping circuit 11, a drive circuit 12, superimposed direct current power source 13 And a driving DC power source 14, a current detection circuit 15, an amplification circuit 16, a switching circuit 17, and a reduction tank 18.

The PWM oscillation circuit 10 oscillates a pulse (pulsation) signal as shown in FIG. 2A, the oscillation frequency f can be adjusted in the range of 5 kHz to 30 kHz, and the on / off duty ratio d is , And can be adjusted in the range of 0 to 100%.
As shown in FIG. 2B, the waveform shaping circuit 11 separates the pulse signal of the PWM oscillation circuit 10 into an odd-numbered pulse signal b-1 and an even-numbered pulse signal b-2.
The superimposed DC power supply 13 outputs a substantially flat DC voltage v1 to be superimposed on the pulse signal.
The drive DC power supply 14 controls the peak voltage v1 of the pulse signal.
The driving circuit 12 superimposes a substantially flat DC voltage v2 set by the superimposed DC power supply 13 on the pulse voltage v1 set by the driving DC power supply 14, and shows them as c-1 and c-2 in FIG. As described above, the signals are output as signals that are 180 degrees out of phase.

The reduction tank 18 is provided with two reduction electrodes 19 facing each other, and a common electrode 20 is provided between the reduction electrodes 19. These reduction electrodes 19 are not limited to a pair of two, but may be a plurality of pairs.
A current detection circuit 15 made of a resistor or the like is inserted between the common terminal c-0 of the drive circuit 12 and the common electrode 20, and an amplification circuit 16 is connected to both ends of the current detection circuit 15, and the amplification circuit 16 The PWM oscillation circuit 10, the superimposed DC power supply 13, and the driving DC power supply 14 are selectively connected via the switching circuit 17 to the output side of the output circuit. The value v2 and the voltage value v1 are selectively switched.

Next, the operation of the present invention will be described.
Water is put into the reduction tank 18 and the circuit is switched on to start electrolysis. As this water, tap water, industrial water (groundwater), or water that does not contain a mixture of chemicals such as those obtained by softening these waters with a commercial water softening device is used.
Water Soft water Water volume 160 liters Room temperature 24 ℃
For example, the PWM oscillation circuit 10 outputs a pulse signal with a duty ratio of 50% at 10 kHz. This pulse signal is separated into an odd-numbered pulse signal b-1 and an even-numbered pulse signal b-2 by the waveform shaping circuit 11, and sent to the drive circuit 12. The application of the pulse voltage is to add permeability and affinity to water.
The superimposed DC power supply 13 sets a substantially flat DC voltage v <b> 2 of 10 to 24 V and sends it to the drive circuit 12.
The drive DC power supply 14 is set so that the peak value v1 when the DC voltage v2 is superimposed on the pulse signal is 48V, and sends it to the drive circuit 12.
The voltages shown in FIG. 2C c-1 and c-2 in which a substantially flat DC voltage 10-24V is superimposed on the pulse signal of the drive circuit 12 are applied between the two reduction electrodes 19.

  When the time-dependent change of the oxidation-reduction potential when a voltage in which a substantially flat DC voltage of 10 to 24 V is superimposed on the pulse voltage is applied to the water-soluble cutting / grinding fluid in the reduction tank 18, the characteristic curve of FIG. P was obtained. According to this characteristic curve P, the target −250 mV was obtained in 60 minutes. In addition, even after 60 minutes, the reduction potential gradually decreases.

When the water-soluble cutting / grinding fluid is used as a cutting / grinding fluid, the reduction electrode 19 is corroded and soiled, the current flowing through the reduction electrode 19 is reduced, and reduced as shown by the dotted curve Q in FIG. The potential shifts in the + direction. This decrease in the current flowing through the reduction electrode 19 is detected by the current detection circuit 15 and sends a signal to the switching circuit 17 via the amplification circuit 16. Assuming that the PWM oscillation circuit 10 is selected by the switching circuit 17, the PWM oscillation circuit 10 is controlled to increase the current by increasing the duty ratio so as to widen the pulse width so as to approximate the curve P in FIG. . If the current is increased too much, there is a danger, so the upper limit is 5A.
Conversely, if the drive current of the drive circuit 12 increases for some reason, it is detected by the current detection circuit 15, and the pulse width is narrowed by the PWM oscillation circuit 10 via the amplifier circuit 16 and the switching circuit 17 to reduce the current. . In this way, the drive current is kept at a constant value.

