Sponge roller and its roller support shaft

Abstract

The roller support shaft 10 comprises a roller support portion 14 having an outer circumferential surface 15 over which the roller body 2 is placed, an internal flow path 16 extending axially within the roller support portion 14 and closed at one end, a plurality of outlet holes 24 communicating from the internal flow path 16 to the outer circumferential surface 15, and a shaft end opening 18 that opens the other end of the internal flow path 16 axially outward to allow cleaning fluid to flow into the internal flow path 16. The roller support portion 14 has a flow path expansion region 28 at least on the other end side of the axial center 25 where the cross-sectional area S3 of the internal flow path 16 is larger than the opening area S1 of the shaft end opening 18. In the flow path expansion region 28, the area occupancy rate of the plurality of outlet holes 24 relative to the outer circumferential surface 15 is 2% or more and less than 6%.

Description

TECHNICAL FIELD

[0001] The present invention relates to a cleaning sponge roller and a roller support shaft thereof. BACKGROUND ART

[0002] In manufacturing processes of aluminum hard disks, glass disks, wafers, photomasks, liquid crystal glass substrates and the like, high-precision polishing using various abrasive grains such as silicon oxide, alumina and ceria, so-called polishing processing, is performed in order to finish the surface into an extremely highly accurate surface. Abrasive grains and polishing debris adhere to the surface of the polished object after polishing processing, and sufficient cleaning needs to be performed after the polishing processing to remove these substances.

[0003] As cleaning methods after polishing processing, there are methods using ultrasonic cleaning and jet water flow. To obtain high cleaning effects and reduce damage to substrates, scrub cleaning using a sponge body made of an elastic porous body (for example, a polyvinyl acetal-based porous body) is widely used. In addition, as cleaning liquid, not only DI water but also various chemicals suitable for each substrate such as acids, alkalis and solvents are usually used. For example, as cleaning liquids for silicon wafers, a mixed solution of ammonia water and hydrogen peroxide solution, dilute hydrofluoric acid, a mixed solution of hydrochloric acid and hydrogen peroxide solution and the like are known.

[0004] There are various shapes of sponge bodies made of elastic porous bodies. Among these, a brush roller-shaped sponge body having a large number of protrusions on the outer circumferential surface of a cylinder is suitably used for scrub cleaning (cleaning processes). Good cleaning effects can be obtained by rotating the sponge body and continuously bringing the apexes of the protrusions into contact with the cleaning surface of an object to be cleaned. Since the object to be cleaned only contacts the protrusions of the sponge body, there are advantages that compared to a flat sponge body having no protrusions, friction is smaller and damage to the object to be cleaned is less, or impurities easily pass between the protrusions together with the cleaning liquid and are removed from the object to be cleaned.

[0005] In the cleaning process, a dedicated cleaning device is typically used for each substrate, and the cleaning sponge roller consists of a sponge body and a core (roller support shaft). The core is inserted through the inner diameter of the sponge body and fixedly supports the inner circumferential surface of the sponge body. The sponge roller is mounted on the cleaning device by connecting both ends of the core to the rotational drive unit of the cleaning device, and the sponge body is rotated together with the core while the sponge body is in contact with the object to be cleaned (or, in the case of a sponge body with protrusions, the protrusions and the object to be cleaned).

[0006] Some devices supply cleaning fluid to the object to be cleaned or to the sponge body from the top or sides using nozzles, but to further enhance cleaning performance, some devices also supply cleaning fluid from inside the core to the inside of the sponge body.

[0007] A known technique for supplying cleaning fluid from inside a core to the inside (inner surface) of a sponge body involves providing a hollow cylindrical rigid core with an axially extending internal channel, and multiple outflow holes that penetrate from the internal channel to the outer surface of the core. One end of the core is supported so as not to rotate relative to the drive-rotating shaft support of the cleaning device, and the other end is supported so as not to rotate relative to the driven-rotating shaft support of the cleaning device. One end of the internal channel is closed, and the other end is open. At the other end of the core supported by the driven-rotating shaft support, the internal channel and the cleaning fluid supply passage of the cleaning device are in communication. The cleaning fluid is introduced from the cleaning fluid supply passage into the internal channel of the core, supplied from the internal channel to the inner surface of the sponge body through multiple outflow holes, and flows out to the outer surface of the sponge body after passing through the continuous pores of the sponge body. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Patent No. 3628959 [Overview of the initiative] [Problems that the invention aims to solve]

[0009] When a sponge roller is first used after being mounted on the cleaning device, a start-up cleaning is performed as a preparatory step before the actual scrubbing to improve the cleanliness of the sponge. Specifically, after mounting the sponge on the cleaning device, scrubbing is performed using a dummy wafer. During the start-up cleaning, for example, a monitor wafer is used midway through to count the actual number of defects on the wafer, and the start-up is completed when it is confirmed that the number of defects has fallen below a certain number. Alternatively, the number of wafers that need to be processed (a specified number) until the number of defects on the wafer is sufficiently reduced can be determined in advance, and the start-up is completed when the cleaning of the specified number of wafers is finished.

[0010] During startup cleaning, in the upstream region of the core where cleaning water flows in, the flow of cleaning fluid from the internal channel to the outlet may be more difficult compared to the downstream region. If the amount of cleaning fluid flowing from the internal channel to the outlet varies between the upstream and downstream sides, variations will occur in the amount of cleaning fluid flowing out from the outer surface of the core (the amount of cleaning fluid supplied to the sponge body). This can result in startup cleaning not being performed equally across the entire axial region, potentially leading to the startup cleaning being completed with a low level of cleanliness of the sponge body in the upstream side, or requiring a long time for startup cleaning. If startup cleaning is completed with a low level of cleanliness of the sponge body, it may lead to wafer contamination during subsequent use.

