JPH04332377A - Drying device for work - Google Patents

Abstract

PURPOSE:To improve the drying efficiency and drying accuracy by a method wherein a work is prevented from contamination due to dust existing in a vacuum tank when the work is dried through vacuum drying after drying it with hot pure water. CONSTITUTION:A vacuum tank 30 in a vacuum drying unit 3 is constituted of a tank main body 31, having a double structure in which an inner tank 33 for receiving a work 1 is provided in a pressure vessel or an outer tank 32, a lid body 34, opening and/or closing said tank main body 31 and provided with a pressure resistant structure, while a venting hole 52, communicating the inner tank with the outer tank, is provided on the bottom wall of the inner tank 33 and the outer tank 32 is connected to a vacuum pump 40. The lid body 34 is provided with a leak hole 62, opened in the inner tank 33 and opened or closed freely by a leak valve 63. A pressure in the inner tank is kept in a condition that it is higher than a pressure in the outer tank at all times and, therefore, dust existing in the outer tank will never invade into the inner tank and, on the contrary, the dust in the inner tank can be discharged smoothly into the outer tank through the venting hole 52.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drying apparatus for drying a workpiece that is wet due to cleaning or the like.

0002

2. Description of the Related Art Conventionally, as disclosed in Japanese Patent Application Laid-Open No. 64-53549, a workpiece wet from cleaning or the like is immersed in warm pure water at a predetermined temperature, warmed, and then slowly pulled up. A hot pure water drying method that uses its own heat to dry is known. Such a hot pure water drying method does not use an organic solvent, so there is no problem of environmental pollution, and the equipment and management are simple, so it is attracting attention as the most suitable method for drying various types of workpieces.

However, in the above warm pure water drying method,
If water collects in a part of the workpiece when it is lifted from hot pure water, not only will the drying of that part be delayed and it will take time to finish, but also stains may remain due to the partial drying delay. Therefore, there is a problem when drying a workpiece having a shape in which water tends to accumulate, for example, a workpiece having a wide upward facing surface, a blind hole, a recessed part, etc. In particular, when a workpiece is pulled out of warm pure water, it gradually cools down as the heat of vaporization is removed through drying, and as the workpiece cools down, it becomes difficult to dry.
If you don't evaporate it as quickly as possible, there's a high chance that a stain will remain in that area.

[0004] A hot air drying method is also known in which the workpiece is dried by blowing hot air onto it, but such hot air drying method is not effective enough in practice because the inside of the blind hole tends to become a blind spot. can't get it.

[0005] In order to solve such problems, the present inventors proposed a drying device that combines hot pure water drying and vacuum drying in Japanese Patent Application No. 15915/1999, and the present inventors have proposed a drying device that combines warm pure water drying and vacuum drying, and eliminates the residual adhesion on the workpiece after hot pure water drying. We succeeded in rapidly removing the residual moisture by vacuum drying, preventing the formation of stains due to residual moisture, and significantly improving drying accuracy.

However, in the above-mentioned improved drying apparatus, when vacuum drying a workpiece, there are cases in which the vacuum chamber is depressurized by a vacuum pump, and a leak valve is opened after vacuum drying is completed to return the vacuum chamber to atmospheric pressure. In some cases, dust present in the vacuum chamber may fly up and circulate within the chamber without being discharged outside the chamber, adhering to the workpiece and contaminating it.

For this reason, for example, when returning a vacuum chamber to atmospheric pressure, a method called the slow leak method is used, in which the pressure is slowly raised to atmospheric pressure over time, but it takes 20 to 30 minutes to reach atmospheric pressure. It is inefficient because it requires

[0008]

[Problems to be Solved by the Invention] An object of the present invention is to prevent the workpiece from being contaminated by dust existing in the vacuum chamber when vacuum drying the workpiece, and to improve drying efficiency and drying accuracy. It is in.

