JP4706388B2 - Surface processing method - Google Patents

Description

  The present invention relates to a surface processing method in which a high-pressure water stream containing cavitation bubbles is made to collide with the surface of a workpiece, and compressive stress is applied to the surface of the workpiece, deburring, cleaning, or the like.

When applying compressive stress to a metal material, removing burrs generated in the processed part of the metal material, or cleaning dirt adhering to the surface of the metal material, a high-pressure water stream containing cavitation bubbles is applied to the surface of the metal material. There is a way to hit. That is, it is possible to perform a process such as applying a compressive stress to the surface of the metal material by a large impact pressure generated locally when the cavitation bubbles collapse on the surface of the metal material.
And the technique which gives a compressive stress to a metallic material by injecting a high-pressure water stream toward a metallic material in the air is disclosed (refer patent document 1). In this technique, a two-layer water flow composed of a high-speed water flow and a low-speed water flow surrounding the high-speed water flow is injected in the air. As a result, cavitation bubbles are generated in the two-layer water flow due to the speed difference between the high-speed water flow and the low-speed water flow.

However, according to the above-described conventional method, it may be difficult to concentrate the cavitation bubbles on the processed portion of the metal material. That is, cavitation bubbles in the two-layer water flow ejected from the ejection nozzle diverge, and it may be difficult to concentrate a sufficient amount of cavitation bubbles on the processed portion.
Therefore, it is difficult to efficiently guide the generated cavitation bubbles to the processed portion, and it may be difficult to efficiently perform the surface processing.

Japanese Patent No. 2957976

  The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a surface processing method capable of efficiently performing surface processing by concentrating cavitation bubbles on a processing portion. .

1st invention is the method of processing the surface of the said to-be-processed object by injecting a jet water flow to a to-be-processed object,
The jet stream is a two-layer jet stream composed of a high-pressure stream and a low-pressure stream surrounding the high-pressure stream, including cavitation bubbles,
Between the jet nozzle for jetting the jet water flow and the workpiece, a concentration jig having a through hole that includes the processed portion of the workpiece in a plan view,
By passing the jet water flow through the through hole of the concentration jig, the cavitation bubbles are concentrated on the processed portion of the workpiece ,
The workpiece is formed with a hole, and when the inner surface of the hole is processed by the jet water flow, the through hole of the concentration jig is formed in the hole of the workpiece. In the surface processing method, wherein the concentration jig is arranged so that the through hole and the hole are connected to each other (Claim 1).
A second invention is a method of processing a surface of the workpiece by injecting a jet water stream onto the workpiece,
The jet stream is a two-layer jet stream composed of a high-pressure stream and a low-pressure stream surrounding the high-pressure stream, including cavitation bubbles,
Between the jet nozzle for jetting the jet water flow and the workpiece, a concentration jig having a through hole that includes the processed portion of the workpiece in a plan view,
By passing the jet water flow through the through hole of the concentration jig, the cavitation bubbles are concentrated on the processed portion of the workpiece,
The workpiece is included in the through-hole of the concentration jig in a plan view, and the outer surface of the workpiece is processed by the jet water flow.
A reflecting jig having a reflecting surface that reflects the high-pressure water flow is disposed downstream of the processed portion of the workpiece and the jet water flow, and the high-pressure water flow is jetted and reflected on the reflecting surface. Thus, the surface processing method is characterized in that the jet water flow is applied to the outer surface of the workpiece (claim 8).

Next, the effects of the present invention will be described.
In the surface processing method, the cavitation bubbles are concentrated on the processed portion of the workpiece by passing a jet of water through the through hole of the concentration jig disposed between the ejection nozzle and the workpiece. Thereby, it can suppress that the cavitation bubble which generate | occur | produces around the high-pressure water flow in a jet water flow spreads outward, and can concentrate a cavitation bubble toward the process part of a to-be-processed body. A sufficiently large compressive stress can be applied to the processed portion by the large impact pressure that is locally generated when the cavitation bubbles concentrated in the processed portion collapse in the processed portion. Further, if burrs are generated on the surface of the workpiece, the burrs can be removed, and if dirt is attached, the dirt can be washed.

Moreover, since the stagnation region of the jet water flow is formed between the workpiece and the through hole of the concentration jig, the pressure of the jet water flow in the processed portion is improved and the cavitation bubbles are easily collapsed. Thereby, the surface processing of a process part can be performed effectively.
Moreover, since the through-hole of the concentration jig includes the processed portion in a plan view, the jet water flow can be applied to the entire processed portion.

  As described above, according to the present invention, it is possible to provide a surface processing method capable of efficiently performing surface processing by concentrating cavitation bubbles on a processing portion.

In the present invention (claims 1 , 8 ), the workpiece includes, for example, one made of metal, resin, ceramic or the like.
Moreover, the said surface processing method can be used, for example, when giving a compressive stress (peening) to a process part, removing a burr | flash, or wash | cleaning stain | pollution | contamination.
In addition, said "inclusion in planar view" means the state by which the whole process part is arrange | positioned inside a through-hole, when it sees from the injection direction of a jet water flow. The same applies to the following.

