Cavitation treatment method and cavitation treatment device

Abstract

A cavitation treatment method includes: immersing a nozzle (23), which sprays a jet (C1) of a treatment liquid (11) with cavitation bubbles, an object (50a), which includes a groove portion (53) that extends left and right as viewed from the nozzle (23) and has edge portions (56) at the front and rear, in the treatment liquid (11), and a guide portion (30); the guide part (30) is provided with a flow rectifying part (32) for enabling the jet flow (C1) to flow in the front-back direction and a blocking part (33) for blocking the front end of the flow rectifying part (32); an edge section (56) that causes the blocking section (33) to approach the front side; spraying the jet (C1) from the nozzle (23); and introducing the jet flow (C1) from the rear side into the rectification part (32) and causing the jet flow (C1) to collide with the blocking part (33), thereby changing the flow direction of the jet flow (C1) and causing the jet flow (C1) to collide with the bottom part (54) of the groove part (53).

Description

Technical Field

[0001] The present invention relates to a cavitation treatment method and a cavitation treatment device for performing cavitation treatment on the surface of an object. Background Art

[0002] In the past, cavitation treatment was performed on metal objects (Japanese Patent No. 6872929). In cavitation treatment, a jet of fluid containing cavitation bubbles (bubbles) is made to collide with the object, and the surface of the object is treated by the impact force when the cavitation bubbles collapse. Through cavitation treatment, compressive residual stress can be applied to the surface of the object.

[0003] Objects to be subjected to cavitation treatment have various shapes and sizes. In order to perform appropriate cavitation treatment, it is necessary to make the jet collide with the surface of the object in an appropriate manner according to the conditions of the object. Summary of the invention

[0004] An object of the present invention is to provide a cavitation treatment method and a cavitation treatment device for performing cavitation treatment on the bottom of a groove portion of an object.

[0005] The first aspect of the present invention is a cavitation treatment method, comprising:

[0006] The nozzle, the object and the guide part are immersed in the treatment liquid, the nozzle ejecting a jet of the treatment liquid with cavitation, the object including a groove part extending left and right and having edges at the front and rear as viewed from the nozzle, and the guide part including a rectifying part for making the jet flow in the front-rear direction and a blocking part for blocking the front end of the rectifying part;

[0007] Bringing the blocking portion close to the edge portion on the front side;

[0008] ejecting the jet from the nozzle; and

[0009] The jet is introduced into the rectifying portion from the rear side and is made to collide with the blocking portion, thereby changing the flow direction of the jet and causing the jet to collide with the bottom of the groove portion.

[0010] A second aspect of the present invention is a cavitation treatment device having:

[0011] A tank storing a treatment solution;

[0012] a nozzle, the nozzle being immersed in the tank and ejecting a jet of the treatment liquid;

[0013] a holding portion, the holding portion being arranged in the groove and holding an object, the object including a groove portion extending left and right as viewed from the nozzle and having edges at the front and rear; and

[0014] A guide portion, the guide portion being arranged below the object and comprising:

[0015] a rectifying groove extending rearward from a position below the groove portion and allowing the jet to flow; and

[0016] The blocking portion has an upper edge portion which is arranged close to the edge portion on the front side and extends in the left-right direction, is connected to the front end of the rectifying groove, and blocks the rectifying groove.

[0017] During the cavitation treatment, the object, the nozzle and the guide are immersed in the treatment liquid stored in the tank. In the treatment liquid, a jet of the treatment liquid is ejected from the nozzle toward the guide. The treatment liquid is, for example, water. The treatment liquid may also be a treatment liquid in which an abrasive is mixed with water. The abrasive may also be turbid in the treatment liquid stored in the tank.

[0018] The object is made of metal. Examples of the metal constituting the object are heat-resistant alloys, aluminum alloys, magnesium alloys, titanium, titanium alloys, and steel. Examples of the object are mechanical parts, medical equipment parts, and medical instruments. Examples of mechanical parts are gears, piping, valves, pipe joints, and aerospace parts. Medical instruments may also be surgical implants. Aerospace parts may also be aircraft engine parts and other aircraft parts, rocket engine parts, spacecraft parts, satellite parts, and rocket piping. The object may also be manufactured by additive manufacturing.