[0009]

[Means for Solving the Problems] In order to solve the above problems, the drying method of the present invention includes a warm pure water drying section that dries a wet workpiece by immersing it in warm pure water, warming it, and then pulling it up, and a warm pure water drying section that dries the workpiece that has been dried with warm pure water. It is composed of a vacuum drying section that evaporates moisture remaining on the workpiece by placing it under reduced pressure in a vacuum chamber, and a conveying means that transports the workpiece from the warm pure water drying section to the vacuum drying section. The vacuum chamber in the section is composed of a double-structured chamber body with an inner chamber for accommodating a workpiece inside an outer chamber serving as a pressure vessel, and a pressure-resistant lid for opening and closing the chamber body. , the bottom wall of the inner tank is provided with a ventilation hole that communicates both the inner and outer tanks, the outer tank is connected to a vacuum pump, and the lid body is
It is characterized in that a leak hole is provided that opens into the inner tank and can be opened and closed by a valve.

[0010] The inner tank can be elastically supported inside the outer tank by elastic means such as a spring.

[0011] Further, an infrared transmitting portion for transmitting infrared rays is formed in at least a part of the side wall of the inner tank, and an infrared rays transmitting portion for irradiating infrared rays to the workpieces in the inner tank is formed between the inner tank and the outer tank. A heater may be provided.

[0012] The lid body is provided with an inner tank sealing part that seals the inner tank first when the tank body is closed, and an outer tank sealing part that seals the outer tank later. It is desirable to configure the tank body so that it is closed at the same time.

[0013] Furthermore, an absolute filter can be provided inside the lid body for filtering leak air flowing into the inner tank from the leak hole.

[0014]

[Operation] The workpiece that has been dried with warm pure water is sent to the vacuum drying section, housed in a vacuum chamber, and vacuum dried. here,
When the outer tank is suctioned by a vacuum pump to reduce the pressure in the vacuum tank, the air in the outer tank is directly sucked in, but the air in the inner tank is sucked through the vent in the bottom wall, which is then throttled. In order to fulfill this role, the pressure in the inner tank is always kept slightly higher than the pressure in the outer tank. Therefore, even if dust is thrown up into the outer tank during suction, it will not enter the inner tank. Further, dust in the inner tank is quickly sucked and discharged.

[0015] When the vacuum drying is completed, the valve is opened and the vacuum tank is returned to atmospheric pressure, but in this case, leak air first flows into the inner tank and increases the pressure in the inner tank, and then,
Since it flows into the outer tank through the vent hole in the bottom wall and increases the pressure in the outer tank, the pressure in the inner tank is always maintained higher than that in the outer tank. Therefore, even if dust flies up in the outer tank due to a leak, it will not enter the inner tank, and the dust in the inner tank will be smoothly discharged into the outer tank through the ventilation hole.

[0016]

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The drying apparatus shown in FIG. 1 includes a warm pure water drying section 2 that dries a wet workpiece 1 sent from a cleaning mechanism or the like by immersing it in warm pure water, warming it, and then pulling it up, and a vacuum chamber for drying the workpiece 1 that has been dried with warm pure water. a vacuum drying section 3 that evaporates moisture remaining on the workpiece by placing it under reduced pressure in the vacuum drying section 3; and the warm pure water drying section 2.
The hot pure water drying section 2, the vacuum drying section 3, and the conveying means 4 are arranged in a clean room where the indoor air is purified. ing.

The warm pure water drying section 2 is equipped with a warm pure water tank 11 for storing warm pure water 10 from which impurities have been removed and heated to a predetermined temperature. A pure water source 13 is connected via a heater 12 using steam or the like as a heat source, and pure water is heated to a predetermined temperature by the heater 12 and continuously supplied in a predetermined amount from the pure water source 13. There is. Note that the heater 12 may be provided at the inner bottom of the warm pure water tank 11 to heat the pure water within the tank.

A bubble remover 14 is installed inside the warm pure water tank 11, and the bubble remover 14 is used to remove bubbles generated when the warm pure water is supplied or when the pure water is heated by the heater 12 provided in the tank. It is desirable to collect the air bubbles and discharge them to the outside through the discharge pipe 14a. This can prevent the air bubbles from causing the surface of the warm pure water 10 to ripple and adversely affecting the drying of the warm pure water.

