Cleaning equipment

Abstract

To perform washing by keeping a distance between a washing surface of an object to be washed and a nozzle constant in a washing device.SOLUTION: A washing device 1 includes: a table 28 which holds an object 90 to be washed on a holding surface 282; a rotary mechanism 29 which rotates the table 28 with a center of the holding surface 282 as a center; and a nozzle 10 which jets two-fluid mixed with water and air toward the holding surface 282. The washing device washes the holding surface 282. The washing device 1 further includes: a lifting mechanism 11 which moves the nozzle 10 to the holding surface 282 in a vertical direction; and a positioning section 12 which positions the nozzle 10 at a proper height position with respect to the holding surface 282 after lowering the nozzle 10 by the lifting mechanism 11.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a cleaning device for cleaning a support surface of a table. [Background technology]

[0002] For example, as disclosed in Patent Document 1, Patent Document 2, or Patent Document 3, a grinding device that grinds wafers is equipped with a cleaning device that sprays a two-fluid mixture of water and air onto the upper surface of a wafer held on the holding surface of a chuck table to clean the upper surface of the wafer. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-200785 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-133399 [Patent Document 3] Japanese Patent Application Publication No. 2020-077728 Summary of the Invention [Problem to be solved by the invention]

[0004] The cleaning device described above can perform good cleaning using the two fluids sprayed from the nozzle by maintaining a constant distance between the tip of the nozzle spraying the two fluids and the top surface of the wafer. However, it is necessary to adjust the height of the nozzle relative to the top surface of the ground wafer using a jig or the like, and it is difficult to maintain the same distance between the nozzle tip and the top surface of the wafer each time.

[0005] The two-fluid jet from the nozzle also cleans the holding surface of the chuck table. Therefore, the height of the nozzle must be changed according to the height of the holding surface of the chuck table. Also, the height position of the nozzle when cleaning the holding surface must be different from the height position of the nozzle when cleaning the top surface of the wafer.

[0006] Therefore, the cleaning device has a problem of performing cleaning while maintaining a constant distance between the surface of the object to be cleaned and the nozzle. [Means for solving the problem]

[0008] The present invention, which solves the above-mentioned problems, is a cleaning device that includes a table that holds an object to be cleaned on a holding surface, a rotation mechanism that rotates the table around the center of the holding surface, and a nozzle that sprays a two-fluid mixture of water and air toward the holding surface, and cleans the object to be cleaned held on the holding surface.The cleaning device also includes a lifting mechanism that moves the nozzle vertically to the holding surface, a guide rail that supports the nozzle so that it can be raised and lowered, and a back pressure nozzle with an injection port facing the holding surface, and sprays fluid from the injection port onto the top surface of the object to be cleaned held by the holding surface, and positions the nozzle, which can be raised and lowered by the back pressure of the fluid, at an appropriate height position relative to the top surface of the object to be cleaned held by the holding surface, and cleans the object to be cleaned.

[0010] Further, in order to solve the above-mentioned problems, the present invention provides a cleaning device comprising a table that holds an object to be cleaned on a holding surface, a rotation mechanism that rotates the table around the center of the holding surface, and a nozzle that sprays a two-fluid mixture of water and air toward the holding surface, and that cleans the holding surface or the top surface of the object to be cleaned held by the holding surface, the device comprising: a box that houses the nozzle and has an open bottom, a lifting mechanism that moves the box in a direction perpendicular to the holding surface, a lifting mechanism that supports the box so that it can be raised and lowered, and a spray nozzle that faces the holding surface, The injection port is formed in an annular shape on the lower surface of the box, The box is lowered by the lifting mechanism, fluid is sprayed from the nozzle onto the holding surface, and the back pressure of the fluid forms a gap between the bottom surface of the box and the holding surface, or between the bottom surface of the box and the top surface of the object to be cleaned, and the nozzle is positioned at an appropriate height relative to the holding surface or the top surface of the object to be cleaned, thereby cleaning the holding surface or the top surface of the object to be cleaned. [Effects of the Invention]

[0011] The cleaning device according to the present invention includes an elevation mechanism that moves the nozzle perpendicular to the holding surface, and a positioning unit that uses the elevation mechanism to lower the nozzle and position it at an appropriate height relative to the holding surface. This makes it possible to maintain a constant distance between the holding surface and the nozzle that sprays the two-fluid. Therefore, even if the height of the holding surface changes due to periodic grinding with a grinding wheel (self-grinding), such as the holding surface of a chuck table of a grinding machine, the holding surface can be cleaned effectively. Furthermore, since the two-fluid nozzle can be positioned at a constant distance from the top surface of the workpiece, the top surface of the workpiece can be cleaned effectively. For example, if the positioning unit is a roller connected to the nozzle and contacts the holding surface or a reference surface (e.g., a surface at the same height as the holding surface) arranged in a ring shape relative to the holding surface, or if the positioning unit is equipped with a guide rail that supports the nozzle so that it can be raised and lowered, and a back-pressure nozzle that is connected to the nozzle, is raised and lowered by the guide rail, and has an injection port facing the holding surface, and is configured so that fluid is injected onto the holding surface from the injection port and the nozzle is positioned at an appropriate height position by the back pressure of the fluid, then there is no need to provide a control unit that performs complex control to adjust the height of the two-fluid nozzle even if the height of the surface to be cleaned changes, and the cleaning device can be made smaller.

[0012] The cleaning device of the present invention sprays fluid from the nozzle of the back pressure nozzle onto the top surface of the object to be cleaned held by the holding surface of the table, and positions the nozzle, which can be raised and lowered freely by the back pressure of the fluid, at an appropriate height relative to the top surface of the object to be cleaned held by the holding surface.The nozzle can spray two fluids from the nozzle at a fixed distance onto the top surface of the object to be cleaned, thereby enabling the top surface of the object to be cleaned to be cleaned well.

[0013] The cleaning device of the present invention lowers a box using a lifting mechanism, sprays fluid into the box from a nozzle, and creates a gap between the bottom of the box and the holding surface, or between the bottom of the box and the top surface of the object to be cleaned held on the holding surface, using the back pressure of the fluid sprayed from the opening of the box.The nozzle is positioned at an appropriate height relative to the holding surface or the top surface of the object to be cleaned held on the holding surface, and the two fluids can be sprayed from the nozzle at a fixed distance toward the holding surface or the top surface of the object to be cleaned, thereby enabling the holding surface or the top surface of the object to be cleaned to be cleaned well.