[0011] Therefore, the present invention aims to provide a cleaning sponge roller and its roller support shaft that can perform startup cleaning efficiently and reliably. [Means for solving the problem]

[0012] To achieve the above objective, a first aspect of the present invention is a cleaning sponge roller in which the inner circumferential surface of a cylindrical roller body made of an elastic porous material is supported on a roller support shaft, wherein the roller support shaft comprises a roller support portion having an outer circumferential surface over which the roller body is placed, an internal flow path extending axially within the roller support portion and closed at one end, a plurality of outflow holes communicating from the internal flow path to the outer circumferential surface, and a shaft end opening that opens the other end of the internal flow path axially outward to allow cleaning liquid to flow into the internal flow path. The roller support portion has a flow path expansion region in which the cross-sectional area of ​​the internal flow path is larger than the opening area of ​​the shaft end opening, at least on the other end side of the axial center, and in the flow path expansion region, the area occupancy rate of the plurality of outflow holes relative to the outer circumferential surface is 2% or more and less than 6%.

[0013] A second aspect of the present invention is a cleaning sponge roller in which the inner circumferential surface of a cylindrical roller body made of an elastic porous material is supported on a roller support shaft, wherein the roller support shaft comprises a roller support portion having an outer circumferential surface over which the roller body is placed, an internal flow path extending axially within the roller support portion and closed at one end, a plurality of outlet holes communicating from the internal flow path to the outer circumferential surface, and a shaft end opening that opens the other end of the internal flow path axially outward to allow cleaning liquid to flow into the internal flow path. The roller support portion has a flow path expansion region in which the cross-sectional area of ​​the internal flow path is larger than the opening area of ​​the shaft end opening, at least on the other end side of the axial center, and the ratio of the cross-sectional area of ​​the internal flow path in the flow path expansion region to the opening area of ​​the shaft end opening is 120% or more.

[0014] A third aspect of the present invention is a sponge roller according to the second aspect, wherein in the flow path expansion region, the area occupancy rate of the plurality of outflow holes relative to the outer surface is 2% or more and less than 6%.

[0015] A fourth aspect of the present invention is a sponge roller according to any of the first to third aspects, wherein both the cross-section of the internal flow path and the shaft end opening are circular in shape, and the diameter of the internal flow path is larger than the diameter of the shaft end opening.

[0016] A fifth aspect of the present invention is a sponge roller according to any of the first to fourth aspects, wherein the entire axial area of ​​the roller support portion is the flow path expansion region.

[0017] A sixth aspect of the present invention is a roller support shaft that supports the inner circumferential surface of a cylindrical roller body made of an elastic porous material, comprising: a roller support portion having an outer circumferential surface over which the roller body is placed; an internal flow path extending axially within the roller support portion and closed at one end; a plurality of outlet holes communicating from the internal flow path to the outer circumferential surface; and a shaft end opening that opens the other end of the internal flow path axially outward to allow cleaning liquid to flow into the internal flow path. The roller support portion has a flow path expansion region in which the cross-sectional area of ​​the internal flow path is larger than the opening area of ​​the shaft end opening, at least on the other end side of the axial center, and in the flow path expansion region, the area occupancy rate of the plurality of outlet holes relative to the outer circumferential surface is 2% or more and less than 6%.

[0018] A seventh aspect of the present invention is a roller support shaft that supports the inner circumferential surface of a cylindrical roller body made of an elastic porous material, comprising: a roller support portion having an outer circumferential surface over which the roller body is placed; an internal flow path extending axially within the roller support portion and closed at one end; a plurality of outlet holes communicating from the internal flow path to the outer circumferential surface; and a shaft end opening that opens the other end of the internal flow path axially outward to allow cleaning liquid to flow into the internal flow path. The roller support portion has a flow path expansion region in which the cross-sectional area of ​​the internal flow path is larger than the opening area of ​​the shaft end opening, at least on the other end side of the axial center, and the ratio of the cross-sectional area of ​​the internal flow path in the flow path expansion region to the opening area of ​​the shaft end opening is 120% or more.

[0019] An eighth aspect of the present invention is a roller support shaft according to the seventh aspect, wherein in the flow path expansion region, the area occupancy rate of the plurality of outflow holes relative to the outer circumferential surface is 2% or more and less than 6%.

[0020] A ninth aspect of the present invention provides the roller support shaft according to any one of the sixth to eighth aspects, wherein both a cross-section of the internal flow path and the shaft end opening are circular, and a diameter of the internal flow path is larger than a diameter of the shaft end opening.

[0021] A tenth aspect of the present invention provides the roller support shaft according to any one of the sixth to ninth aspects, wherein the entire axial region of the roller support portion is the flow path enlarged region. Effects of the Invention

[0022] According to the present invention, the roller support portion of the roller support shaft has a flow path enlarged region where a cross-sectional area of an internal flow path is larger than an opening area of a shaft end opening, at least on the other end side relative to an axial center, an area occupancy rate of the plurality of outflow holes with respect to an outer peripheral surface in the flow path enlarged region is 2% or more and less than 6%, and / or a ratio of a cross-sectional area of the internal flow path in the flow path enlarged region to an opening area of the shaft end opening is 120% or more. Therefore, start-up cleaning for improving the cleanliness of a sponge body can be performed efficiently and reliably. Brief Description of the Drawings

[0023] [Figure 1] FIG. 1 is a side view, partially in cross section, of a core of a sponge roller according to an embodiment of the present invention. [Figure 2] FIG. 2 is a side cross-sectional view showing a state before one end of the core of FIG. 1 is attached to a driving-side shaft support portion. [Figure 3] FIG. 3 is a side cross-sectional view showing a state where one end of the core of FIG. 1 is attached to a driving-side shaft support portion. [Figure 4] FIG. 4 is a side cross-sectional view showing a state before the other end of the core of FIG. 1 is attached to a driven-side shaft support portion. [Figure 5] FIG. 5 is a side cross-sectional view showing a state where the other end of the core of FIG. 1 is attached to a driven-side shaft support portion. [Figure 6] FIG. 6 is a cross-sectional view of the core of FIG. 1 taken along a plane orthogonal to the axial direction, where (a) shows one embodiment and (b) shows another embodiment. [Figure 7] FIG. 7 is a view of one end of the core of FIG. 2 as viewed from the outside in the axial direction. [Figure 8]This is a view of the other end of the core in Figure 4, seen from the axial direction outward. [Figure 9] This is a schematic diagram of an evaluation test apparatus for assessing core performance. [Figure 10] Figure 9 is a cross-sectional view of the evaluation test apparatus. [Figure 11] This table shows the specifications of the cores of the examples and comparative examples. [Figure 12] This table shows the test results for the examples and comparative examples. [Figure 13] This figure shows the test results for Example 1. [Figure 14] This figure shows the test results for Example 2. [Figure 15] This figure shows the test results for Example 3. [Figure 16] This figure shows the test results for Example 4. [Figure 17] This figure shows the test results for Example 5. [Figure 18] This figure shows the test results for Example 6. [Figure 19] This figure shows the test results of the comparative example. [Modes for carrying out the invention]

[0024] A cleaning sponge roller 1 according to one embodiment of the present invention will be described with reference to Figures 1 to 8. As shown in Figure 1, the sponge roller 1 comprises a sponge body (roller body) 2 and a core (roller support shaft) 10.