A collection groove 1 is provided around the warm pure water tank 11 to collect warm pure water overflowing from the warm pure water tank 11.
7 is formed, and the warm pure water collected in the collection groove 17 is discharged to the outside through a collection pipe 18. In this case, a heat-resistant filter 19 is provided in the recovery pipe 18, and after the impurities in the warm pure water are removed by the filter 19, the warm pure water is supplied to the heater 12 or the pure water source 13 and reused cyclically. It may be configured as follows.

A drying chamber 21 surrounded by a partition wall 20 is formed above the hot pure water tank 11. The drying chamber 21 is for accelerating the drying of the work 1 pulled up from the warm pure water 10, and has an exhaust pipe 2 connected to an exhaust port 22.
3 is connected to an exhaust fan 25 via a mist catch 24, and the exhaust fan 25 sucks in and discharges water vapor that evaporates from the water surface and the surface of the workpiece 1, so that the water vapor comes into contact with the workpiece 1 and destroys the workpiece. It is designed to prevent it from getting wet. At this time, in order to more effectively prevent contact by suctioning water vapor in an almost horizontal direction,
1 is provided with a plurality of flaps 26 whose angle can be freely adjusted to generate horizontal airflow. In addition, the pure water collected by the mist catch 24 is sent to the drain pipe 27.
It is discharged through the collection pipe 18 through the collection pipe 18.

On the other hand, the vacuum chamber 3 in the vacuum drying section 3
As is clear from FIG. 2, the tank body 31 is made up of a tank main body 31 with a rectangular double structure and a lid 34 for opening and closing the tank main body 31, and the tank main body 31 has an outer tank 32 configured as a pressure vessel. It has a structure in which an inner tank 33 for accommodating a workpiece is disposed, and a suction port 32a is formed at the lower end of the outer tank 32. 37
, a filter 38, and a sorption trap 39 to a vacuum pump 40, and the inside of the vacuum chamber 30 is reduced to a predetermined degree of vacuum by the vacuum pump 40.

In the figure, 41 is an exhaust fan, and 42 is a suction pipe line 36 between the vacuum pump 40 and the sorption trap 39.
a check solenoid valve connected to the check solenoid valve 42;
The vacuum pump 40 is opened by opening the suction line 36.
This prevents the atmosphere from flowing back to the vacuum chamber 30 side.

An infrared heater 45 is provided inside the outer tank 32 in a space between it and the inner tank 33 for irradiating infrared rays onto the work 1 in the inner tank 33. On the surface is a vacuum chamber 3 heated by the infrared heater 45.
A cooling pipe 46 for cooling the outer tank 32 is wound around the cooling pipe 46, and a cooling medium such as water is passed through the cooling pipe 46. A gasket 48 for sealing 34 is provided.

On the other hand, the inner tank 33 is made of a material with excellent heat resistance and corrosion resistance, such as stainless steel, aluminum alloy, and glass. A large number of ventilation holes 52 are drilled to communicate with each other, and panels 53 made of a heat-resistant material such as quartz glass that transmit infrared rays from the infrared heater 45 are attached to the four side walls and the bottom wall. Infrared transmitting portions 54 are respectively formed. In addition, in the illustrated embodiment,
A panel 53 made of a heat-resistant material such as quartz glass is also stretched over the bottom wall of the inner tank 33 to form an infrared transmitting section 54, and the vent hole 52 is provided in the panel 53. There is no need to form the infrared transmitting section 54 or to provide the infrared heater 45.

The inner tank 33 also has a bottom wall 3 of the outer tank 32.
2b through an elastic means 55 such as a spring, and when the lid 34 is opened, the upper end of the inner tank 33 is slightly raised above the upper end of the outer tank 32 by the biasing force of the elastic means 55. It's starting to stand out. Furthermore, the surface of the inner tank 33 is mirror polished to prevent dust from adhering to the surface.