[0019] The groove portion of the object extends, for example, from the left end to the right end of one side of the object. The groove portion is open to the left and right end surfaces at both ends. The groove portion may extend in a straight line. The groove portion may extend in a curved manner. The cross-sectional shape of the groove portion may be, for example, U-shaped or V-shaped. The cross-sectional shape of the groove portion may also be a shape with a constant width from the bottom to the opening. The cross-sectional shape of the groove portion may also be a shape with a variable width from the bottom to the opening. The cross-sectional shape of the groove portion may also be constant along the direction in which the groove portion extends. The cross-sectional shape of the groove portion may also be deformed along the direction in which the groove portion extends. The object may also have one groove portion. The object may also have multiple groove portions.

[0020] When the object is a gear, it may be a spur gear, helical gear, internal gear, herringbone gear, bevel gear, etc., where the teeth (tooth grooves) are arranged on a circle. In addition, when the object is a gear, it may be a rack where the teeth (tooth grooves) are arranged on a straight line. A rack can be regarded as a gear with an infinite radius.

[0021] The rectifying portion of the guide portion is, for example, a groove extending forward and backward. The rectifying portion is, for example, a groove extending from the rear end to the front end of one side of the guide portion. The rectifying portion is open at both ends to the front and rear end face sides. The rectifying portion may also extend in a straight line. The rectifying portion may also extend in a curved manner. In the case where the rectifying portion is a groove, the shape of the cross section of the rectifying portion is, for example, a U-shape or a V-shape. The shape of the cross section of the rectifying portion may also be a shape with a constant width from the bottom to the opening. The shape of the cross section of the rectifying portion may also be a shape with a variable width from the bottom to the opening. The shape of the cross section of the rectifying portion may also be constant along the direction in which the rectifying portion extends. The shape of the cross section of the rectifying portion may also be deformed along the direction in which the rectifying portion extends. The rectifying portion may also be composed of one groove. The rectifying portion may also be composed of multiple grooves.

[0022] The blocking portion of the guide portion is, for example, a wall provided at the front end of the rectifying portion. The blocking portion may also protrude further toward the object than the rectifying portion. The blocking portion may also be a portion integral with the portion blocking the front end of the rectifying portion, protruding toward the object. The blocking portion may also have a component separate from the portion blocking the front end of the rectifying portion, and the separate component protrudes toward the object.

[0023] The injection diameter of the nozzle is, for example, 0.5 mm to 3 mm, and the injection pressure of the jet is, for example, 10 MPa to 200 MPa.

[0024] The inclination angle of the jetting direction of the jet may also be less than 45 degrees.

[0025] Alternatively, the left-right position of the object may be fixed and the nozzle may be moved in the left-right direction. Alternatively, the left-right position of the nozzle may be fixed and the object may be moved in the left-right direction.

[0026] When the object is a gear having teeth (tooth grooves) arranged on a circumference, the gear may be rotated about its central axis in order to move the tooth grooves forward and backward.

[0027] When the object is a gear (rack) in which teeth (tooth grooves) are arranged in a straight line, the gear may be translated in the front-rear direction in order to move the tooth grooves forward and backward.

[0028] When the gear as the object is rotated or moved, the rotation or movement of the gear may be synchronized with the left-right movement of the nozzle or the gear. For example, the nozzle or the gear may be moved left-right every time the gear rotates.

[0029] According to the cavitation treatment method and the cavitation treatment device of the present invention, it is possible to perform cavitation treatment on the bottom of the groove portion of the object. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a cavitation treatment device according to a first embodiment.

[0031] Figure 2 It is an enlarged view of the guide portion and the spur gear of the first embodiment.

[0032] Figure 3 yes Figure 2 Cross-sectional view along line III-III.