Further, the workpiece is formed with a hole, and when the inner surface of the hole is processed by the jet water flow, the through-hole of the concentration jig is formed on the workpiece. the holes are encompasses in plan view, place the concentration jig such that the through hole and the hole is connected.
Thereby , cavitation bubbles can be concentrated in the hole, and the inner surface of the hole can be efficiently surface processed.

In addition, a reflecting jig having a reflecting surface that reflects the high-pressure water flow is disposed in the opening of the hole or on the side opposite to the side where the jet water flow is introduced, and the high-pressure water flow is transferred to the reflecting surface. by reflecting erupted, it is preferable to apply the water jet on the inner surface of the hole portion (claim 2).
In this case, the jet water flow containing the cavitation bubbles can be reflected on the reflecting surface of the reflecting jig, and the jet water flow can be efficiently applied to the processed portion.
In addition, the cavitation bubbles can be efficiently collapsed by the rapid pressure increase of the jet water flow around the reflecting surface due to the reflection of the high-pressure water flow on the reflecting surface. At this time, a very large impact pressure is locally generated, and a sufficiently large compressive stress can be applied to the inner surface of the hole of the workpiece.

The reflecting jig is disposed in an opening on the opposite side to the side where the jet water flow is introduced in the hole, and a recess including the opening in a plan view is formed on the reflecting surface. (Claim 3 ).
In this case, the processing of the opening on the side opposite to the side where the jet water flow is introduced in the hole can be effectively performed. That is, if the opening is in direct contact with the reflecting jig, it may be difficult to effectively apply cavitation bubbles to the opening. Therefore, by providing the concave portion on the reflecting surface, a gap can be formed between the opening and the reflecting surface, and a jet water flow is introduced into the gap to effectively process the opening. Can do.

Moreover, it is preferable that the said reflection jig has a movable part which can be penetrated to the said hole (Claim 4 ).
In this case, the reflecting jig is inserted into the hole and moved appropriately so that the cavitation bubbles are efficiently collapsed inside the hole, and the surface processing of the inner surface of the hole is performed more effectively. Can do. Thereby, surface processing can be performed uniformly over the whole axial direction of a hole.
Further, the cavitation bubbles can be collapsed intensively in a desired processing portion such as a burr generation portion in the hole portion.

Further, the reflecting surface is preferably inclined with respect to the axial direction of the hole portion (claim 5).
In this case, the jet water flow introduced into the hole is reflected by the reflecting surface, whereby the jet water flow is guided in a direction having an angle with respect to the axial direction of the hole. Therefore, the cavitation bubbles in the jet water flow are guided to the inner surface of the hole and collapsed, so that the inner surface can be effectively processed. Further, a stagnation region of the jet water flow is formed between the inclined reflecting surface and the inner surface of the hole, so that the pressure of the jet water flow is improved and the cavitation bubbles are easily collapsed. Thereby, the surface processing of a process part can be performed effectively.
The reflective surface is preferably a conical surface. In this case, cavitation bubbles can be uniformly guided to the inner surface of the entire circumference of the hole.

Further, the reflection jig can close the opening of the hole (claim 6 ).
In this case, the stagnation region of the jet water flow is more easily formed inside the hole. Therefore, the cavitation bubbles guided to the hole are sufficiently collapsed in the vicinity of the inner surface of the hole, and the surface processing can be performed efficiently.

In addition, the reflection jig can also partially open the opening of the hole and adjust the outflow amount of the jet water flow from the opening (Claim 7).
In this case, the pressure of the jet water flow applied to the processed portion can be adjusted, and the cavitation bubbles can be collapsed in a state suitable for performing the surface processing of the hole. Therefore, appropriate surface processing can be performed according to the workpiece.

In the second invention, the workpiece is included in a plan view in the through hole of the concentration jig, the outer surface of the workpiece you processed by the water jet.
Thereby , cavitation bubbles can be concentrated on the outer surface of the workpiece, and the outer surface can be efficiently processed.

Further, a reflecting jig having a reflecting surface for reflecting the high-pressure water flow is disposed downstream of the processed portion of the workpiece, and the high-pressure water flow is jetted to the reflecting surface and reflected. by, Ru against the water jets on the outer surface of the workpiece.
Thereby , the jet water flow containing a cavitation bubble can be reflected in the reflective surface of the said reflective jig, and a jet water flow can be efficiently applied to a process part.
In addition, the cavitation bubbles can be efficiently collapsed by the rapid pressure increase of the jet water flow around the reflecting surface due to the reflection of the high-pressure water flow on the reflecting surface. At this time, a very large impact pressure is locally generated, and a sufficiently large compressive stress can be applied to the outer surface of the workpiece.

