JP2005021819A - Work washing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To securely purify a work by a compact device. <P>SOLUTION: The work washing device is provided with a work storage vessel 1 and an air current generating means 2. A space 3 for air current passage is formed between the outer circumferential face as the face to be washed in a work W and the inner circumferential face of the storage chamber. Gas such as air is circulated at a high speed along the face to be washed in the work W by the operation of the air current generating means 2. Thus, stains stuck to the face to be washed in the work W can be removed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a workpiece cleaning apparatus.
[0002]
[Prior art]
As shown in FIG. 3, the dynamic pressure bearing W is usually composed of a cylindrical sleeve Ws and a shaft Wt in the sleeve Ws, and oil O is filled between the sleeve Ws and the shaft Wt. This oil is filled by immersing the assembly of the sleeve Ws and the shaft Wt in the oil in the process of manufacturing the hydrodynamic bearing. Oil adheres to the outer peripheral surface of the sleeve Ws after oil filling.
[0003]
The oil attached in this way changes the reflectance of the laser during the appearance inspection of the hydrodynamic bearing W by laser irradiation, and causes an inaccurate measurement. In addition, when the dynamic pressure bearing W is incorporated in a device such as a hard disk driver, there are problems such as the adhered oil adhering to unnecessary portions of the incorporating device, or preventing the sleeve Ws from being fixed to the device by bonding. Arise.
[0004]
Therefore, for the hydrodynamic bearing W after assembly, it is necessary to remove the oil adhering to the outer peripheral surface of the sleeve Ws by washing. As a workpiece cleaning device that cleans a hydrodynamic bearing after assembly as a workpiece, there is a device that removes dirt such as oil by applying ultrasonic waves while the workpiece is immersed in a cleaning liquid (Patent Literature). 1).
[0005]
[Patent Document 1]
Japanese Patent Laid-Open No. 2000-199519
[Problems to be solved by the invention]
In the above-mentioned workpiece cleaning apparatus, since the workpiece is present in the cleaning liquid for a while after cleaning, dirt once removed from the workpiece may be reattached to the workpiece during the presence. Difficult to clean. In particular, when the workpiece is a hydrodynamic bearing after assembly, the oil filled in the hydrodynamic bearing flows into the cleaning liquid and adheres to the surface of the hydrodynamic bearing, or the amount of oil filled in the hydrodynamic bearing is reduced. There may be a shortage.
[0007]
Further, in the above workpiece cleaning apparatus, since the entire workpiece is immersed in the cleaning liquid, a large amount of cleaning liquid is required, which not only increases the cost, but also requires the work wet with the cleaning liquid to be dried, which increases the size of the entire apparatus. Yes.
[0008]
The problem to be solved by the present invention is to provide a workpiece cleaning apparatus that can clean a workpiece reliably, can be cleaned at a low cost without requiring a large amount of cleaning liquid, and can be downsized as a whole. .
[0009]
[Means for Solving the Problems]
In order to achieve the above-described problems, the workpiece cleaning apparatus of the present invention accommodates a workpiece having a chamber in which an airflow passage gap is formed between the workpiece and the surface to be cleaned in a state where the workpiece is accommodated therein. The apparatus includes a container and airflow generation means for generating a cleaning airflow in the airflow passage gap by sucking or pumping gas to the airflow passage gap.
[0010]
In the workpiece cleaning apparatus having the above-described configuration, a cleaning airflow is generated by air or the like in the airflow passage gap between the workpiece and the inner surface of the accommodation chamber due to the operation of the airflow generation means, and the cleaning airflow is applied to the outer surface of the workpiece. It distributes at high speed along the cleaning surface. By this cleaning airflow, dirt such as abrasive powder and cutting waste adhering to the surface to be cleaned is removed from the surface to be cleaned and discharged to the outside of the work container.
[0011]
In this case, since a large amount of cleaning liquid is not used, the apparatus can be miniaturized. Further, since the dirt once detached from the surface to be cleaned of the work is immediately discharged by the air flow, there is no possibility of reattaching to the work.