[0033] Figure 4 yes Figure 3 The IV-IV line sectional view is an explanatory diagram of the flow of the jet in the first embodiment.

[0034] Figure 5 It is a plan view for explaining the flow of the jet in the first embodiment.

[0035] Figure 6 It is an enlarged view of the guide portion and the rack according to the second embodiment.

[0036] Explanation of symbols

[0037] 11 Treatment fluid

[0038] 23 Nozzle

[0039] 30 Guide

[0040] 32. Rectification Unit

[0041] 33 Occlusion

[0042] 50a Spur gear (object)

[0043] 50b Rack (object)

[0044] 53 tooth groove (groove)

[0045] 54 Tooth bottom (bottom)

[0046] 56 Front edge (edge)

[0047] 57 rear edge (edge)

[0048] C1 Jet DETAILED DESCRIPTION

[0049] <First Embodiment>

[0050] like Figure 1 As shown, the cavitation treatment device 100 of the present embodiment includes a groove 10, a jet portion 20, a guide portion 30, a holder 40, and a high-pressure fluid supply source 60. The cavitation treatment device 100 performs cavitation treatment on a spur gear (object) 50a.

[0051] In addition, as described later, the ejection unit 20 has a nozzle 23. The front, back, left, and right directions are determined by the direction viewed from the nozzle 23. Specifically, the direction away from the nozzle 23 is set as the front direction, and the direction approaching the nozzle 23 is set as the rear direction. In this embodiment, the front and back directions and the left and right directions are both horizontal directions. That is, in Figure 1 In the figure, the right side is the front direction, the left side is the rear direction, the back side of the paper is the left direction, and the front side of the paper is the right direction. The front and back directions and the left and right directions may not be horizontal directions.

[0052] The spur gear 50a is made of metal. Figure 2 As shown, the spur gear 50a has a plurality of teeth 51. The plurality of teeth 51 are arranged on the circumference. Each tooth 51 protrudes toward the outer peripheral side. The tooth 51 is a shape that becomes thinner and thinner toward the front end. The front end of the tooth 51 is a tooth top surface 52 that is a plane. A tooth groove 53 is formed between adjacent teeth 51. The tooth groove 53 is a shape in which the groove width becomes wider toward the opening side. The bottom of the tooth groove 53 is a tooth bottom 54. The tooth bottom 54 is a surface that connects the roots of the teeth 51 adjacent on both sides to each other. The tooth bottom 54 is a curved surface that becomes concave toward the opening side of the tooth groove 53. The tooth groove 53 is a groove portion of the object. The tooth bottom 54 is the bottom of the groove portion. The tooth bottom 54 is the object portion of the cavitation treatment.

[0053] like Figure 1 as well as Figure 5 As shown, the spur gear 50a is arranged in a state where the central axis 55 extends in the left-right direction. Figure 2 As shown, when focusing on the lower part of the spur gear 50a, a plurality of teeth 51 extending left and right are arranged front and back. Moreover, a tooth groove 53 extending left and right is formed between the front and rear teeth 51. The tooth groove 53 is open toward the lower side. In a certain tooth groove 53, the rear side of the tooth top surface 52 of the tooth 51 on the front side is the front edge of the tooth groove 53, that is, the front edge 56. In a certain tooth groove 53, the front side of the tooth top surface 52 of the tooth 51 on the rear side is the rear edge of the tooth groove 53, that is, the rear edge 57.

[0054] like Figure 1 As shown, the tank 10 stores a treatment liquid 11. The treatment liquid 11 is, for example, water. The tank 10 may also have a device for circulating the stored treatment liquid 11.

[0055] like Figure 1 As shown, the spraying portion 20 has a supply pipe 21 , an outlet pipe 22 , and a nozzle 23 .

[0056] The supply pipe 21 is, for example, a straight pipe extending in the up-down direction. The processing liquid 11 supplied from the high-pressure fluid supply source 60 passes through the inside of the supply pipe 21. The high-pressure fluid supply source 60 may be, for example, a pump.