Further, by placing the jet nozzles into water, it is preferable to eject toward the該噴out nozzle into air and the injection water flow (claim 9).
In this case, cavitation bubbles can be generated in the jet water flow at an early stage, that is, cavitation collapse energy can be generated at a position near the nozzle tip of the jet nozzle. Therefore, even if the distance between the workpiece and the ejection nozzle is reduced, the surface processing with cavitation bubbles can be sufficiently performed. As a result, efficient surface processing can be performed at a desired position.

Further, an impact sensor capable of detecting the impact energy applied to the workpiece by the jet water flow is disposed on the workpiece or a holding jig for holding the workpiece, and the impact sensor It is preferable to control the machining time based on the integrated value of the impact energy detected by (Claim 10 ).
In this case, it is possible to easily and efficiently perform appropriate surface processing on the processed portion of the workpiece. For example, a piezoelectric film sensor can be used as the impact sensor.

Example 1
A surface processing method according to an embodiment of the present invention will be described with reference to FIGS.
The surface processing method of this example is a method of processing the surface of the workpiece 3 by injecting a jet water stream 2 onto the workpiece 3 as shown in FIG.
The jet water stream 2 is a two-layer jet water stream including a high-pressure water stream 21 and a low-pressure water stream 22 surrounding the high-pressure water stream 21, and includes cavitation bubbles 23.

A concentration jig 7 having a through-hole 71 that includes the processed portion 31 of the workpiece 3 in a plan view is disposed between the ejection nozzle 1 that ejects the jet water flow 2 and the workpiece 3.
Then, by passing the jet water flow 2 through the through hole 71 of the concentration jig 7, the cavitation bubbles 23 are concentrated on the processed portion 31 of the workpiece 3.

As shown in FIGS. 2 and 3, the workpiece 3 is formed with a hole 32, and the inner surface of the hole 32 is processed by the jet water flow 2. In this example, the hole 32 and the through hole 71 are circular holes. The inner diameter of the through hole 71 of the concentrating jig 7 is larger than the inner diameter of the hole 32 of the workpiece 3, and the concentrating jig is connected so that the through hole 71 and the hole 32 are connected as shown in FIG. 7 is arranged. In this example, the processed portion 31 of the workpiece 3 is mainly the inner surface of the hole 32. Further, the workpiece 3 has a cross hole 33 that crosses the hole 32. Since burrs often occur at the intersections between the holes 32 and the intersecting holes 33, the burrs can be removed by the surface processing method of this example.
Moreover, compressive stress can be given to the processed part 31 (peening), or dirt can be washed.

  As shown in FIG. 1, the reflecting jig 6 having the reflecting surface 61 that reflects the high-pressure water flow 21 is disposed in the opening 322 opposite to the side where the jet water flow 2 is introduced in the hole 32. Then, the jet water stream 2 is applied to the inner surface of the hole 32 by jetting the high-pressure water stream 21 to the reflecting surface 61 and reflecting it.

  As shown in FIGS. 2 and 3, the workpiece 3 has a substantially cylindrical outer shape. The hole 32 penetrates in the axial direction, and the cross hole 33 is formed so as to intersect the hole 32. It penetrates. The hole 32 is provided with a taper at an opening 321 opened on one surface of the workpiece 3, and a step is provided at an opening 322 opened on the other surface. The workpiece 3 is made of aluminum. Note that the workpiece 3 is not limited to aluminum, and can be constituted by, for example, SCM415, SUS303, SUS304, or the like, and the present machining method can also be applied to workpieces made of resin, ceramic, or the like.

The concentration jig 7 is provided with a through hole 71 having an inner diameter slightly larger than the opening 321 of the hole 32 of the workpiece 3 as shown in FIG. It consists of an annular body having a diameter. Moreover, the concentration jig | tool 7 can set the internal diameter of the through-hole 71 to 8 mm, and can set axial direction thickness to 11 mm, for example. The concentration jig 7 is made of, for example, SUS303, SUS304, SCM, resin, ceramic, or the like.
The reflecting jig 6 has a disk shape, and is arranged so that the reflecting surface 61 is perpendicular to the axial direction of the hole 32 of the workpiece 3. The reflecting jig 6 is made of, for example, SUS303, SUS304, SCM, resin, ceramic, or the like.

  As shown in FIG. 1, the reflection jig 6, the workpiece 3, and the concentration jig 7 are stacked and received and held in the receiving recess 151 of the holding jig 15 in this order. The reflecting jig 6 closes the opening 322 of the hole 32. The housing recess 151 of the holding jig 15 is open vertically downward, and the jet water flow 2 is applied to the workpiece 3 through the through hole 71 of the concentration jig 7 from below vertically.

That is, in injecting the jet water stream 2 onto the workpiece 3, as shown in FIG. 1, the jet water stream 2 is directed from the two-layer jet nozzle 1 arranged in water toward the workpiece 3 arranged in the air. Erupt.
First, as shown in FIG. 1, an ejection nozzle 1 having a first ejection port 11 and a second ejection port 12 surrounding the first ejection port 11 is disposed in water.

