JP7397434B2 - Workpiece cleaning device and workpiece cleaning method - Google Patents

Description

The present invention relates to a workpiece cleaning device and a workpiece cleaning method.

2. Description of the Related Art Conventionally, cleaning apparatuses for cleaning workpieces such as metal products have been known (for example, see Patent Document 1). The cleaning device described in Patent Document 1 includes a cleaning tank that stores cleaning liquid, a rocking table provided in the cleaning tank, and an elevating mechanism that is connected to the rocking table and raises and lowers the rocking table. Then, the cleaning basket containing the metal products is placed on a rocking table in the cleaning tank, and the lifting mechanism raises and lowers the rocking table to shake the cleaning basket and metal products immersed in the cleaning liquid. let

JP2015-202421A

By the way, the inventor of the present application used the cleaning device described in Patent Document 1 to place a cleaning basket containing a plurality of thin plate-shaped workpieces on a rocking table with each workpiece in an upright state, and to operate the lifting mechanism. We considered raising and lowering the rocking table by However, in this case, the following inconvenience may occur. In other words, if the workpieces are in close contact with each other or the workpieces are in close contact with the side of the cleaning basket, the workpieces may not be separated from each other or the workpieces may not be separated from the cleaning basket even if the rocking table is raised and lowered by the lifting mechanism. Failure to do so may result in insufficient cleaning.

An object of the present invention is to provide a workpiece cleaning device and a workpiece cleaning method that can improve workpiece cleaning performance.

A workpiece cleaning device for achieving the above object is a device that cleans a plurality of thin plate-shaped workpieces stored in a rack in a cleaning tank in which cleaning liquid is stored. , a mounting section on which the rack can be placed; a lifting mechanism connected to one end of the mounting section for raising and lowering the one end; and a lifting mechanism provided below the mounting section in the cleaning tank; a guide member having a guide surface that guides movement of the other end of the mounting section opposite to the one end as the one end of the mounting section is raised and lowered by a lifting mechanism; , when placed on the mounting section, the plurality of works are arranged side by side along the direction from the one end to the other end of the mounting section, and the plurality of works are spaced apart from each other in the thickness direction. It has a plurality of storage parts that can be stored in an upright state.

According to the same configuration, the rack has a plurality of storage units capable of storing a plurality of workpieces in an upright position and spaced apart from each other in the thickness direction when the racks are placed on the mounting portion in the cleaning tank. It has a department. Therefore, it is possible to suppress adhesion between the works. Furthermore, when one end of the placement unit is raised or lowered by the lifting mechanism, the other end of the placement unit is moved upwardly onto the guide surface of the guide member along the direction from the same end to the other end. reciprocate. In this way, by reciprocating the other end of the placement part, it is possible to positively apply a force to the rack in the direction in which the storage parts are arranged side by side. This makes it easier for the workpiece to be temporarily separated from the side surface of the storage section, allowing the entire workpiece to be treated with the cleaning liquid. Therefore, the cleaning performance of the workpiece can be improved.

In addition, a workpiece cleaning method for achieving the above purpose involves sequentially immersing a rack containing a plurality of thin plate-like workpieces into a plurality of cleaning tanks in which cleaning liquid is stored, thereby cleaning the workpieces in stages. The method includes a cleaning step of supplying fresh cleaning liquid to a first cleaning tank in which the rack is last immersed among the plurality of cleaning tanks; The cleaning liquid overflowing from the cleaning tank is stored in a first storage tank provided corresponding to the first cleaning tank, and after the cleaning liquid stored in the first storage tank is filtered, the cleaning liquid is removed from the first cleaning tank. and storing the cleaning liquid overflowing from the first storage tank in a second storage tank provided corresponding to a second cleaning tank in which the rack is immersed immediately before the first cleaning tank; The cleaning liquid stored in the second storage tank is filtered and then supplied to the second cleaning tank, and the cleaning liquid overflowing from the second cleaning tank is stored in the second storage tank.

According to this method, a rack containing a plurality of thin plate-shaped works is sequentially immersed in a plurality of cleaning tanks to clean the works in stages.
Here, many impurities separated from the workpiece by cleaning exist in the upper layer of the cleaning liquid in the first cleaning tank and the second cleaning tank (hereinafter referred to as cleaning tank). In the cleaning tank, since the upper layer of the cleaning liquid overflows, most of the impurities are discharged together with the overflowing cleaning liquid into the first storage tank and the second storage tank (hereinafter referred to as storage tanks). Therefore, it is possible to suppress the impurities from remaining in the upper layer of the cleaning liquid in the cleaning tank. This can prevent the impurities from re-adhering to the surface of the workpiece when the rack is pulled up from the cleaning tank.

Further, the cleaning liquid in the storage tank corresponding to the cleaning tank is filtered and then supplied to the cleaning tank. Thereby, the cleaning liquid in the cleaning tank is gradually replaced, so that the quality of the cleaning liquid in the cleaning tank can be maintained substantially constant.

Further, in the cleaning tank, a flow of the cleaning liquid is formed by supplying the cleaning liquid from the storage tank corresponding to the cleaning tank. This flow of the cleaning liquid can prevent the impurities from re-adhering to the surface of the workpiece.

Further, according to the above method, in addition to the cleaning liquid overflowing from the second cleaning tank, the cleaning liquid overflowing from the first storage tank is stored in the second storage tank. Since the proportion of impurities contained in the cleaning liquid in the first cleaning tank is lower than the proportion of impurities contained in the cleaning liquid in the second cleaning tank, which precedes the first cleaning tank, the amount of new liquid supplied can be suppressed. Also, the purity of the cleaning liquid in the second cleaning tank can be increased.

Therefore, the cleaning performance of the workpiece can be improved.

According to the present invention, the cleaning performance of a workpiece can be improved.

FIG. 1 is a perspective view showing the entire cleaning device of the first embodiment from diagonally above. FIG. 2 is a diagram corresponding to FIG. 1 and a perspective view showing the cleaning tank in a broken state. FIG. 3 is a perspective view showing the entire rack of the same embodiment. FIG. 4 is a sectional view taken along line 4-4 in FIG. 3. FIG. 4 is a cross-sectional view taken along line 5-5 in FIG. 3. (a) is a sectional view taken along line 6-6 in FIG. 2, and (b) is an enlarged sectional view showing part A in (a). (a) is a plan view showing the whole cleaning device of the same embodiment, and (b) is an enlarged plan view showing an enlarged portion B of (a). FIG. 8 is a cross-sectional view taken along line 8-8 in FIG. 7, in which (a) is a cross-sectional view showing a state in which one end of the placing part is not lifted; (b) is a cross-sectional view showing a state in which one end of the placing part is lifted; A diagram showing a lifted state. FIG. 2 is a schematic diagram showing the configuration of a cleaning device according to a second embodiment. The liquid circuit diagram which shows the structure of the alkaline cleaning part of the same embodiment. FIG. 3 is a liquid circuit diagram showing the configuration of the rinse cleaning section of the same embodiment.