[0057] The outlet pipe 22 is connected to the lower end of the supply pipe 21. The outlet pipe 22 has a variable angle relative to the supply pipe 21. The direction of the front end of the outlet pipe 22 can be adjusted within a range of at least 0 to 90 degrees (vertically downward) based on the front-rear direction.

[0058] The nozzle 23 is connected to the front end of the outlet pipe 22. The nozzle 23 ejects a jet C1 of the treatment liquid 11. By changing the direction of the outlet pipe 22, the ejection direction of the jet C1 changes. The treatment liquid 11 is supplied to the nozzle 23 from the high-pressure fluid supply source 60 through the supply pipe 21 and the outlet pipe 22. The jet C1 includes many cavitations. The ejection part 20 can move in three axial directions, namely the horizontal direction (front-back direction and left-right direction) and the up-down direction. The ejection speed (pressure) of the jet C1, the ejection angle, and the movement of the ejection part 20 in the three-axis direction are controlled by a control device (not shown). The ejection aperture (inner diameter) of the nozzle 23 is, for example, 0.5 mm to 3 mm.

[0059] like Figure 1 As shown, the guide portion 30 includes a base portion 31 , a rectifying portion 32 , and a closing portion 33 .

[0060] The base portion 31 is a rectangular block that is long in the front-to-back direction. Figure 3 As shown, the width of the base portion 31 in the left-right direction may be wider than the width of the spur gear 50 a in the left-right direction.

[0061] like Figure 3 As shown, the rectifying portion 32 has a plurality of (six in this embodiment) protrusions 321 and a plurality of (five in this embodiment) rectifying grooves 322. A plurality of protrusions 321 are formed on the upper surface of the base portion 31. A plurality of rectifying grooves 322 are formed between adjacent protrusions 321. Each protrusion 321 extends in the front-to-back direction. A plurality of protrusions 321 are arranged left and right. The protrusions 321 extend from the rear end to the front end of the base portion 31. The protrusions 321 are shaped to become thinner toward the upper side. Each rectifying groove 322 extends in the front-to-back direction. A plurality of rectifying grooves 322 are arranged left and right across the protrusions 321. The rectifying grooves 322 extend from the rear end to the front end of the base portion 31. Both ends of the rectifying grooves 322 are open on the end surface side. The rectifying grooves 322 are shaped such that the groove width widens toward the upper side. The width and depth of the rectifying grooves 322 are the same as the width and depth of the tooth grooves 53 of the spur gear 50a.

[0062] The blocking portion 33 has a rectangular plate-shaped wall portion 331. The wall portion 331 is mounted on the front end surface of the base portion 31. The wall portion 331 serves as a wall to block the front end of the rectifying groove 322. The rear side surface of the wall portion 331 is a vertical surface. The upper end portion of the front side surface of the wall portion 331 can be inclined relative to the vertical surface. That is, the upper end portion of the wall portion 331 is a shape that becomes thinner and thinner toward the upper side. The upper edge portion 332 of the upper side of the wall portion 331 extends in the left-right direction. The upper edge portion 332 protrudes further to the upper side than the upper end of the protrusion 321 of the rectifying portion 32. The protruding height of the upper edge portion 332 based on the upper end of the protrusion 321 can be shorter than the depth of the rectifying groove 322. The rear side surface of the wall portion 331 can also be inclined relative to the vertical surface.

[0063] like Figure 1 As shown, the holding portion 40 holds the spur gear 50a. The holding portion 40 has a rotating shaft 41 extending in the left-right direction. The holding portion 40 has a rotating device (not shown) composed of a motor or the like. The rotating device rotates the rotating shaft 41. The rotating action of the rotating shaft 41 is controlled by a control device (not shown). The spur gear 50a is mounted on the rotating shaft 41. The spur gear 50a rotates around the central axis 55 together with the rotating shaft 41.