Then, the high-pressure water stream 21 is ejected from the first ejection port 11 toward the air, and the low-pressure water stream 22 having a lower pressure than the high-pressure water stream 21 is ejected from the second ejection port 12 toward the air.
The jet water stream 2 composed of the high-pressure water stream 21 and the low-pressure water stream 22 surrounding the high-pressure water stream 21 includes cavitation bubbles 23.
The jet water stream 2 is jetted toward the concentration jig 7, the workpiece 3 and the reflection jig 6 held in the holding jig 15 in the air.

  The jet nozzle 1 has a high-pressure water nozzle 131 connected to the first jet port 11 and a low-pressure water nozzle 132 connected to the second jet port 12. The low-pressure water nozzle 132 is coaxially disposed so as to surround the high-pressure water nozzle 131. The high-pressure water nozzle 131 is provided with an orifice 133 at the first jet port 11. In addition, a first taper portion 134 whose diameter decreases toward the tip is formed in the outer portion of the orifice 133.

The low-pressure water nozzle 132 is formed with a second taper portion 135 whose diameter decreases toward the tip at the outer portion of the first taper portion 134.
High pressure water 210 is supplied to the high pressure water nozzle 131, and low pressure water 220 is supplied to the low pressure water nozzle 132. The supply pressure of the high-pressure water 210 is, for example, 10 to 50 MPa, and the supply pressure of the low-pressure water 220 is, for example, 0.05 to 0.1 MPa.

  Although the jet nozzle 1 is arranged coaxially, the processing capability can be partially increased by decentering the low-pressure water nozzle 132 with respect to the high-pressure water nozzle 131. As a result, cavitation bubbles can be concentrated on the side where the low-pressure channel is largely provided. That is, it is possible to perform surface processing more effectively by decentering the low-pressure channel on the side where the processing capability is desired to be increased.

Further, the ejection nozzle 1 is disposed in the stored water 42 stored in the water tank 41. And the 1st spout 11 and the 2nd spout 12 have faced the vertically upper direction, and are located in the stored water 42, ie, the lower part of the water surface 421.
Specifically, the ejection nozzle 1 is arranged at a position where the distance d between the nozzle tip 14 of the ejection nozzle 1 and the water surface 421 is 15 mm or less.

  With such an arrangement and configuration, cavitation bubbles 23 can be generated in the two-layer jet water flow 2 at an early stage, that is, cavitation collapse energy can be generated at a position close to the nozzle tip 14 of the ejection nozzle 1. Therefore, even if the distance between the workpiece 3 and the ejection nozzle 1 is reduced, the surface processing with cavitation bubbles can be sufficiently performed.

As a result, the surface processing of the workpiece 3 can be performed in a narrow space. Moreover, since the distance from the ejection nozzle 1 is short and the two-layer jet water flow 2 having a stable flow can be applied to the inner surface (processed portion 31) of the hole 32 of the workpiece 3 through the reflective surface 61. The spray water flow 2 can be applied in a concentrated manner at a desired position. Therefore, it is possible to efficiently perform surface processing on necessary portions.
Further, since the distance d between the nozzle tip 14 of the ejection nozzle 1 and the water surface 421 is 15 mm or less, it is possible to sufficiently ensure the impact force when the spray water flow 2 collides with the reflection surface 61 of the reflection jig 6. The surface processing of the workpiece 3 can be sufficiently performed.

FIG. 4 is a diagram showing the entire apparatus for generating the jet water flow 2. The high pressure water nozzle 131 of the jet nozzle 1 is supplied with high pressure water 210 from the high pressure pump 53, and the low pressure water nozzle 132 is low pressure. Low pressure water 220 is supplied from the pump 54. The high-pressure pump 53 and the low-pressure pump 54 are arranged in supply water 52 stored in a water supply tank 51 different from the water tank 41. The supply water 52 is supplied to the ejection nozzle 1 as high-pressure water 210 and low-pressure water 220 by a high-pressure pump 53 and a low-pressure pump 54, respectively.
The high-pressure water 210 supplied to the high-pressure water nozzle 131 is jetted as the high-pressure water stream 21 from the first jet nozzle 11. The low-pressure water 220 supplied to the low-pressure water nozzle 132 is jetted as the low-pressure water stream 22 from the second jet nozzle 12.

Next, the function and effect of this example will be described.
In the surface processing method, the cavitation bubble 23 is passed through the through-hole 71 of the concentration jig 7 disposed between the jet nozzle 1 and the workpiece 3 to cause the cavitation bubbles 23 to pass through the workpiece 3. Concentrate on the processed portion 31. Thereby, it can suppress that the cavitation bubble 23 which generate | occur | produces around the high-pressure water flow 2 in the jet water flow 2 diverges outward, and can concentrate the cavitation bubble 23 toward the process part 31 of the to-be-processed body 3. FIG. .

