Method for washing condenser aluminum fin of oil cooler equipped in machine tool

Abstract

To provide a method for safely washing aluminum fins of a condenser of an oil cooler equipped in a machine tool.SOLUTION: In a cleaning method comprising washing aluminum fins of a condenser 24 of an oil cooler 5 with a high-pressure washer 31, and simultaneously absorbing wastewater from this washing with a wet vacuum cleaner 35, in order to avoid a risk that a fan motor 51 gets wet during washing to lower its insulation resistance value, an inspection process is added to measure the insulation resistance value of the fan motor and a power supply board before turning on the power after the washing, thereby reducing a risk of power breaker tripping due to poor insulation of these components.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a method for cleaning the aluminum fins of the condenser of an oil cooler installed on a machine tool in a metal processing factory that produces automobile engine parts and the like. [Background technology]

[0002] Oil coolers are essential in factories that have machine tools, machining centers, NC lathes, etc. that precisely process large metal parts such as automobile engine parts. In the above-mentioned factory, oil cooled by an oil cooler is supplied to heat-generating parts such as the spindle of the machine tool to cool the heat generated from the spindle during part machining, and the parts are machined while absorbing the heat, thereby maintaining machining precision. The machine tool mentioned above maintains the precision of machining parts by measuring changes in oil temperature, spindle temperature, etc., and maintaining the oil temperature at a predetermined constant temperature or at a reference temperature based on the room temperature. If the oil temperature deviates significantly from the reference value, the spindle will undergo thermal deformation, making it impossible to machine parts with the desired precision, resulting in defective parts. As a countermeasure, if the oil temperature deviates from the reference value, an alarm will sound and the machine tool will stop. The system is designed so that the machine tool will resume operation once the oil has returned to the specified value after dissipating heat for a while.

[0003] FIG. 1 is a configuration diagram for explaining the role of the oil cooler 5 in a machine tool. Heat 2 generated when machining metal with machine tool 1 is cooled (heat absorbed) by oil 4 and collected in oil tank 3. The collected oil 4 is supplied to oil cooler 5, where it is heat exchanged (cooled 6), and the exhaust heat is released into the room through the aluminum fins of the condenser of oil cooler 5.

[0004] FIG. 2 is a detailed explanatory diagram of the oil cooler 5. 2, the portion surrounded by a solid line is a configuration diagram of the oil cooler 5. Hot oil 4 collected in the oil tank 3 is supplied to an evaporator 22 by an oil pump 21, where it is heat exchanged (cooled) and returned to the machine tool 1.

[0005] The cooling circuit configuration (solid line portion) of the oil cooler 5 will be described. The cooling circuit of the oil cooler 5 connects four components with copper pipes, and the refrigerant freon circulates within the copper pipes, transferring heat by changing the state of the refrigerant freon. When hot oil 4 enters the evaporator 22, the liquid refrigerant freon absorbs heat from the oil 4, evaporates, becomes gasified, and is supplied to the compressor 23. The gasified refrigerant freon is compressed in the compressor 23 and changes state to high-temperature, high-pressure liquid refrigerant freon. The heat of the high-temperature, high-pressure liquid refrigerant freon is released into the room through the condenser aluminum fins 24. The high-pressure liquid refrigerant freon, which has released heat and cooled, passes through the expansion valve 25 and becomes low-temperature, low-pressure liquid refrigerant freon. The above process is repeated to cool the oil 4.

[0006] As mentioned above, the liquid refrigerant freon that returns to the evaporator 22 absorbs heat from the oil and changes from liquid to gaseous refrigerant freon. This change in state of refrigerant freon, and the principle of the heat pump, are used to absorb heat 2 generated during metal processing, maintaining the processing precision of the machine tool.