Four stands 58 are disposed inside the inner tank 33 as support means for supporting the cassette 57 containing the workpieces 1. These stands 58 are fixed on the bottom wall 32b of the outer tank 32, penetrate the bottom wall of the inner tank 33, and protrude into the inner tank 33.

The lid body 34 can be raised and lowered by a driving means such as a fluid pressure cylinder, and can be moved up and down by a transport arm 80.
A seal for the inner tank is disposed so as to be horizontally movable in an open position that does not interfere with the loading and unloading of the inner tank, and is provided on its outer periphery to abut against the upper end of the inner tank 33 to shut off the inside and outside of the inner tank 33. Part 6
0, and an outer tank sealing part 61 that contacts the gasket 48 at the upper end of the outer tank 32 to seal the outer tank 32. When the lid body 34 descends from the raised open position to close the tank body 31, the inner tank sealing part 60 first comes into contact with the upper end of the inner tank 33 that protrudes above the outer tank 32. After the inner tank 33 is elastically sealed by the elastic means 55, the outer tank sealing part 61 seals the upper end of the outer tank 32 with a slight delay.

A sealing member 60a such as a gasket is attached to the inner tank sealing portion 60, but the sealing member 60a may be omitted. However, in this case,
It is necessary to finish the upper end of the inner tank 33 and the inner tank sealing part 60 of the lid body 34 to a mirror surface with good planar precision so that they can come into close contact. Further, the gasket 48 at the upper end of the outer tank 32 can be attached to the outer tank sealing part 61 side of the lid 34, or it can be omitted. However, in this case as well, the upper end of the outer tank 32 and the outer tank sealing part 60 of the lid body 34
As in the case described above, it is necessary to finish the surface to a mirror surface with good planar accuracy.

A leak hole 62 for supplying leak air to the inside of the vacuum chamber 30 is formed at the top of the lid 34 so as to open into the inner tank 33 when the lid 34 is closed. The leak hole 62 is connected to the atmosphere via a leak valve 63 and an automatic flow rate adjustment valve 64 that can adjust the air flow rate, and the interior of the lid body 34 is designed to prevent foreign matter such as dust contained in the supplied leak air. Filter 68 for removing
is provided. The filter 68 is an absolute filter such as a Hepa filter that covers the upper part of the inner tank 33 and supplies leak air from the leak valve 63 into the inner tank 33 as a vertical laminar flow. Therefore, the leaked air improves the atmosphere inside the inner tank 33 without causing turbulence. In addition, 69 in the figure is a baffle plate.

[0030] The above leak valve 63 and automatic flow rate adjustment valve 6
4, an inert gas source 66 for supplying an inert gas such as nitrogen gas is connected via an on-off valve 67, and vacuum drying can be performed while continuously supplying the inert gas. It looks like this.

Furthermore, the above-mentioned transport means 4 for transporting the workpiece 1
has a transport arm 80 that suspends the cassette 57 containing the workpiece 1, and the transport arm 80 is disposed so as to be movable along a guide 81, and its movement is controlled by a ball screw, timing belt, or cylinder. This is done by a driving means such as. The transport arm 80 is composed of a hook 82 for suspending the cassette 57, a driving means consisting of a ball screw 83 and a motor 84 for raising and lowering the hook 82, and a pair of guides 85 for guiding the raising and lowering of the hook 82. There is. The driving means for the hook 82 may also be configured by a timing belt, a cylinder, or the like.

[0032] The drying apparatus having the above structure is disposed, for example, after the cleaning mechanism, and is used to dry the workpiece 1 that is sent in a wet state due to cleaning, and operates as follows. That is, the work 1 placed in the cassette 57 is suspended by the transfer arm 80 and transferred to the warm pure water tank 1 in the warm pure water drying section 2.
When the workpiece 1 is brought to the top of the workpiece 1, the hook 82 is lowered and the workpiece 1 is immersed together with the cassette 57 in the warm pure water 10.

