JP4868504B2 - Liquid leakage prevention device for treatment tank - Google Patents

Description

  The present invention relates to a processing tank liquid leakage preventing apparatus for preventing a processing liquid from leaking from a work inlet / outlet of a processing tank in a plating apparatus for plating while transferring a flat workpiece in a vertical posture.

  Various types of apparatuses for plating a flat work such as a printed circuit board are provided. Among these apparatuses, the plating apparatus for continuously transferring a flat workpiece in a vertical posture does not require a jig, and is equipped with a bath liquid jet mechanism to enable high-speed plating. It is used a lot because there is. In a plating apparatus that continuously transfers such a flat work in a vertical posture, the flat work enters and exits the treatment tank below the treatment liquid surface, so that the treatment liquid leaks from the work entrance / exit. Thus, for example, a mechanism for preventing leakage of the processing liquid from the work inlet / outlet as provided in the processing apparatus disclosed in Patent Document 1 is provided.

  The liquid leakage prevention mechanism of the processing tank equipped in the processing apparatus disclosed in Patent Document 1 is provided with a vertical slit for allowing a workpiece to pass through the end wall of the processing compartment, and the vertical corresponding to the slit. The rods or pipes that are loosely placed in pairs in the treatment bath in any direction are arranged as seals, and these rods or pipes are connected to each other by liquid pressure or to the end walls of the treatment compartments each time. It is configured to be crimped. In this mechanism, the rod or tube is a roller having a generally cylindrical cross section, and since the roller is rotated by the workpiece passing therethrough, it is possible to dispense with a roller driving device and to handle a workpiece that is extremely sensitive to friction. There is an effect that becomes possible.

  However, in the invention shown in Patent Document 1, the roller is pressure-bonded and sealed to the end wall of the processing compartment, and the friction force becomes a resistance force, and a large tensile force acts on the work that rotates the roller. Become. Further, it is difficult to keep the roller in a completely vertical state, and if the roller is inclined even slightly, an upward or downward force is applied to the passing workpiece. The force acting on such a workpiece is not particularly problematic if it is a workpiece with a certain thickness and strength like a conventional printed circuit board, but it will be used with the progress of high-density mounting of electronic devices in recent years. There is a problem that a workpiece such as a flexible circuit board having an extremely large thickness and a low strength is damaged, such as wrinkles.

  In order to solve such problems, the applicant of the present application reduces the tensile force acting on the workpiece, thereby preventing the leakage of the processing tank from being damaged even if the workpiece is extremely thin and low in strength. Is pending as Japanese Patent Application No. 2006-94852. The invention of this Japanese Patent Application No. 2006-94852 is a processing tank in which a workpiece is sandwiched between two sets of seal rollers disposed in the vicinity of a slit provided on a side wall through which a workpiece of the processing tank enters and exits to prevent liquid leakage. In the liquid leakage prevention device, a bearing whose outer diameter does not exceed the outer diameter of the sealing roller is attached to the upper and lower ends of each sealing roller, and a position restricting member for contacting each bearing is provided in the treatment tank, and the work of each sealing roller is provided. The movement in the outer direction of the processing tank in a plane parallel to the surface is limited to a range in which each seal roller and the side wall of the processing tank do not contact and form a slight gap.

According to the invention of Japanese Patent Application No. 2006-94852, each sealing roller and the side wall of the processing tank do not contact each other and a slight gap is formed, so that a frictional force due to contact between the sealing roller and the side wall does not occur, and the sealing roller Can be rotated with a very small force because it is supported by the bearing, and since a large tensile force does not work on the workpiece, it will not damage even a thin workpiece with a low thickness and the conventional problem will be solved become. However, the bearings attached to the seal roller are immersed in the processing liquid, or even if a bearing with a material and structure that can withstand the processing liquid is used, the life of the bearing is limited. There is a problem in that it takes time and effort to do so, and the operation of the plating apparatus must be stopped during replacement.
Japanese National Patent Publication No. 9-505638

  The present invention solves the above-described problems, and even if the workpiece is extremely thin and low in strength, the workpiece is not damaged, and a processing tank that does not use a component having a limited life such as a bearing is used. The present invention has been made to provide a liquid leakage prevention device.

