Cavitation treatment method

Abstract

The purpose of the present invention is to improve the effect of a cavitation treatment method for performing cavitation treatment on the surface of an object in the atmosphere. [Solution] A gear (target object) 40 is placed in the atmosphere above the liquid surface 111 of a stored liquid 11 containing an abrasive 12, a nozzle 20 having a nozzle 21 is placed above the gear 40, and a jet C1 of liquid is sprayed from the nozzle 21 toward the target object 40, thereby performing cavitation treatment on the surface 401 of the gear 40.

Description

[Technical Field]

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

[0002] Cavitation treatment has traditionally been performed on the surface of metal objects in the atmosphere (Patent Publication No. 2957976). Cavitation treatment involves striking the object with a jet of liquid containing cavities (gas bubbles), and treating the surface of the object with the impact force generated when the cavities collapse. Cavitation treatment can produce effects such as peening, which adds compressive residual stress to the surface of the object, and improving sliding properties by forming dimples on the surface of the object, as well as cleaning, peeling, cutting, and deburring. Summary of the Invention [Problem to be solved by the invention]

[0003] The shapes and sizes of objects that can be treated with atmospheric cavitation vary widely, and depending on the conditions of the object, conventional cavitation treatment may not be effective enough. The present invention aims to improve the effectiveness of a cavitation treatment method for performing cavitation treatment on the surface of an object in the atmosphere. [Means for solving the problem]

[0004] A first aspect of the present invention is The object is placed in the atmosphere above the liquid surface of the stored liquid containing the abrasive; a nozzle having a nozzle hole disposed above the object; A liquid jet is ejected from the nozzle toward the object, and a cavitation treatment is performed on the surface of the object. It is something , the jet collides with the liquid surface, causing the stored liquid containing the abrasive to scatter, and the scattered stored liquid is caught in the jet and collides with the surface. This is a cavitation treatment method.

[0005] The object is made of metal. Examples of metals constituting the object include heat-resistant alloys, aluminum alloys, magnesium alloys, titanium, titanium alloys, steel, and corrosion-resistant steel. Examples of the object are machine parts, medical equipment parts, and medical instruments. Examples of machine parts include gears, piping, valves, piping joints, and aerospace parts. Examples of medical instruments include surgical implants. Examples of aerospace parts include aircraft engine parts and other aircraft parts, rocket engine parts, spacecraft parts, satellite parts, and rocket piping.

[0006] The abrasive is abrasive particles. The abrasive is, for example, ceramic, alumina, garnet, or zirconia. In the tank, the abrasive may be precipitated in the stored liquid. The abrasive may also be turbid in the stored liquid.

[0007] The height from the top surface of the object to the liquid level is, for example, 200 mm to 600 mm. When the abrasive settles in the stored liquid, the layer height of the abrasive is desirably approximately uniform within the tank. The layer height of the abrasive is, for example, 20 mm to 50 mm. The height from the liquid level of the stored liquid to the layer surface of the abrasive is, for example, 50 mm to 100 mm. When the height from the liquid level of the stored liquid to the layer surface of the abrasive is 50 mm to 100 mm, when the jet enters the stored liquid, the abrasive splashes off the stored liquid and splashes into the tank.

[0008] The liquid is stored in a tank. The liquid is, for example, water. The liquid may contain a rust inhibitor.

[0009] The liquid to be jetted is, for example, water, and may contain a rust inhibitor.

[0010] The nozzle has an orifice diameter of, for example, 0.5 mm to 3 mm, and the jet pressure of the jet is, for example, 10 MPa to 200 MPa.

[0011] The nozzle may be placed directly above the object, with the jet being ejected directly downward from the nozzle. The nozzle may be placed diagonally above the object, with the jet being ejected diagonally downward from the nozzle.

[0012] The cavitation treatment is performed on a part or the entire surface of the object. The recess is a portion of the surface of the object that is recessed from the surrounding area. The recess may be a groove or a hole.

