Nozzle

Abstract

A nozzle ejecting liquid and nozzle device ejecting a liquid upon mixing an abrasive into a liquid jet stream, obtains a converged jet stream. A nozzle includes: a main body; a buffer chamber in the body, whose central axis is an axis line being the liquid jet stream central line; a constrictor part ejecting the liquid, in a buffer chamber plane on a buffer chamber front side and whose central axis is the axis line; a disk plate inside the buffer chamber, facing the plane on the buffer chamber front side and whose central axis is the axis line; a supporting member supporting the disk plate within the buffer chamber; a supply opening in the body supplying the liquid; and an inflow channel along a direction different from the axis line extending direction, opened on a disk plate rear side and the buffer chamber and communicating with the opening.

Claims

1. A nozzle adapted to eject liquid, comprising: a main body; a buffer chamber provided in the main body, whose central axis is an axis line serving as a center line of a jet stream of a liquid, which has an internal space whose outer shape is of a cylinder, and which cylinder has a front end plane surface and a rear end surface; a constrictor part adapted to eject the liquid, provided on the front end plane surface of the buffer chamber in a direction of the axis line and whose central axis is the axis line; a disk having a front plane surface and a back surface and provided inside the buffer chamber, the front plane surface of the disk facing the front end plane surface of the buffer chamber and whose central axis is the axis line, there being a gap between the front plane surface of the disk and the front end plane surface of the buffer chamber, the disk having a diameter smaller than the diameter of the buffer chamber, and which disk has a groove provided on the front plane surface thereof; a supporting member adapted to support the disk within the buffer chamber, the supporting member having a shaft provided on the back surface of the disk, the shaft being of a cylindrical shape whose central axis is the axis line; a supply opening provided in the main body, adapted to supply the liquid; and an inflow channel provided along a direction different from an extending direction of the axis line, and connected to the buffer chamber at a location between the back surface of the disk and the rear end surface of the buffer chamber, the inflow channel communicating with the supply opening, wherein the groove has an internal space whose outer shape is of a cylinder whose central axis is the axis line, or of a truncated cone shape whose section broadens as the internal space approaches the one side, and the disk partitions the buffer chamber into a storage chamber rear of the disk, a disk-shaped rectification space front of the disk, and an annular-shaped communication passage, the storage chamber communicating to the inflow channel, the communication passage being space between a circumferential surface of the disk and an inner circumferential surface of the buffer chamber.

2. The nozzle according to claim 1, wherein the front end plane surface of the buffer chamber is adapted to be opened, the constrictor part is provided in a hollow cylindrical constrictor member whose central axis is the axis line, the constrictor member is adapted to close the opening on the front end plane surface of the buffer chamber, and the nozzle further comprises: a housing having a reception chamber adapted to contain the constrictor member and a jet stream flow channel provided on the same axis as the axis line, the jet stream flow channel opened on the front end plane surface of the buffer chamber and communicated with the reception chamber; and a pressing member adapted to sandwich the constrictor member contained within the reception chamber between the housing and the main body by pressing and fixing the housing toward the main body.

3. The nozzle according to claim 1, wherein the main body has an insertion hole provided on the same axis as the axis line and opened on the other side of the main body, the insertion hole communicating with the buffer chamber, the supporting member is disposed penetrating through the insertion hole, and the nozzle further comprises: a sealing member adapted to seal between the supporting member and the insertion hole; and a fixing member adapted to fix the supporting member to the main body from the other side.

4. A nozzle device having a nozzle as set forth in claim 1, the nozzle device adapted to eject liquid upon mixing an abrasive medium into a jet stream of the liquid, the nozzle device comprising: a hollow cylindrical mixing section having an inlet end and provided on an end of the constrictor part that is opposite the end of the constrictor part that is on the front end plane surface of the buffer chamber, and communicating with the constrictor part and on the same axis as the axis line, the mixing section having an abrasive flow inlet via which the abrasive medium is flowed into along a direction different from an extending direction of the axis line; and a hollow cylindrical ejection conduit provided on an outlet end of the mixing section, communicating with the mixing section and on the same axis as the axis line.

