JP2708844B2 - Cleaning method and cleaning equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) A cleaning method and a cleaning apparatus according to the present invention are used for removing dirt such as oil adhered to the surface of various articles, and particularly perform finish cleaning. It is useful in cases.

(Prior art) Mold, porous sintered metal for air bearing, IC board, etc.
BACKGROUND ART Generally, dirt such as oil adhered to the surface of various articles is cleaned by using an organic solvent such as chlorofluorocarbon and trichloroethylene as a cleaning liquid.

An example of a cleaning apparatus for performing a cleaning operation by using such an organic solvent as a cleaning liquid is described in Jpn.
The apparatus shown in No. 5 will be described as an example.

As shown in FIG. 2, this cleaning apparatus has a cleaning tank 2 having a bottomed cylindrical shape having an open top and a lid 1 capable of sealing an upper end opening in an airtight manner, and a heater for heating and evaporating an organic solvent. A vapor supply means 4 for feeding the vapor of the organic solvent into the cleaning tank 2 through a pipe 5; a storage tank 6 for storing an organic solvent for cleaning to be fed into the cleaning tank 2; 6 comprises two pipes 7 and 8 connecting the washing tank 2 and a liquid sending pump 9 provided in the middle of one of the pipes 8.
A supply / discharge means 20 for supplying / discharging the liquid organic solvent in between, a heater 10 for heating and evaporating the liquid organic solvent, and a cooler 11 for condensing the vapor of the organic solvent are combined to form a condensed organic solvent. A still 12 for feeding the solvent to the storage tank 6, an intake pipe 16 for feeding air into the washing tank 2, and a vacuum pump 13
Is connected to the end of the discharge pipe 19 provided with
An evaporating pipe 14 for feeding the organic solvent vapor discharged from the evaporator 12 to the still 12 and an exhaust pipe 15 for discharging air from the washing tank 2.

When the object to be cleaned 17 is to be cleaned by the cleaning apparatus of the present invention configured as described above, the lid 1 is opened and the object to be cleaned is opened.
After accommodating 17 in the cleaning tank 2, the lid 1 is closed and the vacuum pump 13 is operated to discharge the air in the cleaning tank 2 through the exhaust pipe 15.

After the air in the cleaning tank 2 is discharged, the organic solvent in the storage tank 6 is fed into the cleaning tank 2 through the pipe 7 constituting the supply / discharge means 20 to clean the object 17 to be cleaned. At this time, by energizing the ultrasonic vibrators 18, 18 fixed to the bottom of the cleaning tank 2, ultrasonic vibration is applied to the organic solvent in the cleaning tank 2 so that the object 17 to be cleaned is efficiently cleaned. To

When the cleaning operation with the liquid organic solvent is completed, the liquid feed pump 9 constituting the supply / discharge means 20 is operated,
The vapor of the organic solvent is supplied from the vapor supply means 4 into the cleaning tank 2 while the liquid organic solvent in the cleaning tank 2 is gradually returned to the storage tank 6 through the pipe 8.

As a result, a part of the object 17 to be cleaned in the cleaning tank 2 is exposed on the liquid surface of the liquid organic solvent, and the vapor of the organic solvent is condensed at the exposed portion. A so-called steam cleaning in which the surface is cleaned is performed.

When all of the liquid organic solvent in the cleaning tank 2 has been returned to the storage tank 6 while performing the steam cleaning, the vacuum pump 13 provided in the middle of the discharge pipe 19 is operated to leave the liquid organic solvent in the cleaning tank 2. The organic solvent vapor is discharged into the distiller 12 through the drainage pipe 14. In this way, the distillation apparatus 12 is connected through the discharge pipe 19 and the
The vapor of the organic solvent discharged into the condenser is condensed and liquefied by the cooler 11 provided in the distiller 12, and is recovered. Vacuum pump
When the inside of the cleaning tank 2 reaches a predetermined degree of vacuum with the operation of 13, the vacuum pump 13 is stopped, and air is sent into the cleaning tank 2 through the suction pipe 16.

As a result, when the pressure in the cleaning tank 2 rises to about the atmospheric pressure, the lid 1 of the cleaning tank 2 is opened, and the object 17 to be cleaned after the cleaning work is taken out.

(Problems to be Solved by the Invention) However, in the case of the conventional or prior-art cleaning apparatus configured and operated as described above, the following inconvenience occurs.