[0064] like Figure 1 as well as Figure 2 As shown, the injection portion 20, the guide portion 30, the holding portion 40 and the spur gear 50a are arranged in the tank 10 and immersed in the processing liquid 11. The guide portion 30 is arranged in front of the nozzle 23 and below the nozzle 23. The direction of the nozzle 23 is configured so that the jet C1 is sprayed toward the guide portion 30. That is, the injection direction of the jet C1 is forward and inclined downward. The inclination angle θ of the injection direction relative to the front-to-back direction is, for example, not less than 15 degrees and not more than 45 degrees. The holding portion 40 is arranged on the left side of the guide portion 30. The holding portion 40 holds the spur gear 50a on its right side. The spur gear 50a is arranged above the guide portion 30. The left-right center of the guide portion 30 is substantially consistent with the left-right center of the spur gear 50a. The height position of the guide portion 30 is a position where the upper edge portion 332 of the wall portion 331 is separated from the tooth top circle 501 of the spur gear 50a by a small gap. The tooth top circle 501 is the trajectory of the tip of the tooth 51 when the spur gear 50a rotates. The interval between the upper edge 332 and the tooth top circle 501 is, for example, less than 1 mm. In addition, the height position of the blocking portion 33 relative to the base portion 31 can also be adjusted so that it can also cope with the situation where the diameter or module of the spur gear as the object is different. In addition, the height position of the guide portion 30 relative to the holding portion 40 can also be adjusted.

[0065] The cavitation treatment device 100 configured in this way can spray the jet C1 to the spur gear 50a. In this embodiment, the tooth bottoms 54 of all the tooth grooves 53 of the spur gear 50a are the areas to be cavitated. That is, the tooth bottoms 54 of all the tooth grooves 53 of the spur gear 50a are given the effect of cavitation treatment.

[0066] like Figure 2 As shown in FIG. 1 , the upper edge 332 of the wall portion 331 is in a state close to the front edge 56 of a tooth groove 53 of the spur gear 50a. That is, the tooth groove 53 faces the front end of the rectifying groove 322. Figure 5 As shown in FIG. 1 , the left-right center of the nozzle 23 is aligned with the left-right center of the guide portion 30. When the high-pressure fluid supply source 60 is activated, the jet C1 is ejected from the nozzle 23. Figure 4 as well as Figure 5 As shown, the jet C1 is introduced into the rectifying portion 32 of the guide portion 30 from the upper rear side while diffusing up, down, left and right (C11). The jet C1 is dispersed in a plurality of (5) rectifying grooves 322, and flows toward the front side in the rectifying grooves 322 (C12). The front end of the rectifying groove 322 is blocked by the wall portion 331. The rectifying groove 322 is open at the top. Therefore, the jet C1 collides with the wall portion 331 at the front end of the rectifying groove 322. Then, the jet C1 changes the direction of flow and flows toward the upper side (C13). Since the tooth groove 53 and the front end portion of the rectifying groove 322 face each other, the jet C1 is immersed in the tooth groove 53 and collides with the innermost part of the tooth groove 53, that is, the tooth bottom 54. Then, the tooth bottom 54 is subjected to cavitation treatment.

[0067] During the cavitation treatment, the spur gear 50a is rotated to treat all the tooth bottoms 54 arranged on the circumference. The tooth bottoms 54 of the tooth grooves 53 facing the front end of the rectifying grooves 322 become the treatment objects of the cavitation treatment. Figure 1 as well as Figure 2 As shown, when the spur gear 50a is rotated clockwise, the tooth grooves 53 arranged front and back are substantially moved backward at the lower part of the spur gear 50a. Therefore, the tooth grooves 53 facing the front end of the rectifying groove 322 are replaced in sequence, and the jet C1 collides with the tooth bottoms 54 arranged front and back in sequence. Thus, the tooth bottoms 54 arranged front and back are cavitated in sequence. In addition, the spur gear 50a can be rotated continuously. The spur gear 50a can also be rotated intermittently. For example, the spur gear 50a can also be rotated by an angle corresponding to one tooth 51 each time.