5. The nozzle according to claim 1, wherein the gap is 1 to 4 times a diameter of the constrictor part.

6. The nozzle according to claim 1, wherein the groove has an internal space whose outer shape is of a cylinder whose central axis is the axis line.

7. The nozzle according to claim 1, wherein the groove has an internal space whose outer shape is of truncated cone shape whose section broadens as the internal space approaches the one side.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a longitudinal sectional view of a nozzle in the present embodiment.

(2) FIG. 2 shows a front view of the nozzle in the present embodiment.

(3) FIG. 3 shows a longitudinal sectional view of a nozzle device in the present embodiment.

(4) FIG. 4 shows a front view of the nozzle device in the present embodiment.

(5) FIG. 5 is a flow line map showing a flow of liquid inside a nozzle in Embodiment 1.

(6) FIG. 6 is a vector plot diagram showing a velocity of the flow of liquid inside the nozzle in Embodiment 1.

(7) FIG. 7 is a contour diagram showing a vorticity of the flow of liquid inside the nozzle in Embodiment 1.

(8) FIG. 8 is a flow line map showing a flow of liquid inside a nozzle in Embodiment 2.

(9) FIG. 9 is a vector plot diagram showing a velocity of the flow of liquid inside the nozzle in Embodiment 2.

(10) FIG. 10 is a contour diagram showing a vorticity of the flow of liquid inside the nozzle in Embodiment 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(11) According to the present invention, a convergent jet stream is obtainable in a nozzle that ejects liquid and a nozzle device which ejects liquid upon mixing an abrasive into a jet stream of the liquid.

(12) (Structure)

(13) With reference to the drawings, details of an embodiment of the present invention will be described. FIG. 1 shows a sectional view taken along line I-I in FIG. 2. FIG. 2 is a front view of a nozzle 10. FIG. 1 and FIG. 2 show the bottom half of the drawing in an enlarged manner, to describe the structure of an inflow channel. In the following descriptions, for convenience, directions in FIG. 1 and FIG. 3 are called as follows: left direction as front, right direction as rear, upwards direction as up, and downwards direction as down (or bottom). Moreover, in FIG. 2 and FIG. 4, the right direction and left direction are called right and left, respectively.

(14) A nozzle 10 includes: a main body 11; a buffer chamber 29 provided in the main body 11, whose central axis is an axis line 28 that is the central line of a jet stream J of the liquid; a constrictor part 35 for ejecting the liquid, provided in a plane 291 of the buffer chamber 29 on a front side thereof as one side of a direction of the axis line 28 and whose central axis is the axis line 28; a disk plate 30 provided inside the buffer chamber 29, the disk plate 30 facing the plane 291 of the buffer chamber 29 on the front side thereof and whose center axis is the axis line 28; a supporting member 31 for supporting the disk plate 30 within the buffer chamber 29; a supply opening 121 provided in the main body 11 for supplying the liquid; and an inflow channel 12 provided along a direction different from an extending direction of the axis line 28, the inflow channel 12 opened on a side rear of the disk plate 30 of the buffer chamber 29, which rear side serves as the other side, and which inflow channel 12 communicates with the supply opening 121.

(15) The main body 11 is a substantially rectangular parallelepiped block. The supply opening 121 for supplying the liquid to be ejected is provided in an upper part of the main body 11. Furthermore, the axis line 28 lies in a lateral direction (in the embodiment, a front-rear direction) in a lower part of the main body, which axis line 28 is the center through which the liquid is ejected. The buffer chamber 29 is provided in the center of the lower part of the main body 11. On a rear side of the lower part of the main body 11, an insertion hole 36 is provided, which insertion hole 36 has a step of a smaller diameter. The front side of the lower part of the main body is partially cut out, to house a housing 21. The main body 11 is made of material that is corrosion-resistant to liquid and that can resist pressure of the fluid, such as austenitic stainless steel and precipitation hardening stainless steel.

