JP2006314910A - Metallic work cleaning system, cleaning method and production method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a metallic work cleaning system, a cleaning method, and a production method, by which rust after cleaning rust a metallic work can be suppressed more successfully compared with conventional cleaning systems and methods. <P>SOLUTION: According to an embodiment, rust after cleaning on a metallic work Wk can be successfully suppressed for a long time by cleaning the work Wk with the use of oxidation reduction potential water with a negative ORP value, compared with conventional cleaning systems and cleaning methods that use tap water as cleaning water. More specifically, rust after cleaning on the metallic work Wk can be suppressed for 4 to 25 days by using oxidation reduction potential water with ORP of -500 mV or less and/or dissolved hydrogen content between 1.0 and 2.0 ppm, pH ranging from 7.0 to 7.8, and by keeping the temperature (of the oxidation reduction potential water to be supplied to a nozzle 202) at 38°C or less and/or the temperatures of portions of the metallic work Wk against which the oxidation reduction potential water collides at 28°C or less. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a metal workpiece cleaning system, a cleaning method, and a manufacturing method.

Conventionally, as a cleaning system for removing foreign matter (oil, chips, so-called burrs that are not separated from metal workpieces) adhering to a metal workpiece, cleaning water (for example, tap water) is removed from a nozzle. In other words, a so-called high-pressure jet cleaning system is known in which a high-pressure and high-speed jet is caused to collide with a metal workpiece (for example, see Non-Patent Document 1).
Japan Institute of Invention and Innovation, “Patent Map by Technical Field”, [online], JPO Homepage, [Search April 12, 2005], Internet [URL: http://www.jpo.go.jp/shiryou/ s_sonota / map / sennzyo / 1 / 1-7.htm]

  By the way, as a result of experiments conducted by the inventors of the present invention on the conventional cleaning system described above, the following was found. That is, it was found that when a metal workpiece washed with tap water was dried (natural drying or forced drying), rust was generated on the surface of the metal workpiece immediately after the drying process or drying.

  The present invention has been made in view of the above circumstances, and provides a metal workpiece cleaning system, a cleaning method, and a manufacturing method capable of suppressing the occurrence of rust in a metal workpiece after cleaning as compared with the conventional one. Objective.

  In order to achieve the above object, a metal workpiece cleaning system according to the first aspect of the present invention is a metal workpiece cleaning system for cleaning a metal workpiece, in which water and hydrogen gas are mixed by stirring and redox. An oxidation-reduction potential water production device for generating oxidation-reduction potential water having a negative potential, and an injection cleaning device having a nozzle for injecting oxidation-reduction potential water toward a metal workpiece However, it has characteristics.

  The invention according to claim 2 is characterized in that, in the metal workpiece cleaning system according to claim 1, the water temperature of the oxidation-reduction potential water is set to 38 degrees or less and supplied to the nozzle.

  The invention of claim 3 is characterized in that, in the metal workpiece cleaning system according to claim 1 or 2, the water temperature of the oxidation-reduction potential water is set to 33 ° C. or more and supplied to the nozzle.

  According to a fourth aspect of the present invention, in the metal workpiece cleaning system according to any one of the first to third aspects, the temperature of the portion of the metal workpiece where the redox potential water collides is 28 degrees or less. It is characterized in that it is configured to supply the nozzle with the water temperature of the oxidation-reduction potential water at a predetermined temperature or lower.

  According to a fifth aspect of the present invention, in the metal workpiece cleaning system according to any one of the first to fourth aspects, the temperature of the portion of the metal workpiece where the redox potential water collides is 24 degrees or more. It is characterized in that the water temperature of the oxidation-reduction potential water is set to a predetermined temperature or higher and is supplied to the nozzle.

  A sixth aspect of the present invention is the metal workpiece cleaning system according to any one of the first to fifth aspects, wherein the oxidation-reduction potential water production device has a dissolved hydrogen amount that is an amount of hydrogen gas dissolved in water per unit volume. It is characterized by being configured to produce redox potential water having a pH of 1.0 to 2.0 ppm and / or a redox potential of −500 mV or less and a pH of 7.0 to 7.8.

  A seventh aspect of the present invention is the metal workpiece cleaning system according to any one of the first to sixth aspects, further comprising a moisture removing device for removing moisture adhering to the metal workpiece after cleaning by the jet cleaning device. However, it has characteristics.

  The invention according to claim 8 is the metal workpiece cleaning system according to claim 7, wherein the moisture removing device blows off the moisture adhering to the metal workpiece by blowing gas to the metal workpiece after cleaning by the jet cleaning device. And a dryer configured to heat the metal workpiece from which moisture has been blown off and evaporate the moisture.

  A ninth aspect of the present invention is the metal workpiece cleaning system according to any one of the first to eighth aspects, wherein the oxidation-reduction potential water production device includes a gas-liquid mixing pump that sucks, mixes and discharges hydrogen gas together with water. A mixer for increasing the dissolved amount of hydrogen gas with respect to the water discharged from the gas-liquid mixing pump, the mixer being connected to the gas-liquid mixing pump outlet and along the axial direction of the pipe And a plurality of mixing walls for partitioning the inside of the pipeline into a plurality of regions and allowing the passage of water and repeating the strength of the fluid pressure in the pipeline. However, it has characteristics.

  A tenth aspect of the present invention is the metal work cleaning system according to any one of the first to ninth aspects, wherein degassing is performed to remove gas in advance from water that is agitated and mixed with hydrogen gas by a redox potential water production apparatus. It is characterized by comprising an apparatus, a dechlorination apparatus for removing residual chlorine, and a soft water apparatus for removing metal ions.

  In the metal workpiece cleaning method according to the invention of claim 11, water and hydrogen gas are stirred and mixed to generate redox potential water having a negative redox potential, and the redox potential water is discharged from the nozzle. It is characterized in that the metal workpiece is cleaned by spraying.

  The invention of claim 12 is characterized in that, in the metal workpiece cleaning method according to claim 11, the temperature of the oxidation-reduction potential water supplied to the nozzle is set to 38 degrees or less.

  The invention of claim 13 is characterized in that, in the metal workpiece cleaning method according to claim 11 or 12, the temperature of the oxidation-reduction potential water supplied to the nozzle is set to 33 ° C. or more.

  According to a fourteenth aspect of the present invention, in the method for cleaning a metal workpiece according to any one of the eleventh to thirteenth aspects, the temperature of the portion of the metal workpiece where the redox potential water collides is set to 28 degrees or less. However, it has characteristics.

  According to a fifteenth aspect of the present invention, in the method for cleaning a metal workpiece according to any one of the eleventh to fourteenth aspects, the temperature of the portion of the metal workpiece where the redox potential water collides is 24 degrees or higher. However, it has characteristics.

  According to a sixteenth aspect of the present invention, in the metal workpiece cleaning method according to any of the eleventh to fifteenth aspects, the redox potential water has a dissolved hydrogen amount of 1. which is the amount of hydrogen gas dissolved in water per unit volume. It is characterized by 0 to 2.0 ppm and / or a redox potential of −500 mV or less and a pH of 7.0 to 7.8.

  A seventeenth aspect of the invention is the method for cleaning a metal workpiece according to any one of the eleventh to sixteenth aspects, further comprising a moisture removal step of removing moisture adhering to the metal workpiece after cleaning with pre-oxidation-reduction potential water. It has features.

  The invention according to claim 18 is the method for cleaning a metal workpiece according to claim 17, wherein the moisture removing step includes a draining step of blowing gas to the metal workpiece and blowing away the moisture, and heating the metal workpiece after the draining step. And a drying process for evaporating moisture.