At this time, in the warm pure water drying section 2,
Warm pure water 10 heated to a predetermined temperature is continuously supplied in a predetermined amount into the warm pure water tank 11 , and the overflowing warm pure water flows into the recovery groove 17 and is discharged through the recovery pipe 18 . The air is exhausted by exhaust fan 25
The water vapor that is sucked in by the water and evaporated from the water surface is discharged along with this air flow in a nearly horizontal direction.

When the workpiece 1 is immersed in warm pure water 10 for a certain period of time and warmed, the hook 82 slowly rises.
The workpiece 1 is pulled out of the warm pure water at a slow speed that does not cause ripples on the liquid surface. As a result, the workpiece 1 is sequentially dried by its own heat starting from the portion drawn out from the warm pure water, and hot pure water drying is performed. In addition, in the drying chamber 21, water vapor evaporated from the water surface is discharged in a substantially horizontal direction by an exhaust fan 25 so as not to come into contact with the workpiece 1, so that the surface of the dried workpiece is re-wetted by the water vapor. Therefore, there is no uneven drying or staining caused by rewetting.

The appropriate temperature of the hot pure water 10 varies depending on the type of workpiece 1 and the heat resistance of the filter 19 and other incidental equipment, but it is desirable to keep the temperature as high as possible within a range that does not cause thermal denaturation. For example, when the workpiece is glass or metal, a temperature of about 80° C. is suitable. Of course, the temperature may be lower than this. In addition, the immersion time of the work 1 in the warm pure water 10 and the pulling speed when lifting it from the warm pure water 10 vary depending on the temperature of the warm pure water 10 and the type of the work 1, but for example, the temperature of the warm pure water is 80°C. In this case, if the workpiece is a flat plate glass used for instrument covers, etc., the immersion time is about 30 to 60 seconds, and the pulling speed is 8 to 12 mm/s.
If the workpiece is a die-cast aluminum product, the immersion time may be about 30 to 60 seconds, and the pulling speed may be about 5 to 8 mm/sec. Incidentally, after the workpiece is completely pulled up from the warm pure water, the workpiece may be raised at a faster speed than the above-mentioned lifting speed in order to speed up the subsequent work.

When the hot pure water drying is completed, the workpiece 1 is sent to the vacuum drying section 3 by the transfer arm 80 before the heat cools down. The transfer arm 80 transfers the vacuum chamber 3 with the lid 34 released.
0, the hook 82 is lowered and the work 1 is placed on the stand 58 in the inner tank 33 while being placed in the cassette 57. Then, the hook 82 that has released the cassette 57 rises, and the lid body 34 descends to release the tank body 3.
1 is closed (see Figure 2). At this time, the inner tank sealing part 60 of the lid body 34 first contacts the upper end of the inner tank 33 that protrudes above the outer tank 32 to seal the inner tank 33, and then the lid body 34 is further lowered together with the inner tank 33 while compressing the elastic means 55, so that the outer tank sealing part 61 seals the upper end of the outer tank 32. By sealing the inner tank 33 and the outer tank 32 over time in this way, it is possible to prevent dust from entering the inner tank 33 when the lid body 34 pressurizes the gasket 48 at the upper end of the outer tank 32. can be reliably prevented.

When the lid 34 is completely closed, the infrared heater 45 is turned on, the exhaust electromagnetic valve 37 is opened, and the vacuum chamber 30 is depressurized by the vacuum pump 40. This depressurization is performed by suctioning the inside of the outer tank 32 with the vacuum pump 40, so the air inside the outer tank 32 is directly suctioned and discharged, but the air inside the inner tank 33 is removed through the vent holes in the bottom wall.
At this time, the air hole 52 serves as a throttle, so that the pressure inside the inner tank 33 is always kept slightly higher than the pressure in the outer tank 32. Therefore, even if dust is raised in the outer tank 32 due to air turbulence caused by suction, it will not enter the inner tank 33, and on the other hand, the dust in the inner tank 33 will quickly flow through the ventilation hole 52. It is sucked in and expelled.