(16) The inflow channel 12 is provided in the main body 11. The supply opening 121 of the inflow channel 12 is provided in the upper part of the main body 11. A flow outlet 122 of the inflow channel 12 is provided rear of the disk plate 30 of the buffer chamber 29. Since the flow outlet 122 is provided rear of the disk plate 30, the liquid flown out from the flow outlet 122 to the buffer chamber 29 does not disturb the structure of the flow in the rectification space 292 later described. The inflow channel 12 intersects at right angles with the axis line 28. A liquid supply means 45 is connected to the supply opening 121 via a pipe. As the liquid supply means 45, an ultrahigh pressure pump may be used, which generates a high pressure of 100 MPa to 500 MPa.

(17) The inflow channel 12 and the axis line 28 need not to be perpendicular to each other; the inflow channel 12 and the axis line 28 face different directions.

(18) The buffer chamber 29 is a substantially cylindrical hole provided near the bottom plane (lower of) the main body 11, having the axis line 28 serve as its center. The outer shape of the internal space of the buffer chamber 29 is of a cylindrical shape. The buffer chamber 29 has a section larger than a section of the inflow channel 12. The buffer chamber 29 may be of a barrel shape whose middle part is slightly broadened in diameter. Moreover, corner sections thereof may be rounded.

(19) The front side of the buffer chamber 29 is opened. The constrictor part 35 is provided in a constrictor member 16 shaped of a hollow cylinder whose central axis is the axis line 28. The constrictor member 16 is provided so as to close an opening on the front side of the buffer chamber 29. The opening of the buffer chamber 29 is closed and liquid sealed by the plane 291 of the constrictor member 16, to obtain a sealed space. The plane 291 of the constrictor member 16 defines a plane on the front side of the buffer chamber 29. The opening of the buffer chamber 29 in the main body 11 has a tapered plane 27 with a smoothly finished surface. Since the outer shape of the internal space of the buffer chamber 29 is of a cylindrical shape, an inflow channel structure of inside the nozzle 10 becomes extremely compact. Therefore, a nozzle 10 having a small exterior dimension is obtainable.

(20) The disk plate 30 is provided inside the buffer chamber 29 with the axis line 28 serving as a center thereof, positioned close to the constrictor member 16 but keeping a slight gap L2 provided between the plane 291 of the constrictor member 16. The gap L2 is preferably around 1 to 4 times a diameter d of the constrictor part 35. A diameter D2 of the disk plate 30 is slightly smaller than a diameter D1 of the buffer chamber 29. Preferably, a cylindrical groove 34 whose central axis is the axis line 28 is provided on a plane of the disk 30 on the front side (the constrictor part 35 side). That is to say, the outer shape of the inner space of the groove 34 is of a cylindrical shape whose central axis is the axis line 28. Peripheral edges of the disk plate 30 may be chamfered or rounded. The disk plate 30 partitions the buffer chamber 29 into a storage chamber 294 rear of the disk plate 30 and a disk-shaped rectification space 292 that has a rectifying function. An annular space between a circumferential plane of the disk plate 30 and an inner circumferential plane of the buffer chamber 29 functions as a communication passage 293 that communicates the storage chamber 294 with the rectification space 292. The liquid flows in a flat manner from the storage chamber 294, through the communication passage 293 and from the outer circumference of the rectification space 292 to towards the center, and is ejected from the constrictor part 35.

(21) The shape of the groove 34 may be a truncated cone shape instead of the cylindrical shape, in which its section broadens as it approaches the constrictor part 35 (front side). In the case of a truncated cone shape, the change in sectional area in a radial direction of the inflow channel becomes calm, and can further prevent the vortex generation.

(22) The supporting member 31 is provided on a plane rear of the disk plate 30. The supporting member 31 is molded integrally with the disk plate 30. The supporting member 31 is a substantially cylindrical member including, in order from the front side, a shaft 311, an insertion section 312, and a screw section 313. The shaft 311 is desirably as narrow as possible. If the diameter of the shaft 311 is great, Karman vortex may easily generate on an opposite plane (lower side) of the shaft 311 seen from the flow outlet 122. Therefore, the diameter of the shaft 311 is produced as narrow as possible.