[0007] As machine tool 1 continues to operate, hot oil 4 generated within the machine tool turns into oil mist and leaks out into the surrounding area of ​​machine tool 1. The oil cooler 5 equipped on machine tool 1 absorbs the oil mist that leaks out into the surrounding area, and the condenser aluminum fins 24 (see Figure 3) become dirty with the oil mist. As a countermeasure against oil mist contamination, a filter made of nonwoven fabric or the like is used on the front surface (the surface that draws in air) of the condenser aluminum fins 24 to prevent the oil mist from entering, but after several years, the oil mist accumulates on the condenser aluminum fins 24 and becomes clogged. As the oil hardens over time, factories remove the hardened oil by brushing or using an air nozzle, and repeatedly perform maintenance on the condenser aluminum fins 24, but these methods are insufficient to remove the oil mist contamination.

[0008] Furthermore, if the condenser aluminum fins 24 become covered in oil, the oil cooler 5 may be removed from the machine tool 1 and transported to the oil cooler 5 manufacturer's service center, where maintenance and inspection may be carried out through a process of disassembly, chemical spraying, and cleaning with a high-pressure washer. [Prior art documents] [Patent documents]

[0009] As a result of searching patent documents regarding the cleaning and washing of aluminum fins of the condenser of an oil cooler, we found Patent Document 1.

[0010] Patent Document 1 was filed by the inventors and describes a method for cleaning an oil cooler while it is installed in a machine tool. [Patent Document 1] Japanese Patent Application Publication No. 2017-034397 Summary of the Invention [Problem to be solved by the invention]

[0011] The oil cooler manufacturer's method of cleaning the oil cooler 5 involves removing the oil cooler 5 from the machine tool 1 and transporting it away, which requires a grace period of 2 to 3 weeks for cleaning, maintenance, and inspection. During that time, in order to operate the machine tool 1, it is necessary to install a spare oil cooler, which requires time and expense, and this poses a problem that can lead to significant losses. Furthermore, the added time and effort of removal, installation, and transportation means that the cleaning, maintenance, and inspection costs incurred by the oil cooler manufacturer are high.

[0012] As a solution to the above problem, the oil cooler 5 is installed in the machine tool 1 and the condenser The mifin 24 is washed with a high-pressure washer 31, and the waste liquid from the washing is sucked up by a wet vacuum cleaner 35. The inventors have filed a patent application for Patent Document 1 (see FIG. 3) which features the above-mentioned invention.

[0013] When cleaning the condenser aluminum fins 24 with the high-pressure washer 31, the cleaning liquid may splash and wet the electrical components such as the control board 54 and fan motor 51, so it is necessary to protect these components thoroughly with vinyl or a rag beforehand. The control board 54 is positioned so that repairs can be easily performed by removing the oil cooler housing panel, and so it can be relatively easily protected with a rag, etc. However, the fan motor 51 is located in the center of the condenser aluminum fins 24, and other components (control board, compressor, piping, etc.) are generally located around the fan motor 51, so it is not easy to protect the fan motor 51 by simply removing the housing panel.

[0014] Furthermore, if the power is turned on immediately after cleaning, and the control board 54 or fan motor 51 becomes wet and the insulation resistance value decreases, the power breaker will be tripped when the power is turned on, preventing operation of the machine tool 1. In the worst case scenario, the control board 54 may be damaged, resulting in a malfunction. [Means for solving the problem]

[0015] The present invention has been made in view of the above-mentioned problems, and from a first viewpoint, as shown in FIG. 3, is devised to enable protection of a fan motor 51 to be performed in a short time. When the oil cooler 5 is disassembled and the arrangement of the fan motor 51 is observed, it can be seen that the fan motor 51 is installed in the center of the condenser aluminum fins 24 at a distance (gap) of 50 to 100 mm from the condenser aluminum fins 24. Waterproof plastic cardboard 52 (commonly known as "pladan" for short, 2 to 4 mm thick) can be cut to a size that can be inserted into the gap, thereby preventing the cleaning liquid from entering the fan motor 51. The plastic cardboard 52 can be cut with scissors or the like to a size that can be inserted into the gap between the condenser aluminum fins 24 and the fan motor 51, and by inserting it, the cleaning liquid can be prevented from entering the fan motor 51. Note that a vinyl waterproof sheet or the like can also be used instead of the plastic cardboard 52.