[0025] The sponge body 2 is cylindrical in shape, and the core 10 is mounted on the inner diameter portion of the sponge body 2. The outer surface of the sponge body 2 may be a flat curved surface, or it may be a brush shape in which multiple protrusions 3 integrally protrude from the curved surface. The example in Figure 1 is a brush-shaped sponge body 2.

[0026] The sponge body 2 is made of an elastic porous material having fine, continuous pores, such as a polyvinyl acetal porous material (PVAt porous material) that is elastic in a hydrated state. The PVAt porous material hardens in a dry state and softens in a wet state. Furthermore, the PVAt porous material has excellent water absorption and water retention properties, exhibits desirable flexibility and moderate rebound elasticity when wet, and also has excellent abrasion resistance.

[0027] The core 10 is inserted through the inner diameter of the sponge body 2 and fixedly supports the inner circumferential surface of the sponge body 2. For example, the outer circumference of the core 10 and the inner circumferential surface of the sponge body 2 may be fixed together with an adhesive, or the outer diameter of the core 10 may be made larger than the inner diameter of the sponge body 2, and the core 10 may be press-fitted into the inner diameter of the sponge body 2, thereby fixedly supporting the sponge body 2 on the core 10 by the elastic force of the sponge body 2. Furthermore, when manufacturing the sponge body 2, the core 10 may be used instead of the core rod that forms the hollow portion of the sponge body 2, thereby fixing or supporting the sponge body 2 on the core 10. In this case, after the reaction, the sponge body 2 is removed from the mold with the core 10 still attached, washed with water, and enters the outflow hole 24 described later. With this fixed support, the sponge body 2 rotates together with the core 10 around the rotation axis 4 when attached to the washing device.

[0028] The core 10 is cylindrical in shape and made of metal or hard resin. It integrally comprises a cylindrical core body 11 that penetrates axially (in the direction along the rotation axis 4), a drive-side shaft end 12 fixed to one end (drive side) of the core body 11, and a driven-side shaft end 13 fixed to the other end (driven side) of the core body 11. The material of the core 10 is not particularly limited, but when using a hard resin material, it can be appropriately selected from polyethylene, polypropylene, polyacetal, polycarbonate, fluororesin, and rigid polyvinyl chloride, taking into consideration strength and resistance to chemicals used. Furthermore, as a molding method for the core 10, for example, injection molding, casting, or grinding can be appropriately selected.

[0029] The sponge body 2 is placed over the outer circumferential surface of the core body 11, and the inner circumferential surface of the core body 11 defines an internal flow path 16 that extends in the axial direction. The cross-section of the internal flow path 16 (cross-section perpendicular to the axial direction) is a uniform circular shape in the axial direction, and one end (downstream side) of the internal flow path 16 is closed by the drive-side shaft end 12. A through hole 17 that penetrates in the axial direction is formed in the center of the driven-side shaft end 13, and the other end (upstream side) of the internal flow path 16 communicates with the outside through the through hole 17. The inner periphery of the through hole 17 defines a circular shaft end opening 18 that opens the other end of the internal flow path 16 axially outward to allow cleaning fluid to flow into the internal flow path 16. Flange-shaped portions 29 may be fixed to the outer circumferential surfaces of one end and the other end (both ends) of the core 10 to prevent axial movement and deformation of the sponge body 2 relative to the core 10.

[0030] As shown in Figures 2 to 5, the cleaning device is provided with a drive-side shaft support 31 that supports the drive-side shaft end 12 of the core 10 and a driven-side shaft support 32 that supports the driven-side shaft end 13, both facing each other. The core 10 is supported by being sandwiched from both axial sides by the drive-side shaft support 31 and the driven-side shaft support 32, and as the drive-side shaft support 31 rotates, the core 10 and the driven-side shaft support 32 rotate in response. The drive-side shaft support 31 is provided to be movable along the rotation axis 4 within a predetermined range and is biased toward the driven-side shaft support 32 by a biasing member such as a spring (not shown). The core 10 can be attached to and detached from the cleaning device by grasping the drive-side shaft support 31 and moving the drive-side shaft support 31 away from the driven-side shaft support 32 against the biasing force. Note that the structure for detachably attaching the core 10 to the cleaning device is not limited to the above, and any attachment structure can be used.

[0031] As shown in Figures 2, 3, and 7, the end face of the drive-side shaft support portion 31 has a rectangular drive-side engagement hole 33 and a drive-side contact projection 34 that tapers out from the center of the bottom surface of the drive-side engagement hole 33. The corresponding drive-side shaft end portion 12 has a rectangular drive-side engagement projection 19 that is inserted into and engages with the drive-side engagement hole 33, and a tapered hole-shaped drive-side contact recess 20 that contacts the drive-side contact projection 34 when the drive-side engagement projection 19 is inserted into the drive-side engagement hole 33.

[0032] The drive-side shaft end 12 is fitted and attached to the drive-side shaft support 31 by engaging the drive-side engagement projection 19 with the drive-side engagement hole 33 and bringing the drive-side contact projection 34 into contact with the drive-side contact recess 20. The engagement between the drive-side engagement hole 33 and the drive-side engagement projection 19 prevents relative rotation between the drive-side shaft support 31 and the drive-side shaft end 12. Furthermore, by bringing the tapering drive-side contact projection 34 into contact with the tapered hole-shaped drive-side contact recess 20, the drive side of the core 10's axis can be aligned with the rotation center of the drive-side shaft support 31.