<First embodiment>
A first embodiment of a workpiece cleaning apparatus will be described below with reference to FIGS. 1 to 8.
As shown in FIGS. 1 and 2, the workpiece cleaning apparatus according to the present embodiment includes a rack 20 that can store a plurality of thin plate-shaped works 10 at intervals in the thickness direction, and A cleaning tank 30 is provided for cleaning the plurality of workpieces 10 together with the rack 20.

The work 10 of this embodiment is a separator for a fuel cell. The workpiece 10 is made of a metal material such as stainless steel, and has a substantially rectangular plate shape with a thickness of several hundred μm.
First, the rack 20 will be explained.

As shown in FIG. 3, the rack 20 has a rectangular plate shape that is long in the vertical direction in the figure, and has a pair of side plates 21 facing each other, and extends along the opposing direction of each side plate 21. It has a pair of connecting members 22 that connect one end in the longitudinal direction and the other end in the longitudinal direction. Each connecting member 22 is connected to one end of each side plate 21 in the lateral direction. Each side plate 21 and each connecting member 22 are made of stainless steel, for example.

A handle 21a is provided protruding from the other end of each side plate 21 in the lateral direction. In this embodiment, the side plate 21 and the handle 21a are integrally formed. Each side plate 21 and each connecting member 22 constitute an outer frame of the rack 20.

As shown in FIGS. 3 and 4, groove members 23 made of a hard resin material are fixed by adhesive to the inner surfaces of each side plate 21, that is, the surfaces facing each other.
As shown in FIG. 3, each groove member 23 has a plurality of pairs of support grooves 23a extending along the lateral direction of each side plate 21 and supporting both ends of each workpiece 10 in the longitudinal direction of each side plate 21. They are arranged in parallel with each other at a predetermined interval.

Each support groove 23a is open at both ends in the extending direction (the lateral direction of each side plate 21). Both ends of the workpiece 10 are inserted into the support groove 23a through openings on the other end side in the extending direction of the support groove 23a. That is, in the extending direction of the support groove 23a, one end side is the front side in the storage direction of the workpiece 10, and the other end side is the rear side in the storage direction of the workpiece 10.

As shown in FIG. 4, the width W1 of each support groove 23a is the same in the extending direction of each support groove 23a.
As shown in FIG. 3, between the pair of connecting members 22, there is a connecting member extending along the longitudinal direction of each side plate 21 (vertical direction in the same figure), and on the front side in the storage direction of the workpiece 10 and along the longitudinal direction of each side plate 21. Two columnar support members 24 that restrict displacement in both directions are provided at intervals in opposing directions of each side plate 21 .

As shown in FIG. 5, each support member 24 includes a cylindrical core portion 25 made of a metal material connected to a pair of connecting members 22, and a covering portion made of a hard resin material that covers the entire circumference of the core portion 25. 26.

The covering portions 26 are provided at a plurality of small diameter portions 26a provided at equal intervals in the longitudinal direction of the side plate 21 (up and down direction in the figure), and one each is provided between the small diameter portions 26a adjacent to each other. It also has a plurality of large diameter portions 26b each having a large outer diameter. Moreover, the covering part 26 has an inclined part 26c, which is provided between the small diameter part 26a and the large diameter part 26b, and whose outer diameter is continuously increased from the small diameter part 26a to the large diameter part 26b. There is. A support recess 26d is constituted by one small diameter portion 26a and a pair of inclined portions 26c adjacent to the small diameter portion 26a. The vertical width W2 of the small diameter portion 26a is larger than the thickness d of the workpiece 10 (W2>d).

By abutting the front edge of the workpiece 10 in the storage direction against the support recess 26d, displacement of the workpiece 10 in both the front side and the longitudinal direction of each side plate 21 is restricted.
Next, the cleaning tank 30 will be explained.

As shown in FIGS. 1 and 2, the cleaning tank 30 has a box-shaped tank main body 31 having a rectangular opening 31a in plan view at the top, and a flange 32 provided around the entire circumference at the edge of the opening 31a. are doing. A portion of the flange portion 32 corresponding to one side of the opening 31a is provided with a projecting portion 33 that projects further toward the outer periphery than the portion corresponding to the other side. Furthermore, a projecting wall portion 34 that protrudes upward is provided on the outer peripheral edge of the collar portion 32 over the entire circumference.

As shown in FIGS. 6 to 8, a pair of guide members 35 are provided inside the tank body 31 and extend along the direction in which the overhang portion 33 extends.
In addition, hereinafter, the direction in which each guide member 35 extends will be referred to as an extending direction L, and the direction perpendicular to both the extending direction L and the up-down direction will be referred to as a width direction W.

As shown in FIGS. 6(a) and 7(a), the pair of guide members 35 are arranged at intervals in the width direction W.
As shown in an enlarged view in FIG. 6(b), each guide member 35 extends along the vertical direction, is bent at its upper end, extends inward in the width direction W, and has an L-shaped cross section. is doing.

As shown in FIGS. 7 and 8, both ends of each guide member 35 in the extending direction L are fixed to the inner surface of the tank body 31. As shown in FIGS.
As shown in FIGS. 2 and 6 to 8, a mounting section 40 on which the rack 20 can be mounted is provided inside the tank body 31.

The mounting section 40 is provided above the guide surface 35a, which is the upper surface of each guide member 35, and includes a pair of first frames 41 extending along the extending direction L.
Between each of the first frames 41, a plurality of (three in this embodiment) support rods 42 extend along the width direction W, connect the first frames 41, and support the rack 20 from below. They are provided at intervals in the extending direction L. Further, between each of the first frames 41, a pair of regulating rods 43 are provided which extend along the width direction W, connect the first frames 41 to each other, and regulate the mounting position of the rack 20 in the extending direction L. are provided at intervals in the extending direction L. The pair of regulation rods 43 are arranged above the three support rods 42 and on the outer side of the three support rods 42 in the extending direction L.