In this manner, the pressure inside the vacuum chamber 30 is reduced to a predetermined degree of vacuum (for example, about 4.5 torr), and the workpiece is vacuum-dried.

When the degree of vacuum inside the vacuum chamber 30 is to be gradually increased, the leak valve 63 is opened and the automatic flow rate adjustment valve 6 is closed.
4 should be gradually closed. Further, when performing vacuum drying while flowing inert gas, the leak valve 63 is closed and the automatic flow rate adjustment valve 64 is opened by the required amount to allow the required amount of inert gas from the inert gas source 66 to flow.

Note that the infrared heater 45 is connected to the lid 34.
The temperature may be controlled to reach the set temperature from the beginning without turning it on by closing the switch.

[0041] Furthermore, when reducing the pressure in the vacuum chamber 30,
It is also possible to reduce the pressure while supplying leak air into the tank through the leak valve 63 at the initial stage of the pressure reduction. in this case,
The automatic flow rate adjustment valve 64 is in a state where the opening degree is narrowed, and leak air purified from the leak valve 63 through the filter 68 is sucked into the inner tank 33, and the leak air is sucked into the inner tank 33 through the vent hole 52 in the bottom wall.
flows out of the tank. Therefore, the dust existing in the inner tank 33 is discharged by the leak air and the inside of the inner tank 33 is purified, and the pressure inside the inner tank 33 is reduced between the inner tank 33 and the outer tank 33.
Since the pressure between the inner tank 3 and
Dust generated between the outer tank 3 and the inner tank 33 is prevented from entering the inner tank 33.

After the above-mentioned leak has been performed for a certain period of time, the automatic flow rate adjustment valve 64 and the leak valve 63 are closed, and the vacuum chamber 30 is depressurized to a predetermined degree of vacuum.

By the vacuum drying, moisture that has adhered to the upward facing surface, blind holes, recesses, etc. of the workpiece 1 and could not be completely removed by the warm pure water drying is immediately evaporated and removed, and the workpiece 1 is quickly dried. Therefore, stains do not occur due to water droplets remaining for a long time after drying with hot pure water.

At this time, the degree of vacuum in the inner tank decreases slightly due to the evaporated moisture, so the pressure in the inner tank 33 decreases
The pressure between the inner tank 33 and the outer tank 32 is maintained at a state slightly higher than the pressure between the inner tank 33 and the outer tank 32. Therefore, dust generated from the infrared heater 45 and the like does not enter the inner tank 33 and adhere to the workpiece 1. .

The time required for the vacuum drying described above depends on the type of workpiece, but usually about 30 to 300 seconds is sufficient.

When the vacuum drying is completed, the leak valve 63 and the automatic flow rate adjustment valve 64 are opened, and the exhaust solenoid valve 37 is opened.
is closed at a predetermined timing, the inside of the vacuum chamber 30 becomes atmospheric pressure, and then the lid body 34 is opened and the workpiece 1 is taken out together with the cassette 57 by the transfer arm 80 and sent to the next process. It will be done.

When inert gas is used for drying, while the leak valve 63 is closed and the inert gas is sent through the automatic flow rate adjustment valve 64, the exhaust solenoid valve 37 and automatic flow rate adjustment are performed at a predetermined timing. By closing the valve 64, the inside of the vacuum chamber 30 becomes atmospheric pressure. That is, when the exhaust solenoid valve 37 is closed while inert gas is being sent, the vacuum chamber 3
Since the internal pressure at 0 continues to rise, the automatic flow rate adjustment valve 64 is closed when the inside of the tank reaches atmospheric pressure.