[0033] As shown in Figures 4, 5, and 8, the end face of the driven shaft support portion 32 is formed with a rectangular driven-side engagement projection 35 and a driven-side contact projection 36 that tapers off from the center of the top surface of the driven-side engagement projection 35. The corresponding through hole 17 of the driven shaft end portion 13 has a rectangular driven-side engagement hole 21 into which the driven-side engagement projection 35 is inserted and engages, a tapered driven-side contact recess 22 that contacts the driven-side contact projection 36 when the driven-side engagement projection 35 is inserted into the driven-side engagement hole 21, and a communication hole 23 that connects the driven-side contact recess 22 and the internal flow path 16. The driven-side engagement hole 21, the driven-side contact recess 22, and the communication hole 23 are arranged in order from the end face of the driven shaft end portion 13 toward the internal flow path 16, and the inner end periphery of the communication hole 23 defines the shaft end opening 18.

[0034] The driven shaft end 13 is fitted and attached to the driven shaft support 32 by engaging the driven-side engaging projection 35 with the driven-side engaging hole 21 and bringing the driven-side contact projection 36 into contact with the driven-side contact recess 22. The engagement between the driven-side engaging hole 21 and the driven-side engaging projection 35 prevents relative rotation between the driven-side shaft support 32 and the driven-side shaft end 13. Furthermore, by bringing the tapering driven-side contact projection 36 into contact with the tapered hole-shaped driven-side contact recess 22, the driven side of the core 10's axis can be aligned with the rotation center of the driven-side shaft support 32.

[0035] A circular hole-shaped cleaning fluid supply passage 37 is formed in the center of the driven shaft support portion 32, penetrating in the axial direction. By attaching the core 10 to the cleaning device, the internal flow path 16 communicates with the cleaning fluid supply passage 37 via the shaft end opening 18. A cleaning fluid supply pipe (not shown) is connected to the cleaning fluid supply passage 37, and cleaning fluid is introduced from the cleaning fluid supply pipe into the internal flow path 16 via the cleaning fluid supply passage 37.

[0036] As shown in Figure 1, a sponge body 2 is placed over the outer circumferential surface 15 of the roller support portion 14 of the core 10, and the roller support portion 14 has a plurality of outflow holes 24 that communicate from the internal flow path 16 to the outer circumferential surface 15. The inner diameter of the outflow holes 24 is smaller than the inner diameter of the internal flow path 16.

[0037] As shown in Figure 5, the cleaning fluid introduced into the internal flow path 16 from the cleaning fluid supply passage 37 of the driven shaft support portion 32 flows through a plurality of outlet holes 24 and is supplied to the inner circumferential surface of the sponge body 2, and flows out to the outer surface of the sponge body 2 after passing through the continuous pores of the sponge body 2. In this embodiment, the roller support portion 14 is provided only on the core body 11, but the roller support portion 14 may also extend from the core body 11 to the drive shaft end portion 12 and / or the driven shaft end portion 13, and outlet holes 24 may be formed on the drive shaft end portion 12 and / or the driven shaft end portion 13.

[0038] In the present embodiment, the cross-sectional shape of the core 10 (the annular shape of the core body 11 shown in FIG. 6) is uniform in the axial direction, and the diameter (inner diameter) of the internal flow path 16 is uniform (the same diameter) in the axial direction over the entire area of the roller support portion 14. The plurality of outflow holes 24 are arranged substantially uniformly on the outer peripheral surface 15 of the roller support portion 14. In the arrangement pattern of the outflow holes 24 of the present embodiment, the outflow holes 24 are arranged at equal intervals along the axial direction, and are arranged in a grid pattern at equal intervals along the circumferential direction, but other arrangement patterns such as a staggered arrangement may also be employed. Further, the plurality of outflow holes 24 may penetrate radially from the rotation shaft as shown in FIG. 6(a), or may penetrate non-radially as shown in FIG. 6(b).

[0039] As shown in FIG. 4, the diameter (inner diameter) of the shaft end opening 18 is larger than the diameter (inner diameter) of the cleaning liquid supply path 37, and the diameter (inner diameter) of the internal flow path 16 is larger than the diameter of the shaft end opening 18. That is, the opening area S1 of the shaft end opening 18 is larger than the cross-sectional area (cross-sectional area orthogonal to the axis) S2 of the cleaning liquid supply path 37, and the cross-sectional area (cross-sectional area orthogonal to the axis) S3 of the internal flow path 16 is larger than the opening area S1 of the shaft end opening 18 (S2 < S1 < S3). In the present embodiment, in a state where the driven-side shaft end portion 13 is fitted and attached to the driven-side shaft support portion 32, the tip end of the driven-side contact projection 36 reaches the shaft end opening 18 (see FIG. 5), the cross-sectional area S2 of the cleaning liquid supply path 37 serves as the cleaning liquid flow path cross-sectional area (inlet cross-sectional area) at the shaft end opening 18, and the cleaning liquid flow path cross-section expands from the shaft end opening 18 toward the internal flow path 16 (S2 < S3).

[0040] As shown in FIG. 1, the roller support portion 14 of the core 10 can be divided into a downstream region 26 on the drive-side shaft end 12 side from the axial center (the longitudinal center of the attached sponge body 2) 25, and an upstream region 27 on the driven-side shaft end 13 side from the axial center 25. In the core 10 of the present embodiment, the cross-sectional area S3 of the internal flow path 16 is equal to the cross-sectional area of the shaft end opening 18 over the entire area of the roller support portion 14 (both the downstream region 26 and the upstream region 27) (opening area) which is larger than S1. That is, in the present embodiment, the entire area of the roller support portion 14 is a flow path enlarged region 28 where the cross-sectional area S3 of the internal flow path 16 is larger than the opening area S1 of the shaft end opening 18.