As shown in FIGS. 2, 8(a), and 8(b), one end of each first frame 41 in the extending direction L (the right end in FIG. 8(a)) is moved up and down into the cleaning tank 30. An elevating mechanism 60 is attached for raising and lowering.

The elevating mechanism 60 includes an elevating section 50 that is swingably connected to one end of each first frame 41 of the placing section 40 and an actuator 70 that moves the elevating section 50 up and down.
The elevating section 50 includes a pair of second frames 51 connected to one end of each first frame 41 via a swing mechanism 110. Each second frame 51 includes an elongated portion 51a that extends above the collar portion 32 along the vertical direction, and an overhang portion 33 that is bent at the upper end of the elongated portion 51a and extends in the extending direction L. It has a short part 51b that extends above the body, and has a generally L-shape as a whole.

Each second frame 51 is provided with a plurality of connecting rods 52 (three in this embodiment) extending along the width direction W and connecting the second frames 51 to each other at intervals in the vertical direction. ing. Specifically, two connecting rods 52 are provided between the long parts 51a of each second frame 51, and one connecting rod 52 is provided between the short parts 51b.

A connecting plate 53 having a rectangular plate shape is connected between the short parts 51b of each second frame 51. An actuator 70 that raises and lowers the elevating section 50 is connected to the connecting plate 53.

As shown in FIGS. 2, 8(a), and 8(b), an air cylinder 72 having a rod 72a that can project upward is attached to the projecting portion 33 of the tank body 31. The upper end of the rod 72a is connected to a joint 71 fixed to the lower surface of the connecting plate 53.

As shown in FIG. 7B, a bearing 111 is fitted into one end of each first frame 41 in the extending direction L from the inside in the width direction W. As shown in FIG. A bolt 113 is inserted into the bearing 111 from the inside in the width direction W. The bolt 113 is inserted into a bolt hole (not shown) at the lower end of the second frame 51 (long portion 51a), and a nut 114 is screwed onto the tip of the bolt 113. Note that a collar 112 is provided between the bearing 111 and the lower end of the second frame 51.

As shown in FIG. 7(b), FIG. 8(a), and FIG. 8(b), the lower end portion of the elongated portion 51a of each second frame 51 is attached to the bottom of the tank body 31 as the elevating portion 50 moves up and down. A wheel 121 rolling on the inner surface is rotatably provided. The wheel 121 projects further outward in the extending direction L than the elongated portion 51a. A bolt 123 is inserted into the wheel 121 from the outside in the width direction W. The bolt 123 is inserted into a bolt hole (not shown) at the lower end of the second frame 51, and a nut 124 is screwed onto the tip of the bolt 123. Note that a plurality of rollers (all not shown) held by a retainer are provided inside the wheel 121.

As shown in FIGS. 6 and 7, on the inner surface of the tank body 31, a portion facing the wheel 121, that is, a portion on which the wheel 121 slides, is provided with a rectangular plate-shaped reinforcing plate 36 that is long in the vertical direction. Fixed.

As shown in FIGS. 7 and 8, the other end of each first frame 41 in the extending direction L (lower end in FIG. A bearing 101 as a rotatable body is rotatably provided. The bearing 101 is provided with a flange portion 101a that restricts inward displacement in the width direction W when the bearing 101 moves on the guide surface 35a. A bolt 103 is inserted into each bearing 101 from the outside in the width direction W. The bolt 103 is inserted into a bolt hole (not shown) at the other end of the first frame 41, and a nut 104 is screwed onto the tip of the bolt 103. Note that a collar 102 is provided between the bearing 101 and the other end of the first frame 41.

As shown in FIGS. 6 to 8, a heater 80 is provided inside the tank body 31 to heat the cleaning liquid. The heater 80 is attached from the outside of the tank body 31 through the side wall of the tank body 31 and is located below the guide member 35 .

Note that a discharge part (not shown) is provided at the bottom of the tank body 31 for discharging the cleaning liquid inside the tank body 31 to the outside.
As shown in FIGS. 8(a) and 8(b), the rack 20 has the handle 21a on the upper side, that is, the support member 24 on the lower side, and the direction in which the plurality of support grooves 23a are arranged in parallel extends. It is possible to place it on the placing section 40 only when it is aligned with the direction L. At this time, the plurality of works 10 accommodated in each support groove 23a of the rack 20 are in an upright state. Note that each support groove 23a in this embodiment corresponds to a plurality of storage parts according to the present invention.

Next, the operation of this embodiment will be explained.
The work 10 stored in the rack 20 is cleaned as follows.
As shown in FIG. 8A, first, the rack 20 containing a plurality of works 10 is placed on the mounting section 40, and the cleaning liquid is stored in the tank body 31 of the cleaning tank 30. In addition, illustration of the work 10 is omitted in the figure.

Next, as shown in FIG. 8(b), the air cylinder 72 is driven to cause the rod 72a to protrude upward, thereby raising the elevating section 50. As a result, one end of the mounting section 40 connected to the lower end of the elevating section 50 via the swinging mechanism 110 is lifted. Accordingly, the other end of the mounting section 40 is moved on the guide surface 35a via the bearing 101 in the extending direction L toward the side closer to the one end.

Subsequently, the elevating part 50 is lowered from the state where one end of the placing part 40 is lifted. As a result, as shown in FIG. 8(a), one end portion of the mounting section 40 is lowered. Accordingly, the other end of the mounting section 40 is moved on the guide surface 35a via the bearing 101 in the extending direction L to the side away from the one end.

In this way, as the elevating section 50 moves up and down, one end of the placing section 40 is moved up and down, while the other end is reciprocated in the extending direction L.
Thereafter, by repeating these operations, the rack 20 placed on the placing section 40 is reciprocated both in the vertical direction and in the front-back direction.

According to the workpiece cleaning apparatus according to the present embodiment described above, the following effects can be obtained.
(1) The cleaning device for the workpiece 10 is provided in the cleaning tank 30, includes a mounting section 40 on which the rack 20 can be mounted, and an elevating mechanism that is connected to one end of the mounting section 40 and raises and lowers the same end. It is equipped with 60. Further, it is provided below the placing section 40 in the cleaning tank 30, and is configured to prevent the other end of the placing section 40 opposite to the one end from moving as the lifting mechanism 60 raises and lowers the one end of the placing section 40. A guide member 35 having a guide surface 35a for guiding is provided. The racks 20, when placed on the mounting section 40, are arranged in parallel along the direction from one end of the mounting section 40 to the other end, and hold the plurality of works 10 at intervals from each other in the thickness direction. It has support grooves 23a as a plurality of storage parts that can be stored in an upright state.