  In order to solve the above problems, the apparatus for preventing leakage of a treatment tank according to the present invention is provided with a workpiece entry / exit in a vertical direction on a side wall through which a workpiece of a treatment tank for treating a flat workpiece is entered and exited. Two seal roller storage parts with a U-shaped cross-section in the vicinity of the outlet are provided as a set with two openings facing each other. The seal roller is stored in the seal roller storage part, and the upper and lower ends of the seal roller. The seal roller and the inner surface of the side wall of the seal roller storage unit do not come into contact with each other and the movement of the seal roller in the outer direction in the plane parallel to the work surface of each seal roller is not in contact with each other. A movement restriction mechanism that restricts the range to be formed is provided in the seal roller storage section or the processing tank, and a drive device that applies a rotational force in the same direction as the workpiece transfer direction to each seal roller is provided. It is intended to.

Here, the seal roller abuts or engages with the upper end and lower end of the seal roller so that the seal roller moves in a direction away from the workpiece surface in a range in which the distance between the seal rollers does not exceed the maximum thickness of the workpiece. It is preferable to provide a movement limiting mechanism for limiting, and it is preferable that the driving device generate a constant rotational force regardless of the rotational speed. Furthermore, the rotational force applied to the seal roller from the drive device is greater than the resistance force of the movement limiting mechanism, and the difference between the rotational force applied to the seal roller and the resistance force of the movement limiting mechanism reduces the frictional force between the seal roller and the workpiece. It is preferable not to exceed.

  According to the present invention, there is provided a movement restricting mechanism for restricting movement of the processing tank in the outer direction in a plane parallel to the work surface, and a driving device that applies a rotational force in the same direction as the work transfer direction to each seal roller. Therefore, the frictional force due to the seal roller coming into contact with the inner wall of the seal roller storage portion does not occur, and the resistance force of the movement limiting mechanism is canceled out by the rotational force applied from the drive device. As a result, it can rotate with extremely small force and no large tensile force is applied to the workpiece, so it will not be damaged even if the workpiece is thin and low in strength, and parts with a limited life such as bearings are not used. Therefore, there is an advantage that the labor for replacement is not required and the operation of the plating apparatus does not need to be stopped. Since the resistance force of the movement limiting mechanism is very small, the driving device has an advantage that a large force is not required.

  In addition, when a movement restriction mechanism is provided that restricts the range of movement of each seal roller in the direction away from the workpiece surface, the cross section of each seal roller case can be enlarged and does not contact the workpiece of the seal roller. The processing liquid can be sufficiently stored on the side. This increases the force that presses the seal rollers against each other due to the fluid pressure, thereby improving the close contact between the seal rollers and between the seal roller and the workpiece, reducing liquid leakage from the seal roller and preventing the seal roller and the workpiece from slipping. There are advantages.

  Furthermore, when the driving device generates a constant rotational force regardless of the rotational speed, there is an advantage that the resistance force of the movement limiting mechanism is reliably canceled even when the workpiece transfer speed is changed, The rotational force applied to the seal roller from the drive device is greater than the resistance force of the movement limiting mechanism, and the difference between the rotational force applied to the seal roller and the resistance force of the movement limiting mechanism does not exceed the frictional force between the seal roller and the workpiece. In such a case, a force in the direction of travel is applied from the seal roller to the workpiece, and the tensile force for rotating the seal roller does not act on the workpiece. There is an advantage that it can be transported.

Next, the best mode for carrying out the present invention will be specifically described with reference to the drawings.
1 to 3 show the configuration of the apparatus for preventing leakage of a treatment tank according to the present invention. Seal roller cases 1 and 2 serving as a pair of seal roller storage portions each having a U-shaped cross section are shown. The seal roller cases 1 and 2 are respectively provided with cylindrical seal rollers 3 and 4 that are movable in the horizontal direction so that the openings are opposed to each other. A movement restriction mechanism that restricts the movement range is provided.

The seal rollers 3 and 4 are moved by the movement limiting mechanism so that the seal rollers 3 and 4 and the inner surface of the side walls of the seal roller cases 1 and 2 do not come into contact with each other in the outer direction of the processing tank in a plane parallel to the workpiece surface. The movement in the direction away from the workpiece surface in a direction perpendicular to the workpiece surface is limited to a range in which a slight gap is formed, and is limited to a range in which the distance between the seal rollers 3 and 4 does not exceed the maximum thickness of the workpiece. These seal roller cases 1 and 2 are attached to the outside of the side plate provided with the work entry / exit of the processing tank, and the seal rollers 3 and 4 are arranged on both sides of the work entry / exit with the work passage therebetween. At this time, it is convenient to easily adjust the position and the like by providing the mounting plate portions 5 and 6 on the seal roller cases 1 and 2 respectively and attaching them to the side walls.