[0013] When a jet of water is sprayed from above toward an object, it hits the object and then hits the liquid surface below. The impact of the jet causes droplets of the stored water containing abrasives to rise. The jet then picks up the abrasives contained in the droplets. The impact of the abrasives on the object along with the liquid improves the effectiveness of the cavitation treatment. [Effects of the Invention]

[0014] According to the present invention, the effect of a cavitation treatment method for performing cavitation treatment on the surface of an object in the atmosphere can be improved. [Brief explanation of the drawings]

[0015] [Figure 1] Overall view of cavitation treatment equipment [Figure 2] Enlarged view of the area where the jet collides with the gear DETAILED DESCRIPTION OF THE INVENTION

[0016] 1, the cavitation treatment device 100 of this embodiment includes a tank 10, a nozzle 20, a nozzle moving device 22, a driving device 32, and a support unit 30. The cavitation treatment device 100 performs cavitation treatment on a gear (target object) 40.

[0017] The tank 10 stores a stored liquid 11 and an abrasive 12. The stored liquid 11 is, for example, water. The cavitation treatment device 100 may include a liquid circulation device that circulates the stored liquid 11.

[0018] The abrasive 12 settles in the stored liquid 11. Desirably, the layer height H1 of the abrasive 12 is approximately uniform within the tank 10. The layer height H1 is, for example, 20 mm to 50 mm. The height H2 from the liquid level 111 of the stored liquid 11 to the layer surface of the abrasive 12 is, for example, 50 mm to 100 mm. The height H3 from the top surface of the gear 40 to the liquid level 111 is, for example, 200 mm to 600 mm.

[0019] The nozzle moving device 22 moves the nozzle 20 relative to the drive device 32 in the front-rear direction, the left-right direction, and the up-down direction.

[0020] The nozzle 20 has an orifice 21. The nozzle 20 sprays a jet C1 of liquid supplied from a high-pressure fluid supply source (not shown) from the orifice 21. The liquid may be the stored liquid 11. When the liquid is the stored liquid 11, the stored liquid 11 is filtered to eliminate the abrasive 12 from being sprayed. The jet C1 includes many cavities. The nozzle 20 sprays the jet C1, for example, vertically downward. The jet C1 is a straight rod-shaped jet. The nozzle 20 may be rotated around the spraying direction of the jet C1 by the nozzle moving device 22. The orifice diameter (inner diameter) of the nozzle 20 is, for example, 0.5 mm to 3 mm.

[0021] The driving device 32 is disposed at the center in the depth direction of the tank 10. The driving device 32 rotates the gear (object) 40 integrally with the support part 30 around the rotation axis 31. The rotation axis 31 extends in the horizontal direction. The support part 30 is disposed above the liquid surface 111 of the stored liquid 11. The support part 30 has a round bar shape extending along the rotation axis 31. The support part 30 supports a gear 40.

[0022] As shown in FIG. 2, gear 40 has a plurality of teeth 41 arranged side by side on a circumference. Tooth spaces 42 are formed between adjacent teeth 41. The bottom of tooth space 42 is tooth root 43. Tooth space 42 is a recess in the object, and tooth root 43 is the bottom of the recess. Gear 40 may be, for example, a spur gear, helical gear, internal gear, double helical gear, bevel gear, or rack. A rack can be considered as a gear with an infinite radius.

[0023] A control device (not shown) controls the jet pressure, jet flow rate, and jet speed of the jet C1, the movement of the nozzle 20, and the drive device 32.

[0024] The cavitation treatment method of this embodiment is as follows. First, the liquid 11 is stored in the tank 10. Then, the abrasive 12 is placed in the liquid 11 and allowed to settle. At this time, the nozzle 20 and the support part 30 are located in the atmosphere above the liquid surface 111 of the liquid 11. Next, the gear 40 is fixed to the support part 30. The gear 40 is fixed in an attitude in which its rotation axis 44 is oriented horizontally and coincides with the rotation axis 31 of the drive device 32. Next, the drive unit 32 is driven to rotate the support portion 30 and the gear 40 . Next, the nozzle 20 is placed above the gear 40, and the distance between the nozzle 20 and the gear 40 is set to a distance suitable for cavitation treatment. The distance suitable for cavitation treatment is about 50 to 200 times the nozzle diameter of the nozzle 20. Next, a high-pressure fluid supply source (not shown) is activated to eject a jet C1 from the nozzle 20. The jet C1 collides with the gear 40, causing a cavitation process on the surface 401 thereof. Next, each time the gear 40 rotates once, the nozzle 20 is moved a predetermined distance in the direction of the rotation axis 44 of the gear 40. The nozzle 20 may be moved along the rotation axis 44 at a predetermined feed amount per rotation. This causes the entire surface 401 of the gear 40 to be subjected to the cavitation treatment.