  The invention of claim 19 is the method for cleaning a metal workpiece according to any one of claims 11 to 18, wherein a deaeration step for removing gas from water mixed with hydrogen gas in advance and stirring, and residual chlorine It is characterized by a dechlorination step for removing and a water softening step for removing metal ions.

  The method for manufacturing a metal workpiece according to the invention of claim 20 is characterized in that the method for cleaning a metal workpiece according to any one of claims 11 to 19 is provided in a part of the process.

[Inventions of Claims 1, 2, 4, 6, 11, 12, 14, 16, 20]
According to the inventions of the first, eleventh and twentieth aspects configured as described above, it is possible to suppress the generation of rust in the metal workpiece after cleaning, as compared with the prior art. Here, it is more preferable to set the water temperature of the oxidation-reduction potential water supplied to the nozzle to 38 ° C. or less (inventions of claims 2 and 12). Further, it is more preferable that the temperature of the portion of the metal workpiece where the redox potential water collides is 28 degrees or less (inventions of claims 4 and 14). Furthermore, the redox potential water has a dissolved hydrogen amount of 1.0 to 2.0 ppm and / or a redox potential of −500 mV or less, which is the amount of hydrogen gas dissolved in water per unit volume, and has a pH of 7.0 to 7.0. It is preferably 7.8 (Invention of Claims 6 and 16).

[Inventions of Claims 3, 5, 13, 15]
According to the third, fifth, thirteenth and fifteenth aspects of the present invention, foreign matters adhering to the metal workpiece, particularly oil, can be reliably removed.

[Inventions of Claims 7 and 17]
According to the seventh and seventeenth aspects of the present invention, the generation of rust in the metal workpiece is suppressed by removing the water adhering to the metal workpiece.

[Inventions of Claims 8 and 18]
According to the eighth and 18th aspects of the present invention, moisture attached to the metal workpiece can be reliably removed by heating the metal workpiece and evaporating the moisture. In addition, by blowing gas before drying, most of the water adhering to the metal workpiece is blown away. ) Is reduced.

[Invention of claim 9]
According to the ninth aspect of the present invention, in the process in which water mixed with hydrogen gas passes through the mixer, the fluid pressure applied to the water is repeatedly increased and decreased, the dissolved amount of hydrogen gas in water is improved, and the redox potential is increased. The oxidation-reduction potential of water can be further lowered.

[Inventions of Claims 10 and 19]
According to the tenth and nineteenth aspects of the present invention, since the oxidizing substances (dissolved oxygen and residual chlorine) contained in the redox potential water are reduced, the erosion corrosion (oxidizing substance) of the metal work caused by the collision of the redox potential water. It is possible to prevent the chemical corrosion due to (2) and physical erosion due to collision of redox potential water). Moreover, since metal ions in water are removed, it is possible to prevent the scale from being generated when the washed metal workpiece is dried.

  Hereinafter, an embodiment according to the present invention will be described with reference to FIGS. As shown in FIG. 1, the metal workpiece cleaning system 10 of the present embodiment is, for example, a plate valve body (hereinafter referred to as “metal workpiece Wk”) made of a metal containing iron (specifically, an SPCC material). ) As part of the manufacturing system M. The metal workpiece cleaning system 10 is a redox potential water that generates redox potential water (having reducibility) having a negative redox potential (hereinafter referred to as “ORP”) by dissolving hydrogen gas in water. Manufacturing apparatus 100, jet cleaning apparatus 200 that removes and cleans foreign matter adhering to metal workpiece Wk by oxidation-reduction potential water, and water removal for removing water from metal workpiece Wk cleaned by jet cleaning apparatus 200 The apparatus 300 is provided as a main part.

First, the oxidation-reduction potential water production apparatus 100 will be described with reference to FIGS.
The oxidation-reduction potential water production apparatus 100 includes, for example, a main pipe MP that is connected to a water supply pipe (not shown) and through which water flows, and the main pipe MP includes various devices. Hereinafter, each part of the oxidation-reduction potential water production apparatus 100 will be described in order from the upstream side of the main pipe MP. A solenoid valve SV0 is provided at the upstream end of the main pipe MP. A prefilter 11, a water softening device 12, and an activated carbon filter 13 are provided on the downstream side of the solenoid valve SV0.

  The pre-filter 11 removes foreign matters, for example, 1 μm or more mixed in tap water. Further, the soft water device 12 removes metal ions (for example, ions of calcium, magnesium, sodium, potassium, etc.) in tap water. Moreover, the residual chlorine contained in tap water is removed by the activated carbon filter 13. Normally, tap water is flowed in the order of the prefilter 11, the soft water device 12, and the activated carbon filter 13. However, by operating the switching valve, the tap water is directly flowed from the prefilter 11 to the activated carbon filter 13 without passing through the soft water device 12. Is also possible. Here, the ORP of tap water can be lowered by removing residual chlorine, which is an oxidizing substance, from tap water. The step of passing tap water through the water softening device 12 corresponds to the “softening step” of the present invention, and the step of passing the tap water through the activated carbon filter 13 corresponds to the “dechlorination step” of the present invention. The activated carbon filter 13 corresponds to the “dechlorination device” of the present invention.

  An active water device 14 is provided downstream of the activated carbon filter 13. The water heater 14 is configured to collect static electricity generated by friction of tap water flowing through a plastic pipe, for example, on an electrode attached to the outside of the pipe and radiate it into the water. The water heater 14 is detachable from the main pipe MP, and the main pipe MP is provided with a bypass pipe BP that bypasses the water heater 14. Thereby, even if the water heater 14 is removed from the main pipe MP, it is possible to flow tap water.

  Here, the quality of the generated redox potential water can be stabilized by passing the tap water through the water heater 14. Specifically, it is possible to maintain the dissolved hydrogen amount (the amount of hydrogen gas dissolved in water per unit volume) and the ORP over a relatively long period of time.

  A raw water tank 15 for storing the tap water that has passed through the devices 11 to 13 is provided on the downstream side of the water heater 14. The raw water tank 15 is provided with a liquid level meter L and a water temperature meter T, and the measured values are output to a control unit (not shown).

  Note that the control unit adjusts the amount of water stored in the raw water tank 15 based on the measurement result of the liquid level meter L. Specifically, for example, the maximum water storage amount of the raw water tank 15 is 150L, and when the water storage amount becomes 20L or less, the control unit opens the solenoid valve SV0 at the upstream end of the main pipe MP to the raw water tank 15. On the other hand, when the amount of stored water reaches 120L, the solenoid valve SV0 is closed and the supply of tap water to the raw water tank 15 is stopped.

  A drain pipe DP is connected to the raw water tank 15. For example, when tap water stored in the raw water tank 15 becomes unnecessary due to a change in the quality of tap water, the drain pipe DP is discharged from the drain pipe DP. can do. Further, the tap water overflowed from the raw water tank 15 can be discharged to the outside from the drain pipe DP.

  As shown in FIG. 2, in the oxidation-reduction potential water production apparatus 100, a plurality of units for actually measuring the supply amount (flow rate) of tap water supplied to a gas-liquid mixing pump 17 described later is provided downstream of the raw water tank 15. Water flow meter F is provided. In the present embodiment, as the water flow meter F, an ultrasonic flow meter and an impeller flow meter are provided. And the actual value of the water flow rate by these water flowmeters F is output to the control part which is not illustrated. One water flow meter F may be used.