  Gears 7 and 8 are respectively attached to the lower ends of the seal rollers 3 and 4, and the gears 7 and 8 are meshed with each other with the same number of teeth. A drive shaft 9 is provided in the vertical direction in the vicinity of the seal roller case 1, a pulley 10 is attached to the upper end of the drive shaft 9, and a gear 11 is attached to the lower end, and the gear 11 is the lower end of the seal roller 3. Is engaged with a gear 7 attached to the. In the figure, reference numerals 12 and 13 denote support arms that support the drive shaft 9 in the vertical direction, and are fixed to the mounting plate 5. A motor 14 is attached to the upper edge of the treatment tank, and a belt 16 is stretched between a pulley 15 attached to the shaft of the motor 14 and a pulley 10 attached to the upper end of the drive shaft 9. . The motor 14 used here is preferably a torque motor that generates a constant rotational force regardless of the rotational speed.

  4 to 6 show a first example of the movement restriction mechanism. The support rollers 17 and 18 are provided at the upper ends of the seal rollers 3 and 4, respectively. Spacers 19, 20, 21, and 22 are provided at the upper ends to contact the support shaft portions 17 and 18 and restrict the movement of the seal rollers 3 and 4, respectively. Although not shown, support shafts are also provided at the lower ends of the seal rollers 3 and 4, respectively, and spacers that contact the support shafts are similarly provided at the lower ends of the seal roller cases 1 and 2.

The movement of the processing tank in the outer direction in a plane parallel to the work surface of the seal rollers 3 and 4 causes the support shaft portions 17 and 18 and the spacers 19 and 21 to contact each other, and at the same time, supports the lower ends of the seal rollers 3 and 4. Since the shaft and the spacer at the lower end of the seal roller cases 1 and 2 are in contact with each other, the seal rollers 3 and 4 and the inner surface of the side wall of the seal roller cases 1 and 2 are not in contact with each other and are limited to a range in which a slight gap is formed. The Further, the movement of the seal rollers 3 and 4 in the direction away from the workpiece surface is in contact with the support shaft portions 17 and 18 and the spacers 20 and 22, and at the same time, the support shaft portion at the lower end of the seal rollers 3 and 4 and the seal roller. When the spacers at the lower ends of the cases 1 and 2 come into contact with each other, the distance between the seal rollers 3 and 4 is limited to a range not exceeding the maximum thickness of the workpiece.

  7 to 9 show a second example of the movement restriction mechanism, and support holes 23 and 24 are provided at the upper ends of the seal rollers 3 and 4, respectively. Support pins 25 and 26 having smaller diameters than the support holes 23 and 24 are inserted into the support holes 23 and 24, respectively. The support pins 25 and 26 are fixed to the lids of the seal roller cases 1 and 2. Although not shown, support holes are also provided at the lower ends of the seal rollers 3 and 4, and it is necessary to insert support pins having a smaller diameter than the support holes in the support holes. The support pins can be appropriately fixed to the seal roller cases 1 and 2 or the tank wall of the treatment tank.

As a result, the movement range of the sealing rollers 3 and 4 is limited to the range of the gap formed between the support holes 23 and 24 and the support pins 25 and 26, and is parallel to the work surface of the sealing rollers 3 and 4. The movement of the treatment tank in the in-plane direction is within the range in which the seal rollers 3 and 4 and the inner surface of the side wall of the seal roller cases 1 and 2 do not come into contact with each other to form a slight gap. Movement in the direction away from the surface vertically is limited to a range in which the distance between the seal rollers 3 and 4 does not exceed the maximum thickness of the workpiece.

  10 to 12 show a third example of the movement limiting mechanism. Sleeves 27 and 28 having a smaller diameter than the seal rollers 3 and 4 are rotatably attached to the upper ends of the seal rollers 3 and 4, respectively. Spacers 29, 30 and 31, 32 are provided at the upper ends of the seal roller cases 1 and 2 so as to contact the sleeves 27 and 28 and restrict the movement of the seal rollers 3 and 4, respectively. Although not shown, sleeves are also attached to the lower ends of the sealing rollers 3 and 4, respectively, and spacers that contact the sleeves are similarly provided at the lower ends of the sealing roller cases 1 and 2.