That is, in the case of the conventional or prior-art cleaning apparatus, the pressure in the cleaning tank 2 becomes higher than the atmospheric pressure (the pressure in the cleaning tank 2 becomes positive) as the cleaning operation proceeds. Occurs.

When the inside of the cleaning tank 2 containing an organic solvent such as Freon becomes a positive pressure, in order to prevent the leakage of the organic solvent vapor, the lid 1 provided at the upper end opening of the cleaning tank 2 is closed. It is necessary to provide a tightening mechanism for pressing against the packing provided on the upper edge portion, and it is inevitable that the structure of the cleaning device becomes complicated.

In addition, when airtightness of the lid portion becomes poor due to improper tightening or damage to the packing, vapor of the organic solvent present in the cleaning tank 2 leaks into the atmosphere, and environmental destruction such as ozone layer destruction occurs. Cause it.

Further, even when a cleaning solution containing an organic solvent or more is used, if highly infectious bacteria are attached to the object to be cleaned, the lid 1 is used to prevent the bacteria from leaking out.
Must be sufficiently airtight, and a similar problem arises.

The cleaning method and the cleaning apparatus of the present invention solve the above-mentioned disadvantages.

(Means for Solving the Problems) Among the cleaning method and the cleaning apparatus of the present invention, first, the cleaning method is:
The object to be cleaned is placed in a washing tank that can be sealed, and the cleaning liquid is poured into the cleaning tank until the object to be cleaned is immersed. Then, the cleaning liquid is gradually discharged. The same type of cleaning liquid vapor is sent at a higher temperature than the cleaning liquid.

In the cleaning method of the present invention, the discharge amount of the cleaning liquid is set to be equal to or more than the supply amount of the cleaning liquid vapor, so that the pressure in the cleaning tank is maintained at a negative pressure during the cleaning operation. And

Further, as shown in FIG. 1, the cleaning apparatus of the present invention comprises a cleaning tank 2 which can be hermetically sealed with an object 17 to be cleaned stored therein, and a cleaning tank 2 as shown in FIG. A discharge pump capable of discharging the fluid in the cleaning tank 2 such as a liquid pump 9 provided in the middle of a pipe 8 for feeding a cleaning liquid such as an organic solvent to a storage tank 6 (see FIG. 2), and heating the cleaning liquid. It has a heater 3, and is constituted by steam supply means 4 which is generated by heating steam or which sends steam of a washing liquid such as an organic solvent into the washing tank 2.

Further, in the case of the cleaning apparatus of the present invention, a pressure sensor 21 for detecting the pressure in the cleaning tank 2, an amount of electricity supplied to the heater 3 of the steam supply means 4, and a liquid sending pump 9 serving as the discharge pump are provided.
And a controller 22 for controlling at least one of the operation speeds.

The controller 22 controls the heater 3 of the steam supply unit 4.
At least one of the amount of electricity supplied to the cleaning tank and the operation speed of the liquid supply pump 9 as a discharge pump is controlled so that the discharge amount of the cleaning liquid from the cleaning tank 2 is equal to or more than the supply amount of the cleaning liquid vapor into the cleaning tank 2. By doing so, it functions so that the pressure in the cleaning tank 2 detected by the pressure sensor 21 is always maintained at a negative pressure.

(Operation) In the case of the cleaning method and the cleaning apparatus of the present invention configured as described above, the pressure in the cleaning tank 2 is maintained at a negative pressure during the cleaning operation. The lid 1 provided in the section is pressed toward the upper edge of the opening of the cleaning tank 2 by the atmospheric pressure applied to the outer surface of the lid 1.

As a result, the lower surface of the lid 1 and the cleaning tank 2 can be removed without providing a fastening mechanism for pressing the lid 1 against the upper edge of the opening of the cleaning tank 2.
Air tightness between the upper edge of the opening can be ensured,
It is also possible to prevent the vapor of the cleaning liquid such as the organic solvent existing in the cleaning tank 2 and the bacteria adhering to the object to be cleaned from leaking to the outside due to improper tightening or damage caused by packing.

That is, in the case of the cleaning device of the present invention, the controller 22 adjusts one or both of the amount of electricity supplied to the heater 3 and the operation speed of the liquid feed pump 9 based on the signal from the pressure sensor 21, and The supply amount of the cleaning liquid vapor into the cleaning tank should not exceed the discharge amount of the cleaning liquid from the cleaning tank 2.