[0014] The cleaning device of the present invention lowers a box using a lifting mechanism, sprays fluid onto the holding surface from a nozzle formed, for example, in a ring shape on the underside of the box so as to face the holding surface, and creates a gap between the underside of the box and the holding surface, or between the underside of the box and the top surface of the object to be cleaned, using the back pressure of the fluid.The nozzle is positioned at an appropriate height relative to the holding surface or the top surface of the object to be cleaned, and the two fluids can be sprayed from the nozzle at a fixed distance onto the holding surface or the top surface of the object to be cleaned, thereby enabling the holding surface or the top surface of the object to be cleaned to be cleaned well. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a perspective view of a grinding device equipped with a cleaning device according to a first embodiment of the present invention. [Figure 2] FIG. 10 is a side view illustrating a state in which a holding surface is being cleaned with two fluids by the cleaning device of the first embodiment in which the positioning unit is a roller. [Figure 3] FIG. 10 is a perspective view of a grinding device equipped with a cleaning device according to a second embodiment of the present invention. [Figure 4] FIG. 10 is a side view illustrating a state in which the holding surface before self-grinding is being subjected to two-fluid cleaning by the cleaning device of the second embodiment. [Figure 5] FIG. 10 is a side view illustrating a state in which a holding surface that has been self-grinded and is now lower in height than before self-grinding is being subjected to two-fluid cleaning by the cleaning device of the second embodiment. [Figure 6]FIG. 10 is a side view illustrating a state in which the upper surface of the workpiece, which has been self-ground and held by the holding surface, is being two-fluid cleaned by the cleaning device of the second embodiment. [Figure 7] FIG. 10 is a perspective view of a grinding device equipped with a cleaning device according to a third embodiment of the present invention. [Figure 8] FIG. 11 is a side view illustrating a state in which the holding surface of the table is being cleaned with two fluids by the cleaning device of the third embodiment. [Figure 9] FIG. 11 is a side view illustrating a state in which the upper surface of a workpiece held by suction on the holding surface of a table is being cleaned with two-fluid cleaning by the cleaning device of the third embodiment. [Figure 10] FIG. 11 is a perspective view illustrating a state in which the upper surface of a workpiece held by suction on the holding surface of a table is being cleaned with two-fluid cleaning by the cleaning device of the third embodiment. [Figure 11] FIG. 10 is a perspective view of a grinding device equipped with a cleaning device according to a fourth embodiment of the present invention. [Figure 12] FIG. 10 is a side view illustrating a state in which the holding surface of the table is being cleaned with two fluids by the cleaning device of the fourth embodiment. [Figure 13] FIG. 10 is a perspective view illustrating an injection port formed in a ring shape on the bottom surface of the box of the cleaning device of the fourth embodiment. [Figure 14] FIG. 10 is a side view illustrating a state in which the upper surface of a workpiece held by suction on the holding surface of a table is being cleaned with two-fluid cleaning by the cleaning device of the fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0016] The grinding apparatus 2 shown in FIG. 1 is an apparatus that grinds a workpiece 90 (which will become an object to be cleaned 90 after grinding) held on a table 28 using a grinding mechanism 23. The front (-Y direction side) of a base 20 of the grinding apparatus 2 is a carry-in / out area where the workpiece 90 is carried in and out of the table 28, and the rear (+Y direction side) of the base 20 is a processing area where the grinding mechanism 23 performs grinding on the workpiece 90 held on the table 28. The grinding apparatus 2 is equipped with a cleaning apparatus 1 according to the present invention (hereinafter referred to as the cleaning apparatus 1 of embodiment 1). The grinding apparatus 2 may be a two- or more-axis grinding apparatus that includes a rough grinding mechanism and a finish grinding mechanism and that can position the workpiece 90 below the rough grinding mechanism or the finish grinding mechanism using a rotating turntable.

[0017] 1, a surface 900 (hereinafter referred to as the bottom surface 900) of the workpiece 90 facing downward has a plurality of devices formed thereon and is protected by a protective tape (not shown). A back surface 903 (hereinafter referred to as the top surface 903) of the workpiece 90 facing upward becomes the surface to be ground.

[0018] 1 has a circular outer shape in a plan view, and includes, for example, a circular plate-shaped porous member 280 and a frame 281 that supports the porous member 280. The porous member 280 is connected to a suction source 289 such as an ejector mechanism or a vacuum generator, and the suction force generated by the suction source is transmitted to a holding surface 282, which is the upper surface of the porous member 280, thereby allowing the table 28 to suction and hold the workpiece 90 on the holding surface 282. The holding surface 282 of the porous member 280 and an upper surface 283 of the frame 281 are flush with each other and at the same height.

[0019] As shown in FIG. 1, table 28 is surrounded by cover 284 and can be rotated by rotation mechanism 29 around a rotation axis whose axial direction is the Z-axis direction (vertical direction) and passes through the center of holding surface 282, and can be moved back and forth in the Y-axis direction on base 20 by a Y-axis feed unit (not shown), such as an electric slider, arranged below cover 284 and bellows cover 285 connected to cover 284 and expanding and contracting in the Y-axis direction.

[0020] A column 21 is erected on the rear side of the base 20, and a grinding feed unit 24 is arranged on the front surface of the column 21 on the -Y direction side, which moves the grinding mechanism 23 in the vertical direction (Z-axis direction) perpendicular to the holding surface 282 of the table 28. The grinding feed unit 24 is composed of a ball screw 240 whose axial direction is the Z-axis direction, a pair of guide rails 241 extending parallel to the ball screw 240, a motor 242 connected to the ball screw 240 and rotating the ball screw 240, and a lifting plate 243 whose internal nut is threaded onto the ball screw 240 and whose sides slide against the pair of guide rails 241.As the motor 242 rotates the ball screw 240, the lifting plate 243 moves in the Z-axis direction while being guided by the guide rails 241, and the grinding mechanism 23 attached to the lifting plate 243 also moves in the Z-axis direction.

[0021] The grinding mechanism 23 that grinds the workpiece 90 held by the holding surface 282 of the table 28 includes a rotating shaft 230 whose axial direction is the Z-axis direction, a housing 231 that rotatably supports the rotating shaft 230 by an air bearing or the like formed inside, a motor 232 that rotates and drives the rotating shaft 230, a disk-shaped mount 233 connected to the lower end of the rotating shaft 230, a grinding wheel 234 that is detachably attached to the lower surface of the mount 233, and a holder 235 that supports the housing 231 and is connected to the lifting plate 243.

[0022] The grinding wheel 234 includes a wheel base 236 and a plurality of roughly rectangular parallelepiped segment grinding wheels arranged in a ring shape on the bottom surface of the wheel base 236. The segment grinding wheels are formed by, for example, fixing diamond abrasive grains with a resin bond, a vitrified bond, or the like. The plurality of segment grinding wheels arranged in a ring shape form a ring-shaped grinding wheel 237. Note that a grinding wheel in which the segment grinding wheels are arranged in a ring shape with no gaps, i.e., a grinding wheel with a so-called continuous arrangement, may also be arranged on the underside of the wheel base 236.

[0023] Inside the rotating shaft 230, a flow path (not shown) that is connected to a grinding water supply source and serves as a passage for grinding water is provided, penetrating the axial direction of the rotating shaft 230, and the flow path (not shown) further passes through the mount 233 and opens at the bottom surface of the wheel base 236 so that grinding water can be sprayed toward the annular grinding wheel 237.