According to such a configuration, the rack 20 can store a plurality of works 10 in an upright state while being spaced apart from each other in the thickness direction when the rack 20 is placed on the mounting portion 40 in the cleaning tank 30. It has a plurality of support grooves 23a. Therefore, close contact between the works 10 can be suppressed. Furthermore, when one end of the placing unit 40 is raised or lowered by the lifting mechanism 60, the other end of the placing unit 40 is moved in a direction from the same end to the other end (extending direction L). The guide member 35 reciprocates on the guide surface 35a along the guide surface 35a of the guide member 35. In this way, by reciprocating the other end of the mounting section 40, a force can be positively applied to the rack 20 in the direction in which the support grooves 23a are arranged side by side. Thereby, the workpiece 10 can be easily temporarily separated from the side surface of the support groove 23a, and the entire workpiece 10 can be treated with the cleaning liquid. Therefore, the cleaning performance of the workpiece 10 can be improved.

(2) The elevating mechanism 60 includes an elevating section 50 that is swingably connected to one end of the placing section 40 and an actuator 70 that raises and lowers the elevating section 50.
According to such a configuration, since the placing part 40 and the elevating part 50 are connected so as to be relatively swingable, one end part of the placing part 40 is raised and lowered by raising and lowering the elevating part 50 by the actuator 70. At the same time, the other end of the mounting section 40 is reciprocated in the front-back direction. Therefore, with a simple configuration, the rack 20 placed on the placing section 40 can be moved both in the up-down direction and in the front-back direction.

(3) A bearing 101 as a rotary body movable on the guide surface 35a is provided at the other end of the mounting section 40.
With this configuration, the other end of the mounting section 40 can smoothly move on the guide surface 35a via the bearing 101. Therefore, the other end of the mounting section 40 can be stably reciprocated.

<Second embodiment>
A second embodiment of the workpiece cleaning apparatus will be described below with reference to FIGS. 9 to 11. Note that the same components as in the first embodiment are designated by the same reference numerals, and the components corresponding to the first embodiment are designated by the symbol "2**", which is obtained by adding 200 to the symbol "**" in the first embodiment. ” to omit duplicate explanations.

The workpiece cleaning apparatus (hereinafter referred to as the cleaning apparatus) of the present embodiment cleans the workpieces 10 in stages by sequentially immersing a rack 20 in which a plurality of thin plate-shaped workpieces 10 are stored in a plurality of cleaning tanks. It is.

As shown in FIG. 9, the cleaning apparatus includes an alkaline cleaning section 300 that performs alkaline cleaning on the work 10, and a rinse cleaning section 400 that rinses the work 10 after being alkaline cleaned.

As shown in FIG. 9, the alkaline cleaning section 300 is used in an alkaline cleaning process in which the workpiece 10 is alkaline-cleaned in stages with an alkaline cleaning solution, and includes a plurality of (three in this embodiment) alkaline cleaning tanks. (a first alkali cleaning tank 311, a second alkali cleaning tank 312, and a third alkali cleaning tank 313).

The rinsing unit 400 is used in a rinsing process in which the workpiece 10 that has been alkaline-cleaned is rinsed in stages with a rinsing liquid, and includes a plurality of (four in this embodiment) rinsing tanks ( A first rinse tank 411, a second rinse tank 412, a third rinse tank 413, and a fourth rinse tank 414) are provided.

The cleaning device includes a conveying device 500 that grips the rack 20 and conveys the rack 20 to the cleaning tanks 313, 312, 311, 414, 413, 412, and 411 so as to sequentially immerse the rack 20.

Next, the alkaline cleaning section 300 will be described in detail with reference to FIGS. 9 and 10.
The alkaline cleaning section 300 is used to perform an alkaline cleaning process in which impurities such as oil adhering to the surface of the workpiece 10 during press working are removed using an alkaline cleaning liquid such as NaOH.

As shown in FIGS. 9 and 10, each of the alkaline cleaning tanks 311 to 313 basically has the same configuration as the cleaning tank 30 of the first embodiment. That is, although not shown, each of the cleaning tanks 311 to 313 includes a mounting section 40 on which the rack 20 can be mounted, and a lifting mechanism 60 that is connected to one end of the mounting section 40 and raises and lowers the same end. It is equipped with However, each cleaning tank 311 to 313 is provided with a sub tank 237 and an ultrasonic generator 380, but is not provided with a heater 80.

An alkaline cleaning liquid supply device 360 having a supply flow path 361 for supplying fresh alkaline cleaning liquid is connected to the first alkaline cleaning tank 311 .
The sub-tank 237 is provided along the entire circumference between the upper part of the outer surface of the tank body 231 and the flange part 232, and has a square ring shape. The alkaline cleaning liquid overflowing from the upper edge of the tank body 231 is stored in the sub-tank 237 .

As shown in FIG. 10, the alkaline cleaning liquid stored in each sub-tank 237 is transferred to each sub-tank 237 of each of the alkaline cleaning tanks 311-313 into a first alkali cleaning tank provided corresponding to the three alkaline-cleaning tanks 311-313. A first flow path 320 is connected to each of the storage tank 331, the second alkali storage tank 332, and the third alkali storage tank 333. The first channel 320 is provided with a pump 321 that pumps the alkaline cleaning liquid.

Each alkali storage tank 331 to 333 is divided inside one alkali collecting tank 330.
The alkali collecting tank 330 has a bottom wall 335 in the shape of a rectangular plate, four side walls 336 standing all around from the periphery of the bottom wall 335, and three alkali storage tanks 331 to 333 inside the alkali collecting tank 330. It has a plurality of (two in this embodiment) partition walls 337, 338 that divide the space into two. The upper edge of the partition wall 337 that partitions the first alkali storage tank 331 and the second alkali storage tank 332 is the upper edge of the partition wall 338 that partitions the second alkali storage tank 332 and the third alkali storage tank 333. It is located above. Further, the upper edge of the side wall 336 is located higher than the upper edge of each partition wall 337, 338. Therefore, the height of the liquid level becomes lower in the order of first alkali storage tank 331, second alkali storage tank 332, and third alkali storage tank 333. As a result, when the level of the alkaline cleaning liquid stored in the first alkaline storage tank 331 exceeds the partition wall 337, the alkaline cleaning liquid overflows into the second alkaline storage tank 332. Further, when the level of the alkaline cleaning liquid stored in the second alkaline storage tank 332 exceeds the partition wall 338, the alkaline cleaning liquid overflows into the third alkaline storage tank 333.