[0041] The ratio of the cross-sectional area S3 of the internal flow path 16 of the flow path expansion region 28 to the opening area S1 of the shaft end opening 18 (flow path cross-sectional area ratio) is in the range exceeding 100% (the range where the cross-sectional area S3 of the internal flow path 16 is larger than the opening area S1 of the shaft end opening 18). The flow path cross-sectional area ratio can be calculated by (cross-sectional area S3 of the internal flow path 16 of the flow path expansion region 28) / (opening area S1 of the shaft end opening 18) × 100. A flow path cross-sectional area ratio of 120% or more is preferable.

[0042] Furthermore, in the flow path expansion region 28, the opening ratio (circumferential opening ratio) of the outer surface 15 of the roller support portion 14 due to the multiple outflow holes 24 is set to 2% or more and less than 6%. The circumferential opening ratio (%) of the flow path expansion region 28 is the area occupancy ratio of the multiple outflow holes 24 relative to the outer surface 15 of the roller support portion 14, and can be calculated by (sum of the opening areas of all outflow holes 24 present in the flow path expansion region 28) / (area of ​​the outer surface 15 of the flow path expansion region 28) × 100.

[0043] Furthermore, the roller support portion 14 only needs to have the flow path expansion region 28 at least on the other end side (upstream region 27) of the axial center 25, and the circumferential opening ratio in the flow path expansion region 28 of the upstream region 27 should be 2% or more and less than 6%. For example, a part of the upstream region 27 or a part or all of the downstream region 26 may be a non-flow path expansion region where the cross-sectional area S3 of the internal flow path 16 is less than or equal to the opening area S1 of the axial end opening 18, and the circumferential opening ratio in the non-flow path expansion region may be 6% or more.

[0044] The following reasons explain why the flow path cross-sectional area ratio and circumferential opening ratio of the core 10 are preferable for the startup cleaning of the sponge roller 1 within the above range.

[0045] The cleaning fluid introduced into the core 10 from the cleaning fluid supply pipe via the cleaning fluid supply passage 37 of the driven shaft support portion 32 flows through the internal flow path 16 toward the downstream drive shaft end portion 12. The cleaning fluid flowing through the internal flow path 16 also tends to move radially outward due to the rotation of the core 10. In the upstream region 27 of the roller support portion 14, if the cross-sectional area S3 of the internal flow path 16 is less than or equal to the cross-sectional area S1 of the shaft end opening 18, the downstream momentum of the cleaning water flowing from the shaft end opening 18 into the internal flow path 16 is maintained or increased. As a result, the amount of cleaning fluid flowing out to the sponge body 2 through the outflow hole 24 tends to be less in the upstream region 27 than in the downstream region 26.

[0046] In contrast, in this embodiment, the cross-sectional area S3 of the internal flow path 16 in the upstream region 27 is set to be larger than the cross-sectional area S1 of the shaft end opening 18. This reduces the force with which the cleaning liquid flowing from the shaft end opening 18 into the internal flow path 16 moves downstream, allowing the cleaning liquid to flow smoothly radially outward.

[0047] Furthermore, if the cross-sectional area S3 of the internal flow path 16 of the upstream region 27 is set to be larger than the cross-sectional area S1 of the shaft end opening 18, and the circumferential opening ratio of the upstream region 27 is too high, the amount of cleaning fluid flowing out from the upstream region 27 will become too large, and there is a possibility that the amount of cleaning fluid flowing out from the downstream region 26 will be extremely small compared to the upstream region 27. In order to prevent this imbalance caused by the reversal phenomenon, in this embodiment the circumferential opening ratio of the upstream region 27 is set to less than 6%. Also, if the circumferential opening ratio of the upstream region 27 is too low, flow If the amount of cleaning fluid flowing out from the side region 27 becomes too small, there is a possibility that the amount of cleaning fluid flowing out from the upstream region 27 will be significantly less than that from the downstream region 26. To prevent this imbalance caused by the reversal phenomenon, in this embodiment, the circumferential opening ratio of the upstream region 27 is set to 2% or more. This allows the cleaning fluid to flow out evenly throughout the entire axial area of ​​the core 10, and enables suitable cleaning of the sponge roller 1 from the upright position.

[0048] Furthermore, in this embodiment, since the entire area of ​​the roller support section 14 is used as a flow path expansion region 28, the internal pressure of the internal flow path 16 is lower than the inflow pressure of the cleaning fluid from the shaft end opening 18 throughout the entire area of ​​the roller support section 14. As a result, the internal pressure difference of the internal flow path 16 in the axial direction of the roller support section 14 can be kept small, and the cleaning fluid can be discharged in a balanced manner throughout the entire area of ​​the roller support section 14, allowing for optimal cleaning of the sponge roller 1 from the upright position.

[0049] (Evaluation test) The performance of the core 10 according to the embodiment of the present invention will be described below in comparison with a comparative example. Figure 9 is a schematic diagram of the evaluation test apparatus 40 for evaluating the performance of the core 10, viewed from diagonally above, and Figure 10 is a cross-sectional view of the evaluation test apparatus 40 in Figure 9.

[0050] As shown in Figure 9, the evaluation test apparatus 40 is provided with a drive-side shaft support 31 and a driven-side shaft support 32, which are configured similarly to those of the cleaning apparatus. The core 10 is supported by being sandwiched from both axial sides by the drive-side shaft support 31 and the driven-side shaft support 32, and as the drive-side shaft support 31 rotates, the core 10 and the driven-side shaft support 32 rotate in response. A circular hole-shaped cleaning fluid supply passage 37 (see Figure 5) is formed in the center of the driven-side shaft support 32, penetrating in the axial direction. By attaching the core 10 to the evaluation test apparatus 40, the internal flow path 16 communicates with the cleaning fluid supply passage 37 via the shaft end opening 18 of the driven-side shaft end 13 (see Figure 5). A liquid supply pipe (not shown) is connected to the cleaning fluid supply passage 37, and a test liquid is introduced from the liquid supply pipe into the internal flow path 16 via the cleaning fluid supply passage 37. In this example, water W is used as the test liquid, but other liquids may be used.