(23) The main body 11 has an insertion hole 36 provided on the same axis as the axis line 28 and opened on the rear side of the main body 11, which insertion hole 36 communicates with the buffer chamber 29. The insertion section 312 fits with and is inserted into the insertion hole 36 of the main body 11. Since the insertion section 312 comes into contact with the step part of the insertion hole 36, the insertion hole 36 can receive the pressure of the liquid within the buffer chamber 29. Therefore, the supporting member 31 will not fall out from the main body 11 from the rear side due to the pressure of the liquid within the buffer chamber 29. Since the insertion section 312 is provided fitting with the insertion hole 36, the supporting member 31 is assembled within the buffer chamber 29 with good accuracy.

(24) The outer circumference of the insertion section 312 is provided with an annular groove. A sealing member 32 is inserted within this annular groove. As the sealing member 32, natural rubber, synthetic rubber, a metal O-ring can be used. The sealing member 32 seals between the insertion section 312 and the insertion hole 36. The screw section 313 protrudes to the rear side of the main body 11, that is, the supporting member 31 is disposed penetrating through the insertion hole 36. Furthermore, the screw section 313 of the supporting member 31 is fixed with a nut that serves as a fixing member. A slotted groove, a hexagon socket, two-way taking may be provided on the rear edge of the screw section 313, to prevent the rotation of the supporting member 31 when the nut 33 is tightened to the screw section 313 of the supporting member 31.

(25) Instead of the cylindrical shape, the shaft 311 may be of a shape having a streamline shaped section through which the axis line 28 passes and which reduces the resistance received from the liquid delivered through the inflow channel 12. In this case, the support member 31 may be configured as having for example a pin or key to restrict the rotation of the supporting member 31.

(26) The housing 21 includes a reception chamber 18 for containing the constrictor member 16, and a jet stream flow channel 211 provided on the same axis as the axis line 28, which jet stream flow channel 211 is opened on the front side and is communicated with the reception chamber 18. The housing 21 is fixed to the main body 11 with a bolt 25 (see FIG. 2) that serves as a pressing member.

(27) The constrictor member 16 includes a smooth flat plane 291 that serves as a wall surface of the buffer chamber 29 on the front side thereof. When the nozzle 10 is assembled, the plane 291 closes the opening of the buffer chamber 29 and defines the plane on the front side of the buffer chamber 29. The outer circumferential plane of the constrictor member 16 fits with the inner circumferential plane of the reception chamber 18 of the housing 21. Moreover, the corner sections of the outer circumferential plane with the plane 291 of the constrictor member 16 has a smoothly finished tapered plane 26. The vertical angle of the tapered plane 26 is formed the same as or slightly smaller than the vertical angle of the tapered plane 27.

(28) By the bolt 25 pressing and fixing the housing 21 against the main body 11, the constrictor member 16 contained in the reception chamber 18 is sandwiched between the housing 21 and the main body 11. Moreover, by the bolt 25 pressing the housing 21 against the main body 11, the tapered plane 26 of the constrictor member 16 comes into contact with the tapered plane 27 of the main body 11 and is pressed. Therefore, the part between the buffer chamber 29 and the constrictor member 16 is liquid sealed. By fastening the housing 21 by using two bolts 25, the housing 21 can be fastened to the main body 11 evenly with respect to the axis line 28. Since the housing 21 is evenly fastened, the constrictor part 35 is fixed on the same axis as the axis line 28. Furthermore, the bolt 25 fixes the constrictor member 16 against the pressure of the liquid applied on the buffer chamber 29. Therefore, if the liquid pressure becomes high, excess axial force acts on the bolt 25. By using two bolts 25 in the horizontal directions, it is possible to reduce the axial diameter of the bolt 25. Therefore, it is possible to reduce a length L3 from the axis line 28 to the bottom plane of the main body 11.

(29) Although the tapered plane 27 is provided at the opening of the buffer chamber 29 and the tapered plane 26 is provided at the corner section of the constrictor member 16, it is not limited to this. For example, instead of this, a smooth annular flat plane may be provided around the opening of the buffer chamber 29, and the plane 291 of the constrictor member 16 may be made into contact with this annular flat surface to liquid seal between the constrictor member 16 and the main body 11. In this case, the constrictor member 16 is securely fixed on the same axis as the axis line 28. Moreover, a hollow cylindrical groove may be provided in the main body 11, so that one part of the outer circumferential plane of the constrictor member 16 is fit with and positioned in the main body 11.