[0024] The cleaning device 1 according to the present invention comprises a table 28 that holds the object to be cleaned 90 on the holding surface 282, a rotation mechanism 29 that rotates the table 28 around the center of the holding surface 282, a nozzle 10 that sprays a mixture of water and air toward the holding surface 282, a lifting mechanism 11 that moves the nozzle 10 in a direction perpendicular to the holding surface 282 (Z-axis direction), and a positioning unit 12 that uses the lifting mechanism 11 to lower the nozzle 10 and position the nozzle 10 at an appropriate height relative to the holding surface 282.

[0025] The lifting mechanism 11 is arranged, for example, on the front of a gate-shaped column (not shown) that is erected on the base 20 so as to straddle the movement path of the table 28 in the X-axis direction, and is an air cylinder or an electric cylinder that raises and lowers a rod 111 extending in the Z-axis direction from a cylinder case 110 in the Z-axis direction, and the lower end of the rod 111 is connected to a box 113 that houses, for example, the nozzle 10 and has an opening 112 (see Figure 2) on its underside.

[0026] As shown in FIG. 2, a rectangular opening 112 is formed in the bottom surface of the box 113, and the movement path of the table 30 is located below the opening 112. The nozzle 10 arranged in the box 113 is, for example, a slit nozzle, which extends in the X-axis direction for a length at least equal to or greater than the radius of the holding surface 282, and has a slit-shaped injection port 100 formed on its underside, which can inject two fluids in a band shape.

[0027] A cleaning water source 108, which comprises a pump or the like and is capable of delivering, for example, pure water as cleaning water, is connected to the upper side of the nozzle 10 via water piping such as joints, resin tubing, etc. Also, an air supply source 109, which comprises a compressor or the like and is capable of delivering compressed air, is connected to the upper side of the nozzle 10 via piping such as joints, resin tubing, etc.

[0028] The nozzle 10 housed in the box 113 is not limited to the slit nozzle described above. For example, multiple nozzles may be disposed within the box 113 at equal intervals within a radius extending from the center to the outer periphery of the holding surface 282. In this case, the nozzle may have a linear outer shape extending in the Z-axis direction, for example, and may be a flat pattern nozzle that sprays the two-fluid from a spray port formed at the bottom end thereof, producing a fan-shaped, flat spray pattern, or a full cone pattern nozzle that produces a conical spray pattern. Alternatively, multiple nozzles may be disposed staggered in the circumferential direction of the holding surface 282, and the two-fluids sprayed from each nozzle may clean an annular region near the center of the holding surface 282, an annular region in the middle of the holding surface 282, and an annular region on the outer periphery of the holding surface 282, which rotate relative to each other.

[0029] The positioning unit 12 of the cleaning device 1 of the first embodiment is a roller 12 that is connected to the nozzle 10 via, for example, a box 113 and that comes into contact with the holding surface 282 or an upper surface 283 of a frame 281 that is flush with the holding surface 282 in this embodiment and is arranged in a ring shape relative to the holding surface 282. The roller 12 is rotatably supported, for example, via a rotation shaft on the outer surface of the box 113. As shown in FIG. 2, the lower portion of the roller 12 protrudes a predetermined distance below the lower surface of the box 113. The roller 12 may also be directly connected to the side surface of the nozzle 10 within the box 113.

[0030] The operation of the grinding device 2 when grinding the workpiece 90 held on the table 28 will be described. First, in the attachment / detachment area, the workpiece 90 is placed on the holding surface 282 of the table 28 with their centers substantially aligned. A suction force generated by the suction source 289 is transmitted to the holding surface 282, and the table 28 holds the workpiece 90 on the holding surface 282 by suction.

[0031] Next, table 28 holding workpiece 90 is moved in the +Y direction by a Y-axis feed unit (not shown) to below grinding mechanism 23. Then, the center of rotation of grinding wheel 237 of grinding mechanism 23 is shifted horizontally by a predetermined distance from the center of rotation of workpiece 90, and the grinding wheel 237 is positioned so that its rotational trajectory passes through the center of rotation of workpiece 90.

[0032] The motor 232 rotates the grinding wheel 234, the grinding mechanism 23 is lowered by the grinding feed unit 24, and the rotating grinding stone 237 comes into contact with the upper surface 903 of the workpiece 90 to perform grinding. During grinding, the table 28 rotates at an appropriate rotational speed, and the workpiece 90 held on the holding surface 282 also rotates, so that the grinding stone 237 grinds the entire upper surface 903 of the workpiece 90. In addition, grinding water passing through a flow path (not shown) is supplied to the contact portion between the grinding stone 237 and the workpiece 90 to cool the contact portion.

[0033] Then, after the workpiece 90 has been ground to the desired thickness (the planned finishing thickness), the grinding mechanism 23 rises, and the grinding wheel 237 moves away from the workpiece 90, completing the grinding. For example, when such grinding is performed successively on a plurality of workpieces 90 one by one, grinding debris may adhere to the holding surface 282 of the table 28 shown in FIG. 1, resulting in poor grinding of the workpieces 90. Therefore, the holding surface 282 is cleaned by the cleaning device 1 of the first embodiment at an appropriate timing, such as after grinding of a certain workpiece 90 has been completed and before the next new workpiece 90 is held by suction on the table 28.

[0034] The table 28, which is not holding the workpiece 90 by suction, moves in the Y-axis direction, and the nozzle 10 is positioned above it along the radius from the center of rotation of the holding surface 282 to the outer edge, as shown in Figure 2.

[0035] Next, the nozzle 10 is lowered together with the box 113 by the lifting mechanism 11, and the roller 12, which protrudes a predetermined distance below the bottom surface of the box 113, comes into contact with the holding surface 282. After the roller 12, which serves as a height positioning unit, comes into contact with the holding surface 282, the lowering of the nozzle 10, the box 113, and the roller 12 by the lifting mechanism 11 stops. If the lifting mechanism 11 is provided with a load sensor that measures a load, the contact of the roller 12 with the holding surface 282 may be recognized by a change in the load sensor's value. Alternatively, if the lifting mechanism 11 is an electric cylinder, the contact may be recognized by an increase in the load current value of a motor (not shown) that lowers the rod 111. Alternatively, if the lifting mechanism 11 is an air cylinder, the contact may be recognized by an increase in the internal pressure of the cylinder case 110 shown in FIG. 1. Alternatively, if the lifting mechanism 11 is an air cylinder, the height position of the rising / lowering piston may be detected by a proximity sensor or the like, and the descent of the rod 111 connected to the piston may be recognized. The rollers 12 may be brought into contact with an upper surface 283 serving as a reference surface of the frame 281 that is disposed annularly with respect to the holding surface 282 and is at the same height as the holding surface 282, for example, instead of the holding surface 282.

[0036] 2, by positioning the nozzle 100 of the nozzle 10 at an appropriate height relative to the holding surface 282, it is possible to position the nozzle 100 of the nozzle 10 a predetermined distance L above the holding surface 282. The predetermined distance L is a value selected experimentally, empirically, or theoretically, and is a distance at which the holding surface 282 can be appropriately cleaned by the two-fluid jetted from the nozzle 100 of the nozzle 10, which is a slit nozzle.