[0051] In order to efficiently and reliably improve the cleanliness of the sponge body 2 through the initial cleaning process, it is required that the variation in the amount of cleaning liquid flowing out from the outer circumferential surface 15 of the roller support portion 14 via the outflow holes 24 is small throughout the entire axial area of ​​the roller support portion 14 of the core 10, and that the cleaning liquid is supplied evenly to the sponge body 2. In the comparative test, for each of several cores 10 with different shapes, the roller support portion 14 was divided into 10 equal parts along the axial direction, and the amount of water W flowing out from each region was measured to compare the variation in the amount of water W flowing out from the outer circumferential surface 15 of the roller support portion 14.

[0052] As shown in Figures 9 and 10, the evaluation test apparatus 40 comprises a container 41, a cover 42, and a plurality of partition walls 43 (43A to 43I) (9 in this example). The container 41 is positioned below the sponge roller 1 to collect the water W discharged from the sponge body 2. The cover 42 covers the top and sides of the sponge body 2 to introduce the water W discharged from the sponge body 2 into the container 41. The plurality of partition walls 43 are arranged at equal intervals along the axial direction of the sponge roller 1 in the apparatus space 44 above and to the sides of the sponge body 2 surrounded by the cover 42, dividing the apparatus space 44 partitioned by the cover 42 into a plurality of divided spaces 45 (45A to 45J) (10 in this example). In this embodiment, the upstreammost (leftmost in Figure 9) is referred to as the first divided space 45A, and the divisions proceed in ascending order downstream, with the downstreammost (rightmost in Figure 9) being referred to as the tenth divided space 45J.

[0053] The container 41 is divided into multiple sections 46 (46A to 46J) (10 in this example) from which water W flowing or falling through each divided space 45A to 45J can be collected individually. In this embodiment, the upstream section (left end in Figure 9) is referred to as the 1st section 46A, and the sections are numbered in ascending order towards the downstream side, with the downstream section (right end in Figure 9) being referred to as the 10th section 46J. Sections 46A to 46J are located vertically below each of the divided spaces 45A to 45J and open upwards.

[0054] In the first compartment 46A of the container 41, water W that flows out from the outflow hole 24 in the upstreammost region (first region) of the 10 regions obtained by dividing the roller support portion 14 of the core 10 into 10 equal parts along the axial direction, passes through the sponge body 2 and is discharged, flows down or falls through the divided space 45A of the device's internal space 44 and is collected. In the second compartment 46B, water W that flows out from the outflow hole 24 in the second region from the upstream side of the 10 regions of the roller support portion 14 (second region), passes through the sponge body 2 and is discharged, flows down or falls through the divided space 45B of the device's internal space 44 and is collected. Similarly, the third to tenth regions of the roller support portion 14 correspond to the divided spaces 45C to 45J of the device's internal space 44 and the compartments 46C to 46J of the container 41. In each section 46C to 46J of the container 41, the water W that flows out from the respective outflow holes 24 in the third to tenth regions of the roller support section 14, passes through the sponge body 2, and is discharged, flows down or falls through the respective divided spaces 45C to 45J of the internal space 44 of the device and is collected. The first to fifth regions of the roller support section 14 of the core 10 correspond to the upstream region 27, and the sixth to tenth regions correspond to the downstream region 26.

[0055] The evaluation test was conducted by mounting the core 10, which is equipped with a sponge body 2, to the evaluation test apparatus 40 by supporting the drive-side shaft end 12 and the driven-side shaft end 13 of the core 10 with the drive-side shaft support part 31 and the driven-side shaft support part 32. The sponge body 2 used in the example and the comparative example had the same shape and physical properties (average pore diameter, average porosity, etc.).

[0056] In the test, the core 10 was rotated at a predetermined constant speed, and water W was supplied from the cleaning fluid supply pipe to the internal flow path 16 via the cleaning fluid supply passage 37. During the water W supply, the supply pressure of water W from the liquid supply pipe to the internal flow path 16 was adjusted to be constant. The rotation speed of the core 10 was set to 200 rpm, and the water W supply rate (flow rate) per unit time was set to 1000 mL / min.

[0057] After a predetermined time had elapsed since the start of the test, the rotation of the core 10 and the supply of water W were stopped, and the amount of water W accumulated in each section 46A to 46J of the container 41 was measured. In the performance evaluation, the smaller the difference in the amount of water accumulated in each section 46A to 46J (the smaller the variation between sections 46A to 46J), the more suitable the core 10 was for startup cleaning.

[0058] (Example 1) In Example 1, an evaluation test was conducted using a core 10 that had substantially the same shape as the above embodiment (the entire area of ​​the roller support portion 14 was the flow path expansion region 28), with an inner diameter of 30.0 mm for the internal flow path 16 (flow path expansion region 28), an inner diameter of 18.9 mm for the shaft end opening 18, an inner diameter of 4.0 mm for the outflow hole 24, 152 outflow holes 24, a flow path cross-sectional area ratio of 252%, and a circumferential opening ratio of 5.00% (see Figure 11).

[0059] (Example 2) In Example 2, an evaluation test was conducted using a core 10 that had substantially the same shape as the above embodiment, with an inner diameter of 30.0 mm for the internal flow path 16 (flow path expansion region 28), an inner diameter of 18.9 mm for the shaft end opening 18, an inner diameter of 2.6 mm for the outflow hole 24, 152 outflow holes 24, a flow path cross-sectional area ratio of 252%, and a circumferential opening ratio of 2.11% (see Figure 11).

[0060] (Example 3) In Example 3, an evaluation test was conducted using a core 10 that had substantially the same shape as the above embodiment, with an inner diameter of 30.0 mm for the internal flow path 16 (flow path expansion region 28), an inner diameter of 18.9 mm for the shaft end opening 18, an inner diameter of 3.0 mm for the outflow hole 24, 296 outflow holes 24, a flow path cross-sectional area ratio of 252%, and a circumferential opening ratio of 5.48% (see Figure 11).

[0061] (Example 4) In Example 4, an evaluation test was conducted using a core 10 that had substantially the same shape as the above embodiment, with an inner diameter of 27.0 mm for the internal flow path 16 (flow path expansion region 28), an inner diameter of 18.9 mm for the shaft end opening 18, an inner diameter of 2.6 mm for the outflow hole 24, 152 outflow holes 24, a flow path cross-sectional area ratio of 204%, and a circumferential opening ratio of 2.11% (see Figure 11).