(30) Next described with reference to FIG. 3 and FIG. 4 is a nozzle device 100 that ejects a jet stream J2 in which an abrasive is mixed into a jet stream J of the liquid (see FIG. 1). FIG. 3 shows a sectional view taken along line III-III in FIG. 4. FIG. 4 is a front view of the nozzle device 100.

(31) The nozzle device 100 ejects the jet stream J2 in which the liquid and an abrasive are mixed together. The nozzle device 100 includes the nozzle 10, a mixing section 40 for mixing the liquid with the abrasive, and an ejection conduit 17. Identical members as with the above nozzle 10 are provided with identical reference numerals, and their descriptions are omitted.

(32) The housing 210 includes an insertion through hole 38 on its front side (outlet side), which insertion through hole 38 is of a hollow cylindrical shape whose central axis is the axis line 28. The insertion through hole 38 communicates with the jet stream flow channel 211. The housing 210 includes an introduction hole 212 for introducing the abrasive.

(33) The mixing section 40 is shaped of a hollow cylinder having a void 402 therein, and is inserted into the insertion through hole 38. The outer circumferential plane of the mixing section 40 fits with the insertion through hole 38. The void 402 communicates with the constrictor part 35 via the jet stream flow channel 211, and is provided on the same axis as the axis line 28. The mixing section 40 has an abrasive flow inlet 401 through which the abrasive is flown into along a direction different from the axis line 28. A recessed section (back facing hole, or a flat plane provided by cutting out a part of the outer circumferential plane) 403 is provided on an opening outside in a radial direction of the abrasive inlet 401. The mixing section 40 is inserted so that the abrasive inlet 401 faces the introduction hole 212.

(34) An adaptor 41 is attached to the introduction hole 212. The adaptor 41 fixes a conduit 42 that serves as a passage for the abrasive. The adaptor 41 restricts the rotating direction of the mixing section 40 by being in contact with the bottom plane of the recessed section 403. The conduit 42 is connected to an abrasive supply means 46.

(35) The ejection conduit 17 is of a hollow cylindrical shape, and is inserted inside the insertion through hole 38. The ejection conduit 17 is provided in front of and adjacent to the mixing section 40. The outer circumferential plane of the ejection conduit 17 fits with the insertion through hole 38. Therefore, the ejection conduit 17 is provided on the same axis as the axis line 28. Since the ejection conduit 17 and the mixing section 40 are fit into the insertion through hole 38 and are disposed on the same axis as the axis line 28, an abrasion amount of the ejection conduit 17 and the mixing section 40 is reduced. The ejection conduit 17 and the mixing section 40 may be integrally molded.

(36) The ejection conduit 17 is fixed by a fixing means 19. The fixing means 19 includes a screwing mechanism 191, and an elastic ring 192 disposed surrounding the outer circumference of the ejection conduit 17. By tightening a nut of the screwing mechanism 191, the elastic ring 192 is urged against the outer plane of the ejection conduit 17, and fixes the ejection conduit 17.

(37) (Flow Analysis)

(38) Hereinafter, a structure of the flow of the liquid within the nozzle 10 of the present embodiment will be described in detail, based on fluid analysis results in two more specific Embodiments.

(39) The Embodiments hereinafter are used for describing the effects of the present invention, and the technical scope of the present invention will not be limited by the following embodiments.

Embodiment 1

(40) D1 is an inner diameter (diameter) of the buffer chamber 29, L1 is a length of the buffer chamber, D2 is an outer diameter (diameter) of the disk plate 30, t is a thickness of the disk plate 30, L2 is a distance between the disk plate 30 and the plane 291, and d is an inner diameter (diameter) of the constrictor part 35. Embodiment 1 is the nozzle 10 of the present embodiment, and is a nozzle 10 whose dimensions are: D1=6 mm, L1=5 mm, D2=5 mm, t=0.75 mm, L2=0.5 mm, d=0.2 mm. The nozzle 10 of the present embodiment does not have the groove 34 provided in the disk plate 30.