[0016] In a second aspect, as shown in FIG. 4, a method is provided for inspecting the control board and fan motor 51 for poor protection, i.e., the degree of wetness, after cleaning, thereby providing a method for safely operating the oil cooler 5 and ultimately the machine tool 1. The insulation resistance of the power supply circuit of the control board 54 and the fan motor 51 is measured before cleaning. After cleaning, the same insulation resistance measurement is performed. If the insulation value has decreased, it is determined that the problem is due to cleaning. Then, the control board 54 and the fan motor 51 are dried with a hair dryer or blower until the insulation resistance value is the same as before cleaning. [Effects of the Invention]

[0017] In the present invention, the condenser aluminum fins 24 are attached to the oil cooler 5 installed in the machine tool 1. The high-pressure washer 31 is used to clean the area, and the waste liquid from the cleaning process is simultaneously sucked and collected by a wet vacuum cleaner 35. The cleaning method provides a method for performing cleaning work efficiently and safely. In claim 1, as shown in FIG. 3, the fan motor 51 is condensed so as not to get wet with the cleaning liquid. By inserting a plastic board 52 into the gap between the aluminum fin 24 and the fan motor 51, the cleaning liquid is blocked by the plastic board 52. This has the effect of preventing the occurrence of insulation failure in the fan motor 51 and allowing the cleaning work to be carried out safely.

[0018] In claim 2, the insulation resistance value of the power supply circuit of the control board 54 is inspected after cleaning and before assembling the parts, as shown in Fig. 4. At the same time, a step of inspecting the insulation resistance value of the fan motor 51 is also incorporated, which has the effect of enabling the power-on operation after cleaning to be carried out safely.

[0019] In this way, a cleaning method for an oil cooler 5 is provided which overcomes the above-mentioned problems and has the following characteristics. Feature 1: The cleaning method of the present invention can remove oil mist stains that have been present for many years, which could not be removed by conventional maintenance work on oil coolers 5 in factories, such as brushing or removing oil stains using an air nozzle. Feature 2: In the conventional cleaning method, which requires outsourcing to an oil cooler manufacturer, the machine tool is stopped and does not contribute to production during the time it is removed and transported to the manufacturer. However, since the cleaning is performed while the machine tool is installed, there is no need for the aforementioned work, and the decline in production efficiency due to machine tool stoppages can be reduced. Feature 3: Leaving it at the manufacturer requires a lot of work, such as removal, transportation, installation after returning, and trial operation, and the cost of maintenance and inspection is high. Since these costs are not incurred, the cost of maintenance and inspection of the oil cooler 5 can be reduced. Feature 4: By providing an inspection process that measures the insulation resistance value of the control board 54 and the fan motor 51 before and after cleaning, the machine tool can be safely turned on and operated safely. It can be fully operational. Feature 5: The cleaning method of the present invention can be completed on-site in 2 to 3 hours, which minimizes the impact on production stoppages. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 1 is a structural diagram illustrating the role of an oil cooler 5, which is a product to be cleaned by the present invention, in a machine tool. [Figure 2] FIG. 2 is a diagram for explaining the configuration of the oil cooler 5. As shown in FIG. [Figure 3] FIG. 3 is a diagram showing the configuration of a device for cleaning the condenser aluminum fins 24 according to a first embodiment of the present invention. [Figure 4] FIG. 4 is an explanatory diagram of a second embodiment of the present invention. [Figure 5] FIG. 5 is a diagram illustrating details of the second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0021] The first embodiment of the present invention will be described in detail with reference to FIG. In the present invention, a method is adopted in which an oil mist cleaner is sprayed onto the condenser aluminum fins 24 and then the condenser aluminum fins 24 are washed with a high-pressure washer 31. A nozzle 34 is connected to the high-pressure washer 31 via a water supply hose 32 that supplies tap water and a high-pressure hose 33. This device sprays tap water at high pressure and removes oil mist dirt adhering to the condenser aluminum fins 24 using the water pressure of the high-pressure washer 31. This device also recovers waste oil that is produced during the cleaning process using a wet washer 35.