[0062] (Example 5) In Example 5, an evaluation test was conducted using a core 10 that had substantially the same shape as the above embodiment, with an inner diameter of 24.0 mm for the internal flow path 16 (flow path expansion region 28), an inner diameter of 18.9 mm for the shaft end opening 18, an inner diameter of 2.6 mm for the outflow hole 24, 152 outflow holes 24, a flow path cross-sectional area ratio of 161%, and a circumferential opening ratio of 2.11% (see Figure 11).

[0063] (Example 6) In Example 6, an evaluation test was conducted using a core 10 that had substantially the same shape as the above embodiment, with an inner diameter of 21.0 mm for the internal flow path 16 (flow path expansion region 28), an inner diameter of 18.9 mm for the shaft end opening 18, an inner diameter of 2.6 mm for the outflow hole 24, 152 outflow holes 24, a flow path cross-sectional area ratio of 123%, and a circumferential opening ratio of 2.11% (see Figure 11).

[0064] (Comparative example) In the comparative example, the shape was substantially the same as the embodiment described above, except that the entire roller support portion 14 was a non-expanded flow path region (the opening area of ​​the shaft end opening 18 and the cross-sectional area of ​​the internal flow path 16 of the roller support portion 14 were the same). An evaluation test was conducted using a core 10 with an inner diameter of 18.7 mm for the internal flow path 16 and shaft end opening 18, an inner diameter of 2.6 mm for the outflow hole 24, 80 outflow holes 24, a flow path cross-sectional area ratio of 100%, and a circumferential opening ratio of 1.24% (see Figure 11). Since the comparative example did not have a flow path expansion region 28, the flow path cross-sectional area ratio was calculated using the cross-sectional area of ​​the internal flow path 16 of the upstream region 27 instead of the cross-sectional area of ​​the internal flow path 16 of the flow path expansion region 28.

[0065] (Test results) The test results for Example 1 are shown in Figures 12 and 13, for Example 2 in Figures 12 and 14, for Example 3 in Figures 12 and 15, for Example 4 in Figures 12 and 16, for Example 5 in Figures 12 and 17, for Example 6 in Figures 12 and 18, and for the comparative example in Figures 12 and 19. The horizontal axis in Figures 13 to 19 represents the axial position of the core 10, and each number on the horizontal axis indicates each region (region 1 to region 10) of the roller support section 14 of the core 10. The vertical axis in Figures 13 to 19 represents the ratio of the amount of water accumulated in each section 46 per unit time to the amount of water supplied to the internal flow path 16 per unit time (total water supply), and corresponds to the percentage of water outflow from each region (region 1 to region 10) of the roller support section 14 of the core 10. In each of Examples 1-6 and the Comparative Example, the sum of the outflow rates for regions 1-10 is 100%. However, in Figure 12, the values ​​for the outflow rates of each region are rounded, so the calculated sum of these values ​​does not necessarily equal 100%.

[0066] The test results showed that the difference (range) between the maximum and minimum values ​​of the discharge rate was 2.1% for Example 1, 5.6% for Example 2, 6.3% for Example 3, 6.2% for Example 4, 7.6% for Example 5, 3.5% for Example 6, and 12.7% for the Comparative Example. The standard deviation of the discharge rate was 0.7% for Example 1, 1.5% for Example 2, 2.4% for Example 3, 1.7% for Example 4, 2.2% for Example 5, 1.1% for Example 6, and 4.2% for the Comparative Example. Thus, the range and standard deviation of the discharge rate were smaller for Examples 1-6 than for the Comparative Example, and among Examples 1-6, Example 1 had the smallest range and standard deviation. This indicates that Examples 1-6 showed less variation in water discharge volume depending on the axial position compared to Comparative Example 1, making them suitable for startup cleaning, and that Example 1 was the most suitable among Examples 1-6.

[0067] Furthermore, from the results of Examples 1 to 6 and the comparative examples, it was found that a flow channel cross-sectional area ratio of 120% or more is preferable, a circumferential opening ratio of 2% or more and less than 6% is preferable, and 2.2% or more and 5.4% or less is even more preferable.

[0068] As described above, the core 10 of this embodiment allows the cleaning fluid to flow out in a balanced manner throughout the entire axial area of ​​the core 10, and enables effective cleaning of the sponge roller 1 from the upright position.

[0069] It should be noted that the present invention is not limited to the embodiments and examples described above, and various modifications are possible depending on the design, etc., as long as they do not depart from the technical idea of ​​the present invention.

[0070] For example, in the above embodiment, the drive shaft side of the internal flow path 16 is closed by the drive shaft end 12, a through hole 17 (shaft end opening 18) is formed in the driven shaft end 13, and a cleaning fluid supply passage 37 is provided in the driven shaft support 32, thereby introducing cleaning fluid from the driven side to the internal flow path 16. However, conversely, the driven side may be closed and cleaning fluid may be introduced from the drive side to the internal flow path 16. Specifically, the driven side of the internal flow path may be closed by the driven shaft end (not shown), a through hole (shaft end opening) is formed in the drive shaft end, and a cleaning fluid supply passage 37 may be provided in the drive shaft support 31.

[0071] Furthermore, the configuration in which the drive-side shaft end 12 and the driven-side shaft end 13 of the core 10 are supported by the drive-side shaft support portion 31 and the driven-side shaft support portion 32 is not limited to the above embodiment, and may be supported in other configurations.

[0072] Furthermore, in the above embodiment, a shape in which the diameter of the internal flow path 16 is uniform (same diameter) in the axial direction throughout the entire roller support portion 14 was illustrated and explained as an example. However, the diameter of the internal flow path 16 may differ at different positions in the axial direction. For example, the internal flow path 16 may have a tapered shape in which the diameter gradually expands or contracts from one end to the other in the axial direction, or a tapered shape in which the diameter of the internal flow path 16 gradually expands or contracts from one end and the other end in the axial direction toward the center in the axial direction, or a shape in which the diameter of the internal flow path 16 changes in steps. In addition, the outer circumference shape of the core 10 and the cross-sectional shape of the internal flow path 16 are not limited to circles, but may be polygonal or the like.