  A deaeration device 16 is provided on the downstream side of the water flow meter F. The deaeration device 16 introduces tap water into the vacuum module 16A, and evacuates the vacuum module 16A with a vacuum pump 16B to dissolve the gas dissolved in the tap water (for example, oxygen gas, nitrogen gas, carbon dioxide gas). Etc.). The process of extracting gas from the tap water by the deaeration device 16 corresponds to the “deaeration process” of the present invention.

  The vacuum module 16A is detachable from the main pipe MP, and the main pipe MP is provided with a bypass pipe BP that bypasses the deaeration device 16. Thereby, it becomes possible to supply tap water to the gas-liquid mixing pump 17 without degassing.

  In this embodiment, the vacuum pump 16B includes two vacuum pumps, a so-called water ring vacuum pump or a diaphragm vacuum pump, which are detachable from the vacuum module 16A. A vacuum gauge P1 is provided between the vacuum module 16A and the vacuum pump 16B, and the measured value is output to a control unit (not shown). The control unit controls the vacuum pump 16B based on the measurement value of the vacuum gauge P1 to adjust the degree of deaeration of tap water. One vacuum pump may be used.

  Here, if water is deaerated in advance before mixing with hydrogen gas, it becomes easier to dissolve hydrogen gas in water than in the case of not degassing, and dissolved hydrogen in the generated redox potential water. The amount can be increased or the ORP can be decreased. Further, the dissolved oxygen, which is an oxidizing substance, is removed from the tap water, so that the ORP of the redox potential water can be further reduced. It should be noted that the amount of dissolved hydrogen and ORP in the generated redox potential water can be adjusted by adjusting the degree of vacuum in the vacuum module 16A, that is, the degree of degassing of tap water.

  As shown in FIG. 2, two gas-liquid mixing pumps 17 and 17 having the same specifications are provided on the downstream side of the deaeration device 16 via a solenoid valve SV2. The gas-liquid mixing pumps 17 and 17 suck a predetermined amount of tap water from the raw water tank 15 and suck a predetermined amount of hydrogen gas from a hydrogen gas supply source 18 (specifically, a gas cylinder). After stirring and mixing with hydrogen gas, the mixed fluid is discharged at a predetermined pressure.

  In the present embodiment, tap water and hydrogen gas are always supplied to only one of the two gas-liquid mixing pumps 17, 17. For example, when one gas-liquid mixing pump 17 becomes unusable due to failure or maintenance, the switching valve is operated to supply hydrogen gas and tap water to the other gas-liquid mixing pump 17. It is like that. As a result, even when the gas-liquid mixing pump 17 fails or is maintained, the stirring and mixing of the hydrogen gas and tap water can be continued. Note that hydrogen gas and tap water may be stirred and mixed by always using both of the two gas-liquid mixing pumps 17 and 17.

  The gas-liquid mixing pump 17 is so-called inverter controlled. That is, the AC power from the power source is once converted to DC and a frequency necessary for returning to AC again is generated, and the rotational speed of the AC motor provided in the gas-liquid mixing pump 17 is changed according to the frequency. . Therefore, a rapid flow rate change at the start or stop of operation of the oxidation-reduction potential water production apparatus 100 can be suppressed, and a load applied to the gas-liquid mixing pump 17 and a mixer unit 22 described later can be reduced.

  The gas-liquid mixing pump 17 is detachable from the main pipe MP, and a gas pipe GP extending from the hydrogen gas supply source 18 is connected to a portion immediately before the suction port.

  As shown in FIG. 2, a mass flow controller 19 for measuring and adjusting the supply amount (supply volume) of hydrogen gas to the gas-liquid mixing pump 17 is provided in the middle of the gas pipe GP. Further, the actual measurement value of the hydrogen gas supply amount actually measured by the mass flow controller 19 is output to a control unit (not shown).

  The mass flow controller 19 sets the hydrogen gas supply amount to “0” when the oxidation-reduction potential water production apparatus 100 is stopped, and after the oxidation-reduction potential water production apparatus 100 is operated, a predetermined amount of tap water is supplied to the gas-liquid mixing pump. This state is maintained until supplied to 17. Then, when a predetermined amount of tap water is supplied to the gas-liquid mixing pump 17, supply of hydrogen gas is started. At this time, by gradually increasing the hydrogen gas supply amount, so-called “air biting” in the gas-liquid mixing pump 17 can be suppressed.

  In the gas pipe GP, a check valve 20A for preventing the inflow of tap water into the gas pipe GP is provided immediately before the connection portion with the main pipe MP. A solenoid valve may be provided in place of the check valve 20A, and the solenoid valve may be opened during the supply of hydrogen gas and closed when the supply is stopped.

  In the main pipe MP, on the downstream side of the gas-liquid mixing pump 17, a water heater 14 having the same configuration as the above-described water heater 14 is detachably provided, and the main pipe MP is a bypass pipe bypassing the water heater 14. BP is connected. A check valve 20 </ b> B for preventing backflow is provided between the water heater 14 and the gas-liquid mixing pump 17.

  A mixer unit 22 is provided on the downstream side of the water heater 14. The mixer unit 22 includes a plurality of (for example, three) mixers 22A, 22B, and 22C having the same configuration. Specifically, as shown in FIG. 3, the first mixer 22A and the second mixer 22B are connected in parallel, and the third mixer 22C is connected in series with the first and second mixers 22A and 22B. Make a connected structure. In addition, a pressure gauge P2 is provided on the upstream side of each mixer 22A, 22B, 23C. Here, the pipe length between the first and second mixers 22A, 22B and the third mixer 22C is, for example, 1 meter, but the pipe length can be changed as appropriate. Further, it is preferable to provide a bypass flow path BP for flowing without passing through the third mixer 22C.

  As shown in FIG. 4, the mixers 22 </ b> A, 22 </ b> B, and 22 </ b> C contain a plurality of (for example, 11) mixing walls 40 inside a cylindrical case 30 (corresponding to the “pipe” of the present invention). . First, the cylindrical case 30 will be described.

  The cylindrical case 30 includes a case main body 31, an inflow pipe 32 joined to the upstream end of the case main body 31, and an outflow pipe 33 joined to the downstream end of the case main body 31.

  The case body 31 has a cylindrical shape, and at both ends, a rule portion 37 is formed to join the inflow pipe 32 and the outflow pipe 33. The internal space of the case body 31 has a cylindrical shape with a constant diameter.

  The inflow pipe 32 and the outflow pipe 33 have the same shape. That is, a pipe connection part 34 connected to the main pipe MP is formed at one end of the inflow pipe 32 and the discharge pipe 33, and a rule part 35 is formed at the other end to be joined to the case body 31. . And the outer diameter is expanded in steps from the pipe connection part 34 toward the rule part 35. The inner diameters of the inflow pipe 32 and the outflow pipe 33 are constant.

  Of the inflow pipe 32 and the outflow pipe 33, a cylindrical boss 36 stands from the opening edge (end surface 35 </ b> T of the ferrule portion 35) on the side joined to the case body 31. When the inflow pipe 32 and the outflow pipe 33 are joined to both ends of the case main body 31, the cylindrical boss 36 enters and fits into the internal space of the case main body 31. The above is the description of the cylindrical case 30.

  The mixing wall 40 is as follows. As shown in FIG. 5, the mixing wall 40 has a configuration in which a plurality of small holes 42 are formed through a disc member 41. The disc member 41 is made of, for example, metal (specifically, stainless steel or brass), and the outer diameter thereof is substantially the same as the inner diameter of the case main body 31. The small hole 42 extends in the plate thickness direction (vertical direction in FIG. 3) of the mixing wall 40 and has an inner diameter of, for example, 1 to 3 μm (preferably 2 μm).

