Sponge roller and roller supporting shaft therefor

Abstract

A roller supporting shaft 10 comprises: a roller supporting part 14 which has an outer peripheral surface 15 covered by a roller body 2; an inner flow path 16 which extends in the axial direction inside of the roller supporting part 14 and is closed on one end-side; a plurality of outflow holes 24 which connect the outer peripheral surface 15 with the inner flow path 16; and a shaft end opening 18 which opens the other end-side of the inner flow path 16 to the outside in the axial direction in order to allow a cleaning liquid to flow into the inner flow path 16. The roller supporting part 14 has, at least on the other end-side relative to the center 25 in the axial direction, a flow path expansion region 28 in which the cross-sectional area S3 of the inner 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 ratio of the plurality of outflow holes 24 with respect to the outer peripheral surface 15 is at least 2% and less than 6%.

Description

Sponge roller and its roller support shaft

[0001] The present invention relates to a sponge roller for cleaning and its roller support shaft.

[0002] In the manufacturing process of an aluminum hard disk, a glass disk, a wafer, a photomask, or a liquid crystal glass substrate, etc., in order to finish its surface into an extremely precise surface, high-precision polishing using various abrasive grains such as silicon oxide, alumina, and ceria, so-called polishing process, is carried out. Abrasive grains and polishing debris adhere to the surface of the polished object, and in order to remove these, it is necessary to perform sufficient cleaning after the polishing process.

[0003] As a cleaning method after the polishing process, there are methods using ultrasonic cleaning or jet water flow. However, in order to obtain a high cleaning effect and reduce damage to the substrate, scrub cleaning using a sponge body made of an elastic porous body (for example, a polyvinyl acetal-based porous body) is widely used. Also, as the 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 the cleaning liquid for a silicon wafer, a mixed liquid of ammonia water and hydrogen peroxide water, hydrofluoric acid, a mixed liquid of hydrochloric acid and hydrogen peroxide water, etc. are known.

[0004] The shape of the sponge body of the elastic porous body is diverse. Among them, a sponge body in the shape of a brush roller having a large number of protrusions on the outer peripheral surface of a cylinder is preferably used for scrub cleaning (cleaning process). By continuously contacting the top of the protrusions with the cleaning surface of the object to be cleaned while rotating the sponge body, a good cleaning effect can be obtained. Since the object to be cleaned only contacts the protrusions of the sponge body, compared with a flat sponge body without protrusions, there are advantages such as less friction and less damage to the object to be cleaned, or contaminants 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 is composed 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 shaft support on the driving rotation side of the cleaning device, and the other end is supported so as not to rotate relative to the shaft support on the driven rotation side 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 shaft support on the driven rotation side, 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.

[0008] Patent No. 3628959

[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 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, a phenomenon may occur where the cleaning solution has difficulty flowing from the internal channel to the outlet hole in the upstream region of the core, compared to the downstream region, within the entire axial area of ​​the core. If the amount of cleaning solution flowing from the internal channel to the outlet hole varies between the upstream and downstream sides, variations will occur in the amount of cleaning solution flowing out from the outer surface of the core (the amount of cleaning solution supplied to the sponge body). This can result in startup cleaning not being performed equally across the entire axial area, 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.

[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 by 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 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 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 is a roller support shaft according to any of the sixth to eighth 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.

[0021] A tenth aspect of the present invention is a roller support shaft according to any of the sixth to ninth aspects, wherein the entire axial area of ​​the roller support portion is the flow path expansion region.

[0022] According to the present invention, the roller support portion of the roller support shaft has a flow path expansion region where 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 from the axial center, the area occupancy rate of the multiple outflow holes relative to the outer surface in the flow path expansion region is 2% or more and less than 6%, and / or 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, so that rise cleaning to improve the cleanliness of the sponge body can be performed efficiently and reliably.