The sleeve 27 and 28 and the spacers 29 and 31 come into contact with each other in the outward movement of the processing tank in a plane parallel to the work surface of the seal rollers 3 and 4, and at the same time, the sleeves at the lower ends of the seal rollers 3 and 4 and the seal are sealed. When the spacers at the lower ends of the roller cases 1 and 2 are brought into contact with each other, the seal rollers 3 and 4 and the inner wall of the seal roller cases 1 and 2 are not in contact with each other and are limited to a range in which a slight gap is formed. Further, the sleeves 27 and 28 and the spacers 30 and 32 come into contact with each other to move the seal rollers 3 and 4 in the direction away from the work surface, and at the same time, the sleeves at the lower ends of the seal rollers 3 and 4 and the seal roller cases 1 and 2 are contacted. When the spacer at the lower end of the roller contacts with each other, the distance between the seal rollers 3 and 4 is limited to a range not exceeding the maximum thickness of the workpiece.

  In the treatment tank to which the apparatus for preventing leakage of the treatment tank of the present invention configured as described above is attached, for example, the liquid receiving tanks 34 and 35 are integrally formed on the inlet side and the outlet side of the treatment tank 33 as shown in FIG. Workpiece entry / exit ports 38 and 39 are provided on the side walls 36 and 37 on the work inlet side and the outlet side of the processing tank 33. The seal roller cases 1 and 2 are attached to the outer sides of the side walls 36 and 37 by respective attachment plate portions 5 and 6. It is also possible to attach the seal roller cases 1 and 2 to the inside of the side walls 36 and 37, or to form the seal roller cases 1 and 2 integrally with the side walls 36 and 37.

  Work inlets and outlets 40 and 41 serving as workpiece passages are provided on the side wall on the workpiece inlet side of the liquid receiving tank 34 and the side wall on the workpiece outlet side of the liquid receiving tank 35, respectively. In addition, the liquid processing tanks 34 and 35 pass between the sealing roller 3 and the sealing roller 4 and the like, and the processing liquid leaking from the processing tank 33 and staying in the liquid receiving tanks 34 and 35 is pumped and returned to the processing tank 33. A pump (not shown) is provided. Furthermore, when the processing tank 33 is a chemical tank, a processing liquid jet apparatus, a circulation apparatus, a stirring apparatus, etc. are provided. In the case of a plating tank, an anode is provided, and when it is a washing tank, a shower apparatus is provided. It is done.

  A plurality of processing tanks 33 configured as described above are arranged linearly in the order of processing steps to form a plating line, and a transfer device (not shown) for transferring a workpiece is provided. As the transfer device, for example, a mechanism that clamps and transfers the upper end of the workpiece is preferable, but other known mechanisms can be used as appropriate. Each processing tank 33 is filled with necessary processing liquid, washing water, etc. according to the processing steps, and is circulated, stirred, etc. as necessary. The workpiece W is transferred from the workpiece inlet / outlet 40 on the inlet side through the path of the liquid receiving tank 34, the workpiece inlet / outlet 38, the processing tank 33, the workpiece inlet / outlet 39, the liquid receiving tank 35, and the workpiece inlet / outlet 41 as indicated by arrows. Is done.

  Until the workpiece W enters between the sealing roller 3 and the sealing roller 4, the sealing rollers 3 and 4 are pressed against each other by the liquid pressure of the processing liquid in the sealing roller cases 1 and 2 flowing from the processing tank 33. Then, the treatment liquid is prevented from leaking due to close contact with each other. At the same time, the seal rollers 3 and 4 are pushed in the direction of the side wall of the seal roller cases 1 and 2 farther from the processing tank 33, but both the seal rollers 3 and 4 are moved to the inner wall surfaces of the seal roller cases 1 and 2 by the movement limiting mechanism. A slight gap is formed without contact.