  As shown in FIG. 3, the mixing wall 40 is disposed inside the cylindrical case 30 (specifically, the case main body 31) so as to overlap in the axial direction of the cylindrical case 30. A spacer 45 (for example, an O-ring) is sandwiched between the mixing walls 40. The mixing walls 40 adjacent to each other are overlapped at a predetermined interval by the spacer 45, and the mixing walls 40 allow the internal space of the case body 31 to have a plurality of space portions 46 having a flat cylindrical shape (“region” in the present invention). Is equivalent to In other words, the mixing wall 40 and the space 46 are alternately provided in the case body 31 along the axial direction of the case body 31. Here, the plurality of mixing walls 40 housed inside the case body 31 are fitted inside the case body 31 and are provided on the inflow pipe 32 and the outflow pipe 33 from both ends of the case body 31. , 36 and fixedly arranged inside the case main body 31.

  In the present embodiment, the mixing wall 40 is detachable from the cylindrical case 30, and a plurality of types of mixing walls 40 having different structures (shape of the small holes 42, hole diameter, plate thickness, etc.) are prepared in advance. . Then, an appropriate mixing wall 40 is selected from the plurality of types of mixing walls 40 according to the water quality of the target oxidation-reduction potential water, and can be replaced with the mixing wall 40 mounted on the cylindrical case 30. ing. The mixing wall 40 may be exchanged manually or automatically by an exchange device (not shown).

  Here, the mixed fluid of hydrogen gas and tap water pumped from the gas-liquid mixing pump passes through the mixers 22A, 22B, and 22C as follows. That is, the mixed fluid of hydrogen gas and tap water flows into the cylindrical case 30 from the inflow pipes 32 of the mixers 22A, 22B, and 22C and collides with the uppermost mixing wall 40. The mixed fluid that has collided with the mixing wall 40 is pressurized by being pushed into a plurality of small holes 42 formed in the mixing wall 40 and is divided into a plurality of flow paths.

  The mixed fluid that has passed through the small holes 42 of the mixing wall 40 flows into the uppermost space 46. In this space portion 46, when passing through the small hole 42, the mixed fluid divided into a plurality of flow paths merges and the pressure applied to the mixed fluid decreases.

  When the mixed fluid that has flowed into the uppermost space 46 collides with the second-stage mixing wall 40 and passes through the small holes 42, it is again subjected to a strong pressure and finely divided into a plurality of flow paths. Then, after passing through the second-stage mixing wall 40, it flows into the second-stage space 46, where the mixed fluid that has passed through the mixing wall 40 divided into a plurality of flow paths (small holes 42) joins. , The pressure applied to the mixed fluid decreases. Hereinafter, by alternately passing through the small holes 42 and the space 46 of the mixing wall 40, the mixed fluid repeats the diversion and merging, and the pressure applied to the mixed fluid is repeated. Thereby, the hydrogen gas in the mixed fluid is dissolved in the tap water, and the ORP has a negative value, that is, redox potential water having a reducing property than the tap water is generated. The above is the description of the mixer unit 22.

  As shown in FIG. 2, the oxidation-reduction potential water generated by passing through the gas-liquid mixing pump 17 and the mixer unit 22 is heated downstream of the mixer unit 22 in the oxidation-reduction potential water production apparatus 100. The heater 23 is provided. The heater 23 is detachable from the main pipe MP. Further, a bypass pipe BP that bypasses the heater 23 is connected to the main pipe MP. When it is not necessary to heat the oxidation-reduction potential water or when the heater 23 is removed, the oxidation-reduction potential water can be flowed through the bypass pipe BP.

  In the present embodiment, two heaters 23 and 23 having the same specification are provided, and the oxidation-reduction potential water always passes through only one heater 23. For example, when one heater 23 becomes unusable due to failure or maintenance, the redox potential water passes through the other heater 23 by operating the switching valve. As a result, it is possible to heat the redox potential water even when the heater 23 is broken or maintained. Note that the oxidation-reduction potential water may always be passed through both the two heaters 23 and 23.

  Here, a water temperature gauge T is provided on the downstream side of the heater 23 of the main pipe MP, and the measured value is output to a control unit (not shown). In addition, the water quality (the amount of dissolved hydrogen or ORP) of oxidation-reduction potential water can be stabilized by heating the oxidation-reduction potential water to a predetermined water temperature higher than room temperature. Further, in cleaning the metal workpiece Wk described later, foreign matters (particularly oil) adhering to the metal workpiece Wk can be effectively removed.

  On the downstream side of the heater 23, an instrument connection pipe KP branched from the main pipe MP is provided, and a dissolved hydrogen meter Hm is detachably attached in the middle of the instrument connection pipe KP. The dissolved hydrogen meter Hm measures the dissolved hydrogen amount of the oxidation-reduction potential water, and outputs the measurement result to a control unit (not shown). The meter connection pipe KP is provided with a solenoid valve SV4 and a metering valve 25 for making the flow rate of oxidation-reduction potential water supplied to the dissolved hydrogen meter Hm constant.

  A generated water tank 26 is provided on the downstream side of the instrument connection pipe KP. The generated water tank 26 is constituted by, for example, a closed tank, and the redox potential water generated here is temporarily stored. A circulation pipe CP for circulating the redox potential water upstream of the gas-liquid mixing pump 17 is connected to the generated water tank 26. The product water tank 26 is connected with a supply pipe SP for supplying redox potential water to an injection cleaning device 200 described later.

  In the middle of the circulation pipe CP, a flow meter F3 (in this embodiment, an impeller-type flow meter) for measuring the flow rate of the redox potential water that circulates is provided.

  On the other hand, a supply pump 27 is provided in the middle of the supply pipe SP. The supply pump 27 discharges the redox potential water stored in the generated water tank 26 at a predetermined pressure (for example, 0.1 to 0.3 MPa), and the open / close valve 28 is opened to generate redox potential water. It is supplied from the water tank 26 to the jet cleaning device 200. In addition, a check valve 20 </ b> C for preventing the backflow of oxidation-reduction potential water from the jet cleaning device 200 to the oxidation-reduction potential water production device 100 is provided in the middle of the supply pipe SP. In addition, since the supply pump 27 is inverter controlled similarly to the gas-liquid mixing pump 17 described above, the oxidation-reduction potential water can be stably supplied to the jet cleaning device 200.

  Further, a drain pipe DP is connected to the generated water tank 26, and the quality of the redox potential water (the amount of dissolved hydrogen, the water temperature, the ORP, etc.) changes when the conditions for generating the redox potential water are changed. When the redox potential water stored in the generated water tank 26 becomes unnecessary, the redox potential water can be discharged from the drain pipe DP. Further, the oxidation-reduction potential water overflowing from the generated water tank 26 can also be discharged to the outside from the drain pipe DP.

  The generated water tank 26 is provided with a liquid level gauge L. The control unit calculates the amount of stored water based on the measurement result of the liquid level meter L, and controls the amount of redox potential water generated. Specifically, the maximum water storage amount of the generated water tank 26 is, for example, 200 L, and the control unit, for example, supplies tap water and hydrogen gas to the gas-liquid mixing pump 17 when the water storage amount becomes 160 L or more. The supply is stopped and the solenoid valve SV3 provided in the circulation pipe CP is opened, and the oxidation-reduction potential water stored in the generated water tank 26 is circulated. When the amount of stored water becomes 50 L or less, supply of tap water and hydrogen gas to the gas-liquid mixing pump 17 is started, and the solenoid valve SV3 is closed to stop the circulation of redox potential water.