  A sufficiently large compressive stress can be applied to the processed portion 31 by the large impact pressure that is locally generated when the cavitation bubbles 23 concentrated on the processed portion 31 collapse in the processed portion 31. Further, if burrs are generated on the surface of the workpiece 3 (the inner surface of the hole 32), the burrs can be removed, and if dirt is adhered, the dirt can be washed.

Further, a stagnation region of the jet water flow 2 is formed between the workpiece 3 and the through hole 71 of the concentration jig 7, and the pressure of the jet water flow 2 in the processed portion 31 is improved and the cavitation bubbles 23 are collapsed. It becomes easy. Thereby, the surface processing of the process part 31 can be performed effectively.
Further, since the inner diameter of the through hole 71 of the concentration jig 7 is larger than that of the processed portion 31, the jet water flow 2 can be applied to the entire processed portion 31.

  Further, the inner diameter of the through hole 71 of the concentration jig 7 is larger than the inner diameter of the hole 32 of the workpiece 3, and the concentration jig 7 is arranged so that the through hole 71 and the hole 32 are connected. Therefore, the cavitation bubbles 23 can be concentrated in the hole 32 and the inner surface of the hole 32 can be efficiently processed.

Further, the reflecting jig 6 is disposed in the opening 322 in the hole 32, and the high-pressure water flow 21 is jetted to the reflecting surface 61 to be reflected, so that the jet water flow 2 is applied to the inner surface of the hole 32. Therefore, the jet water stream 2 including the cavitation bubbles 23 can be reflected on the reflecting surface 61 of the reflecting jig 6 so that the jet water stream 2 can be efficiently applied to the processing portion.
Further, the cavitation bubbles 23 can be efficiently collapsed by the rapid pressure increase of the pressure of the jet water flow 2 around the reflection surface 61 due to the reflection of the high-pressure water flow 21 on the reflection surface 61. At this time, an extremely large impact pressure is locally generated, and a sufficiently large compressive stress can be applied to the inner surface of the hole 32 of the workpiece 3.

  Further, since the jet nozzle 1 is disposed in the water and the jet water stream 2 is jetted from the jet nozzle 1 toward the air, cavitation bubbles 23 are generated in the jet water stream 2 at an early stage, that is, the jet nozzle 1 Cavitation decay energy can be generated at a position close to the nozzle tip 14. Therefore, even if the distance between the workpiece 3 and the ejection nozzle 1 is reduced, the surface processing with the cavitation bubbles 23 can be sufficiently performed. As a result, efficient surface processing can be performed at a desired position.

  Further, since the reflecting jig 6 closes the opening 322 of the hole 32, the stagnation region of the jet water flow 2 is more easily formed inside the hole 32. Therefore, the cavitation bubble 23 guided to the hole 32 is sufficiently collapsed in the vicinity of the inner surface of the hole 32, and the surface processing can be performed efficiently.

  As described above, according to this example, it is possible to provide a surface processing method capable of efficiently performing surface processing by concentrating cavitation bubbles on a processing portion.

(Example 2)
In this example, as shown in FIG. 5, the reflecting jig 6 is arranged so that the opening 322 of the hole 32 is partially opened and the jet water flow 2 flows out from the opening 322.
That is, the holding jig 15 has a communication hole 152 that communicates with the housing recess 151 and opens on the opposite side of the housing recess 151. The reflection jig 6 is disposed inside the communication hole 152, and a clearance 153 is provided between the reflection jig 6 and the communication hole 152.
Thereby, a part of the jet water flow 2 injected to the workpiece 6 flows out from the opening 322 of the hole 32 to the clearance 153.
Others are the same as in the first embodiment.

In the case of this example, the pressure applied to the processed portion 31 can be adjusted, and the cavitation bubbles 23 can be collapsed in a state suitable for performing the surface processing of the hole 32. Therefore, appropriate surface processing can be performed in accordance with the workpiece 31.
In addition, the same effects as those of the first embodiment are obtained.

(Example 3)
In this example, as shown in FIG. 6, the reflecting jig 6 is arranged in the opening 322 of the hole 32, and the recess 611 having an inner diameter larger than that of the opening 322 is formed in the reflecting surface 61.
Further, the workpiece 3 in this example has no stepped portion formed in the opening 322 of the hole 32. In addition, the depth of the said recessed part 611 is about 1 mm, for example.
Others are the same as in the first embodiment.

In the case of this example, the processing of the opening 322 on the side opposite to the side where the jet water flow 2 is introduced in the hole 32 can be effectively performed. That is, if the opening 322 is in direct contact with the reflecting jig 6, it may be difficult to effectively apply the cavitation bubbles 23 to the opening 322. Therefore, by providing the concave portion 611 in the reflective surface 61, a gap 612 can be formed between the opening 322 and the reflective surface 61, and the jet water flow 2 is introduced into the gap 612, Processing can be performed effectively.
In addition, the same effects as those of the first embodiment are obtained.