[0068] In addition, as the cavitation bubbles grow and collapse in the jet C1, the intensity of the cavitation treatment changes according to the distance from the nozzle 23. The so-called intensity of the cavitation treatment refers to, for example, the strength of the compressive residual stress imparted, the density or depth of the pits formed on the surface. Therefore, when performing the cavitation treatment, the strongest treatment is performed at the point with the most suitable distance from the nozzle 23, and the degree of treatment becomes weaker as the distance from this point is distanced away. The distance suitable for cavitation treatment is, for example, about 40 to 100 times the jet diameter of the nozzle 23. Therefore, if the jet diameter of the nozzle 23 is 1 mm, the distance between the nozzle 23 and the tooth bottom 54 is preferably 40 mm to 100 mm. This distance is actually the distance that the jet C1 passes through. That is, if Figure 4 The dashed arrows C11 to C13 indicate the distance from the nozzle 23 through the rectifying groove 322 , colliding with the wall portion 331 to change direction, and reaching the tooth bottom 54 .

[0069] During the cavitation treatment, the nozzle 23 (injection unit 20) may be moved left and right. The strongest cavitation treatment is performed on the central axis of the jet C1, and the degree of treatment becomes weaker as it moves left and right away from the central axis. Therefore, when the width of the spur gear 50a in the left and right direction is wider than the prescribed width, the cavitation treatment is not performed sufficiently on the portion of the tooth bottom 54 that is away from the central axis of the jet C1 left and right. In this case, as Figure 5 As shown, by moving the nozzle 23 to the left and right, the central axis of the jet C1 also moves, and the cavitation process is performed on the entire left and right sides of the tooth bottom 54.

[0070] In addition, the nozzle 23 may be moved continuously. The nozzle 23 may be moved intermittently. For example, the nozzle 23 may be moved in such a manner that its left-right position is consistent with each rectifying groove 322. In addition, the spur gear 50a (holding portion 40) may be moved left-right while the nozzle 23 is fixed. That is, the left-right positions of the nozzle 23 and the spur gear 50a may be changed relatively.

[0071] The steps of the cavitation treatment method of the present embodiment performed by the cavitation treatment apparatus 100 are as follows.

[0072] First, the treatment liquid 11 is stored in the tank 10. The amount of the treatment liquid 11 stored is an amount that can immerse the spur gear 50a to a sufficient depth. The sufficient depth is, for example, 300 mm to 500 mm. At this time, the injection unit 20, the guide unit 30, and the holding unit 40 are located above the liquid surface of the treatment liquid 11.

[0073] Next, the spur gear 50a is fixed to the holding portion 40. The spur gear 50a is held so that the central axis 55 extends in the left-right direction.

[0074] Next, the relative positions of the injection unit 20, the guide unit 30, and the spur gear 50a are set. Specifically, the direction of the nozzle 23, the distance between the nozzle 23 and the spur gear 50a, the distance between the blocking unit 33 and the spur gear 50a, etc. are appropriately set.

[0075] Next, the spraying unit 20 , the guide unit 30 , and the holding unit 40 (the spur gear 50 a ) are moved downward and immersed in the processing liquid 11 stored in the tank 10 .

[0076] Next, the high-pressure fluid supply source 60 is activated to eject the jet C1 from the nozzle 23. The jet C1 reaches the tooth bottom 54 of the tooth groove 53 via the guide portion 30, and performs cavitation processing.

[0077] Next, the spur gear 50a is rotated. In addition, the nozzle 23 is moved left and right as necessary.

[0078] Thus, the jet C1 is ejected from the nozzle 23, the spur gear 50a is rotated, and the nozzle 23 is moved as needed. Thus, the tooth bottom 54 is cavitated. By making the jet C1 flow in the rectifying groove 322, the jet C1 does not disperse around, but collides with the tooth bottom 54 of the treatment target area.