[0037] For example, if the nozzles arranged in the box 113 are multiple nozzles and are flat pattern nozzles or full cone pattern nozzles, the predetermined distance L between the nozzle outlets of each nozzle and the holding surface 282 is a distance that prevents the cleaning powers of the two fluids sprayed from the multiple nozzles from canceling each other out in each area onto the holding surface 282. In this case, the predetermined distance L may be a value that prevents the areas from overlapping. Note that the predetermined distance L may be determined by changing the distance at which cleaning is performed, an image of the holding surface 282 after cleaning is captured by a camera, and the distance at which no circular or annular remaining dirt remains in the captured image.

[0038] In this state, cleaning water is supplied to the nozzle 10 from a cleaning water source 108 shown in Figure 2, and high-pressure air is supplied to the nozzle 10 from an air supply source 109. Inside the nozzle 10, the cleaning water and air are mixed to become two-fluid T, and the two-fluid T is sprayed in a band shape toward the holding surface 282 from the injection port 100 of the nozzle 10. As the table 28 rotates, the entire surface of the holding surface 282 is cleaned by the two-fluid T, and fine grinding dust and other deposits adhering to the holding surface 282 are washed away. The roller 12 rotates in accordance with the rotation of the holding surface 282, and does not damage the holding surface 282.

[0039] 2 is shorter than the predetermined appropriate distance L, the band-shaped two-fluid T sprayed from the spray nozzle 100 reaches the rotating holding surface 282 with more force than appropriate, resulting in some areas of the two-fluid T bouncing off the holding surface 282 and insufficient cleaning of the entire surface of the holding surface 282. Furthermore, if the distance from the holding surface 282 to the spray nozzle 100 of the nozzle 10 is longer than the predetermined appropriate distance L, the band-shaped two-fluid T sprayed from the spray nozzle 100 reaches the rotating holding surface 282 with less force than appropriate, resulting in insufficient cleaning of the entire surface of the holding surface 282. However, the cleaning device 1 according to the present invention uses the roller 12, which is a positioning unit, to set the distance between the holding surface 282 and the spray nozzle 100 of the nozzle 10 to the predetermined distance L, thereby enabling appropriate two-fluid cleaning of the holding surface 282.

[0040] The cleaning water contained in the two-fluid T that has washed away the deposits flows down from above the table 28 through the gap between the box 113 and the holding surface 282, and flows down into a water case (not shown) from drainage holes formed on the sides of the cover 284 and the bellows cover 285 shown in Fig. 1. Then, two-fluid cleaning of the holding surface 282 is performed for a predetermined time.

[0041] Even when the nozzle 10 is not a slit nozzle as in the present embodiment, but a plurality of nozzles are arranged in the box 113 at equal intervals within a radius from the center of the holding surface 282 to the outer periphery, and each of the plurality of arranged nozzles sprays the two-fluids that spread out in a fan-like shape downward, by using the roller 12 to set the distance between the holding surface 282 and the nozzles of the plurality of nozzles to a predetermined distance L, it is possible to properly perform two-fluid cleaning of the holding surface 282. Here, if the distance from the holding surface 282 to the nozzles of the plurality of nozzles were shorter than the predetermined appropriate distance L, the two-fluids sprayed from the nozzles of each nozzle would reach the rotating holding surface 282 without sufficiently spreading out in a fan-like shape, resulting in areas of the holding surface 282 where the two-fluids have difficulty reaching, resulting in insufficient cleaning; however, this situation does not occur. Furthermore, if the distance from the holding surface 282 to the nozzles of the multiple nozzles is longer than a predetermined appropriate distance L, the two fluids sprayed from the nozzles of the multiple nozzles will spread out too much in a fan shape, causing the two fluids to collide and interfere with each other in the air before reaching the rotating holding surface 282. As a result, there will be areas on the holding surface 282 where it is difficult for the two fluids to reach, resulting in insufficient cleaning of the holding surface 282, but this situation will not occur.

[0042] For example, when the grinding process described above is performed on a plurality of workpieces 90 one by one in succession, grinding debris may adhere to the holding surface 282 of the table 28 shown in Fig. 1, resulting in poor grinding of the workpieces 90. To address this, the holding surface 282 is ground with the grinding wheel 237 so that the holding surface 282 is parallel to the bottom surface of the grinding wheel 237. The height of the holding surface 282 after self-grinding is lower than the height before self-grinding.

[0043] When the lowered holding surface 282 is cleaned by the cleaning device 1 in this way, the nozzle 10 is lowered together with the box 113 by the lifting mechanism 11, and the lower portion of the roller 12, which protrudes a predetermined distance below the bottom surface of the box 113, comes into contact with the holding surface 282. The roller 12, which is a height positioning unit, comes into contact with the holding surface 282, and the lowering of the nozzle 10, box 113, and roller 12 by the lifting mechanism 11 stops. This makes it possible to position the injection port 100 of the nozzle 10 a predetermined distance L (see FIG. 2) above the holding surface 282, whose height has been lowered by self-grinding, and makes it possible to properly perform two-fluid cleaning of the holding surface 282 after self-grinding.

[0044] 1 and 2 of the first embodiment of the present invention includes a positioning unit 12 (roller 12) that uses the lifting mechanism 11 to lower the nozzle 10 and position the nozzle 10 at an appropriate height relative to the holding surface 282. This makes it possible to maintain a constant distance (predetermined distance L) between the holding surface 282 and the nozzle 10, thereby enabling appropriate two-fluid cleaning of the holding surface 282. Furthermore, even if the height of the holding surface 282 changes, the distance between the holding surface 282 and the nozzle 10 can be set to the predetermined distance L simply by using the lifting mechanism 11 to lower the nozzle 10 until the roller 12 contacts the holding surface 282. This eliminates the need for a control unit that performs complex control to adjust the height of the nozzle 10, allowing the cleaning device 1 to be made smaller.

[0045] The grinding device 2 may be equipped with a cleaning device 3 of a second embodiment shown in Fig. 3 instead of the cleaning device 1 of the first embodiment shown in Fig. 1. The cleaning device 3 of the second embodiment and the cleaning device 1 of the first embodiment have substantially the same configuration as each other, and in Fig. 3, parts configured similarly to the cleaning device 1 of Fig. 1 are assigned the same reference numerals as in Fig. 1. The following will focus on the configuration of the cleaning device 3 of the second embodiment that differs from the cleaning device 1 of the first embodiment.

[0046] The positioning unit 32 provided in the cleaning device 3 includes a guide rail 320 that supports the nozzle 10 so that it can move up and down, and a back pressure nozzle 33 that is connected to the nozzle 10, can move up and down by the guide rail 320, and has an injection port 330 (see FIG. 4) that faces the holding surface 282 of the table 28. Note that the structure of the guide rail 320 is shown in a simplified form in FIG. 3.