From the above, the first alkaline storage tank 331 is supplied with the alkaline cleaning liquid that is pressure-fed from the first channel 320 connected to the sub-tank 237 of the first alkaline cleaning tank 311 .
The second alkaline storage tank 332 is supplied with the alkaline cleaning liquid that is pressure-fed from the first channel 320 connected to the sub-tank 237 of the second alkaline cleaning tank 312 and the alkaline cleaning liquid that has overflowed in the first alkaline storage tank 331. Ru.

The third alkaline storage tank 333 is supplied with the alkaline cleaning liquid that is pressure-fed from the first channel 320 connected to the sub-tank 237 of the third alkaline cleaning tank 313 and the alkaline cleaning liquid that has overflowed in the second alkaline storage tank 332. Ru.

Each alkali storage tank 331 to 333 is provided with a heater 381 that heats the alkaline cleaning liquid. Note that in FIG. 10, illustration of the heater 381 provided in the second alkali storage tank 332 is omitted.

A discharge channel 340 for discharging the alkaline cleaning liquid is connected to a portion of the bottom wall 335 of the alkali collection tank 330 that constitutes the bottom of the third alkali storage tank 333 . The discharge passage 340 is provided with a valve 341 that opens and closes the discharge passage 340 .

A second channel 350 is connected to each alkali storage tank 331-333 for supplying an alkaline cleaning liquid to the corresponding alkali cleaning tank 311-313. Each second flow path 350 is provided with a pump 351 that pumps the alkaline cleaning liquid and a filter 352 that filters the alkaline cleaning liquid in order from the upstream side. Note that in FIG. 10, illustration of the second alkali cleaning tank 312 and the second flow path 350 connected thereto is omitted.

From the above, the alkaline cleaning liquid is supplied to each of the alkaline cleaning tanks 311 to 313 through the second flow path 350, while the alkaline cleaning liquid is discharged through the first flow path 320.
Note that the first alkaline cleaning tank 311 is supplied with the alkaline cleaning liquid through the second flow path 350 and also with fresh alkaline cleaning liquid from an alkaline cleaning liquid supply device 360 having a supply flow path 361 .

Next, the rinse cleaning section 400 will be described in detail with reference to FIGS. 9 and 11.
The rinsing cleaning section 400 is for performing a rinsing cleaning process to remove the alkaline cleaning liquid adhering to the surface of the workpiece in the above-mentioned alkaline cleaning process.

The rinse cleaning section 400 has basically the same configuration as the alkaline cleaning section 300. Therefore, hereinafter, parts having the same configuration as the alkaline cleaning section 300 will be designated with the symbol "4**", which is the addition of "100" to the symbol "3**" corresponding to the alkaline cleaning section 300. Duplicate explanations may be omitted.

A rinsing liquid supply device 460 having a supply channel 461 for supplying a new rinsing liquid is connected to the first rinsing tank 411 .
The new rinsing liquid of this embodiment is pure water. Here, pure water is water that has an electrical conductivity of 1.0 μS/cm or less at 25° C. and contains almost no impurities.

As shown in FIG. 11, each sub-tank 237 of each of the rinsing tanks 411 to 414 transfers the rinsing liquid stored in each sub-tank 237 to a first rinsing tank provided corresponding to the four rinsing tanks 411 to 414. A first flow path 420 is connected to each of a storage tank 431, a second rinse storage tank 432, a third rinse storage tank 433, and a fourth rinse storage tank 434.

Each rinse storage tank 431 to 434 is partitioned inside one rinse collection tank 430.
The rinse collection tank 430 has a plurality of (three in this embodiment) partition walls 437, 438, and 439 that partition the inside of the rinse collection tank 430 into four rinse storage tanks 431 to 434.

The upper edge of the partition wall 437 is located higher than the upper edge of the partition wall 438. Further, the upper edge of the partition wall 438 is located higher than the upper edge of the partition wall 439. Therefore, the height of the liquid level becomes lower in the order of the first rinse storage tank 431, the second rinse storage tank 432, the third rinse storage tank 433, and the fourth rinse storage tank 434. As a result, when the level of the rinse liquid stored in the first rinse storage tank 431 exceeds the partition wall 437, the rinse liquid overflows into the second rinse storage tank 432. Furthermore, when the level of the rinse liquid stored in the second rinse storage tank 432 exceeds the partition wall 438, the rinse liquid overflows into the third rinse storage tank 433. Furthermore, when the level of the rinse liquid stored in the third rinse storage tank 433 exceeds the partition wall 439, the rinse liquid overflows into the fourth rinse storage tank 434.

A first channel 420 is connected to each sub-tank 237 of each of the rinsing tanks 411-414 to supply the rinsing liquid stored in each sub-tank 237 to each of the rinsing storage tanks 431-434.

From the above, the first rinsing storage tank 431 is supplied with the rinsing liquid that is pressure-fed from the first channel 420 connected to the sub-tank 237 of the first rinsing tank 411 .
The second rinse storage tank 432 is supplied with the rinse liquid that is pressure-fed from the first channel 420 connected to the sub-tank 237 of the second rinse tank 412 and the rinse liquid that has overflowed in the first rinse storage tank 431. Ru.

The third rinse storage tank 433 is supplied with the rinse liquid that is pressure-fed from the first channel 420 connected to the sub-tank 237 of the third rinse tank 413 and the rinse liquid that has overflowed in the second rinse storage tank 432. Ru.

The fourth rinsing storage tank 434 is supplied with the rinsing liquid that is pressure-fed from the first channel 420 connected to the sub-tank 237 of the fourth rinsing tank 414 and the rinsing liquid that has overflowed in the third rinsing storage tank 433. Ru.

A discharge channel 440 for discharging the rinse cleaning liquid is connected to a portion of the bottom wall 435 of the rinse collecting tank 430 that constitutes the bottom of the fourth rinse storage tank 434 . The discharge passage 440 is provided with a valve 441 that opens and closes the discharge passage 440 .

Each of the rinsing tanks 411 to 414 is supplied with a rinsing liquid through a second flow path 450, and is discharged through a first flow path 420.
The first rinsing tank 411 is supplied with the rinsing liquid through the second flow path 450 and also with new rinsing liquid through a rinsing liquid supply device 460 having a supply flow path 461 .