[0022] An air / liquid separation tank 37 is installed at the tip of the suction hose 36 of the wet vacuum cleaner 35. By installing the air / oil separation container 37 between the hose 43 that sucks up the waste liquid and the suction hose 36 of the wet vacuum cleaner 35, the oil in the collected waste liquid can be treated smoothly.

[0023] The heat exhausted from the condenser aluminum fins 24 is released into the room by a fan motor 51. The fan motor 51 is installed at the center of the condenser 24 with a distance (gap) of about 50 to 100 mm so that the heat can be efficiently exhausted.

[0024] The invention of claim 1 inserts a plastic board 52 into the gap between the condenser 24 and the fan motor 51, This prevents the cleaning liquid from reaching the fan motor 51. By inserting the plastic board 52 in this way, the fan motor 51 will not get wet with tap water from the high-pressure washer nozzle 34.

[0025] FIG. 4 illustrates a second embodiment of the present invention. In FIG. 4, a fan motor The three lead wires 53 of 51 are connected to a control board 54. To measure the insulation resistance value of the fan motor 51, remove the connector 56 of the three lead wires from the control board 54, and measure the insulation resistance value between the earth terminal 57 of the insulation meter 55 and the lead wires a, b, and c of the fan motor 51. If this value is the same as the insulation resistance value before cleaning, the inspection is passed; if it is lower, dry the fan motor 51 with a hair dryer.

[0026] The insulation resistance value of the control board 54 is measured between the earth terminal 57 of the insulation meter and the R, S, and T terminals of the three power lines 58 supplied to the control board 54. If this value does not change before and after cleaning, the inspection is passed. If the value after cleaning is small, dry the control board 54 with a hairdryer until the insulation resistance value returns to the value before cleaning.

[0027] Figure 5 is a flow chart of the cleaning process and work procedure for the oil cooler 5, which incorporates the measurement and inspection process of the insulation resistance value. In Figure 5, the inspection process of measuring the insulation resistance value in steps 2 and 6 has been added to the conventional work procedure. [Industrial Applicability]

[0028] The present invention was implemented for cleaning the condenser aluminum fins 24 of an oil cooler 5, but it can also be used for cleaning the condenser aluminum fins of spot coolers, window air conditioners, wall-mounted air conditioners, etc. [Explanation of symbols]

[0029] 1 Machine tools 3 Oil Tank 5 Oil cooler 21 Oil pump 22 Evaporator 23 Compressor 24 Condenser 25 Expansion valve 31 High-pressure washer 35 Wet vacuum cleaner 37 Air-oil separator tank 51 Fan motor 52 Waterproof plastic cardboard (pladan) 53 Fan motor lead wire 54 Control board 55 Insulation Tester

Claims

1. This cleaning method for the aluminum fins of the condenser of an oil cooler equipped on a machine tool is performed by using a high-pressure washer to clean oil mist-caused dirt from the condenser while the machine tool is still installed, and then absorbing and recovering the waste liquid after cleaning with a wet vacuum cleaner.The method for cleaning the aluminum fins of the condenser of an oil cooler is characterized by processing waterproof cardboard to a size that can be inserted into the gap between the aluminum fins of the condenser of the oil cooler and the fan motor, and inserting the plastic cardboard into the gap.

2. The method for cleaning the aluminum fins of the condenser of an oil cooler according to claim 1, characterized in that the insulation resistance values ​​of the power circuit of the control board of the oil cooler and the fan motor are measured before cleaning the aluminum fins of the condenser of the oil cooler, and the same measurement is made after cleaning.If the insulation resistance value decreases after cleaning, it is determined that this is due to an effect caused by cleaning, and the fins are dried using a blower or a blower with a heater until the insulation resistance value becomes the same as before cleaning.

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