[0012]
In the above configuration, the airflow generation means includes a suction type air machine such as a vacuum pump or a vacuum fan. In addition to this, the air flow generating means may be a device that sends a gas such as pressurized air into the air flow passage gap to generate an air flow in the air flow passage gap, such as a pressure pump or a blower fan. Good.
[0013]
The work container may be any container as long as the work is accommodated therein. However, when the work is, for example, cylindrical or rectangular, and the inner periphery has a surface to be cleaned, the container is cylindrical or rectangular. A core located on the inner peripheral side of the cylindrical workpiece is included as a part. The core forms an airflow passage gap with the inner peripheral surface of the workpiece.
[0014]
In the workpiece cleaning apparatus having the above configuration, when a cleaning liquid input means, for example, a nozzle, is provided on the gas air inflow side of the airflow passage gap between the workpiece and the container, for example, a nozzle is provided. It is possible to introduce a volatile cleaning liquid into the airflow passage gap. The injected volatile cleaning liquid acts on the dirt adhering to the surface to be cleaned of the workpiece and removes it from the surface to be cleaned, so oily dirt such as oil and sticky dirt are removed. Is effective.
[0015]
In this case, since it is sufficient that the cleaning liquid has an amount sufficient to cover the entire surface to be cleaned of the workpiece, the amount of the cleaning liquid used can be suppressed to a small amount compared to the case of immersing the workpiece. Further, since the cleaning liquid is quickly vaporized by being in contact with the gas flow, the surface to be cleaned of the workpiece is in a dry state free from dirt. Therefore, there is no need for a separate process and device for drying the workpiece. From this point, the apparatus can be downsized.
[0016]
In the workpiece cleaning apparatus having the above-described configuration, the flow rate of the gas flowing along the surface to be cleaned of the workpiece is adjusted by changing the size of the airflow passage gap between the workpiece and the container or the capability of the airflow generation means. be able to.
[0017]
The flow rate of the cleaning airflow is preferably in the range of 10 m to 100 m per second. When the flow rate of the cleaning airflow is less than 10 m / second, the effect of removing dirt is insufficient. When the flow rate exceeds 100 m / s, the cleaning effect does not increase much with respect to the increase in the capacity of the airflow generation means, which is practically uneconomical.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a configuration diagram of a workpiece cleaning apparatus according to an embodiment of the present invention, and FIG. 2 is a process diagram showing an operation of the workpiece cleaning apparatus of FIG. In this embodiment, the workpiece to be cleaned is applied to a hydrodynamic bearing, but is not limited to this.
[0019]
With reference to FIG. 1, the workpiece cleaning apparatus of the present embodiment includes a container 1 for a workpiece W and an airflow generation means 2 in order to clean the outer peripheral surface of the hydrodynamic bearing.
[0020]
The work W is a hydrodynamic bearing, and as shown in FIG. 3, the work W includes a sleeve Ws and a shaft Wt rotatably inserted into the sleeve Ws, and the shaft Wt extends from one axial end surface of the sleeve Ws. It is the shape where the one end side of Wt protruded.
[0021]
The workpiece storage container 1 has a cylindrical storage chamber 11 whose upper side is open, and the storage chamber 11 has a storage volume larger than the outer dimensions of the workpiece W. The workpiece W is accommodated in the storage chamber 11 in a predetermined posture, that is, with the shaft Wt facing downward. In a state where the workpiece W is accommodated in the workpiece storage container 1, an airflow passage gap 3 having a certain thin width is formed between the outer peripheral surface (surface to be cleaned) of the sleeve Ws of the workpiece W. . The width of the airflow passage gap 3 is about 0.5 mm to 1 mm while the outer diameter of the workpiece W is 10 mm.
[0022]
A plurality of protrusions 12 are formed on the inner peripheral surface of the storage chamber 11 of the workpiece storage container 1. These protrusions 12 all have the same protruding height, and thereby contact the outer peripheral surface of the sleeve Ws from around the workpiece W, so that the gap between the outer peripheral surface of the workpiece W and the inner peripheral surface of the storage chamber 11 is increased. The width | variety of the gap 3 for the airflow passage which can be formed is regulated to fixed width.
[0023]
A recess 13 in which the shaft Wt of the workpiece W is fitted and an annular protrusion 14 that receives the end surface of the sleeve Ws around the shaft Wt are formed on the bottom of the storage chamber 11. In the work container 1, a ventilation path 4 is opened from the bottom of the storage chamber 11 to the outside.