[0047] 3 and 4, which is a straight nozzle, is attached to the outer surface of nozzle 10 and can be raised and lowered in the Z-axis direction together with nozzle 10, which is a slit nozzle, within box 113. Nozzle 10, back-pressure nozzle 33, guide rail 320, and box 113 can be raised and lowered in the Z-axis direction as a unit by lifting mechanism 11. An air supply source 109 is connected to back-pressure nozzle 33.

[0048] 4 includes a guide case 321 fixed to the inner surface of the box 113 and extending in the Z-axis direction, and a piston 322 that slides within the guide case 321 along the inner wall of the guide case 321 and has its lower end connected to the upper surface of the nozzle 10. An air exhaust port 324 is formed at the top of the guide case 321 to allow the piston 322 to move up and down within the guide case 321. Although not shown, when air is not being injected from the back pressure nozzle 33, the piston 322 of the positioning unit 32 is in contact with and supported by the inner bottom surface of the guide case 321.

[0049] The following describes a case where the holding surface 282 of the table 28 is cleaned using the cleaning device 3 of the second embodiment shown in Fig. 3. The table 28, which is not holding the workpiece 90 by suction, moves in the Y-axis direction, and the nozzle 10 is positioned above the holding surface 282 along a radius from the center of rotation to the outer periphery, as shown in Fig. 4. Cleaning water is supplied to the nozzle 10 from a cleaning water source 108 shown in Fig. 4, and high-pressure air is supplied to the nozzle 10 from an air supply source 109, and the two-fluid T is sprayed in a strip shape from the nozzle 100 toward the holding surface 282.

[0050] At the same time, the nozzle 10, together with the box 113 and the positioning unit 32, is lowered by the lifting mechanism 11 until the nozzle 10, the box 113, and the positioning unit 32 are positioned at a predetermined height Z1 (so-called origin height Z1), at which point the lowering of the nozzle 10, the box 113, and the positioning unit 32 by the lifting mechanism 11 stops. In this state, the piston 322 of the positioning unit 32 is in contact with and supported by the inner bottom surface of the guide case 321 (not lifted).

[0051] 4 supplies a constant amount of air B (fluid B) per minute to the back pressure nozzle 33, causing the air B to be sprayed downward from the nozzle 330. The amount of air B supplied to the back pressure nozzle 33 is an amount that enables the nozzle 100 of the nozzle 10 to be positioned a predetermined distance L above the holding surface 282, which is at a height Z2, due to the back pressure of the air B sprayed from the back pressure nozzle 33 and onto the holding surface 282. The predetermined distance L is selected experimentally, empirically, or theoretically, and is a value that allows the holding surface 282 to be appropriately cleaned by the two fluids T sprayed from the nozzle 100 of the nozzle 10. Note that the nozzle 10, the box 113, and the positioning unit 32 may be lowered by the lifting mechanism 11 while a predetermined amount of air B is being sprayed from the nozzle 330 of the back pressure nozzle 33. The fluid sprayed from the nozzle 330 may be water. The flow rate of the air or water sprayed from the nozzle 330 may be changed to achieve the predetermined distance L.

[0052] 4, due to the back pressure of air B injected from the nozzle 330 of the back pressure nozzle 33 toward the holding surface 282, the back pressure nozzle 33, the nozzle 10, and the piston 322 connected to the nozzle 10 and guided by the guide case 321 rise in the +Z direction within the box 113 so as to move away from the holding surface 282. The nozzle 100 of the nozzle 10 is then positioned at height Z3, a predetermined distance L above the holding surface 282. This state is maintained by continuing to supply a constant amount of air B per minute from the air supply source 109 to the back pressure nozzle 33, and the table 28 is rotated, so that the entire holding surface 282 is properly cleaned with the two-fluid T.

[0053] Next, we will explain the case where the holding surface 282, which is at height Z2 of the table 28 shown in Figure 4, is self-ground and the height shown in Figure 5 is reduced to height Z4, which is lower than before self-grinding, and then cleaned by the cleaning device 3.

[0054] The nozzle 10, together with the box 113 and the positioning unit 32, is lowered by the lifting mechanism 11 until it is positioned at a predetermined height Z1, at which point the lowering of the nozzle 10, the box 113, and the positioning unit 32 by the lifting mechanism 11 stops. In this state, the piston 322 of the positioning unit 32 is in contact with and supported by the inner bottom surface of the guide case 321 (not lifted).

[0055] Then, as shown in Fig. 5, the two-fluid T is sprayed in a band shape from the nozzle 100 of the nozzle 10 toward the holding surface 282 after self-grinding. In addition, a constant amount of air B per minute (the same amount as in the case shown in Fig. 4) is supplied from the air supply source 109 to the back pressure nozzle 33, and the air B is sprayed downward from the nozzle 330. Due to the back pressure of the air B sprayed from the nozzle 330 toward the holding surface 282, the back pressure nozzle 33, the nozzle 10, and the piston 322 guided by the guide case 321 rise in the +Z direction within the box 113 so as to move away from the holding surface 282, as shown in Fig. 5. Here, the amount of air B supplied per minute from the air supply source 109 to the back pressure nozzle 33 is the same in the cases shown in FIG. 4 and FIG. 5 . Therefore, when the lift distance of the back pressure nozzle 33 and the like is smaller in the case shown in FIG. 5 than in the case shown in FIG. 4 , the ejection port 100 of the nozzle 10 is positioned at height Z5, which is a predetermined distance L above the holding surface 282. This state is maintained by continuing to supply a constant amount of air B per minute from the air supply source 109 to the back pressure nozzle 33. Note that a constant amount of water may also be supplied per minute from the back pressure nozzle 33. Furthermore, as the table 28 rotates, the entire holding surface 282 is cleaned by the two-fluid T for a predetermined time, and then the water ejected from the back pressure nozzle 33 prevents the holding surface 282 from drying.

[0056] As described above, the cleaning device 3 of the second embodiment of the present invention can maintain the distance L between the nozzle 10 of the nozzle 10 and the holding surface 282 simply by lowering the nozzle 10, the back pressure nozzle 33, etc. to a predetermined height Z1 without performing complex height control using the lifting mechanism 11 and then spraying a constant amount of fluid (air B or water) from the nozzle 330 of the back pressure nozzle 33 that constitutes the positioning unit 32 onto the holding surface 282, thereby enabling appropriate two-fluid cleaning of the holding surface 282. Furthermore, even if the height of the holding surface 282 changes as shown in FIGS. 4 and 5 , the back pressure of the fluid sprayed from the back pressure nozzle 33 automatically adjusts the distance between the holding surface 282 and the nozzle 100 of the nozzle 10 that sprays the two-fluid T to the predetermined distance L. This eliminates the need for a control unit that performs complex control to adjust the height of the nozzle 10, thereby enabling the cleaning device 3 to be made more compact.