[0073] Furthermore, although the above embodiment illustrates a configuration in which the inner circumferential surface of the core body 11 demarcates the internal flow channels 16 of the core 10, the core 10 may be used instead of the core rod for forming the hollow portion of the sponge body 2 when manufacturing the sponge body 2, and the sponge body 2 may be made to bulge inward from the inner circumferential surface of the core body 11, thereby demarcating the internal flow channels 16 with the inner circumferential surface of the sponge body 2 that bulges inward from the inner circumferential surface of the core body 11. In other words, the internal flow channels 16 provided by the core 10 may be demarcated by the core body 11 or by the inner circumferential surface of the sponge body 2. [Industrial applicability]

[0074] This invention can be widely applied to sponge rollers for cleaning. [Explanation of symbols]

[0075] 1: Sponge roller 2: Sponge body (roller body) 3: Protrusion 4: Rotation axis 10: Core (Roller support shaft) 11: Core 12: Drive side shaft end 13: Driven side shaft end 14: Roller support section 15: Outer surface of the roller support 16: Internal flow path 17: Through hole 18: Shaft end opening 19: Drive-side engaging projection 20: Drive side contact recess 21: Driven side engagement hole 22: Driven side contact recess 23:Communication hole 24:Outflow hole 25: Axial center of the roller support 26: Downstream area 27:Upstream area 28: Flow channel expansion area 29: Flange section 31: Drive-side shaft support section 32: Driven side shaft support part 33: Drive side engagement hole 34: Drive side contact projection 35: Driven side engagement protrusion 36: Driven side contact projection 37: Cleaning fluid supply path 40: Evaluation Test Equipment 41: Container 42: Cover 43: Bulkhead 44: Space inside the device 45:Divided space 46: Plot S1: Aperture area of ​​shaft end opening S2: Cross-sectional area of ​​the cleaning fluid supply path S3: Cross-sectional area of ​​the internal flow path

Claims

1. A cleaning sponge roller in which the inner circumferential surface of a cylindrical roller body made of an elastic porous material is supported by a roller support shaft, The aforementioned roller support shaft is A roller support portion having an outer surface over which the roller body is placed, An internal flow path extending axially within the roller support portion and closed at one end, Multiple outflow holes communicating from the internal flow path to the outer surface, The internal passage is provided with an axial end opening that opens axially outward at the other end of the internal passage in order to allow cleaning fluid to flow into the internal passage, The roller support portion has a flow path expansion region in which the cross-sectional area of ​​the internal flow path is larger than the opening area of ​​the shaft end opening, at least on the other end side of the axial center, In the aforementioned flow path expansion region, the area occupancy rate of the plurality of outflow holes relative to the outer surface is 2% or more and less than 6%. A sponge roller characterized by the following features.

2. A cleaning sponge roller in which the inner circumferential surface of a cylindrical roller body made of an elastic porous material is supported by a roller support shaft, The aforementioned roller support shaft is A roller support portion having an outer surface over which the roller body is placed, An internal flow path extending axially within the roller support portion and closed at one end, Multiple outflow holes communicating from the internal flow path to the outer surface, The internal passage is provided with an axial end opening that opens axially outward at the other end of the internal passage in order to allow cleaning fluid to flow into the internal passage, The roller support portion has a flow path expansion region in which the cross-sectional area of ​​the internal flow path is larger than the opening area of ​​the shaft end opening, at least on the other end side of the axial center, The ratio of the cross-sectional area of ​​the internal flow path in the flow path enlargement region to the opening area of ​​the shaft end opening is 120% or more. In the aforementioned flow path expansion region, the area occupancy rate of the plurality of outflow holes relative to the outer surface is 2% or more and less than 6%. A sponge roller characterized by the following features.

3. The cross-section of the internal flow path and the shaft end opening are both circular in shape. The diameter of the internal flow path is larger than the diameter of the shaft end opening. A sponge roller according to claim 1 or 2.

4. The entire axial area of ​​the roller support portion is the flow path expansion region. A sponge roller according to claim 1 or 2.

5. A roller support shaft that supports the inner circumferential surface of a cylindrical roller body made of an elastic porous material, A roller support portion having an outer surface over which the roller body is placed, An internal flow path extending axially within the roller support portion and closed at one end, Multiple outflow holes communicating from the internal flow path to the outer surface, The internal passage is provided with an axial end opening that opens axially outward at the other end of the internal passage in order to allow cleaning fluid to flow into the internal passage, The roller support portion has a flow path expansion region in which the cross-sectional area of ​​the internal flow path is larger than the opening area of ​​the shaft end opening, at least on the other end side of the axial center, In the aforementioned flow path expansion region, the area occupancy rate of the plurality of outflow holes relative to the outer surface is 2% or more and less than 6%. A roller support shaft for a sponge roller, characterized by the above.

6. A roller support shaft that supports the inner circumferential surface of a cylindrical roller body made of an elastic porous material, A roller support portion having an outer surface over which the roller body is placed, An internal flow path extending axially within the roller support portion and closed at one end, Multiple outflow holes communicating from the internal flow path to the outer surface, The internal passage is provided with an axial end opening that opens axially outward at the other end of the internal passage in order to allow cleaning fluid to flow into the internal passage, The roller support portion has a flow path expansion region in which the cross-sectional area of ​​the internal flow path is larger than the opening area of ​​the shaft end opening, at least on the other end side of the axial center, The ratio of the cross-sectional area of ​​the internal flow path in the flow path enlargement region to the opening area of ​​the shaft end opening is 120% or more. In the aforementioned flow path expansion region, the area occupancy rate of the plurality of outflow holes relative to the outer surface is 2% or more and less than 6%. A roller support shaft for a sponge roller, characterized by the above.

7. The cross-section of the internal flow path and the shaft end opening are both circular in shape. The diameter of the internal flow path is larger than the diameter of the shaft end opening. A roller support shaft for a sponge roller according to claim 5 or 6.

8. The entire axial area of ​​the roller support portion is the flow path expansion region. The roller support shaft according to claim 5 or 6.

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