  That is, when the amount of redox potential water stored in the generated water tank 26 is equal to or higher than a preset upper limit, the generation of new redox potential water is stopped and the existing redox potential water is circulated. When below the set lower limit, the circulation is stopped and generation of new redox potential water is started. Here, the redox potential water is circulated and repeatedly passed through the gas-liquid mixing pump 17 and the mixers 22A, 22B, and 22C, so that the dissolved hydrogen amount of the redox potential water is increased and the ORP is set to a lower value. Can do.

  The generated water tank 26 is provided with a water temperature gauge T. The water temperature gauge T measures the water temperature of the oxidation-reduction potential water supplied to the jet cleaning apparatus 200 (specifically, the nozzle 202) shown in FIG. Further, the control unit controls the heater 23 so that the oxidation-reduction potential water supplied to the jet cleaning device 200 (stored in the generated water tank 26) becomes a set water temperature to be described later, based on the measurement value of the water temperature gauge T. Is controlled.

  Although not shown, the generated water tank 26 is provided with a hydrogen gas concentration meter that detects the concentration of hydrogen gas stored in the generated water tank 26, and the measurement result is output to a control unit (not shown). The control unit may output an alarm when the measurement result of the hydrogen gas concentration meter exceeds a predetermined upper limit concentration and stop the operation of the oxidation-reduction potential water production apparatus 100.

  In addition to the above-described configuration, a switching valve for switching a water flow path, a connection part for connecting an external device or a pipe, in addition to the above-described configuration, is provided at a predetermined position of the main pipe MP of the oxidation-reduction potential water production apparatus 100. A water collection valve for collecting water is provided. In addition, each connecting portion of the main pipe MP and the water heater 14, the vacuum module 16A, the gas-liquid mixing pump 17, and the heater 23 is a so-called union connection and can be attached and detached relatively easily. Yes.

  And according to the oxidation-reduction potential water production apparatus 100 described above, tap water (pH 7.0 to 7.5, ORP + 150 mV or more) is used as raw water, pH 7.0 to 7.8, ORP-500 mV or less, dissolved hydrogen amount. Redox potential water having a concentration of 1.0 to 2.0 ppm is generated. That is, the redox potential can be set to a negative value lower than that of tap water and the amount of dissolved hydrogen can be increased while maintaining the pH neutral. The above is the description of the oxidation-reduction potential water production apparatus 100.

  Next, the jet cleaning apparatus 200 will be described with reference to FIGS. The jet cleaning apparatus 200 sprays oxidation-reduction potential water at a high pressure and a high speed to collide with the metal workpiece Wk, and removes foreign matter (oil, chips, or chips from the metal workpiece Wk as the foreign matter adhering to the metal workpiece Wk. Remove burrs that are not separated.

  Specifically, the jet cleaning device 200 includes a high-pressure pump 203 connected to the supply pipe SP of the oxidation-reduction potential water production device 100 as shown in FIG. The high-pressure pump 203 discharges the redox potential water produced by the redox potential water production apparatus at a predetermined pressure (for example, 10 to 15 MPa), and the open / close valve 204 is opened to cause the pipe body 201 to be redox. Potential water is supplied. The pipe body 201 is provided with a plurality of nozzles 202 for injecting redox potential water toward the metal workpiece Wk. The pipe body 201 is provided on both sides of the metal workpiece Wk (upper surface side and lower surface side in FIG. 6A), and automatically moves at a predetermined speed with respect to the fixed metal workpiece Wk. It is the structure which injects redox potential water.

  The distance H1 between the injection port of the nozzle 202 provided in the pipe body 201 and the surface of the metal workpiece Wk is, for example, 40 mm. As shown in FIG. 7, the oxidation-reduction potential water ejected from the nozzle 202 is diffused in a substantially fan shape from the ejection port toward the metal workpiece Wk. The spread angle θ1 of the redox potential water sprayed from the nozzle 202 (see FIG. 6A) is, for example, 75 degrees. Further, the nozzles 202 provided in the same pipe body 201 are arranged so that the portions of the metal workpiece Wk where the redox potential water collides (portions surrounded by the dotted line m in FIG. 7) do not overlap each other. ing. In other words, the oxidation-reduction potential water ejected from one nozzle 202 intersects with the oxidation-reduction potential water ejected from another nozzle 202 provided in the same pipe body 201 so that the collision force does not drop. It has become.

  Further, the piping body 201 moves horizontally in the direction indicated by the thick arrow in FIG. 7 with respect to the metal workpiece Wk, so that the redox potential water jetted from one nozzle 202 of the metal workpiece Wk. The collision portions each form a belt-like region Q, and a boundary portion with the belt-like region Q formed by another adjacent nozzle 202 overlaps, for example, by about 2 mm. This ensures that the redox potential water sprayed from the nozzle 202 collides with both surfaces of the metal workpiece Wk. Furthermore, in the present embodiment, the inclination angle of the piping body 201 causes the intersection angle θ2 (see FIG. 6B) between the center line of the nozzle 202 and the surface of the metal workpiece Wk to be, for example, 90 degrees to 105 degrees. It is adjustable in the range.

  The description of the spray cleaning apparatus 200 is as described above. Next, the moisture removing apparatus 300 will be described. The moisture removing device 300 includes a blower 301 and a dryer 302. The blower 301 blows a gas (for example, air) at a high speed and a high pressure on the metal workpiece Wk cleaned by the jet cleaning device 200, and blows off moisture adhering to the metal workpiece Wk. That is, draining is forcibly performed.

  Specifically, as shown in FIG. 8, the blower 301 includes a gas injection nozzle 301 a that blows air while automatically moving with respect to the metal workpiece Wk, and a blower 301 b that supplies air to the gas injection nozzle 301 a. The air speed of the air injected from the gas injection nozzle 301a can be adjusted between, for example, 60 to 120 m / sec by a control valve 301c provided between the blower 301b and the gas injection nozzle 301a. Yes.

  The injection port of the gas injection nozzle 301a has, for example, an elongated slit shape. As shown in FIG. 9, the air jetted from the gas jet nozzle 301a forms a so-called air curtain, and most of the water adhering to the metal workpiece Wk is blown off when crossing the air curtain. . In the present embodiment, a distance H2 (see FIG. 8) between the ejection port of the gas ejection nozzle 301a and the surface of the metal workpiece Wk is, for example, 180 mm. Further, the air blown out from the gas injection nozzle 301a hits the surface of the metal workpiece Wk from a substantially vertical direction. Further, in the present embodiment, the gas injection nozzle 301a sequentially moves to both sides (the upper surface side and the lower surface side in FIG. 8) of the metal workpiece Wk laid horizontally and blows air, for example. ing.

  On the other hand, the dryer 302 was heated by blowing hot air having a temperature higher than room temperature (for example, 80 degrees at the maximum) to the metal workpiece Wk from which moisture was blown off by the blower 301 and could not be removed by the blower 301. Evaporate moisture. That is, it is forced to dry. Thereby, the moisture adhering to the metal workpiece Wk is completely removed.

  Here, before drying with the dryer 302, if most of the water adhering to the metal workpiece Wk is blown away by the blower 301, compared to the case where the dryer 302 is dried without blowing off the moisture, The amount of scale (solid matter) generated on the surface of the metal workpiece Wk after drying can be reduced. Also, the time required for drying can be shortened.

  In the present embodiment, as described above, since the metal ions in the water are removed by the soft water device 12 in the process of generating the redox potential water, the scale (specifically, carbonates such as calcium and magnesium). Can be more reliably prevented.