[0057] 3 according to a second embodiment of the present invention can be used not only to clean the holding surface 282 of the table 28 as described above, but also to clean the top surface 903 of a workpiece 90 held by suction on the holding surface 282. When grinding is performed successively on multiple workpieces 90 one by one, there are cases where the finished thickness of the second workpiece 90 after grinding is completed is thinner than the finished thickness of the first workpiece 90 after grinding is completed. In this case, too, two-fluid cleaning can be performed by adjusting the distance from the top surface 903 of the second workpiece 90 to the injection port 100 of the nozzle 10, just as in the case where the holding surface 282 of the table 28 changes before and after self-grinding. That is, due to the back pressure of the air B sprayed from the back pressure nozzle 33, the distance from the upper surface 903 of the second workpiece 90, which is lower in height than the upper surface 903 of the first workpiece 90, to the nozzle 100 of the nozzle 10 is adjusted to the same value as the distance when the upper surface 903 of the first workpiece 90 is cleaned with two-fluid.

[0058] For example, a case will be described in which a new workpiece 90 is held by suction on the table 28 whose holding surface 282 has been cleaned after self-grinding as shown in FIG. 5, the workpiece 90 is then ground, and then the upper surface 903 of the workpiece 90 held by suction on the holding surface 282 is subjected to two-fluid cleaning.

[0059] 6, the nozzle 10, together with the box 113 and the positioning part 32, is lowered by the lifting mechanism 11, and positioned at a predetermined height Z1 (the same origin height Z1 as when cleaning the holding surface 282). The positioning by the lifting mechanism 11 stops the descent of the nozzle 10, box 113, and positioning part 32 until they reach the origin height Z1. In this state, the piston 322 of the positioning part 32 is in contact with and supported by the inner bottom surface of the guide case 321 (not lifted).

[0060] Then, air B is supplied from the air supply source 109 to the back pressure nozzle 33 at a constant rate per minute (for example, the same rate as in the case shown in FIG. 5), and the air B is sprayed downward from the nozzle 330. Due to the back pressure of the air B sprayed toward the upper surface 903, the back pressure nozzle 33, the nozzle 10, and the piston 322 guided by the guide case 321 rise away from the upper surface 903, as shown in FIG. 6. Here, since the amount of air B supplied per minute from the air supply source 109 to the back pressure nozzle 33 is the same in the cases shown in FIG. 5 and FIG. 6, when the lift distance of the back pressure nozzle 33 and the like becomes greater in the case shown in FIG. 6 than in the case shown in FIG. 5 (the rise distance becomes greater by the thickness of the workpiece 90), the nozzle 100 of the nozzle 10 is positioned at height Z6, which is a predetermined distance L above the upper surface 903. This state is maintained by continuously supplying a constant amount of air B per minute from the air supply source 109 to the back pressure nozzle 33. Note that a constant amount of water may be continuously supplied from the back pressure nozzle 33 per minute. Furthermore, as the table 28 rotates, the entire upper surface 903 of the workpiece 90 is cleaned by the two-fluid T, and then the water sprayed from the back pressure nozzle 33 prevents the upper surface of the workpiece 90 from drying.

[0061] As described above, the cleaning apparatus 3 of the second embodiment of the present invention can maintain the predetermined distance L between the nozzle 10 and the upper surface 903 of the workpiece 90 held by the holding surface 282 simply by lowering the nozzle 10, the back-pressure nozzle 33, etc. to the predetermined height Z1 without performing complex height control using the lifting mechanism 11 and then spraying a constant amount of fluid (air B or water) from the nozzle 330 of the back-pressure nozzle 33 that constitutes the positioning unit 32 onto the holding surface 282, thereby enabling appropriate two-fluid cleaning of the upper surface 903 of the workpiece 90. Furthermore, even if the height of the upper surface 903 of the workpiece 90 changes, the back pressure of the fluid sprayed from the back-pressure nozzle 33 automatically adjusts the distance between the upper surface 903 and the nozzle 100 of the nozzle 10 that sprays the two-fluid T to the predetermined distance L. This eliminates the need for a control unit that performs complex control to adjust the height of the nozzle 10, thereby enabling the cleaning apparatus 3 to be made more compact.

[0062] The grinding device 2 may be equipped with a cleaning device 5 of a third embodiment shown in Fig. 7 instead of the cleaning device 1 of the first embodiment shown in Fig. 1. Components configured similarly to the cleaning device 1 of Fig. 1 are denoted by the same reference numerals as in Fig. 1. The cleaning device 5 of the third embodiment will be described below.

[0063] The cleaning device 5, which cleans the holding surface 282 of the table 28 or the upper surface 903 of the object to be cleaned 90 (workpiece 90) held by the holding surface 282, includes a box 50 that houses the nozzle 10 and has an open bottom, a lifting mechanism 11 that moves the box 50 vertically to the holding surface 282, and a lifting mechanism 51 that supports the box 50 so that it can be raised and lowered freely.

[0064] 8, a rectangular opening 500 is formed in the bottom surface of the box 50, and the movement path of the table 28 is located below the opening 500. A nozzle 10 is fixed to the inner surface of the box 50 with its outlet 100 facing the downward opening 500. An air inlet 502 that communicates with the inside of the box 50 is formed through the top surface of the box 50, and an air supply source 109 is connected to the air inlet 502 via a joint and piping.

[0065] 7 and 8, the liftable mechanism 51 includes a base 510 fixed to the lower end of a rod 111 of the liftable mechanism 11 that moves up and down in the Z-axis direction, a pair of guide rails 511 disposed on the front surface of the base 510 on the -Y direction side and extending in the Z-axis direction, and a liftable plate 512 whose sides are in sliding contact with the pair of guide rails 511. A box 50 is fixed to the front surface of the liftable plate 512. In addition, protruding portions 513 that protrude to the left and right are formed on the upper side of the liftable plate 512, and in normal operation (when not lifted), the protruding portions 513 are in contact with the upper surface of the base 510, and the liftable plate 512 and the box 50 are supported on the base 510 so as to be able to move up and down. Note that FIG. 8 shows a simplified view of part of the configuration of the liftable mechanism 51.

[0066] The following describes a case where the holding surface 282 of the table 28 is cleaned using the cleaning device 5 of the third embodiment. As shown in Fig. 8, the table 28, which is not holding the workpiece 90 by suction, moves in the Y-axis direction, and the nozzle 10 is positioned above the holding surface 282 along the radius from the center of rotation to the outer periphery.

[0067] Next, the nozzle 10 is lowered together with the box 50 and the liftable mechanism 51 by the lifting mechanism 11, and the nozzle 10, box 50, and liftable mechanism 51 are positioned at a predetermined height Z1, and the lowering of the nozzle 10, box 50, and liftable mechanism 51 by the lifting mechanism 11 stops.

[0068] For example, in this embodiment, when the nozzle 10, box 50, and liftable mechanism 51 are positioned at a predetermined height Z1, the nozzle 100 of the nozzle 10 is positioned at a height Z3 that is a predetermined distance L above the holding surface 282. Then, without supplying air from the air inlet 502 into the box 50, air is supplied only to the nozzle 10 from the air supply source 109, and cleaning water is supplied to the nozzle 10 from the cleaning water source 108, and the two-fluid T is sprayed in a strip from the nozzle 100 of the nozzle 10 toward the holding surface 282.