Example 4
In this example, as shown in FIG. 7, the reflecting jig 6 having the movable portion 63 that can be inserted into the hole portion 32 of the workpiece 3 is used.
That is, the reflecting jig 6 is movable in the axial direction (arrow Z in FIG. 7) of the fixing portion 64 to be in contact with the workpiece 3 and the hole 32 of the workpiece 3 with respect to the fixing portion 64. And a movable portion 63. And while moving the movable part 63 to the axial direction of the hole part 32, the jet water flow 2 is injected in the hole part 32 of the to-be-processed body 3, and is reflected in the reflective surface 61 of the reflective jig 6. FIG.
Others are the same as in the third embodiment.

In the case of this example, the reflecting jig 6 is inserted into the hole 32 and moved appropriately so that the cavitation bubbles 23 are efficiently collapsed inside the hole 32 and the surface processing of the inner surface of the hole 32 is performed. Can be performed more effectively. Thereby, surface processing can be performed uniformly about the axial direction of the hole 32.
Further, the cavitation bubbles 23 can be collapsed intensively at a desired portion such as a burr generation portion at a crossing portion between the hole portion 32 and the cross hole 33.
In addition, the same effects as those of the third embodiment are obtained.

(Example 5)
In this example, as shown in FIG. 8, a clearance 65 is provided between the fixed portion 64 and the movable portion 63 of the reflecting jig 6.
The clearance 65 is connected to the communication hole 152 of the holding jig 15.
Others are the same as in the fourth embodiment.

In the case of this example, the pressure applied to the processed portion 31 can be adjusted in the same manner as in the third embodiment, and the cavitation bubble 23 is collapsed in a state suitable for surface processing of the hole 32. It becomes possible to make it. Therefore, appropriate surface processing can be performed in accordance with the workpiece 31.
In addition, the same effects as those of the fourth embodiment are obtained.

(Example 6)
In this example, as shown in FIG. 9, the reflecting surface 61 of the reflecting jig 6 is inclined with respect to the axial direction of the hole 32 of the workpiece 3.
In this example, the reflecting surface 61 is a conical surface by making the tip of the movable portion 63 of the reflecting jig 6 have a conical shape.
Others are the same as in the fourth embodiment.

In the case of this example, the jet water flow 2 introduced into the hole 32 is reflected by the reflecting surface 61, whereby the jet water flow 2 is guided in a direction having an angle with respect to the axial direction of the hole 32. Therefore, the cavitation bubbles 23 in the jet water stream 2 are guided to the inner surface (processed portion 31) of the hole 32 and collapsed, and the inner surface can be effectively processed. Further, a stagnation region of the jet water flow 2 is formed between the inclined reflecting surface 61 and the inner surface of the hole 32, so that the pressure of the jet water flow 2 is improved and the cavitation bubbles 23 are easily collapsed. Thereby, the surface processing of the process part 31 can be performed effectively.
Further, since the reflecting surface 61 is a conical surface, the cavitation bubbles 23 can be uniformly guided to the inner surface of the entire circumference of the hole portion 32.
In addition, the same effects as those of the fourth embodiment are obtained.

(Example 7)
In this example, as shown in FIG. 10, an impact sensor 16 capable of detecting the impact energy applied to the workpiece 3 by the jet water flow 2 is disposed on the holding jig 15 that holds the workpiece 3. It is.
Based on the integrated value of impact energy detected by the impact sensor 16, the machining time is controlled.

  For example, the relationship between the integrated value of the impact energy given to the workpiece 3 by the jet water flow 2 and the progress of the surface processing treatment is grasped in advance by means such as experiments and simulations. Then, when the integrated value of the impact energy detected by the impact sensor 16 reaches a predetermined value, the processing is finished.

Note that a piezoelectric film sensor can be used as the impact sensor 16.
Others are the same as in the first embodiment.
In the case of this example, it is possible to easily and efficiently perform an appropriate surface processing on the processed portion 31 of the workpiece 3.
In addition, the same effects as those of the first embodiment are obtained.

(Example 8)
In this example, as shown in FIGS. 11 to 16, the outer surface of the workpiece 30 that is included in the through hole 71 of the concentration jig 7 in a plan view is processed by the jet water flow 2.
In this example, the through hole 71 is a circular hole, and the workpiece 30 is composed of a plurality of cylindrical bodies as described later. The outer diameter of the workpiece 30 is smaller than the inner diameter of the through hole 71 of the concentration jig 7.

  The workpiece 30 has a shape in which three cylindrical bodies are overlapped in the axial direction as shown in FIG. That is, the center of the workpiece 30 is composed of a central small diameter portion 35 having a relatively small outer diameter, and both end portions of the workpiece 30 are respectively a first large diameter portion 36 and a second large diameter having a relatively large outer diameter. Part 360. The corner portions of the first large-diameter portion 36 and the second large-diameter portion 360 are the main processed portions 31. That is, since these parts often have burrs generated by cutting or the like, the burrs are removed by surface processing. Moreover, compressive stress can be given to the processed part 31 (peening), or dirt can be washed.