As a result, the pressure in the cleaning tank 2 is always maintained at or below the atmospheric pressure, and leakage of the cleaning liquid vapor present in the cleaning tank 2 is reliably prevented.

In the above description, the amount of the cleaning liquid sent into the cleaning tank 2 is adjusted by adjusting the amount of electricity supplied to the heater 3 of the steam supply means 4. The control amount 22 can be configured such that the flow area of the valve 23 is adjusted based on a signal from the pressure sensor 21 as the valve 23 provided in the valve 23. In this case, the amount of electricity supplied to the heater 3 does not need to be adjusted, but if it is adjusted, wasteful consumption of power can be prevented. Similarly, a valve 24 provided in the middle of the pipe 8 leading to the liquid feed pump 9 can have an adjustable flow path area so that the discharge amount of the cleaning liquid from the cleaning tank 2 can be adjusted.

Further, even when the work 17 is cleaned with the cleaning liquid, the vacuum pump 13 is appropriately operated to maintain the inside of the cleaning tank 2 at a negative pressure, so that the cleaning liquid vapor can be reliably prevented from leaking. Preferred.

(Effect of the Invention) Since the cleaning method and the cleaning device of the present invention are configured and operated as described above, the leakage of the organic solvent vapor and bacteria existing in the cleaning tank to the outside can be performed without providing a troublesome tightening device. Can be reliably prevented, and the cost reduction of the cleaning device and the function of preventing environmental destruction can be simultaneously achieved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a main part of the cleaning apparatus of the present invention, and FIG.
The figure is a schematic vertical sectional view showing one example of this cleaning device. 1: lid, 2: cleaning tank, 3: heater, 4: steam supply means, 5: pipe, 6:
Reservoir, 7, 8: pipe, 9: liquid feed pump, 10: heater, 11: cooler, 12: still, 13: vacuum pump, 14: exhaust pipe, 15: exhaust pipe, 16: intake pipe, 17: object to be cleaned, 18: ultrasonic transducer, 19: discharge pipe, 20: supply / discharge means, 21: pressure sensor, 22: controller, 23, 2
4: Valve.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-43979 (JP, A) JP-A-2-194883 (JP, A) JP-A-58-210888 (JP, A) JP-A-60- 44082 (JP, A) JP-A 1-179784 (JP, U) JP-B 56-16400 (JP, B2) JP-B 3-31114 (JP, B2) JP-B 7-67552 (JP, B2)

Claims (4)

(57) [Claims] An object to be cleaned is placed in a washing tank which can be freely sealed, and the cleaning liquid is poured into the cleaning tank to such an extent that the object to be cleaned is immersed. A cleaning method in which the same type of cleaning liquid vapor is sent into the cleaning tank at a higher temperature than the cleaning liquid.
A cleaning method characterized by maintaining a negative pressure in a cleaning tank. 2. A cleaning tank which can be hermetically sealed with an object to be cleaned stored therein, and a discharge pump which can discharge a fluid in the cleaning tank.
A heater for heating the cleaning liquid, a vapor supply means for feeding the cleaning liquid vapor generated by heating and evaporating into the cleaning tank, a pressure sensor for detecting a pressure in the cleaning tank, and a power supply amount to the heater. A controller for controlling at least one of the operation speed of the discharge pump, and the controller controls at least one of the amount of electricity supplied to the heater of the steam supply means and the operation speed of the discharge pump to discharge the cleaning liquid. A cleaning device that maintains the pressure in the cleaning tank detected by the pressure sensor at a negative pressure by setting the amount to be equal to or more than the supply amount of the cleaning liquid vapor. 3. An adjusting valve, which is capable of adjusting the flow path area, is provided in the middle of a pipe for feeding the vapor of the cleaning liquid from the vapor supply means to the cleaning tank, and the controller controls the amount of electricity supplied to the heater. The cleaning device according to claim 2, wherein the flow amount of the adjustment valve is adjusted while controlling the amount of electricity supplied to the heater. 4. A second regulating valve, which is capable of adjusting a flow path area, is provided in the middle of a pipe leading to a discharge pump for discharging a cleaning liquid from a cleaning tank, and a controller controls an operation speed of the discharge pump. Alternatively, or while controlling the operating speed of the discharge pump, adjusting the flow area of the second regulating valve.
Or the cleaning device according to claim 3.