[0079] In addition, the order of each process of the cavitation treatment method of this embodiment is not limited to the above order. For example, the injection unit 20, the guide unit 30 and the holding unit 40 can also be set in the tank 10 from the beginning. In this case, after the spur gear 50a is fixed to the holding unit 40 and the relative positions of the injection unit 20, the guide unit 30 and the spur gear 50a are set, the treatment liquid 11 can be stored in the tank 10. The spur gear 50a can also be rotated from the beginning of the cavitation treatment. The nozzle 23 can also be moved left and right from the beginning of the cavitation treatment. The rotation of the spur gear 50a and the movement of the nozzle 23 can also be performed simultaneously.

[0080] The shape of the spur gear 50a is an example. The cavitation treatment method of this embodiment can also be applied to spur gears whose shapes of teeth 51, tooth grooves 53 and tooth bottoms 54 are different from those of the above examples. In addition, the cavitation treatment method of this embodiment can also be applied to gears other than spur gears. Furthermore, the cavitation treatment method of this embodiment can also be applied to objects having grooves other than gears.

[0081] <Second Embodiment>

[0082] like Figure 6 As shown, in this embodiment, the object to be cavitationally treated is the rack 50b. The cavitation treatment device 100 used in this embodiment is different from the device of the first embodiment in that the holding portion 40 is different, and the rest is substantially the same.

[0083] The rack 50b, which is the object of the present embodiment, can be regarded as a gear with an infinite radius. The rack 50b is made of metal. The rack 50b has a plurality of teeth 51. The plurality of teeth 51 are arranged in a straight line. The teeth 51 are shaped to become thinner and thinner toward the front end. The front end of the tooth 51 is a tooth top surface 52 which is a plane. A tooth groove 53 is formed between adjacent teeth 51. The tooth groove 53 is a shape in which the groove width widens toward the opening side. The bottom of the tooth groove 53 is the tooth bottom 54. The tooth bottom 54 is a surface that connects the roots of the teeth 51 adjacent on both sides to each other. The tooth bottom 54 is a curved surface that becomes concave toward the opening side of the tooth groove 53. The tooth groove 53 is the groove portion of the object. The tooth bottom 54 is the bottom of the groove portion. The tooth bottom 54 is the object portion of the cavitation treatment.

[0084] The rack 50b is configured in a state where a plurality of teeth 51 are arranged front and back and protrude downward. A tooth groove 53 extending left and right is formed between the front and rear teeth 51. The tooth groove 53 is open toward the lower side. In a certain tooth groove 53, the rear side of the tooth top surface 52 of the tooth 51 on the front side is the front edge 56 of the tooth groove 53. In a certain tooth groove 53, the front side of the tooth top surface 52 of the tooth 51 on the rear side is the rear edge 57 of the tooth groove 53.

[0085] The holding unit 40 of the cavitation treatment device 100 of this embodiment includes a holding table 42. The holding table 42 fixes the rack 50b with a fastener such as a bolt or a clamp, or fixes the rack 50b by clamping the rack 50b. The holding table 42 can move forward and backward while holding the rack 50b.

[0086] In addition, the holding platform 42 or the rack 50b may be tilted so as to be lowered forward. At this time, the holding platform 42 may be moved along the tilting direction of the holding platform 42. The holding platform 42 may also be moved forward and backward.

[0087] In the present embodiment, the cavitation process is performed on all the tooth bottoms 54 of the rack 50b.

[0088] The steps of the cavitation treatment method of the present embodiment are different from those of the cavitation treatment method of the first embodiment in that the rack 50 b (holding table 42 ) is moved forward and backward, but the other points are substantially the same.

[0089] In order to perform cavitation processing on all the tooth bottoms 54 arranged in a straight line, the rack 50b (holding table 42) is moved back and forth. Figure 6 As shown, when the rack 50b is moved backward, the tooth grooves 53 arranged in front and back are moved backward. Therefore, the tooth grooves 53 facing the front end of the rectifying groove 322 are replaced in sequence, and the jet C1 collides with the tooth bottoms 54 arranged in front and back in sequence. Thus, the tooth bottoms 54 arranged in front and back are cavitated in sequence.