[0023] This is a cross-sectional side view showing a part of the core of a sponge roller according to one embodiment of the present invention. This is a side cross-sectional view showing the state before one end of the core in Figure 1 is attached to the drive-side shaft support. This is a side cross-sectional view showing the state after one end of the core in Figure 1 is attached to the drive-side shaft support. This is a side cross-sectional view showing the state before the other end of the core in Figure 1 is attached to the driven-side shaft support. This is a cross-sectional view of the core in Figure 1 cut by a plane perpendicular to the axial direction, where (a) shows one embodiment and (b) shows another embodiment. This is a view of one end of the core in Figure 2 from the axial outside. This is a view of the other end of the core in Figure 4 from the axial outside. This is a schematic diagram of an evaluation test apparatus for evaluating the performance of the core. This is a cross-sectional view of the evaluation test apparatus in Figure 9. This is a table showing the specifications of the cores of the examples and comparative examples. This is a table showing the test results of the examples and comparative examples. This is a diagram showing the test results of Example 1. This is a diagram showing the test results of Example 2. This is a diagram showing the test results of Example 3. This is a diagram showing the test results of Example 4. This is a diagram showing the test results of Example 5. This figure shows the test results for Example 6. This figure shows the test results for the comparative example.

[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, 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-based porous material (PVAt-based porous material) that is elastic in a hydrated state. The PVAt-based porous material hardens in a dry state and softens in a wet state. Furthermore, the PVAt-based 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 in place 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, and 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 so as 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 engaging projection 19 engages with the drive-side engaging hole 33, and the drive-side contact projection 34 contacts the drive-side contact recess 20, thereby fitting and attaching the drive-side shaft end 12 to the drive-side shaft support 31. The engagement between the drive-side engaging hole 33 and the drive-side engaging 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 through hole 17 of the corresponding 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 shaft support 32 and the driven 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 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 a plurality of outflow holes 24 are formed in the roller support portion 14, communicating 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] The cross-sectional shape of the core 10 in this embodiment (the annular shape of the core body 11 shown in Figure 6) is uniform in the axial direction, and the diameter (inner diameter) of the internal flow path 16 is uniform (same diameter) in the axial direction throughout the entire roller support portion 14. The multiple outflow holes 24 are arranged substantially evenly on the outer circumferential surface 15 of the roller support portion 14. The arrangement pattern of the outflow holes 24 in this embodiment is a grid arrangement in which the outflow holes 24 are spaced equally apart along the axial direction and also spaced equally apart along the circumferential direction, but other arrangement patterns such as a staggered arrangement are also possible. Furthermore, the multiple outflow holes 24 may be arranged radially from the axis of rotation as shown in Figure 6(a), or non-radially as shown in Figure 6(b).

[0039] As shown in Figure 4, the diameter (inner diameter) of the shaft end opening 18 is larger than the diameter (inner diameter) of the cleaning fluid supply passage 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 S2 of the cleaning fluid supply passage 37 (cross-sectional area perpendicular to the axis), and the cross-sectional area S3 of the internal flow path 16 (cross-sectional area perpendicular to the axis) is larger than the opening area S1 of the shaft end opening 18 (S2 < S1 < S3). In this embodiment, with the driven shaft end portion 13 fitted and attached to the driven shaft support portion 32, the tip of the driven contact projection 36 reaches the shaft end opening 18 (see Figure 5), and the cross-sectional area S2 of the cleaning fluid supply passage 37 becomes the flow path cross-sectional area (inlet cross-sectional area) of the cleaning fluid at the shaft end opening 18, and the flow path cross-section of the cleaning fluid expands from the shaft end opening 18 toward the internal flow path 16 (S2 < S3).