FIG. 2 shows the case where the change in current is controlled by the duty ratio (pulse width) of the pulse signal, but the example of FIG. 3 shows an example in which the change is controlled by the superimposed voltage v2. That is, the reduction electrode 19 is corroded and soiled, the current flowing through the reduction electrode 19 is reduced, and the reduction potential shifts in the positive direction as indicated by the dotted curve Q in FIG. This decrease in the current flowing through the reduction electrode 19 is detected by the current detection circuit 15 and sends a signal to the switching circuit 17 via the amplification circuit 16. Assuming that the superimposed DC power supply 13 is selected by the switching circuit 17, the peak voltage v1 is kept as it is, and the superimposed DC power supply 13 is controlled to increase the superimposed voltage v2 to increase the current so as to approximate the curve P in FIG. . If the current is excessively increased, there is a danger, so that the upper limit is set to 5 A as described above.
Conversely, if the drive current of the drive circuit 12 increases for some reason, it is detected by the current detection circuit 15 and the superimposed voltage v2 is lowered by the superimposed DC power supply 13 via the amplifier circuit 16 and the switching circuit 17 to reduce the current. . In this way, the drive current is kept at a constant value.

FIG. 4 shows still another example of controlling with the drive voltage v1. That is, the reduction electrode 19 is corroded and soiled, the current flowing through the reduction electrode 19 is reduced, and the reduction potential shifts in the positive direction as indicated by the dotted curve Q in FIG. This decrease in the current flowing through the reduction electrode 19 is detected by the current detection circuit 15 and sends a signal to the switching circuit 17 via the amplification circuit 16. Assuming that the driving DC power supply 14 is selected by the switching circuit 17, the superimposed voltage v2 of the superimposed DC power supply 13 is left as it is, and the peak voltage v1 is increased to increase the current so as to approximate the curve P in FIG. . If the current is excessively increased, there is a danger, so that the upper limit is set to 5 A as described above.
Conversely, if the drive current of the drive circuit 12 increases for some reason, it is detected by the current detection circuit 15, and the drive voltage v 1 is lowered by the drive DC power supply 14 via the amplifier circuit 16 and the switching circuit 17 to reduce the current. . In this way, the drive current is kept at a constant value.

  In the embodiment, in order to keep the driving current constant, any one of the method of controlling by the duty ratio (pulse width) of the pulse signal, the method of controlling by the superimposed voltage v2, and the method of controlling by the peak voltage v1 can be used. However, any combination of two or more, that is, (1) a method of controlling by the duty ratio (pulse width) of the pulse signal and a method of controlling by the superimposed voltage v2, (2) the duty ratio of the pulse signal (4) A method of combining the method controlled by (pulse width) and the method controlled by peak voltage v1, (3) The method of combining the method controlled by superposed voltage v2, and the method controlled by peak voltage v1, (4) Pulse All combinations of the method of controlling by the duty ratio (pulse width) of the signal, the method of controlling by the superimposed voltage v2, and the method of controlling by the peak voltage v1 are used. It is also possible.

  In the above embodiment, tap water, industrial water (groundwater) or softened water thereof is used, but the water is not limited to straight water, and is a coolant liquid currently used for cutting and grinding. May be. It can also be used to restore the performance of water-soluble cutting and grinding fluids currently used (water mixed with emulsion, soluble, solution, synthetic, etc.). Further, an amine that does not conflict with low environmental regulations for the purpose of rust prevention may be added.

  DESCRIPTION OF SYMBOLS 10 ... PWM oscillation circuit, 11 ... Waveform shaping circuit, 12 ... Drive circuit, 13 ... Superimposed DC power supply, 14 ... Drive DC power supply, 15 ... Current detection circuit, 16 ... Amplification circuit, 17 ... Switching circuit, 18 ... Reduction tank, 19 ... reduction electrode, 20 ... common electrode.

Claims (3)

In an apparatus for generating a reduction potential for water-soluble cutting / grinding fluid generation by applying water to a reduction tank, applying a reduction potential to the reduction electrode, and electrolyzing it into reduced water,
A PWM oscillation circuit for oscillating a pulse signal for obtaining a pulse voltage to be applied to the reduction electrode;
A waveform shaping circuit for shaping a waveform in order to apply the pulse signal generated by the PWM oscillation circuit to the paired reduction electrodes;
A driving DC power supply for controlling the peak value of the pulse voltage;
A superimposed DC power source for obtaining a flat DC voltage superimposed on the pulse voltage;
A drive circuit for applying a substantially flat DC voltage to the pulse voltage and applying it to the reduction electrode. A reduction potential generator for water-soluble cutting / grinding fluid generation, comprising: In addition to the reduction electrode, a common electrode is provided in the reduction tank, a current detection circuit is connected between the common electrode and the common terminal of the drive circuit, and both ends of the current detection circuit are connected to a switching circuit via an amplifier circuit. a PWM oscillating circuit by switching circuits, a driving DC power supply, superimposing a DC power source and a selectively that to be connected, characterized in claim 1 a water-soluble cutting and grinding fluid for generating the reduction according to the amplification circuit Electric potential generator. The switching circuit is configured to select any one of the PWM oscillation circuit, the superimposed DC power supply, and the driving DC power supply, or to select any combination of the PWM oscillation circuit, the superimposed DC power supply, and the driving DC power supply. The apparatus for generating a reduction potential for producing a water-soluble cutting / grinding fluid according to claim 2 .

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