[0069] 8 is a predetermined distance L for properly cleaning the holding surface 282, the entire holding surface 282 is two-fluid cleaned by the two-fluid T as the table 28 rotates. Then, after the two-fluid cleaning of the holding surface 282 has been performed for a predetermined time, the holding surface 282 is dried. The two-fluid T flows out of the box 50 through a gap between the holding surface 282 and the bottom surface of the box 50.

[0070] Next, a case will be described in which the cleaning device 5 of the third embodiment is used to suction-hold the workpiece 90 on the cleaned holding surface 282 of the table 28 shown in Fig. 9, and then two-fluid cleaning is performed on the upper surface 903 of the suction-held workpiece 90. The table 28, which suction-holds the workpiece 90, moves in the Y-axis direction, and the nozzle 10 is positioned above the upper surface 903 of the workpiece 90, along a radius from the center of rotation of the upper surface 903 to the outer periphery.

[0071] The lifting mechanism 11 causes the nozzle 10 to descend together with the box 50 and the lifting mechanism 51, and when the nozzle 10, box 50, and lifting mechanism 51 are positioned at a predetermined height Z1, the descent of the nozzle 10, box 50, and lifting mechanism 51 by the lifting mechanism 11 stops.

[0072] 9, two fluids T are sprayed in a band shape toward the upper surface 903 from the spray port 100 of the nozzle 10. In addition, a constant amount of air B is supplied per minute from the air supply source 109 into the box 50 through the air inlet 502, and the air B is sprayed into the box 50. Furthermore, the back pressure of the air B sprayed from the opening 500 of the box 50 onto the upper surface 903 forms a gap between the lower surface of the box 50 and the upper surface 903 of the workpiece 90 held on the holding surface 282. The amount of air B supplied into the box 50 is an amount that enables the back pressure of the air B sprayed from the opening 500 onto the upper surface 903 to position the outlet 100 of the nozzle 10 a predetermined distance L above the upper surface 903, and the lifting plate 512, which is in sliding contact with a pair of guide rails 511, the box 50 connected to the lifting plate 512, and the nozzle 10 fixed to the inner surface of the box 50, rise in the +Z direction as shown in Figures 9 and 10 from the states shown in Figures 7 and 8. Then, as shown in Figure 9, the outlet 100 of the nozzle 10 is positioned at height Z7, the predetermined distance L above the upper surface 903 (height Z7 that is higher than height Z3 shown in Figure 8 by the thickness of the workpiece 90), and this state is maintained as a constant amount of air B continues to be supplied per minute from the air supply source 109 to the box 50.

[0073] 9, as the table 28 rotates, the entire upper surface 903 of the workpiece 90 is properly cleaned by the two-fluid T. After the two-fluid cleaning of the upper surface 903 has been performed for a predetermined time, the nozzle 10 is raised and retracted. Note that only water may be sprayed from the nozzle 100 of the nozzle 10 to prevent the upper surface 903 from drying out.

[0074] In this way, the cleaning device 5 of the present invention lowers the box 50 using the lifting mechanism 11, sprays air B, which is a fluid, into the box 50 from the nozzle 10, and creates a gap between the underside of the box 50 and the holding surface 282, or between the underside of the box 50 and the upper surface 903 of the workpiece 90 held on the holding surface 282, using the back pressure of the air B sprayed from the opening 500 of the box 50.The nozzle 10 is positioned at an appropriate height relative to the holding surface 282 or the upper surface 903 of the workpiece 90 held on the holding surface 282, and two fluids T can be sprayed from the nozzle 10 at a fixed distance (predetermined distance L) toward the holding surface 282 or the upper surface 903 of the workpiece 90, thereby enabling the holding surface 282 or the upper surface 903 of the workpiece 90 to be cleaned well.

[0075] As shown in Fig. 11, the grinding device 2 may be provided with the cleaning device 6 of the fourth embodiment instead of the cleaning device 5 of the third embodiment shown in Fig. 7. Note that the same reference numerals are used in Fig. 11 to designate parts configured in the same manner as the cleaning device 5 of Fig. 7. The cleaning device 6 of the fourth embodiment will be described below.

[0076] The cleaning device 6, which cleans the holding surface 282 of the table 28 or the upper surface 903 of the workpiece 90, which is the object to be cleaned held by the holding surface 282, includes a box 60 that houses the nozzle 10 and has an open bottom, a lifting mechanism 11 that moves the box 60 vertically to the holding surface 282, a lifting mechanism 51 that supports the box 60 so that it can be raised and lowered, and an injection nozzle 610 (see Figure 12) that faces the holding surface 282.

[0077] 12, a rectangular opening 600 is formed in the bottom surface of the box 60, and the movement path of the table 28 is located below the opening 600. A nozzle 10 is fixed to the inner surface of the box 60 with its nozzle 100 facing the opening 600 downward.

[0078] For example, a back pressure nozzle 61 having an injection port 610 facing the holding surface 282 of the table 28 is disposed on the outer surface of an outer wall 608 of a box 60 shown in Figures 11 and 12. The back pressure nozzle 61 is connected to an air supply source 109 via a joint and piping.

[0079] 12 and 13, the cleaning device 6 may be provided with an annular jet port 609 formed on the bottom surface of the box 60, instead of the jet port 610. That is, in this case, for example, the box 60 shown in FIGS. 12 and 13 has an inner wall 607 and an outer wall 608, and has a double structure with a predetermined gap (space) between the inner wall 607 and the outer wall 608, and the lower end of the gap serves as the jet port 609. In this case, an inlet 602 communicating with the jet port 609 is formed on the top surface of the box 60 shown in FIG. 12, and the inlet 602 is connected to the air supply source 109 via a joint and a pipe.

[0080] The following describes a case where the holding surface 282 of the table 28 shown in Fig. 12 is cleaned using the cleaning device 6 of the fourth embodiment. The table 28, which is not holding the workpiece 90 by suction, moves in the Y-axis direction, and the nozzle 10 is positioned above the holding surface 282 along a radius from the center of rotation to the outer periphery. Next, the nozzle 10 is lowered together with the box 60 and the liftable mechanism 51 by the lifting mechanism 11 shown in Fig. 12, and the nozzle 10, box 60, and liftable mechanism 51 are positioned at a predetermined height Z1, and the lowering of the nozzle 10, box 60, and liftable mechanism 51 by the lifting mechanism 11 stops.

[0081] For example, in this embodiment, when the nozzle 10, the box 60, and the liftable mechanism 51 are positioned at a predetermined height Z1, the nozzle 100 of the nozzle 10 is positioned at a height Z3 that is a predetermined distance L above the holding surface 282. Air is supplied only to the nozzle 10 from the air supply source 109, and cleaning water is supplied to the nozzle 10 from the cleaning water source 108, and the two-fluid T is sprayed in a band shape from the nozzle 100 of the nozzle 10 onto the holding surface 282.