Next, a cleaning process for the workpiece 10 will be explained.
First, the rack 20 containing the work 10 is immersed in the third alkaline cleaning tank 313 by the transport device 500. At this time, the rack 20 is placed on the platform 40 and is swung by the lifting mechanism 60 connected to the platform 40 . Also, at this time, ultrasonic waves are applied to the alkaline cleaning liquid in the third alkaline cleaning tank 313 by the ultrasonic generator 380 . In this way, the workpiece 10 is alkaline-cleaned using the alkaline cleaning liquid.

Next, the transport device 500 lifts the rack 20 from the third alkali cleaning tank 313 and transports it above the second alkali cleaning tank 312 to immerse it in the second alkali cleaning tank 312. Then, the work 10 is subjected to alkaline cleaning in the same manner as in the above embodiment.

Next, the transport device 500 lifts the rack 20 from the second alkali cleaning tank 312 and transports it above the second alkali cleaning tank 312 to immerse it in the first alkali cleaning tank 311. Then, the work 10 is subjected to alkaline cleaning in the same manner as in the above embodiment.

With the above steps, the alkaline cleaning process for the workpiece 10 is completed.
Subsequently, in the same manner as in the alkaline cleaning process, the rack 20 is sequentially immersed in each of the rinsing tanks 414 to 411 using the transport device 500 to rinse the workpiece 10.

With the above steps, the rinsing process for the workpiece 10 is completed.
In the alkaline cleaning process, the alkaline cleaning liquid is constantly supplied to the first alkaline cleaning tank 311 by the alkaline cleaning liquid supply device 360, and is constantly discharged from the third alkali storage tank 333 through the discharge channel 340.

In the rinsing process, the rinsing liquid is constantly supplied to the first rinsing tank 411 by the rinsing liquid supply device 460, and is constantly being discharged from the fourth rinsing storage tank 434 through the discharge channel 440.

Next, the operation of this embodiment will be explained.
A large amount of impurities such as oil separated from the workpiece 10 by the alkaline cleaning process exists in the upper layer of the alkaline cleaning liquid in each of the alkaline cleaning tanks 311 to 313. In each of the alkaline cleaning tanks 311 to 313, since the upper layer of the alkaline cleaning liquid overflows, most of the impurities mentioned above are discharged to each of the alkaline storage tanks 331 to 333 together with the overflowing alkaline cleaning liquid. Therefore, it is possible to suppress the impurities from remaining in the upper layer of the alkaline cleaning liquid in each of the alkaline cleaning tanks 311 to 313. Thereby, when the rack 20 is pulled up from each of the alkaline cleaning tanks 311 to 313, it is possible to suppress the impurities from re-adhering to the surface of the workpiece 10 (above, effect 1).

Furthermore, the alkaline cleaning liquid in each alkali storage tank 331 to 333 corresponding to the alkali cleaning tank is supplied to each alkali cleaning tank 311 to 313 after being filtered by a filter 352 . As a result, the alkaline cleaning liquid in each of the alkaline cleaning tanks 311 to 313 is gradually replaced, so that the liquid quality of the alkaline cleaning liquid in each of the alkaline cleaning tanks 311 to 313 can be maintained approximately constant (above, effect 2). .

Further, in each of the alkaline cleaning tanks 311 to 313, a flow of the alkaline cleaning liquid is formed by supplying the alkaline cleaning liquid from each of the alkali storage tanks 331 to 333 corresponding to the alkali cleaning tank. This flow of the alkaline cleaning liquid can prevent the impurities from adhering again to the surface of the workpiece 10 (action 3).

Furthermore, in addition to the alkaline cleaning liquid overflowing from the second alkali cleaning tank 312 (third alkali cleaning tank 313), the second alkali storage tank 332 (third alkali storage tank 333) contains the first alkali storage tank 331 (the The alkaline cleaning liquid overflowing from the 2 alkaline storage tank 332) is stored. The ratio of impurities contained in the alkaline cleaning liquid in the first alkali cleaning tank 311 (second alkali cleaning tank 312) is the same as that in the second alkali cleaning tank 312 before the first alkali cleaning tank 311 (second alkali cleaning tank 312). It is smaller than the proportion of impurities contained in the alkaline cleaning liquid in the third alkaline cleaning tank 313. From this, it is possible to increase the purity of the alkaline cleaning liquid in the second alkaline cleaning tank 312 (third alkaline cleaning tank 313) while suppressing the supply amount of new liquid (above, effect 4).

Furthermore, many impurities separated from the workpiece 10 in the rinsing process are present in the upper layer of the rinsing liquid in each of the rinsing tanks 411 to 414. In each rinsing tank 411-414, the upper layer of the rinsing liquid overflows, so that most of the impurities are discharged together with the overflowing rinsing liquid into each rinsing storage tank 431-434. Therefore, it is possible to suppress the impurities from remaining in the upper layer of the rinsing liquid in each of the rinsing tanks 411 to 414. This makes it possible to suppress the impurities from re-adhering to the surface of the workpiece 10 when the rack 20 is pulled up from each of the rinsing tanks 411 to 414 (action 5).

Furthermore, the rinse liquid in each of the rinse storage tanks 431 to 433 corresponding to the rinse tank is filtered by a filter 452 and then supplied to each of the rinse tanks 411 to 414. As a result, the rinsing liquid in each of the rinsing tanks 411 to 414 is gradually replaced, so that the liquid quality of the rinsing liquid in each of the rinsing tanks 411 to 414 can be maintained approximately constant (above, operation 6). .

Further, in each of the rinse tanks 411 to 414, a flow of the rinse liquid is formed by supplying the rinse liquid from each of the rinse storage tanks 431 to 434 corresponding to the rinse tank. This flow of the rinsing liquid can prevent the impurities from re-adhering to the surface of the workpiece 10 (above, operation 7).

Furthermore, the overflow from the second rinse tank 412 (third rinse tank 413, fourth rinse tank 414) is stored in the second rinse tank 432 (third rinse tank 433, fourth rinse tank 434). In addition to the rinsing liquid, the rinsing liquid overflowing from the first rinsing storage tank 431 (second rinsing storage tank 432, third rinsing storage tank 433) is stored. The proportion of impurities contained in the rinsing liquid in the first rinsing tank 411 (second rinsing tank 412, third rinsing tank 413) is The proportion of impurities contained in the rinsing liquid in the second rinsing tank 412 (third rinsing tank 413, fourth rinsing tank 414) that precedes the cleaning tank 413) is smaller than the ratio of impurities contained in the rinsing liquid in the second rinsing tank 412 (third rinsing tank 413, fourth rinsing tank 414). From this, it is possible to increase the purity of the rinse liquid in the second rinse tank 412 (third rinse tank 413, fourth rinse tank 414) while suppressing the amount of new liquid supplied (as described above, ).