(41) FIG. 5 to FIG. 7 show a fluid analysis result of the inside of the nozzle of the present Embodiment. The fluid analysis is conducted by using ANSYS CFX-15.0 (general purpose thermal fluid analysis software manufactured by ANSYS). The analysis uses the finite volume method. The fluid is water. The boundary conditions is that the fluid is flown into from the inflow channel 12 at a flow rate of 19.3 [gs.sup.1], and the outlet of the constrictor part 35 is air-released. An inner wall plane is of a No Slip Wall. The analysis model is of a steady-state analysis type, and uses the turbulence model. The turbulence model uses k- model. The mesh is of a structured grid.

(42) FIG. 5 represents a flow line map of an analysis result viewed diagonally from a rear side thereof (opposite side to the constrictor part 35). The directions of front, rear, left, right, up, and down in FIG. 5 are as shown in the drawing (similarly for FIG. 8). The flow lines are displayed in gray scale, with a lighter color for a faster velocity, and a darker color for a slower velocity. A velocity range exceeding 1.010 [ms.sup.1] is displayed in white color. The range with the slowest velocity is displayed in black. The liquid flows into the buffer chamber 29 from the flow outlet 122 at a velocity of 2 to 3 [ms.sup.1]. The fluid gently spreads throughout the internal space of the storage chamber 294 at a velocity of 1 to 3 [ms.sup.1], which is a lower velocity than the flow rate of the inflow channel 12. In the present Embodiment, the shaft 311 is of a cylindrical shape having a diameter of 2 mm, and no large Karman vortex can be seen. The fluid flows from the communication passage 293 surrounding the disk plate 30 to the rectification space 292 in front of the disk plate 30, as though the fluid flows around the disk plate 30. At this time, the liquid flows substantially uniformly in a circumferential direction in the communication passage 293. In the rectification space 292, the fluid flows substantially uniformly in the circumferential direction towards the center of the rectification space 292. At the center of the rectification space 292, the flow suddenly contracts, is redirected into the axis line direction equally from the entire circumference, and flows into the constrictor part 35. Inside the rectification space 292, the flow rate increases in inverse proportion to a square of a radius of the rectification space 292. In the center part of the rectification space 292, the velocity reaches a rate of 6.25 to 8.3310.sup.2 [ms.sup.1] that is of the highest velocity (see FIG. 6).

(43) FIG. 6 shows a vector plot diagram showing the velocity of the flow in the I-I section of FIG. 2. The front, rear, up, and down directions in FIG. 6 are as shown in the drawing (similarly for FIG. 9). FIG. 6 shows a portion of the rectification space 292 in an enlarged manner. The size and gradation of the vector represent the velocity. The color of the vector is represented in gray scale, and a velocity near 0 [ms.sup.1] is represented by a black color and a velocity exceeding 8.3310.sup.2 [ms.sup.1] is represented by a white color. With FIG. 5 and FIG. 6, the velocity display range is largely different. At a position away from the axis line 28, the flow is parallel to the disk plate 30 and is extremely small, at a velocity of 2 to 3 [ms.sup.1] (see FIG. 5). The flow is of a layer form substantially parallel to the disk plate 30 until a position extremely close to the axis 28 (around a diameter of 1 mm), and as the flow approaches the center part, the velocity gradually increases. In a range of the diameter of 1 mm, as the direction of vector of the flow is directed to the center, it gradually tilts (changes) to the constrictor part 35 side, and in a very narrow range in the center, the vector is substantially parallel to the axis line 28. This range has a diameter of around 0.1 mm, which is about half of the diameter d of the constrictor part 35. The range parallel to the constrictor part 35 is a range of about half of the diameter d of the constrictor part 35, and in the vicinity of the constrictor part 35, the flow flows into the constrictor part 35 in a state still including the velocity in the radial direction.

(44) The surroundings of the constrictor part are plotted so that the vector is throttled, and the structure of the flow cannot be read well. On the rear side of the constrictor part 35, the velocity increases upon approaching the constrictor part 35 from a side close to the disk plate 30 in the direction of the axis line 28, and reaches the maximum speed of 8.3310.sup.2 [ms.sup.1] when passing through the constrictor part.