  Here, the process of removing the moisture adhering to the metal workpiece Wk by the moisture removing apparatus 300 corresponds to the “moisture removing process” of the present invention. Further, the step of blowing gas onto the metal workpiece Wk by the blower 301 to blow off the moisture adhering to the metal workpiece Wk corresponds to the “draining step” of the present invention, and the metal workpiece Wk to the metal workpiece Wk from room temperature by the dryer 302. The process of blowing high temperature hot air and heating it to evaporate the moisture corresponds to the “drying process” of the present invention.

  The metal workpiece cleaning system 10 according to the present embodiment includes a water purifier 400 in addition to the above-described configuration. The water purifier 400 collects the redox potential water sprayed on the metal workpiece Wk in the jet cleaning device 200, and performs oil / water separation, oil recovery, solids (chips, burrs, etc.) recovery, etc. Purify the water. Thereafter, water that has cleared the predetermined water quality is supplied to the redox potential water production apparatus 100 as raw material water for redox potential water and reused, and water that has not cleared the predetermined water quality is discharged into the sewer after drainage treatment. It is released. Here, the pH of the oxidation-reduction potential water recovered in the water purification apparatus 400 is substantially the same as tap water, and hydrogen gas dissolved in the oxidation-reduction potential water naturally escapes after being used as washing water. In comparison with cleaning water obtained by adding a pH adjuster, a cleaning agent, a rust preventive agent, etc. to water, reuse and wastewater treatment of redox potential water as raw material water becomes easy.

  The above is the description of the metal workpiece cleaning system 10. The metal workpiece manufacturing system M including the metal workpiece cleaning system 10 includes a rust preventive oil adhesion device 401 as shown in FIG. The rust preventive oil adhering device 401 applies or sprays the rust preventive oil previously purified by the electrostatic oil purifier 401a (specifically, from which dust is removed) to the dried metal workpiece Wk. Thereby, generation | occurrence | production of the rust in the metal workpiece | work Wk can be prevented reliably. In addition, when the metal workpiece Wk to be manufactured as in the present embodiment is a plate valve body used in an automobile, for example, MTF (manual transmission oil) is applied or sprayed as rust preventive oil. Also good.

Next, the manufacturing process and the cleaning process of the metal workpiece will be described.
The metal workpiece Wk is formed through processes such as rolling, cutting, and pressing, and is sent to the appearance inspection process. And the metal workpiece | work Wk which passed the external appearance inspection is sent to a washing | cleaning process.

  That is, the metal workpiece Wk is sent to the jet cleaning apparatus 200 provided in the metal workpiece cleaning system 10. In the jet cleaning apparatus 200, the redox potential water supplied at a predetermined pressure (0.1 to 0.3 MPa) from the redox potential water production apparatus 100 (specifically, the generated water tank 26) by the supply pump 27 is supplied to the high pressure pump 203. The pressure is set to a preset pressure of 10 to 15 MPa from the nozzle 202 and collides with the metal workpiece Wk.

  Here, the oxidation-reduction potential water is heated by the heater 23 before flowing into the generated water tank 26, and the water temperature is adjusted so that, for example, the water temperature in the generated water tank 26 is not less than 33 degrees and not more than 38 degrees. That is, the water temperature of the oxidation-reduction potential water supplied to the nozzle 202 of the jet cleaning apparatus 200 is 33 degrees or more and 38 degrees or less. Here, the reason why the water temperature of the oxidation-reduction potential water in the generated water tank 26 is set to 33 ° C. or more is to remove foreign matters attached to the metal workpiece Wk, in particular, oil.

  When the oxidation-reduction potential water collides, chips and oil adhering to the surface of the metal workpiece Wk are washed away, and burrs not separated from the metal workpiece Wk are separated and removed from the metal workpiece Wk by water pressure. It is.

  The metal workpiece Wk that has been cleaned by the spray cleaning device 200 (where chips, burrs, and oil are removed) is immediately sent (preferably within one minute from the end of the cleaning) to the moisture removing device 300 (moisture removing step). In the moisture removing apparatus 300, first, air is blown by the blower 301 at a wind speed of 60 to 100 m / sec. Then, most of the water adhering to the metal workpiece Wk is blown away. Next, for example, warm air of 80 degrees is blown by the dryer 302. Then, the metal workpiece Wk is heated, and moisture that has not been removed by the blower 301 evaporates. Thereby, the water | moisture content adhering to metal workpiece | work Wk is removed completely. Here, the time from the end of the cleaning of the metal workpiece Wk to the transition to the moisture removal process is set to within 1 minute because rust is generated due to moisture adhering to the metal workpiece Wk and oxygen in the atmosphere. This is for sure prevention. Thus, the cleaning process for the metal workpiece Wk is completed.

  The metal workpiece Wk cleaned and dried through the cleaning process is coated or sprayed with rust preventive oil and then boxed. In addition, the whole process so far, ie, the process from the shaping | molding of the metal workpiece Wk to application | coating of antirust oil is a manufacturing process of the metal workpiece Wk.

Hereinafter, the effects of the present invention will be specifically described with reference to Examples and Comparative Examples.
[Example]
The configuration of the metal workpiece cleaning system 10 of the embodiment according to the present invention is as described above. Here, in the metal workpiece cleaning system 10 of the embodiment, the intersection angle θ2 (see FIG. 6B) between the center line of the nozzle 202 of the jet cleaning apparatus 200 and the surface of the metal workpiece Wk is set to 90 degrees. The pressure of the oxidation-reduction potential water sprayed from the nozzle 202 was set to 15 MPa, and the moving speed of the nozzle 202 was set to be finished in 6 seconds per metal workpiece Wk. Moreover, the speed (wind speed) of the air injected from the gas injection nozzle 301a of the blower 301 was set to 60 m / sec, and the temperature of the warm air coming out of the dryer 302 was set to 80 degrees.

[Comparative example]
Unlike the metal workpiece cleaning system 10 of the embodiment, only the water sprayed onto the metal workpiece Wk is tap water (pH 7.0 to 7.5, ORP + 150 mV or more). Other configurations and setting conditions are implemented. This is the same as the metal workpiece cleaning system 10 in the example.

[experimental method]
(1) Using the metal workpiece cleaning system 10 of the example and the metal workpiece cleaning system of the comparative example, the metal workpiece Wk was cleaned and dried by the above steps. Here, in the cleaning by the metal workpiece cleaning system 10 of the embodiment, the water temperature of the oxidation-reduction potential water stored in the generated water tank 26 of the oxidation-reduction potential water production apparatus 100 (that is, supplied to the nozzle 202) is varied. And the temperature of the portion of the metal workpiece Wk where the redox potential water collides (the portion surrounded by the dotted line m in FIG. 7) was measured. Further, the pH, ORP, and dissolved hydrogen amount of redox potential water injected to the metal workpiece Wk were also measured.
(2) The dried metal workpiece Wk was left in the indoor air, and the presence or absence of rust (so-called red rust) was inspected every day visually or with a microscope.

[Experimental result]

  It was confirmed that the metal workpiece Wk cleaned by the metal workpiece cleaning system of the comparative example had already rusted when taken out from the dryer 302.

  In contrast, in the metal workpiece Wk (Nos. 1 to 8) cleaned by the metal workpiece cleaning system 10 of the example, as shown in Table 1, the generation of rust is suppressed over a long period after drying. I understood that I could do it. Specifically, when the water temperature in the production water tank 26 of redox potential water (pH 7.36, ORP-618 mV, dissolved hydrogen 1.696 ppm) is set to 36 degrees to 38 degrees, redox potential water in the metal workpiece Wk. The temperature of the part (see FIG. 7) where the collision occurred was 26.7 to 27.8 degrees. And when the metal workpiece | work Wk wash | cleaned on these conditions (No. 1-5) was dried and left to stand in air | atmosphere, generation | occurrence | production of rust was not confirmed until the 4th day after starting to air-atmosphere.