  When the workpiece W enters and is transferred between the sealing rollers 3 and 4, the sealing rollers 3 and 4 are in close contact with the workpiece W, respectively, and the leakage of the processing liquid is suppressed. It will be rotated with it. Since the seal rollers 3 and 4 are not in contact with the inner surface of the side wall of the seal roller cases 1 and 2, no frictional force is generated between the seal rollers 3 and 4 and the inner surface of the side wall of the seal roller cases 1 and 2, but the movement is limited. In the first example of the mechanism, since the support shaft portions 17 and 18 and the spacers 19 and 21 come into contact with each other and slide, a frictional force is generated here.

  Further, in the second example of the movement limiting mechanism, between the support holes 23 and 24 and the support pins 25 and 26, and in the third example of the movement limiting mechanism, between the seal rollers 3 and 4 and the sleeves 27 and 28. Each generates friction. In the first example of the movement limiting mechanism, the support shaft portions 17 and 18 are smaller in diameter than the seal rollers 3 and 4 in the sleeve 27 and 28 in the third example of the movement limiting mechanism. If the thicknesses 21, 29, and 31 are adjusted, it is not necessary to reduce the diameter. However, if these are larger in diameter than the sealing rollers 3 and 4, the sealing rollers 3 and 4 are not in close contact with each other, which is inconvenient. The movement limiting mechanism can have any other configuration, but it is inevitable that a frictional force is generated in the movement limiting mechanism. This frictional force is overwhelmingly smaller than the frictional force when the entire length of the sealing rollers 3 and 4 is in contact with the inner wall of the side wall. However, the frictional force is a resistance force when the sealing rollers 3 and 4 are rotated and is constant on the workpiece. Tensile force will work.

  If power is supplied to the motor 14 at this time, the rotational force of the motor 14 is transmitted from the pulley 15 to the drive shaft 9 via the belt 16 and the pulley 10, and further to the seal roller via the gear 11 and the gears 7 and 8. 3 and 4. If the rotational force transmitted from the motor 14 to the seal rollers 3 and 4 is set to be comparable to the resistance force of the movement limiting mechanism, the resistance force is canceled out, and the seal rollers 3 and 4 can rotate with a very small force. The tensile force acting on the workpiece W is extremely small, and even the workpiece W having a small thickness and low strength is not damaged. If this motor 14 is a torque motor that generates a constant rotational force regardless of the rotational speed, there is an advantage that the resistance force of the movement limiting mechanism is surely canceled even when the transfer speed of the workpiece W is changed by the transfer device. is there.

  Furthermore, if the rotational force transmitted from the motor 14 to the sealing rollers 3 and 4 is set to be slightly larger than the resistance force of the movement limiting mechanism, the workpiece W can be given a force in the direction of travel from the sealing rollers 3 and 4 in reverse. Thus, the tensile force for rotating the seal rollers 3 and 4 does not act on the workpiece W. In such a state, the workpiece W is transferred by the transfer device without being affected by the seal rollers 3 and 4. When the rotational force transmitted to the seal rollers 3 and 4 is made larger than the resistance force of the movement limiting mechanism, if the difference between the forces exceeds the frictional force between the seal rollers 3 and 4 and the workpiece W, the seal rollers 3 and 4 Since slip occurs with the workpiece W, it is not preferable to transmit an excessive rotational force to the seal rollers 3 and 4.

  In the treatment tank liquid leakage prevention apparatus of the present invention, the seal rollers 3 and 4 and the side wall inner surfaces of the seal roller cases 1 and 2 are not in close contact with each other, and a slight gap is formed. In comparison, the amount of leakage of the processing liquid is slightly increased, but this type of liquid leakage prevention device is premised on the occurrence of liquid leakage and does not cause any particular problem. Further, the flow direction of the processing liquid leaking from the gap between the seal rollers 3 and 4 and the side wall inner surfaces of the seal roller cases 1 and 2 is perpendicular to the surface of the workpiece W and does not go directly to the gaps 40 and 41. It is not necessary to lengthen the liquid receiving tanks 34 and 35.

  As described above, the sealing rollers 3 and 4 are pressed against each other by the liquid pressure of the processing liquid in the sealing roller cases 1 and 2, but the processing tank 33 and the sealing roller cases 1 and 2 are filled with the processing liquid and sealed. Until the rollers 3 and 4 are pressed against each other, the processing liquid leaks from between the sealing rollers 3 and 4. If a movement restricting mechanism for restricting the movement range of the seal rollers 3 and 4 in the direction away from the workpiece surface is provided, the distance between the seal rollers 3 and 4 does not become too large. There is an advantage that it is possible to reduce the amount of the processing liquid leaking from between the sealing rollers 3 and 4 until the two are pressed against each other.