According to the workpiece cleaning method according to the present embodiment described above, the following effects can be obtained.
(4) In the alkaline cleaning step, a new alkaline cleaning solution is supplied to the first alkaline cleaning tank 311 in which the rack 20 is immersed last among the plurality of alkaline cleaning tanks. In addition, the alkaline cleaning liquid overflowing from the first alkali cleaning tank 311 is stored in a first alkali storage tank 331 provided corresponding to the first alkali cleaning tank 311. After the alkaline cleaning liquid is filtered, it is supplied to the first alkaline cleaning tank 311 . Further, a second alkali storage tank is provided corresponding to the second alkali cleaning tank 312 (third alkali cleaning tank 313) in which the rack 20 is immersed immediately before the first alkali cleaning tank 311 (second alkali cleaning tank 312). The alkaline cleaning liquid overflowing from the first alkali storage tank 331 (second alkali storage tank 332) is stored in the tank 332 (third alkali storage tank 333). In addition, the alkaline cleaning liquid stored in the second alkali storage tank 332 (third alkali storage tank 333) is filtered and then supplied to the second alkali cleaning tank 312 (third alkali cleaning tank 313). Then, the alkaline cleaning liquid overflowing from the second alkali cleaning tank 312 (third alkali cleaning tank 313) is stored in the second alkali storage tank 332 (third alkali storage tank 333).

According to this method, since the above effects 1 to 4 are achieved, the cleaning performance in alkaline cleaning of the workpiece 10 can be improved.
(5) In the rinsing process, a new rinsing liquid is supplied to the first rinsing tank 411 in which the rack 20 is last immersed among the plurality of rinsing tanks. In addition, the rinsing liquid overflowing from the first rinsing tank 411 is stored in a first rinsing storage tank 431 provided corresponding to the first rinsing tank 411. After the rinsing liquid is filtered, it is supplied to the first rinsing tank 411. In addition, the rack 20 is immersed in a second rinse tank 412 (third rinse tank 413, fourth rinse tank 413) immediately before the first rinse tank 411 (second rinse tank 412, third rinse tank 413). The second rinse storage tank 432 (third rinse storage tank 433, fourth rinse storage tank 434) provided corresponding to the first rinse storage tank 431 (second rinse storage tank 432, third rinse storage tank 434) The rinsing liquid overflowing from the tank 433) is stored. In addition, after filtering the rinse liquid stored in the second rinse tank 432 (third rinse tank 433, fourth rinse tank 434), the second rinse tank 412 (third rinse tank 413, fourth rinse tank 434) is filtered. 4 rinse cleaning tank 414). Then, the rinse liquid overflowing from the second rinse tank 412 (third rinse tank 413, fourth rinse tank 414) is transferred to the second rinse tank 432 (third rinse tank 433, fourth rinse tank 434). to be stored.

According to such a method, since the above effects 5 to 8 are achieved, the cleaning performance in rinsing the workpiece 10 can be improved.
(6) In the rinsing process, pure water is supplied to the first rinsing tank 411 as a new rinsing liquid.

According to this method, since pure water containing almost no impurities is used as the new rinse liquid to be supplied to the first rinse tank 411, supplying the new liquid causes a change in the rinse liquid. Contamination with impurities can be suppressed.

(7) The rack 20 immersed in each of the alkaline cleaning tanks 311 to 313 (each of the rinsing tanks 411 to 414) was rocked and ultrasonic waves were applied to the alkaline cleaning liquid (rinsing liquid).

According to such a method, the rack 20 is rocked and the ultrasonic waves are applied to the alkaline cleaning liquid (rinsing cleaning liquid), so that the alkaline cleaning liquid (rinsing cleaning liquid) comes into contact with the surface of the work 10 stored in the rack 20. is stirred. Thereby, the entire workpiece 10 can be cleaned uniformly. Therefore, the cleaning performance in alkaline cleaning (rinsing cleaning) of the workpiece 10 can be further improved.

Note that the above embodiment can be modified and implemented as follows. The above embodiment and the following modification examples can be implemented in combination with each other within a technically consistent range.

- A ball roller can be used instead of the bearing 101.
- The actuator 70 is not limited to having the air cylinder 72. Alternatively, for example, an actuator using a ball screw or an electromagnetic solenoid may be used.

- The heater 80 may be omitted.
- The guide member 35 may be provided at an angle with respect to the projecting portion 33.
- The swing mechanism 110 is not limited to one that rotates around the bearing 111 as in this embodiment. Alternatively, for example, instead of the bearing 111, each second frame 51 may be provided with a sliding shaft extending in the width direction W, and each first frame 41 may be provided with a long hole into which the sliding shaft is inserted. good. The elongated hole extends at an angle so that the other end of the mounting portion 40 is located upward or downward. According to the above configuration, as each second frame 51 moves up and down, each first frame 41 moves relative to the sliding axis in the extending direction of the elongated hole. It is reciprocated in both directions.

- After the rinsing process, a drying process for drying the workpiece 10 may be performed separately.
- Each alkaline cleaning tank 311 to 313 (each rinsing cleaning tank 411 to 414) has a heater for heating the alkaline cleaning liquid (rinsing cleaning liquid) in addition to the ultrasonic generator 380 (ultrasonic generator 480). Good too. In this case, the heater 381 (heater 481) in each of the alkali storage tanks 331 to 333 (each of the rinse storage tanks 431 to 434) can be omitted.

- Each of the alkaline cleaning tanks 311 to 313 (each of the rinse cleaning tanks 411 to 414) may not be equipped with the ultrasonic generator 380 (ultrasonic generator 480).
- The number of alkali cleaning tanks that constitute the alkali cleaning section 300 can be changed as appropriate. That is, the cleaning device may have only one alkaline cleaning tank as long as it has two or more rinsing cleaning tanks. Further, the number of rinsing tanks constituting the rinsing section 400 can be changed as appropriate. That is, the cleaning device may have only one rinsing tank as long as it has two or more alkaline cleaning tanks.

- The cleaning method according to the present invention is not limited to having both an alkaline cleaning step and a rinsing cleaning step, but may include only an alkaline cleaning step or only a rinsing cleaning step. Good too.