  Further, when the water temperature in the generated water tank 26 of redox potential water (pH 7.22, ORP-606 mV, dissolved hydrogen 1.431 ppm) is 33 to 35 degrees, the redox potential water of the metal workpiece Wk collides. The temperature of the portion (see FIG. 7) was 24.6 degrees to 25.1 degrees. And when the metal workpiece Wk cleaned under these conditions (Nos. 6 to 8) is dried and left in the atmosphere, the occurrence of rust is not confirmed until 20 days at the earliest after starting to stand in the air. (No. 6), no rust was observed until the 25th day at the longest (No. 7, 8).

  Furthermore, according to the metal workpiece cleaning system 10 of the example, the removal of the foreign matter adhering to the metal workpiece Wk was also satisfactorily performed, and generation of scale after drying was not confirmed.

  As described above, according to the present embodiment, by washing the metal workpiece Wk with the oxidation-reduction potential water having a negative ORP value, the conventional washing system and washing method using tap water as washing water are used. In comparison, generation of rust in the metal workpiece Wk after cleaning could be suppressed over a long period of time. More specifically, the ORP of the oxidation-reduction potential water is −500 mV or less (preferably −600 mV or less) and / or the dissolved hydrogen amount is 1.0 to 2.0 ppm (preferably 1.4 ppm to 2.0 ppm). , PH 7.0 to 7.8 (preferably pH 7.2 to 7.8), and further the water temperature of the redox potential water supplied to the nozzle 202 (in this embodiment, the water temperature in the product water tank 26), 38 degrees or less (more preferably, 35 degrees or less) and / or the temperature of the portion of the metal workpiece Wk where the redox potential water collides (see FIG. 7) is 28 degrees or less (more preferably, 26 It was possible to suppress the generation of rust in the metal workpiece Wk after washing for 4 to 25 days.

  Further, the water temperature of the oxidation-reduction potential water supplied to the nozzle 202 (water temperature in the generated water tank 26) is 33 degrees or more and / or a portion of the metal workpiece Wk where the oxidation-reduction potential water collides (see FIG. 7). By setting the temperature of the reference) to 24 ° C. or more, the foreign matter adhering to the metal workpiece Wk could be reliably removed.

  In addition, in the process of generating redox potential water, oxidizing substances (dissolved oxygen and residual chlorine) in tap water are removed, and redox potential water itself is reducible. Erosion corrosion due to collision with Wk can be suppressed.

  In addition, when washing | cleaning the metal workpiece | work Wk with oxidation reduction potential water, the following is estimated as a reason for which rust was suppressed over a long period compared with the case where it wash | cleans with tap water. As an example of metal, iron will be described as an example. Generally, when water adheres to iron, rust is generated by the following chemical reaction (oxidation reaction).

Iron ionizes and elutes in water.
Fe → Fe ²⁺ + 2e ⁻ (1)
Water and oxygen react with each other through electrons released from iron to generate hydroxide ions.
2H ₂ O + O ₂ + 4e ⁻ → 4OH ⁻ (2)
Iron ions and hydroxide ions react to produce ferrous hydroxide.
Fe ²⁺ + 2OH ⁻ → Fe (OH) ₂ (3)
Ferrous hydroxide is immediately oxidized by dissolved oxygen in the water or oxygen in the atmosphere to produce ferric hydroxide (red rust).
4Fe (OH) ₂ + 2H ₂ O + O ₂ → 4Fe (OH) ₃ (4)
When ferric hydroxide is dehydrated, it becomes ferric oxide.
2Fe (OH) ₃ → Fe ₂ O ₃ + 3H ₂ O (5)

  When washing with tap water, it is assumed that the reaction of (1) to (4) above progresses during the washing or drying due to the tap water and dissolved oxygen adhering to the metal workpiece Wk and red rust is generated. Is done.

  On the other hand, the case of washing with redox potential water is as follows. That is, the ORP of the oxidation-reduction potential water has a large value on the negative side (specifically, −600 mV or less) as described above. That is, the oxidation-reduction potential water has a strong reducibility compared with tap water (ORP + 150 mV or more). Thereby, when it wash | cleans by oxidation-reduction potential water, progress of said reaction (1)-(4) is suppressed at least from washing | cleaning to drying, and generation | occurrence | production of rust compared with the case where it wash | cleans with tap water. It is estimated that it was suppressed over a long period of time.

[Other Embodiments]
The present invention is not limited to the above-described embodiment. For example, the embodiments described below are also included in the technical scope of the present invention, and various other than the following can be made without departing from the scope of the invention. It can be changed and implemented.
(1) In the above-described embodiment, a gas cylinder is provided as the hydrogen gas supply source 18, but instead of the gas cylinder, for example, a hydrogen gas generator that generates hydrogen gas from water by a chemical reaction may be provided. . In this case, it is preferable to provide a pump for pumping the generated hydrogen gas to the gas-liquid mixing pump 17 in the middle of the gas pipe GP.

(2) In the above embodiment, the metal workpiece Wk is washed only with the oxidation-reduction potential water. However, the metal workpiece Wk may be washed with washing oil before washing with the oxidation-reduction potential water.

(3) In the above embodiment, water softening treatment and activated carbon filtration treatment were performed as pretreatment of tap water used for the generation of redox potential water. In addition to these treatments, ion exchange treatment and ultraviolet sterilization treatment were performed. You may go. The redox potential water produced through such pretreatment can be used for cleaning precision parts.

(4) In the said embodiment, although the SPCC material was illustrated as an example of the metal workpiece Wk, it may be a metal workpiece containing other iron (for example, a galvanized SECC material or stainless steel). . Moreover, the metal (aluminum and brass (brass)) which does not contain iron may be sufficient.

(5) In the above embodiment, the rust preventive oil is applied to the dried metal workpiece Wk. However, for example, it may be sealed in a bag filled with nitrogen gas. In this way, the user of the metal workpiece Wk can save the trouble of removing the rust preventive oil before using the metal workpiece Wk.

(6) In the above embodiment, the nozzle 202 provided in the jet cleaning device 200 and the gas injection nozzle 301a provided in the blower 301 are configured to move relative to the metal workpiece Wk. 301a may be fixed and the metal workpiece Wk may be transported in the order of the jet cleaning device 200 and the water removal device 300 by a transport device (for example, a conveyor).

(7) In the above embodiment, the distance H1 between the injection port of the nozzle 202 for injecting redox potential water and the surface of the metal workpiece Wk was 40 mm. It may be changed according to the state (for example, the thickness of the plate or the amount of adhered foreign matter). Moreover, what is necessary is just to change suitably the pressure of the oxidation reduction potential water injected to the metal workpiece | work Wk within the range of 10-15 MPa according to the state of the metal workpiece | work Wk.

(8) In the above embodiment, as the nozzle 202 for injecting redox potential water, a so-called flat nozzle in which water injected from the injection port diffuses in a substantially fan shape is used. A so-called slit nozzle such as a so-called full cone nozzle or a gas injection nozzle 301a may be used.

(9) In the above embodiment, the metal workpiece Wk is laid horizontally and the redox potential water is sprayed from the upper surface side and the lower surface side thereof, but the metal workpiece Wk is vertically held and held, You may make it spray redox potential water from a horizontal direction. In this way, water is prevented from accumulating on the upper surface of the metal workpiece Wk, and draining can be performed even while the oxidation-reduction potential water is being sprayed.

(10) In the above embodiment, the air blown out from the gas injection nozzle 301a hits the surface of the metal workpiece Wk from a substantially vertical direction, but hits it from a direction inclined with respect to the vertical direction. May be.