In addition, the reflecting jig 6 having the reflecting surface 61 is disposed downstream of the processed portion 31 of the workpiece 30 on the jet water flow 2, and the high-pressure water flow 21 is jetted and reflected on the reflecting surface 61. Thereby, the jet water flow 2 is applied to the outer surface of the workpiece 30.
Specifically, as shown in FIGS. 12 to 16, a concave space 72 is formed in the portion of the through hole 71 of the concentrating jig 7 by the reflecting jig 6 and the concentrating jig 7. A processed portion 31 of the processed body 30 is disposed. In this state, the jet water stream 2 including the cavitation bubbles 23 is jetted toward the concave space 72 as in the first embodiment.
12 to 16, the ejection nozzle 1 and the like are omitted, and only the workpiece 30 and its peripheral part are drawn.

When processing the processing portion 31 at the tip corner of the first large diameter portion 36, as shown in FIG. 12, the processing portion 31 at the tip corner of the first large diameter portion 36 is disposed in the recess space 72, The cavitation bubbles 23 are concentrated on the processed portion 31.
Further, when the processed portion 31 at the corner on the central small diameter portion 35 side in the first large diameter portion 36 is processed, as shown in FIG. 13, the first large diameter portion 36 and the central small diameter portion 35 are formed in the recessed space 72. The cavitation bubbles 23 are concentrated on the processed portion 31 by arranging a part thereof.

  Further, when the processed portion 31 at the corner on the central small diameter portion 35 side in the first large diameter portion 36 and the second large diameter portion 360 is processed at a time, the inner diameters of the through holes 71 are different as shown in FIG. Two types of concentrating jigs 7 and 70 are stacked to form two-step recessed spaces 72 and 720. Then, the second large-diameter portion 360 is disposed in the small-diameter recessed space 720, and the first large-diameter portion 36 is disposed in the large-diameter recessed space 72. As a result, the cavitation bubbles 23 are concentrated on the processed portions 31 at the corners of the first large diameter portion 36 and the second large diameter portion 360 on the central small diameter portion 35 side, respectively. At this time, the end surface 76 of the concentration jig 70 on the reflection jig 6 side plays the same role as the reflection surface of the reflection jig.

Further, when the processed portion 31 at the tip corner of the second large diameter portion 360 is processed, as shown in FIG. 15, a protruding portion 62 protruding from the reflecting surface 61 of the reflecting jig 6 is provided. And it arrange | positions so that this front-end | tip surface of the 2nd large diameter part 360 may contact | abut to this projection part 62, and the jet water flow 2 is sprayed toward the reflective surface 61. FIG.
Thereby, the cavitation bubbles 23 can enter the gap formed between the reflection surface 61 and the tip surface of the second large diameter portion 360, and the cavitation bubbles 23 can be concentrated on the processed portion 31.

Further, as shown in FIG. 16, the workpiece 30 can be moved in the axial direction (arrow Z) with respect to the reflecting jig 6 and the concentration jig 7. The surface processing of the aspect shown in (4) can be performed sequentially. That is, the surface processing of every processed portion 31 in the workpiece 30 can be performed continuously.
Others are the same as in the first embodiment.

In the case of this example, the cavitation bubbles 23 can be concentrated on the outer surface of the workpiece 30, and the outer surface can be processed efficiently.
In addition, the same effects as those of the first embodiment are obtained.

(Comparative example)
In this example, as shown in FIG. 17, the surface processing of the workpiece 3 is performed without arranging the concentration jig (see reference numeral 7 in FIG. 1).
Others are the same as in the first embodiment.

In the case of this example, the jet water stream 2 sprayed toward the hole 32 of the workpiece 3 diverges at the opening 321, and the cavitation bubbles 23 are not sufficiently supplied to the hole 32 and diverge. .
Therefore, it may be difficult to concentrate the cavitation bubbles 23 on the processed portion 31 of the workpiece 3.

In addition, the jet water flow 2 injected into the hole 32 is easily scattered from the opening 322 to the outside, and it is difficult to apply sufficient pressure to the processed portion 31. As a result, the cavitation bubbles 23 do not collapse sufficiently, and the efficiency of the processing process on the processed portion 31 may be reduced.
Therefore, it may be difficult to efficiently perform the surface processing.
On the other hand, according to the present invention, by using the concentration jig 7 (see FIG. 1), the cavitation bubbles 23 can be concentrated on the processed portion 31 and the surface processing can be performed efficiently.

  In each of the above-described embodiments, the mode in which the jet water flow is jetted from the water toward the air is shown. However, the present invention is also applicable to the case where the jet water flow is jetted only in the air or in the water. Can do.