[0025] The behavior of the jet C1 when it collides with the gear 40 will be described in detail. After colliding with the gear 40, the jet C1 travels further downward as a post-collision jet C2 and collides with the liquid surface 111 of the stored liquid 11. The post-collision jet C2 agitates the stored liquid 11, and the abrasive 12 is stirred up into the stored liquid 11. Furthermore, due to the impact of the collision, the stored liquid 11 containing the abrasive 12 is scattered from the liquid surface 111 as droplets 13. Then, as shown in FIG. 2, the droplets 13 are caught up in the jet C1. The abrasive 12 contained in the droplets 13 collides with the jet C1 against the surface 401 of the gear 40, including the tooth bottom 43.

[0026] The surface 401 of the gear 40 is subjected to impact forces due to the collision of the abrasives 12 and impact forces due to the collapse of cavities contained in the jet C1. As a result, compressive residual stress is imparted to the surface 401 of the gear 40. Dimples are then formed on the surface 401 of the gear 40. The jet C1 entrains the droplets 13, which causes the abrasives 12 to be contained in the jet C1, improving the effectiveness of the cavitation treatment.

[0027] The effect of the cavitation treatment method of this embodiment varies depending on various parameters, such as the amount of abrasive 12 contained in the stored liquid 11, the layer height H1 of the abrasive 12, the height H2 from the liquid level 111 to the layer surface of the abrasive 12, the height H3 from the top surface of the gear 40 to the liquid level 111, and the distance between the gear 40 and the nozzle 20. Each parameter may be set depending on the desired effect of the treatment. The effect of the treatment may be adjusted by placing a shield between the gear 40 and the liquid level 111 to block some of the droplets 13.

[0028] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the gist of the present invention, and all technical matters included in the technical ideas described in the claims are subject to the present invention. The above-described embodiments are preferred examples, but a person skilled in the art can realize various alternatives, modifications, variations, or improvements from the contents disclosed in this specification, and these are included in the technical scope described in the appended claims. [Explanation of symbols]

[0029] 11 Retention fluid 111 Liquid level 12 Abrasive material 20 nozzles 21 spout 40 Gear (Object) 401 Surface C1 Jet

Claims

1. The object is placed in the atmosphere above the liquid surface of the stored liquid containing the abrasive; a nozzle having a nozzle hole disposed above the object; A liquid jet is sprayed from the nozzle toward the object, and a cavitation treatment is performed on the surface of the object, the jet collides with the liquid surface, causing the stored liquid containing the abrasive to scatter, and the scattered stored liquid is caught in the jet and collides with the surface. Cavitation treatment method.

2. The jet is a straight rod-shaped jet. The cavitation treatment method according to claim 1 .

3. The jet is a jet of the stored liquid. The cavitation treatment method according to claim 1 .

4. The abrasive is precipitated in the reservoir liquid. The cavitation treatment method according to claim 1 .

5. The nozzle ejects the jet vertically downward. The cavitation treatment method according to claim 1 .

6. The jet is ejected while rotating or moving the nozzle. The cavitation treatment method according to claim 1 .

7. The jet flow is sprayed while rotating or moving the object. The cavitation treatment method according to claim 1 .

8. the object has a recess, The jet is caused to collide with the bottom of the recess. The cavitation treatment method according to any one of claims 1 to 7.

9. the object is a gear, the recess is a tooth groove of the gear, and the bottom is a tooth root of the gear; The cavitation treatment method according to claim 8.

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