(11) In the above embodiment, gas is blown to the metal workpiece Wk to blow off the moisture. For example, even if the metal workpiece Wk is rotated at high speed and drained by centrifugal force or drained by ultrasonic vibration. Good.

(12) In the above embodiment, the nozzle 202 provided in the jet cleaning device 200 is configured to automatically move while jetting redox potential water. For example, the nozzle 202 is connected to the supply pipe SP via a high-pressure hose. The operator may hold the injection nozzle and spray the redox potential water.

(13) In the above embodiment, as pre-treatment of tap water used for the generation of redox potential water, degassing treatment and activated carbon filtration treatment were performed to remove oxidizing substances such as dissolved oxygen and residual chlorine. These processes may not be performed. In this case, an oxidizing substance remains in the redox potential water, but the oxidizing substance is oxidized by the reducing power of the redox potential water itself (or hydrogen dissolved in the redox potential water). You may make it weaken force and suppress generation | occurrence | production of the rust and erosion corrosion in the metal workpiece | work Wk.

(14) In the above embodiment, the blower 301 of the moisture removing apparatus 300 blows air to the metal workpiece Wk. However, if nitrogen gas or argon gas is blown instead of air, rust of the metal workpiece Wk is generated. Occurrence can be prevented more reliably.

(15) In the above embodiment, the distance H2 between the injection port of the gas injection nozzle 301a and the surface of the metal workpiece Wk is 180 mm, but this distance H2 is the state of the metal workpiece Wk (for example, The thickness may be changed according to the thickness of the plate or the amount of adhered foreign matter. Moreover, what is necessary is just to change suitably the wind speed of the gas injected to the metal workpiece | work Wk within the range of 60-120 m / sec according to the state of the metal workpiece | work Wk.

The conceptual diagram of the metal workpiece washing system which concerns on one Embodiment of this invention. Conceptual diagram of redox potential water production equipment Conceptual diagram of mixer unit Cross section of mixer Top view of mixing wall (A) Conceptual diagram of jet cleaning device (B) Partial enlarged view of jet cleaning device Perspective view of spray cleaning device Conceptual diagram of blower Perspective view of blower

Explanation of symbols

10 Metal workpiece cleaning system 12 Soft water device 13 Activated carbon filter (dechlorination device)
16 Deaerator 17 Gas-liquid mixing pump 22A, 22B, 22C Mixer 23 Heater 26 Generation water tank 30 Cylindrical case (pipe)
40 Mixing wall 100 Redox potential water production device 200 Spray cleaning device 202 Nozzle 300 Moisture removal device 301 Blower 302 Dryer M Metal workpiece production system Wk Metal workpiece

Claims (20)

In a metal workpiece cleaning system for cleaning metal workpieces,
An oxidation-reduction potential water production apparatus for producing redox-potential water in which water and hydrogen gas are mixed by stirring to produce a redox-potential water having a negative value;
A metal workpiece cleaning system comprising: an injection cleaning device having a nozzle for injecting the oxidation-reduction potential water toward the metal workpiece.   2. The metal workpiece cleaning system according to claim 1, wherein a water temperature of the redox potential water is set to 38 degrees or less and supplied to the nozzle.   The metal workpiece cleaning system according to claim 1 or 2, wherein a water temperature of the oxidation-reduction potential water is set to 33 degrees or more and supplied to the nozzle.   The temperature of the portion where the oxidation-reduction potential water collides with the metal workpiece is 28 degrees or less, and the temperature of the oxidation-reduction potential water is set to a predetermined temperature or less to be supplied to the nozzle. The metal workpiece cleaning system according to any one of claims 1 to 3, wherein   The temperature of the portion where the oxidation-reduction potential water collides with the metal workpiece is 24 degrees or higher, and the water temperature of the oxidation-reduction potential water is set to a predetermined temperature or higher and is supplied to the nozzle. The metal workpiece cleaning system according to any one of claims 1 to 4, wherein the metal workpiece cleaning system is provided.   The apparatus for producing redox potential water has an amount of dissolved hydrogen that is an amount of hydrogen gas dissolved in water per unit volume of 1.0 to 2.0 ppm and / or an oxidation-reduction potential of −500 mV or less and a pH of 7.0. 6. The metal workpiece cleaning system according to claim 1, wherein the metal workpiece cleaning system is configured to generate redox potential water that is ˜7.8.   The metal workpiece cleaning system according to any one of claims 1 to 6, further comprising a moisture removing device for removing moisture adhering to the metal workpiece after cleaning by the jet cleaning device.   The moisture removing device is configured to blow a gas to the metal workpiece after cleaning by the jet cleaning device to blow away moisture attached to the metal workpiece, and to heat the metal workpiece from which the moisture has been blown off. The metal workpiece cleaning system according to claim 7, comprising a dryer that evaporates moisture. The oxidation-reduction potential water production device includes a gas-liquid mixing pump that sucks, mixes and discharges the hydrogen gas together with the water,
A mixer for increasing the dissolved amount of the hydrogen gas with respect to the water discharged from the gas-liquid mixing pump,
The mixer is connected to a discharge port of the gas-liquid mixing pump;
Provided at intervals along the axial direction of the pipe line, partition the pipe line into a plurality of regions and allow the water to pass therethrough, so that the strength of fluid pressure is repeated in the pipe line A metal workpiece cleaning system according to claim 1, further comprising a plurality of mixing walls.   A degassing device for removing gas from the water mixed with the hydrogen gas by the oxidation-reduction potential water production device in advance, a dechlorination device for removing residual chlorine, and a metal ion removing device. A metal workpiece cleaning system according to any one of claims 1 to 9, further comprising a water softener.   Water and hydrogen gas are stirred and mixed to produce redox potential water having a negative redox potential, and the metal workpiece is washed by jetting the redox potential water from a nozzle. Metal workpiece cleaning method.   The metal workpiece cleaning method according to claim 11, wherein the temperature of the oxidation-reduction potential water supplied to the nozzle is set to 38 ° C. or less.   The metal workpiece cleaning method according to claim 11 or 12, wherein a water temperature of the oxidation-reduction potential water supplied to the nozzle is set to 33 degrees or more.   The method for cleaning a metal workpiece according to any one of claims 11 to 13, wherein a temperature of a portion of the metal workpiece where the redox potential water collides is set to 28 degrees or less.   The method for cleaning a metal workpiece according to any one of claims 11 to 14, wherein a temperature of a portion of the metal workpiece where the oxidation-reduction potential water collides is 24 degrees or more.   The redox potential water has a dissolved hydrogen amount of 1.0 to 2.0 ppm and / or a redox potential of −500 mV or less and a pH of 7.0 to 7 as a hydrogen gas amount dissolved in water per unit volume. The metal workpiece cleaning method according to claim 11, wherein the metal workpiece cleaning method is.   The method for cleaning a metal workpiece according to any one of claims 11 to 16, further comprising a moisture removal step of removing moisture attached to the metal workpiece after the cleaning with the redox potential water.   The water removal step includes a draining step of blowing a gas to the metal workpiece and blowing away the moisture, and a drying step of heating the metal workpiece after the draining step to evaporate the moisture. Item 18. A method for cleaning a metal workpiece according to Item 17.   A degassing step for removing gas from the water to be stirred and mixed with the hydrogen gas; a dechlorination step for removing residual chlorine; and a water softening step for removing metal ions. The metal workpiece cleaning method according to claim 11, wherein the metal workpiece is cleaned. A method of manufacturing a metal workpiece, comprising the metal workpiece cleaning method according to any one of claims 11 to 19 as a part of the process.