[0082] As a result, with the distance between the ejection port 100 of the nozzle 10 and the holding surface 282 being a predetermined distance L for properly cleaning the holding surface 282, the entire holding surface 282 is cleaned by the two-fluid T as the table 28 rotates. Then, after the two-fluid cleaning of the holding surface 282 has been carried out for a predetermined time, the holding surface 282 is dried. Note that the two-fluid T flows out of the box 60 through a gap between the holding surface 282 and the bottom surface of the box 60.

[0083] Next, a case will be described in which the cleaning device 6 of the fourth embodiment is used to suction-hold the workpiece 90 on the cleaned holding surface 282 of the table 28 shown in Fig. 14, and then two-fluid cleaning is performed on the upper surface 903 of the suction-held workpiece 90. The nozzle 10 is positioned above the table 28 that suction-holds the workpiece 90, along the radius from the center of rotation of the upper surface 903 of the workpiece 90 to the outer periphery.

[0084] The nozzle 10 is lowered together with the box 60 and the liftable mechanism 51 by the lifting mechanism 11, and the nozzle 10, box 60 and liftable mechanism 51 are positioned at a predetermined height Z1, at which point the lowering of the nozzle 10, box 60 and liftable mechanism 51 by the lifting mechanism 11 stops.

[0085] Two fluids T are sprayed in a band shape from the nozzle 100 of the nozzle 10 toward the upper surface 903. In addition, a constant amount of air B (fluid B) is supplied per minute from the air supply source 109 to the back pressure nozzle 61, and air B is sprayed from the nozzle 610 of the back pressure nozzle 61. The back pressure of the air B sprayed from the nozzle 610 onto the upper surface 903 forms a gap between the lower surface of the box 60 and the upper surface 903 of the workpiece 90 held on the holding surface 282. The amount of air B supplied into the box 60 is an amount that enables the nozzle 100 of the nozzle 10 to be positioned a predetermined distance L above the upper surface 903 by the back pressure of the air B sprayed from the opening 600 onto the upper surface 903, and the lifting plate 512, which is in sliding contact with the pair of guide rails 511, the box 60 connected to the lifting plate 512, and the nozzle 10 fixed to the inner surface of the box 60 rise in the +Z direction. Then, the nozzle 100 of the nozzle 10 is positioned at a height Z7, a predetermined distance L above the holding surface 282, and this state is maintained by continuing to supply a constant amount of air B per minute from the air supply source 109 to the back pressure nozzle 61.

[0086] Instead of supplying air B to the back pressure nozzle 61, air B can be supplied to the inlet 602 of the box 60, and the back pressure of the air B sprayed from the rectangular annular nozzle 609 on the bottom surface of the box 60 onto the top surface 903 forms a gap between the bottom surface of the box 60 and the top surface 903 of the workpiece 90 held on the holding surface 282, and the back pressure of the sprayed air B positions the nozzle 100 of the nozzle 10 a predetermined distance L above the top surface 903, and this state can be maintained by continuing to supply a constant amount of air B per minute from the air supply source 109 to the nozzle 609 of the box 60. Alternatively, a fixed amount of water may be sprayed per minute from a rectangular annular nozzle 609 on the bottom surface of the box 60, and the nozzle 100 of the nozzle 10 may be positioned a predetermined distance L above the top surface 903. As the table 28 rotates, the entire upper surface 903 is properly cleaned by the two-fluid T.

[0087] The cleaning device according to the present invention is not limited to the first to fourth embodiments, and the grinding process of the workpiece 90, the cleaning process of the upper surface 903 of the workpiece 90, or the cleaning process of the holding surface 282 of the table 28 can be modified as appropriate within the scope in which the effects of the present invention can be achieved. 14 may be connected to an intake source such as a duct fan via duct piping to create a negative pressure inside the box 60, thereby sucking in the spray inside the box 60. A water seal may be formed between the lower end of the box 60, where the nozzle 10 is positioned a predetermined distance L from the holding surface 282 or the upper surface 903 of the workpiece 90 held on the holding surface 282, and the holding surface 282 or the upper surface 903 of the workpiece 90 held by the holding surface 282, to prevent the spray from ejecting from the lower end of the box 60. The water seal may be formed by the two-fluid T ejected from the nozzle 10, or by water ejected from the back-pressure nozzle 61 or the annular injection port 609 at the lower end of the box 60. [Explanation of symbols]

[0088] 1: Cleaning device of embodiment 1 10: Nozzle 100: Spray nozzle 108: Cleaning water source 109: Air supply source 11: Lifting mechanism 110: Rod 111: Cylinder case 113: Box 12: Roller (positioning part) 2: Grinding device 20: Base 21: Column 23: Grinding mechanism 24: Grinding feed unit 28: Table 282: Holding surface 281: Frame 283: Upper surface of frame 29: Rotation mechanism 3: Cleaning device of embodiment 2 32: Positioning portion 320: Guide rail 321: Guide case 322: Piston 33: Back pressure nozzle 330: Injection port 5: Cleaning device of embodiment 3 50: Box 500: Opening 502: Air inlet 51: Lifting mechanism 510: Base 511: Guide rail 512: Lifting plate 6: Cleaning device of embodiment 4 60: Box 600: Opening 602: Inlet 607: Inner wall 608: Outer wall 609: Jet nozzle 61: Back pressure nozzle 610: Jet nozzle 90: Workpiece 903: Top surface of workpiece

Claims

1. A cleaning device that cleans an object held on the holding surface, the cleaning device comprising: a table that holds an object to be cleaned on a holding surface; a rotation mechanism that rotates the table around the center of the holding surface; and a nozzle that sprays a two-fluid mixture of water and air toward the holding surface, a lifting mechanism that moves the nozzle in a direction perpendicular to the holding surface, a guide rail that supports the nozzle so that it can be raised and lowered, and a back pressure nozzle having an injection port facing the holding surface, A cleaning device in which a fluid is sprayed from the spray port onto the top surface of the object to be cleaned held by the holding surface, and the nozzle, which can be raised and lowered by the back pressure of the fluid, is positioned at an appropriate height relative to the top surface of the object to be cleaned held by the holding surface, thereby cleaning the object to be cleaned.

2. A cleaning device comprising: a table that holds an object to be cleaned on a holding surface; a rotation mechanism that rotates the table around the center of the holding surface; and a nozzle that sprays a two-fluid mixture of water and air toward the holding surface, and that cleans the holding surface or the top surface of the object to be cleaned held by the holding surface, a box that houses the nozzle and has an open bottom, a lifting mechanism that moves the box in a direction perpendicular to the holding surface, a lifting mechanism that supports the box so that it can be raised and lowered, and an injection port that faces the holding surface, The injection port is formed in an annular shape on the lower surface of the box, The box is lowered by the lifting mechanism, fluid is sprayed from the nozzle onto the holding surface, and the back pressure of the fluid forms a gap between the bottom surface of the box and the holding surface, or between the bottom surface of the box and the top surface of the object to be cleaned, and the nozzle is positioned at an appropriate height relative to the holding surface or the top surface of the object to be cleaned, thereby cleaning the holding surface or the top surface of the object to be cleaned.

Images