[0040] As shown in Figure 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 of the axial center (the longitudinal center of the mounted sponge body 2) 25, and an upstream region 27 on the driven-side shaft end 13 side of the axial center 25. In the core 10 of this embodiment, the cross-sectional area S3 of the internal flow path 16 is larger than the cross-sectional area S1 of the shaft end opening 18 throughout the entire roller support portion 14 (both the downstream region 26 and the upstream region 27). That is, in this embodiment, the entire roller support portion 14 is a flow path expansion 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 circumferential 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 circumferential surface 15 of the roller support portion 14, and can be calculated by (total opening area of ​​all outflow holes 24 present in the flow path expansion region 28) / (area of ​​the outer circumferential 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 reason why it is suitable for the startup cleaning of the sponge roller 1 that the flow path cross-sectional area ratio and the peripheral surface opening ratio of the core 10 are within the above ranges is as follows.

[0045] The cleaning liquid introduced into the core 10 from the cleaning liquid supply pipe through the cleaning liquid supply path 37 of the driven-side shaft support portion 32 flows toward the drive-side shaft end portion 12 on the downstream side through the internal flow path 16. Further, the cleaning liquid flowing through the internal flow path 16 tends to move radially outward due to the rotation of the core 10. In the upstream region 27 of the roller support portion 14, when 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 momentum of the cleaning water flowing from the shaft-end opening 18 into the internal flow path 16 toward the downstream side is maintained or increased. Therefore, the amount of the cleaning liquid flowing out to the sponge body 2 through the outflow holes 24 tends to be less in the upstream region 27 than in the downstream region 26.

[0046] On the other hand, in the present embodiment, since the cross-sectional area S3 of the internal flow path 16 in the upstream region 27 is set larger than the cross-sectional area S_1 of the shaft-end opening 18, the momentum of the cleaning liquid flowing from the shaft-end opening 18 into the internal flow path 朝着下游侧的趋势被缓和,并且清洗液能够被适当地径向向外流通。

[0047] Further, when the cross-sectional area S3 of the internal flow path 16 in the upstream region 27 is set larger than the cross-sectional area S1 of the shaft-end opening 18, if the peripheral surface opening ratio of the upstream region 27 is too high, the amount of the cleaning liquid flowing out from the upstream region 27 becomes too large, and there is a possibility that the amount of the cleaning liquid flowing out in the downstream region 26 becomes extremely less than that in the upstream region 27. In order to prevent such an imbalance due to the reversal phenomenon, in the present embodiment, the peripheral surface opening ratio of the upstream region 27 is set to less than 6%. Also, if the peripheral surface opening ratio of the upstream region 27 is too low, the amount of the cleaning liquid flowing out from the upper surface side region 27 becomes too small, and there is a possibility that the amount of the cleaning liquid flowing out in the upstream region 27 becomes extremely less than that in the downstream region 26. In order to prevent such an imbalance due to the re-reversal phenomenon, in the present embodiment, the peripheral surface opening ratio of the upstream region 27 is set to 2% or more. Thereby, the cleaning liquid can be discharged in a balanced manner over the entire axial direction of the core 10, and the startup cleaning of the sponge roller 1 can be suitably performed.

[0048] Further, in the present embodiment, since the entire area of the roller support portion 14 is used as the flow path expansion region 28, the internal pressure of the internal flow path 16 is in a state of being reduced with respect to the inflow pressure of the cleaning liquid from the axial end opening 18 throughout the entire area of the roller support portion 14. Therefore, the internal pressure difference of the internal flow path 16 in the axial direction of the roller support portion 14 can be kept small, and the cleaning liquid can be evenly discharged throughout the entire area of the roller support portion 14, and the startup cleaning of the sponge roller 1 can be suitably performed.