[0024]
In the present embodiment, the air flow generating means 2 generates air flow in the air flow passage gap 3 by suction, and includes a vacuum pump, a vacuum fan, etc., and the suction side thereof is connected via a valve 5 and a trap 6. The air passage 4 of the container 1 communicates. Therefore, the suction side of the airflow generation means 2 communicates with the airflow passage gap 3 in the work container 1 via the air passage 4 so that air is sucked from the upper side which is the open side of the container 1. It has become.
[0025]
A valve 5 and a trap 6 are provided between the work container 1 and the air flow generation means 2, and the valve 5 is opened and closed by a signal from the outside. The trap 6 is a solid or liquid contamination from the suction gas. In this embodiment, the dirt removed from the workpiece W is separated by the airflow.
[0026]
Above the workpiece container 1, a cleaning liquid charging means 7 is provided. This cleaning liquid charging means 7 is for charging a volatile cleaning liquid C such as alcohol into the gas inflow side of the airflow passage gap 3 between the work container 1 and the work W. A cleaning liquid C tank 72 and a nozzle 73 are provided. In the cleaning liquid charging means 7, the volatile cleaning liquid C is sucked up from the tank 72 by the operation of the discharge pump 71 and sprayed or dropped from the nozzle 73.
[0027]
Examples of the volatile cleaning liquid C include acetone, hexane, and heptane. In the illustrated example, the entire cleaning liquid charging means 7 is above the container 1, but at least the nozzle 73 of the cleaning liquid charging means 7 may be positioned above the storage chamber 11 of the container 1.
[0028]
In addition, as the cleaning liquid charging means, a volatile cleaning liquid stored at a position higher than the work container 1 may be charged into the airflow passage gap 3 by its own liquid pressure.
[0029]
The operation of the workpiece cleaning apparatus having the above configuration will be described with reference to the process diagram of FIG. 2. In step S 1, the workpiece W is accommodated in the accommodation chamber 11 of the container 1 in a predetermined posture with the shaft Wt of the workpiece W facing downward. To do. This operation may be performed manually or mechanically. In a state where the workpiece W is stored in the storage chamber 11 of the workpiece storage container 1, an airflow passage gap 3 having a certain thin width is formed around the outer peripheral surface of the sleeve Ws that is the surface to be cleaned of the workpiece W.
[0030]
When the workpiece W is set in a predetermined posture, the airflow generation means 2 (vacuum pump in the illustrated example) is activated in step S2, and almost simultaneously with this, in step S3, the suction side valve 5 of the airflow generation means 2 is activated. Is released. Thus, a negative pressure is applied to the airflow passage gap 3 in the work container, and external air is sucked in from the upper side of the airflow passage gap 3 in the direction of the arrow a.
[0031]
In this case, a negative pressure acts on almost the entire surface of the workpiece W. However, since the periphery of the shaft Wt of the workpiece W is covered with the annular protrusion 14, the gap is formed between the shaft Wt and the sleeve Ws. No negative pressure is applied, and the oil O filled in the gap is not sucked out.
[0032]
By sucking air by the air flow generating means 2, an air flow is generated in the direction of arrow B in the air flow passage gap 3, and the air circulates at high speed along the outer peripheral surface which is the surface to be cleaned of the workpiece W. To do. By this air flow, dirt such as abrasive powder and cutting waste adhering to the outer peripheral surface of the workpiece W is removed from the surface to be cleaned and discharged to the outside of the container 1.
[0033]
As described above, while the air is flowing at high speed in the airflow passage gap 3, in step S <b> 4, the cleaning liquid charging unit 7 is activated, and the volatile volatile component is discharged from the nozzle 73 to the upper side of the airflow passage gap 3. A predetermined amount of the cleaning liquid C is supplied by spraying or the like. In FIG. 2, the dotted lines from step S3 to step S5 indicate that the time between both steps S3 and S5, the vacuum pump of the airflow generating means 2 continues to operate, and the valve 5 continues to be open. ing.