[0090] Alternatively, the rack 50b may be moved continuously or intermittently. For example, the rack 50b may be moved a distance corresponding to one tooth 51 at a time.

[0091] In this way, the jet C1 is ejected from the nozzle 23, the rack 50b is moved, and the nozzle 23 is moved as necessary. Thus, the tooth bottom 54 of the rack 50b is cavitated.

[0092] The present invention is not limited to the above-mentioned embodiments, and various modifications can be made within the scope of the main purpose of the present invention, and all technical matters included in the technical ideas recorded in the claims become the objects of the present invention. Although the above-mentioned embodiments show preferred examples, those skilled in the art can implement various alternatives, modifications, variations or improvements based on the contents disclosed in this specification, which are included in the technical scope recorded in the attached claims.

Claims

1. A cavitation treatment method, characterized in that: A nozzle (23), an object (50a, 50b) and a guide portion (30) are immersed in a treatment liquid (11), the nozzle (23) ejecting a jet (C1) of the treatment liquid (11) containing cavitation bubbles, the object (50a, 50b) including a groove portion (53) extending left and right as viewed from the nozzle (23) and having edges (56, 57) in front and back, the guide portion (30) including a rectifying portion (32) for causing the jet (C1) to flow in a front-rear direction and a blocking portion (33) for blocking a front end of the rectifying portion (32); Bringing the blocking portion (33) close to the edge portion (56) on the front side; ejecting the jet (C1) from the (23) nozzle; and The jet (C1) is introduced into the rectifying portion (32) from the rear side, so that the jet (C1) collides with the blocking portion (33), thereby changing the flow direction of the jet (C1) and causing the jet (C1) to collide with the bottom (54) of the groove portion (53).

2. The cavitation treatment method according to claim 1, characterized in that: The left-right positions of the nozzle (23) and the object (50a, 50b) are relatively changed.

3. The cavitation treatment method according to claim 1 or 2, characterized in that: The jetting direction of the jet (C1) is inclined downward relative to the front-rear direction.

4. The cavitation treatment method according to claim 3, characterized in that: The inclination angle of the spraying direction relative to the front-rear direction is not less than 15 degrees and not more than 45 degrees.

5. The cavitation treatment method according to any one of claims 1 to 4, characterized in that: The objects (50a, 50b) are gears (50a, 50b), The groove portion (53) is a tooth groove (53) of the gear (50a, 50b), The bottom (54) is the tooth bottom (54) of the gear (50a, 50b).

6. The cavitation treatment method according to claim 5, characterized in that: The gears (50a, 50b) are rotated or moved in such a way that the tooth grooves (53) move forward and backward, The jet (C1) is caused to collide with the tooth bottoms (54) of the tooth grooves (53) arranged in front and behind in sequence.

7. A cavitation treatment device (100), characterized in that: have: A tank (10), wherein the tank (10) stores a treatment liquid (11); a nozzle (23), the nozzle (23) being immersed in the tank (10) and ejecting a jet (C1) of the treatment liquid (11); a holding portion (40) disposed in the groove (10) and holding an object (50a, 50b), wherein the object (50a, 50b) includes a groove portion (53) extending leftward and rightward as viewed from the nozzle (23) and having edges (56, 57) at the front and rear; and A guide portion (30), the guide portion (30) being arranged below the object (50a, 50b) and comprising: a rectifying groove (322) extending rearward from a position below the groove portion (53) and allowing the jet (C1) to flow; and The blocking portion (33) has an upper edge portion (332) arranged close to the edge portion (56) on the front side and extending in the left-right direction, and is connected to the front end of the rectifying groove (322) to block the rectifying groove (322).

8. The cavitation treatment device (100) according to claim 7, characterized in that: The object (50a) is a gear (50a), The holding portion (40) holds the gear (50a) and has a rotation shaft (41) for rotating the gear (50a) around a central axis.

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