Here, when the leak valve 63 is opened to return the vacuum chamber 30 to atmospheric pressure, the leaked air first flows into the inner chamber 33.
It flows into the inner tank 33 to increase the pressure, and then flows out into the outer tank 32 through the vent hole 52 in the bottom wall to increase the pressure in the outer tank 3.
In order to increase the pressure in the inner tank 33, the pressure in the inner tank 33 is always maintained higher than that in the outer tank 32. Therefore, even if dust flies up inside the outer tank 32 due to a leak, it will not enter the inner tank 33, and on the other hand, the dust inside the inner tank 33 will flow into the outer tank 32 through the ventilation hole 52. Ejected smoothly.

In the above embodiment, a deaerator is provided between the heater 12 and the pure water source 13 in the hot pure water drying section 2, and the deaerator uses the gas dissolved in the pure water before heating. It is also possible to configure the water to be degassed in advance to below the saturated gas amount at the temperature, thereby reliably preventing the generation of bubbles in the warm pure water when heated by the heater 12.

Further, the means for supporting the workpieces accommodated in the inner tank 33 in the vacuum layer 30 is constituted by a hook provided vertically on the lower surface of the lid body 34 instead of the stand 58, and the cassette containing the workpieces is attached to the hook. The lid body 34 is suspended from
It can also be configured to be raised and lowered together. Note that, of course, the workpiece may be directly transported without using the above-mentioned cassette.

[0051]

[Effects of the Invention] According to the present invention, the vacuum tank has a double structure, the outer tank is connected to a vacuum pump, and the bottom wall of the inner tank is provided with a vent hole that communicates both the inner and outer tanks, and A leak hole is provided in the lid that opens into the inner tank, so when the vacuum tank is depressurized by a vacuum pump, or when the vacuum tank is returned to atmospheric pressure after drying, there is always a leak hole that opens into the inner tank. The pressure in the outer tank can be maintained at a level slightly higher than that in the outer tank, which not only reliably prevents dust in the outer tank from entering the inner tank, but also prevents dust in the inner tank from entering. can be quickly discharged out of the tank.

[Brief explanation of drawings]

FIG. 1 is a sectional view schematically showing an embodiment of a drying apparatus of the present invention.

FIG. 2 is a sectional view of the vacuum drying section in the drying device in a dry state.

[Explanation of symbols]

1 Work 2　Warm pure water drying section 3 Vacuum drying section 4 Transport means 10　Warm pure water 30 Vacuum chamber 32 Outer tank 33 Inner tank 34 Lid body 40 Vacuum pump 52 Ventilation hole 68 Filter

Claims (5)

[Claims] [Claim 1] A warm pure water drying section that dries a wet workpiece by immersing it in warm pure water, warming it, and then pulling it up; and a warm pure water drying section that dries the wet workpiece by immersing it in hot pure water, warming it, and then pulling it up; It is composed of a vacuum drying section that evaporates moisture, and a conveyance means that transports the workpiece from the warm pure water drying section to the vacuum drying section, and the vacuum chamber in the vacuum drying section accommodates the workpiece in an outer tank serving as a pressure vessel. It consists of a double-walled tank body with an inner tank for water storage, and a pressure-resistant lid that opens and closes the tank body.The bottom wall of the inner tank is equipped with a ventilation hole that allows communication between the inside and outside tanks. A workpiece drying device characterized in that the outer tank is connected to a vacuum pump, and the lid body is provided with a leak hole that opens into the inner tank and can be opened and closed by a valve. 2. The workpiece drying apparatus according to claim 1, wherein the inner tank is elastically supported inside the outer tank by elastic means. 3. An infrared heater, wherein the inner tank is provided with an infrared transmitting part that transmits infrared rays on at least a part of the side wall, and an infrared heater that irradiates infrared rays to a workpiece in the inner tank through the infrared transmitting part between the inner tank and the outer tank. 3. The workpiece drying apparatus according to claim 1, further comprising: a. [Claim 4] The lid body has an inner tank sealing part that first seals the inner tank when the tank body is closed, and an outer tank sealing part that seals the outer tank later. Claims 1 to 3
A device for drying the workpiece described in any of the above. 5. The workpiece according to claim 1, wherein an absolute filter is provided inside the lid for filtering leak air flowing into the inner tank from the leak hole. drying equipment.