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

[0050] As shown in FIG. 9, the evaluation test apparatus 40 is provided with a drive-side shaft support portion 31 and a driven-side shaft support portion 32 configured in the same manner as the cleaning apparatus. The core 10 is sandwiched and supported from both axial sides by the drive-side shaft support portion 31 and the driven-side shaft support portion 32, and when the drive-side shaft support portion 31 rotates drivenly, the core 10 and the driven-side shaft support portion 32 rotate drivenly. A circular hole-shaped cleaning liquid supply path 37 (see FIG. 5) penetrating in the axial direction is formed in the central portion of the driven-side shaft support portion 32. By attaching the core 10 to the evaluation test apparatus 40, the internal flow path 16 communicates with the cleaning liquid supply path 37 through the axial end opening 18 of the driven-side shaft end portion 13 (see FIG. 5). A liquid supply pipe (not shown) is connected to the cleaning liquid supply path 37, and test liquid is introduced into the internal flow path 16 from the liquid supply pipe through the cleaning liquid supply path 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 (nine in this example) partition walls 43 (43A to 43I). 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 (ten in this example) divided spaces 45 (45A to 45J). In this embodiment, the upstreammost (leftmost in Figure 9) is referred to as the first divided space 45A, and the spaces are numbered in ascending order towards the downstream side, with the downstreammost (rightmost in Figure 9) being referred to as the tenth divided space 45J.

[0053] The container 41 is divided into multiple (10 in this example) compartments 46 (46A to 46J) from which water W flowing or falling through each divided space 45A to 45J can be collected individually. In this embodiment, the upstreammost compartment (leftmost in Figure 9) is referred to as the first compartment 46A, and the compartments are numbered in ascending order towards the downstream side, with the downstreammost compartment (rightmost in Figure 9) being referred to as the tenth compartment 46J. The compartments 46A to 46J are each 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 internal space 44 of the device 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 internal space 44 of the device 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 internal space 44 of the device 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 which 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 is substantially the same as the embodiment described above, except that the entire area of ​​the roller support portion 14 is 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 are 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 does 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 represents each region (region 1 to region 10) of the roller support portion 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 portion 14 of the core 10. In each of Examples 1 to 6 and the Comparative Example, the sum of the outflow rates for regions 1 to 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 to 6 than for the Comparative Example, and among Examples 1 to 6, Example 1 had the smallest range and standard deviation. This indicates that Examples 1 to 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 to 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 by 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, but 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, in the above embodiment, a configuration was illustrated in which the inner circumferential surface of the core body 11 partitions the internal flow path 16 of the core 10. However, when manufacturing the sponge body 2, the core 10 may be used instead of the core rod used to form the hollow portion of 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 partitioning the internal flow path 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 path 16 provided by the core 10 may be partitioned by the core body 11 or by the inner circumferential surface of the sponge body 2.

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

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

Claims

1. A sponge roller for cleaning, wherein the inner circumferential surface of a cylindrical roller body made of an elastic porous material is supported by 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, wherein 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 from the axial center, and the area occupancy rate of the plurality of outlet holes relative to the outer circumferential surface in the flow path expansion region is 2% or more and less than 6%.

2. A sponge roller for cleaning, wherein the inner circumferential surface of a cylindrical roller body made of an elastic porous material is supported by 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, wherein the roller support portion has a flow path expansion region where 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.

3. The sponge roller according to claim 2, characterized in that, in the flow path enlargement region, the area occupancy rate of the plurality of outflow holes relative to the outer surface is 2% or more and less than 6%.

4. The sponge roller according to any one of claims 1 to 3, characterized in that 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.

5. The sponge roller according to any one of claims 1 to 3, characterized in that the entire axial area of ​​the roller support portion is the flow path expansion region.

6. A roller support shaft for a sponge roller, comprising: 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; a plurality of outlet holes communicating from the internal flow path to the outer 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, wherein the roller support portion has a flow path expansion region where 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 surface is 2% or more and less than 6%.

7. A roller support shaft for a sponge roller, comprising: 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; a plurality of outlet holes communicating from the internal flow path to the outer 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, wherein the roller support portion has a flow path expansion region where 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.

8. The roller support shaft according to claim 7, characterized in that, in the flow path enlargement region, the area occupancy rate of the plurality of outflow holes relative to the outer surface is 2% or more and less than 6%.

9. The roller support shaft according to any one of claims 6 to 8, characterized in that 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.

10. The roller support shaft according to any one of claims 6 to 8, characterized in that the entire axial area of ​​the roller support portion is the flow path expansion region.

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