[0034]
The volatile cleaning liquid C supplied from above the work container 1 flows into the airflow passage gap 3 together with the air sucked into the airflow passage gap 3 and flows along the outer peripheral surface of the work W. Thus, it acts on dirt such as oil adhering to the outer peripheral surface of the workpiece W, and this dirt is removed from the outer peripheral surface of the workpiece W by separation or decomposition. The cleaning liquid C after removing the dirt becomes droplets or gas and is discharged to the outside of the container 1.
[0035]
Note that after the volatile cleaning liquid C is introduced, the air flow in the airflow passage gap 3 is continued for a while (specifically, about 2 seconds). Meanwhile, since the volatile cleaning liquid C attached to the outer peripheral surface of the workpiece W is exposed to a high-speed air flow, it is vaporized early and does not remain long on the outer peripheral surface of the workpiece W. It becomes dry without dirt. In particular, when the suction-type airflow generation means 2 is used as in the illustrated embodiment, the inside of the airflow passage gap 3 is in a depressurized state while the airflow generation means 2 is in operation. Vaporization and evaporation are fast, and the workpiece W becomes dry quickly. Therefore, there is no need to dry the workpiece W later.
[0036]
After the cleaning with the volatile cleaning liquid C is completed, in step S5, the air flow generating means 2 is stopped, the valve 5 is closed, and the series of cleaning operations is completed.
[0037]
In the above embodiment, the volatile cleaning liquid C is used so that the work W to which the cleaning liquid adheres is quickly dried. However, if the drying time of the work W is not particularly problematic, a non-volatile cleaning liquid is used. Also good. In the present invention, since the airflow flowing through the airflow passage gap 3 promotes vaporization and evaporation of the cleaning liquid, the work W is dried within a relatively short time even when a non-volatile cleaning liquid is used.
[0038]
Moreover, in the said embodiment, although the container 1 with which the upper part was open | released was used, the container 1 may have a cover body. In that case, the lid of the container 1 needs to be provided with a gas inlet.
[0039]
The workpiece W in the above embodiment has a columnar shape and the outer peripheral surface thereof is a surface to be cleaned, but the workpiece W is not limited to this. When the workpiece is, for example, cylindrical and has a surface to be cleaned on the inner periphery, a part of the container 1 is positioned on the inner periphery of the cylindrical workpiece, and between the inner periphery of the workpiece. What is necessary is just to form the clearance gap 3 for airflow passage of a fixed thin width. When the work has a columnar shape or a shape different from the cylindrical shape, the container 1 may be formed with an internal storage chamber corresponding to the outer shape of the work.
[0040]
Furthermore, in the said embodiment, although the vacuum pump was used as the airflow generation means 2, as an airflow generation means 2, using a feed-in type air machine like a pressurization pump or a ventilation fan, A gas may be sent into the airflow passage gap 3 to generate an airflow in the airflow passage gap 3, or a suction type air machine and a feed type air machine may be used in combination.
[0041]
【The invention's effect】
According to the present invention, the surface to be cleaned of the workpiece is cleaned by the cleaning airflow in the airflow passage gap, so that the possibility of dirt and the like reattaching to the workpiece is reduced, and the cleaning air is included in the cleaning airflow. Sometimes, it does not require a large amount of cleaning liquid as in the past, and it is not necessary to set a separate drying process and drying device for the work wet with the cleaning liquid. Become.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a workpiece cleaning apparatus according to an embodiment of the present invention. FIG. 2 is a process diagram showing the operation of the workpiece cleaning apparatus of FIG. 1. FIG. 3 is a sectional view of a hydrodynamic bearing which is an example of a workpiece. Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Work container 11 Storage chamber 2 Airflow generation means 3 Airflow passage gap W Workpiece

Claims (2)

A workpiece storage container having a storage chamber in which a gap for airflow passage is formed between the workpiece and the surface to be cleaned in the state in which the workpiece is stored therein, and gas is sucked or pumped to the gap for airflow passage An airflow generating means for generating an airflow for cleaning in the airflow passage gap. In the workpiece washing apparatus according to claim 1,
A workpiece cleaning apparatus provided with a cleaning liquid input means for supplying a cleaning liquid into the airflow passage gap from the gas inflow side of the storage chamber.

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