(45) FIG. 7 is a contour diagram showing a vorticity in the I-I section of FIG. 2. The front, rear, up, and down directions in FIG. 7 is as shown in the drawing (similarly for FIG. 10). The vorticity is displayed in gradations of the gray scale; a white color in a case of a high vorticity, and a black color in a case of a low vorticity. A point with the lowest vorticity is a position farthest away from the constrictor part 35 in the storage chamber 294, and is displayed in the black color. The vorticity appears from mid-degree to relatively high, from the vicinity of the front edge of the flow outlet 122 to the communication passage 293. Furthermore, a vortex of a mid-degree is generated in the vicinity of the bottom side (peripheral plane side of the disk plate 30) of the communication passage 293. Furthermore, a vortex is generated on the bottom side (front plane side of the disk plate 30), rear of the rectification space 292 and along the front plane of the disk plate 30, and the vorticity is the highest in the vicinity of the outer edges on the front plane side of the disk plate 30. This vortex gradually decreases upon approach to the center part of the rectification space 292. The vortex in the vicinity of the front plane of the disk plate 30 spreads thinly substantially axis symmetrically, having the axis line 27 serving as its center, in the center section of the rectification space 292. In the front of the rectification space 292, a vortex is generated thinly and broadly along the plane 291. Furthermore, the vortex is concentrated in a narrow range surrounding the constrictor part 35 in a substantially hemisphere shape. In the vicinity of the radial direction center part of the rectification space 292, the vorticity is slightly low in the cylindrical range from the center part to the rear in the front and rear direction along the axis line 28. Moreover, across a narrow range along the axis line 28 of the radial direction center part of the rectification space 292 (cylindrical range of a diameter 0.04 mm) and across the center part in the axis line 28 direction (front and rear direction) to the disk plate 30, a range with a substantially same diameter as the constrictor part 35 (range of the diameter 0.3 mm) hardly has any vortex generated.

(46) As described above, the liquid flown from the flow outlet 122 into the buffer chamber 29 is received in the storage chamber 294. The liquid spreads gently throughout the whole storage chamber 294, and flows out from the communication passage 293 substantially uniformly from its front peripheral sections. The liquid flows from the storage chamber 294 to the communication passage 293 circumferentially, substantially uniformly in the axis line 28 direction. Furthermore, the liquid flows in from the peripheral sections into the rectification space 292. The liquid flows in the rectification space 292, parallel to the disk plate 30 and uniformly in a radial direction, and increasing its velocity toward the center of the rectification space 292. The direction of this flow rotates at the center of the rectification space 292, in a corolla shape of a morning glory (morning glory shape) so as to be perpendicular to the disk plate 30. In a cylindrical range having the substantially same diameter as the constrictor part 35, the liquid flows into the constrictor part 35 with low turbulence and in high velocity along the axis line 28, with a substantially uniform flow.

(47) The liquid flowing from the flow outlet 122 to the buffer chamber 29 is received in the storage chamber 294, is spread throughout the entire storage chamber 294, is passed through the communication passage 293 and flowed toward the center from the peripheral section of the rectification space 292, and is contracted toward the constrictor part at the center part of the rectification space 292 and ejected, to obtain a jet stream J with low turbulence.

Embodiment 2

(48) In the present embodiment, a fluid analysis result is shown, according to a nozzle in which a groove 34 is added to the disk plate 30 of the nozzle in Embodiment 1. The diameter of the groove 34 is 1.5 mm, and the depth thereof is 0.2 mm Other nozzle shapes and analysis conditions, and further conditions of the diagram drawings are the same as Embodiment 1, and thus detailed descriptions thereof are omitted.

(49) FIG. 8 shows a flow line map of the analysis results seen diagonally from the rear side. The flow line map is substantially the same as Embodiment 1, so detailed descriptions thereof are omitted.