DESCRIPTION OF SYMBOLS 10...Workpiece, 20...Rack, 21...Side plate, 21a...Handle, 22...Connection member, 23...Groove member, 23a...Support groove, 24...Support member, 25...Core part, 26...Coating part, 26a...Small diameter part , 26b...large diameter part, 26c...slanted part, 26d...support recessed part, 30...cleaning tank, 31...tank body, 31a...opening, 32...flange part, 33...projection part, 34...protruding wall part, 35... Guide member, 35a... Guide surface, 36... Reinforcement plate, 40... Placement part, 41... First frame, 42... Support bar, 43... Regulating bar, 50... Lifting part, 51... Second frame, 51a... Long length Part, 51b...Short part, 52...Connection rod, 53...Connection plate, 60...Elevating mechanism, 70...Actuator, 71...Joint, 72...Air cylinder, 72a...Rod, 80...Heater, 101...Bearing, 101a...Flange Part, 102... Collar, 103... Bolt, 104... Nut, 110... Rocking mechanism, 111... Bearing, 112... Collar, 113... Bolt, 114... Nut, 121... Wheel, 123... Bolt, 124... Nut, L... Extending direction, W... Width direction, W1... Width, W2... Width, 231... Tank body, 232... Flange, 237... Sub-tank, 300... Alkali cleaning section, 311... First alkali cleaning tank, 312... Second alkali Washing tank, 313... Third alkali washing tank, 320... First flow path, 321... Pump, 330... Alkali collection tank, 331... First alkali storage tank, 332... Second alkali storage tank, 333... Third alkali storage tank. Tank, 335...bottom wall, 336...side wall, 337, 338...partition wall, 340...discharge channel, 341...valve, 350...second channel, 351...pump, 352...filter, 360...alkaline cleaning liquid supply device, 361... Supply channel, 380... Ultrasonic generator, 381... Heater, 400... Rinse cleaning section, 411... First rinse tank, 412... Second rinse tank, 413... Third rinse tank, 414... Third 4 rinsing cleaning tank, 420...first channel, 421...pump, 430...rinsing collection tank, 431...first rinsing storage tank, 432...second rinsing storage tank, 433...third rinsing storage tank, 434...fourth Rinse storage tank, 435... Bottom wall, 436... Side wall, 437, 438, 439... Partition wall, 440... Discharge channel, 441... Valve, 450... Second channel, 451... Pump, 452... Filter, 460... Rinse Cleaning liquid supply device, 461... Supply channel, 480... Ultrasonic generator, 481... Heater, 500... Transport device.

Claims (7)

An apparatus comprising a rack for storing a plurality of thin plate-like works constituting a separator of a fuel cell, and a cleaning tank in which a cleaning liquid is stored, and cleaning the works stored in the rack in the cleaning tank. And,
a mounting part provided in the cleaning tank and capable of mounting the rack;
an elevating mechanism connected to one end of the mounting section and elevating and lowering the same end;
The device is provided below the mounting portion in the cleaning tank, and is configured to prevent movement of the other end of the mounting portion opposite to the one end as the one end of the mounting portion is raised and lowered by the elevating mechanism. A guide member having a guide surface for guiding,
The rack includes a pair of side plates facing each other, a plurality of pairs of support grooves provided on opposing surfaces of the side plates to support both ends of the workpiece, and a columnar support member located between the side plates. , has
The plurality of pairs of support grooves are arranged in parallel along a direction from the one end to the other end of the mounting section when the rack is placed on the mounting section, and the plurality of support grooves are arranged in parallel along a direction from the one end to the other end of the mounting section, and are configured such that they can be stored at intervals in their thickness direction and in an upright position,
The support member extends along the direction in which the plurality of pairs of support grooves are arranged side by side at the lower end of the rack when the rack is placed on the placement section, and is arranged in parallel in the direction in which the plurality of support grooves are arranged side by side. and having a plurality of support recesses supporting the lower edge of each of the workpieces,
Workpiece cleaning equipment. The elevating mechanism includes an elevating section that is swingably connected to the one end of the mounting section, and an actuator that raises and lowers the elevating section.
The workpiece cleaning device according to claim 1. A rotating body movable on the guide surface is provided at the other end of the mounting section.
A workpiece cleaning device according to claim 1 or 2. A workpiece cleaning method using the workpiece cleaning device according to any one of claims 1 to 3, comprising:
A cleaning step is provided in which a plurality of the cleaning tanks are used and the racks storing a plurality of the workpieces are sequentially immersed in the plurality of cleaning tanks in which the cleaning liquid is stored, thereby cleaning the workpieces in stages. picture,
The washing step includes:
Supplying new cleaning liquid to a first cleaning tank in which the rack is last immersed among the plurality of cleaning tanks, and supplying the cleaning liquid overflowing from the first cleaning tank to the first cleaning tank. the cleaning liquid stored in the first storage tank is filtered and then supplied to the first cleaning tank;
The cleaning liquid overflowing from the first storage tank is stored in a second storage tank provided corresponding to a second cleaning tank in which the rack is immersed immediately before the first cleaning tank, while the second storage tank After filtering the cleaning liquid stored in the cleaning tank, supplying the cleaning liquid to the second cleaning tank, and storing the cleaning liquid overflowing from the second cleaning tank in the second storage tank.
How to clean the workpiece. The rack, which is immersed in the cleaning tank and placed on the placement part, is swung by the lifting mechanism and ultrasonic waves are applied to the cleaning liquid.
The method for cleaning a workpiece according to claim 4. an alkaline cleaning step of cleaning the workpiece with alkali by immersing the rack in an alkaline cleaning tank in which an alkaline cleaning solution is stored;
After the alkaline cleaning step, a rinsing step of rinsing the workpiece stepwise by sequentially immersing the rack in a plurality of rinsing tanks storing a rinsing liquid;
The rinsing cleaning process is for performing the cleaning process,
In the rinsing step, pure water is supplied as a new rinsing liquid to a first rinsing tank in which the rack is immersed last among the plurality of rinsing tanks.
The method for cleaning a workpiece according to claim 4 or 5. an alkaline cleaning step of stepwise alkaline cleaning the workpiece by sequentially immersing the rack in an alkaline cleaning tank storing an alkaline cleaning solution;
After the alkaline cleaning step, a rinsing step of rinsing the workpiece by immersing the rack in a rinsing tank in which a rinsing liquid is stored;
The alkaline cleaning step is to perform the cleaning step,
The method for cleaning a workpiece according to any one of claims 4 to 6.