Sectional explanatory drawing which shows the surface processing method in Example 1. FIG. The perspective view of the to-be-processed body and the concentration jig | tool in Example 1. FIG. Sectional drawing of the to-be-processed body in Example 1. FIG. Sectional explanatory drawing which shows the surface processing method in Example 1. FIG. Sectional explanatory drawing of the reflective jig | tool in Example 2. FIG. Sectional explanatory drawing of the reflective jig | tool in Example 3. FIG. Sectional explanatory drawing of the reflective jig | tool in Example 4. FIG. Sectional explanatory drawing of the reflective jig | tool in Example 5. FIG. Sectional explanatory drawing of the reflective jig | tool in Example 6. FIG. Sectional explanatory drawing which shows the surface processing method in Example 7. FIG. The side view of the to-be-processed body in Example 8. FIG. Sectional explanatory drawing which shows the surface processing of the front-end | tip corner | angular part of the 1st large diameter part in Example 8. FIG. Sectional explanatory drawing which shows the surface processing of the center small diameter part side corner | angular part of a 1st large diameter part in Example 8. FIG. Sectional explanatory drawing which shows the surface processing of the center small diameter part side corner | angular part of the 1st large diameter part and 2nd large diameter part in Example 8. FIG. Sectional explanatory drawing which shows the surface processing of the front-end | tip corner | angular part of the 2nd large diameter part in Example 8. FIG. Sectional explanatory drawing which shows the method of carrying out surface processing of all the process parts of the to-be-processed body in Example 8 continuously. Cross-sectional explanatory drawing which shows the surface processing method in a comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Jet nozzle 2 Jet water flow 21 High pressure water flow 22 Low pressure water flow 23 Cavitation bubble 3, 30 Work piece 31 Processing part 32 Hole part 6 Reflecting jig 61 Reflecting surface 7 Concentrating jig 71 Through-hole

Claims (10)

A method of processing the surface of the workpiece by injecting a jet water stream onto the workpiece,
The jet stream is a two-layer jet stream composed of a high-pressure stream and a low-pressure stream surrounding the high-pressure stream, including cavitation bubbles,
Between the jet nozzle for jetting the jet water flow and the workpiece, a concentration jig having a through hole that includes the processed portion of the workpiece in a plan view,
By passing the jet water flow through the through hole of the concentration jig, the cavitation bubbles are concentrated on the processed portion of the workpiece ,
The workpiece is formed with a hole, and when the inner surface of the hole is processed by the jet water flow, the through hole of the concentration jig is formed in the hole of the workpiece. In a plan view, and the concentration jig is arranged so that the through hole and the hole are connected to each other . In Claim 1, the reflection jig which has the reflective surface which reflects the above-mentioned high-pressure water stream is arranged in the inside of the above-mentioned hole part or the opening opposite to the side which introduces the above-mentioned jet-water stream, A surface processing method according to claim 1, wherein the jet water flow is applied to the inner surface of the hole by jetting and reflecting on the reflecting surface. In Claim 2, the said reflective jig is distribute | arranged to the opening part on the opposite side to the side which introduce | transduces the said jet water flow in the said hole part, The said opening part is included in planar view in the said reflective surface. A surface processing method, wherein a recess is formed . 4. The surface processing method according to claim 2, wherein the reflecting jig has a movable portion that can be inserted into the hole . 5. The surface processing method according to claim 4, wherein the reflecting surface is inclined with respect to the axial direction of the hole . 6. The surface processing method according to claim 2, wherein the reflecting jig closes the opening of the hole . 6. The surface according to claim 2, wherein the reflecting jig partially opens an opening of the hole and adjusts an outflow amount of the jet water flow from the opening. Processing method. A method of processing the surface of the workpiece by injecting a jet water stream onto the workpiece,
The jet stream is a two-layer jet stream composed of a high-pressure stream and a low-pressure stream surrounding the high-pressure stream, including cavitation bubbles,
Between the jet nozzle for jetting the jet water flow and the workpiece, a concentration jig having a through hole that includes the processed portion of the workpiece in a plan view,
By passing the jet water flow through the through hole of the concentration jig, the cavitation bubbles are concentrated on the processed portion of the workpiece,
The workpiece is included in the through-hole of the concentration jig in a plan view, and the outer surface of the workpiece is processed by the jet water flow.
A reflecting jig having a reflecting surface that reflects the high-pressure water flow is disposed downstream of the processed portion of the workpiece and the jet water flow, and the high-pressure water flow is jetted and reflected on the reflecting surface. The surface processing method according to claim 1, wherein the jet water flow is applied to the outer surface of the workpiece. The surface processing method according to claim 1, wherein the jet nozzle is disposed in water, and the jet water flow is jetted from the jet nozzle toward the air . The impact sensor according to any one of claims 1 to 9, wherein the impact energy applied to the workpiece by the jet water flow is detected on the workpiece or a holding jig that holds the workpiece. Is provided, and a processing time is controlled based on an integrated value of impact energy detected by the impact sensor .

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