(50) FIG. 9 is a vector plot diagram showing the velocity of the flow in the I-I section of FIG. 2. In the present Embodiment also, the direction of the flow tilts (changes) forwards in the vicinity of the center (a range of 1 mm in diameter). In the space rear of the constrictor part 35, a flow parallel to the axis line 28 is generated in a slightly thicker range as compared to Embodiment 1. The range of the flow parallel to the axis 28 is of the range having the diameter of 0.2 mm being the same degree as the constrictor part 35. In the peripheral regions of the groove 34, the liquid flows along the bottom plane of the groove 34 (parallel to the surface of the disk plate 30). Further, in the vicinity of the center of the groove 34, a flow in the axis line direction of a velocity of 2.0810.sup.2 [ms.sup.1] or lower is generated. The liquid flows from the entire groove 34 gathering towards the constrictor part 35 in a morning glory form.

(51) In the vicinity of the groove 34 inside the rectification space 292, the flow parallel to the flat plate 30 once gently spreads as like increasing the width in the axis line 28 direction towards the inside of the groove 34. By the liquid spreading as like increasing the width in the direction of the axis line 28, a flow of a layer form parallel to the axis line 28, broadly spread in the radial direction of the axis line 28 as compared to Embodiment 1, is generated. By generating a thick flow parallel to the axis line 28 that is directed to the constrictor part 35, the straightness of the jet stream J can be further enhanced than that in Embodiment 1.

(52) FIG. 10 is a contour diagram showing a vorticity in the I-I section of FIG. 2. In the present Embodiment, an area with a high vorticity is newly generated in the peripheral section of the groove 34. However, in the present Embodiment, among the region rear of the constrictor part 35, a region with low vorticity once spreads in a radial direction by a diameter of 0.3 mm being of the same degree as Embodiment 1 on a front side (disk plate 30 side) for about half of the height (width in the front and rear direction along the axis line 28) of the rectification space 292, and further spreads broadly in the morning glory form across the bottom plane of the groove 34. The size of the region reaches to a diameter of about 1 mm at the bottom plane of the groove 34. The vorticity is particularly low in the center part of the groove 34.

(53) In the nozzle of the present Embodiment, by having the groove 34 provided in the disk plate 30, a flow is generated directed to the constrictor part 35 as though the liquid is collected in a morning glory form from the space within the groove 34. Further, in the present Embodiment, a flow in a layer form is generated in a range having a large radius as compared to Embodiment 1. Therefore, according to the nozzle of the present Embodiment, the turbulence of the jet stream J ejected from the constrictor part 35 is further small, and thus a jet stream J with high convergence is obtainable.

Application Example

(54) As described above based on the Embodiments, according to the nozzle 10 of the present embodiment, a jet stream J having small turbulence and high convergence is obtainable. In a nozzle device 100 using the nozzle 10, a liquid jet stream J having high straightness and convergence is obtainable, so therefore an abrasion amount of the mixing section 40 and the ejection conduit 17 is reduced. Furthermore, since the straightness of the jet stream J is high, the energy density of the jet stream J2 in which an abrasive is mixed into the jet stream J is also improved.

(55) Moreover, since the inner structure can be formed compact, it is possible to reduce the size of the nozzle 10. In particular, when the fluid pressure exceeds 100 MPa, a large inner stress generates on the members that form the surroundings of the flow channel, and may break these members. Therefore, the thickness of the members of the nozzle 10 had to be large to a certain degree. The nozzle 10 of the present embodiment is of a simple structure and can configure the flow channel section small, so it is extremely suitable for high pressure fluids.

(56) The nozzle 10 and nozzle device 100 of the present embodiment is extremely compact, so it is possible to insert inside a bottomed groove section or hole that is subject to work such as processing, and carry out for example work from a side direction different from the inserting direction. In particular, since there is no structural body on the bottom plane side (deep side seen from the supply opening 121) than the buffer chamber 29, it is possible to make the distance L3 (see FIG. 1, FIG. 3) from the axis line 28 to the bottom surface of the main body 11 extremely small.

REFERENCE SIGNS

(57) 10 nozzle 100 nozzle device 11 main body 12 inflow channel 121 supply opening 16 constrictor member 17 ejection conduit 18 reception chamber 19 fixing means 21,210 housing 211 jet stream flow channel 25 bolt (pressing member) 28 axis line 29 buffer chamber 291 plane 30 disk plate 31 supporting member 311 shaft 32 sealing member 33 nut (fixing member) 34 groove 35 constrictor part 36 insertion hole 40 mixing section 401 abrasive inlet