  The movement limiting mechanism for regulating the movement range of the seal rollers 3 and 4 in the direction perpendicular to the workpiece surface is a movement for regulating the movement of the seal rollers 3 and 4 in the outward direction of the processing tank parallel to the workpiece surface. It can be provided separately from the limiting mechanism. Further, the movement of the seal rollers 3 and 4 in both directions can be restricted by one mechanism as in the second example of the movement restriction mechanism.

  As is apparent from the above description, the sealing rollers 3 and 4 do not contact the inner wall of the sealing roller cases 1 and 2, and therefore no frictional force is generated. The sealing rollers 3 and 4 cancel the resistance force due to the movement limiting mechanism. Since the rotational force is transmitted, the seal rollers 3 and 4 can rotate with a very small force, and the tensile force acting on the workpiece W is extremely small. Will not be damaged. The seal rollers 3 and 4 move within a certain range, but the moving distance is not much greater than the thickness of the workpiece, and the meshing of the gears 7, 8, and 11 is released by the movement. There is no problem in the transmission of the rotational force.

It is a top view of the principal part which shows the structure of the liquid leak prevention apparatus of the processing tank of this invention. It is a longitudinal cross-sectional view in the AA part of FIG. It is a longitudinal cross-sectional view in the BB part of FIG. It is a top view of the principal part which shows the 1st example of a movement restriction | limiting mechanism. It is a longitudinal cross-sectional view of the principal part in CC section of FIG. It is a longitudinal cross-sectional view of the principal part in the DD section of FIG. It is a top view of the principal part which shows the 2nd example of a movement restriction | limiting mechanism. It is a longitudinal cross-sectional view of the principal part in the EE part of FIG. It is a longitudinal cross-sectional view of the principal part in the FF part of FIG. It is a top view of the principal part which shows the 3rd example of a movement restriction | limiting mechanism. It is a longitudinal cross-sectional view of the principal part in the GG part of FIG. It is a longitudinal cross-sectional view of the principal part in the HH part of FIG. It is a top view which shows an example of a processing tank.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 2 Seal roller case 3, 4 Seal roller 5, 6 Mounting plate part 7, 8 Gear 9 Drive shaft 10 Pulley 11 Gear 12, 13 Support arm 14 Motor 15 Pulley 16 Belt 17, 18 Support shaft part 19, 20, 21 , 22 Spacer 23, 24 Support hole 25, 26 Support pin 27, 28 Sleeve 29, 30, 31, 32 Spacer 33 Processing tank 34, 35 Receiving tank 36, 37 Side wall 38, 39, 40, 41 Work entry / exit W Work

Claims (4)

  A vertical work entry / exit is provided on the side wall where the work in the processing tank for processing the flat work enters / exits, and a set of two seal roller storage portions having a U-shaped cross section adjacent to the work entry / exit Opening facing each other, storing the seal roller in the seal roller storage part, abutting or engaging with the upper end and lower end of the seal roller, and processing in a plane parallel to the work surface of each seal roller A movement limiting mechanism is provided in the seal roller storage section or processing tank to limit the movement of the tank to the outside direction so that each seal roller does not contact the inner wall of the side wall of the seal roller storage section and forms a slight gap. An apparatus for preventing liquid leakage in a processing tank, characterized in that a driving device is provided for applying a rotational force in the same direction as a workpiece transfer direction to a roller. Movement that restricts the movement of each seal roller in the direction away from the workpiece surface to the extent that the distance between the seal rollers does not exceed the maximum thickness of the workpiece by contacting or engaging the upper and lower ends of the seal roller. The apparatus for preventing leakage of a processing tank according to claim 1, further comprising a limiting mechanism.   The apparatus for preventing leakage of a processing tank according to claim 1 or 2, wherein the driving device generates a constant rotational force regardless of the rotational speed.   The rotational force applied to the seal roller from the drive device is greater than the resistance force of the movement limiting mechanism, and the difference between the rotational force applied to the seal roller and the resistance force of the movement limiting mechanism does not exceed the frictional force between the seal roller and the workpiece. The apparatus for preventing leakage of a treatment tank according to any one of claims 1 to 3, wherein the apparatus is used.

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