JPH09253534A - In-liquid nozzle device for production of cavitation air bubbles - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an underwater nozzle device capable of efficiently producing cavitation air bubbles. SOLUTION: High pressure water from a high pressure pump is jetted from an orifice 22 to an expanded diameter cylindrical hole 28. A spiral groove 30 is formed on a peripheral part of the expanded diameter cylindrical hole 28 and water in the spiral groove 30 is suppressed from moving forward the front of the expanded diameter cylindrical hole 28 by a trough part and a relative speed difference from the high pressure jetting water from the orifice 22 is increased. The cavitation air bubbles are efficiently formed in the spiral groove 30 by the increase in this relative speed difference.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a submerged nozzle device for generating cavitation bubbles, which performs cleaning, deburring, etc. by utilizing the erosion effect of cavitation bubbles.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication (Kokai) No. Hei 5-212317 provides a diameter-increasing cylindrical hole whose diameter is sufficiently enlarged from the nozzle hole and opens to the front. Disclosed is a submerged nozzle device for cavitation bubble generation, in which the efficiency of cavitation bubble generation is improved by injecting into the expanded diameter cylindrical hole.

[0003]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
The problems of the submerged nozzle device for generating cavitation bubbles in Japanese Patent No. 7 are as follows. (A) Cavitation bubbles are formed only in the vicinity of the peripheral portion of the bottom surface of the expanded cylindrical hole, and the generation efficiency is insufficient. (B) It is difficult to appropriately change the taper angle of the tapered portion and the diameter of the orifice with respect to the diameter of the expanded cylindrical hole.

An object of the present invention is to improve a conventional submerged nozzle device for generating cavitation bubbles.

[0005]

A submerged nozzle device (10) for producing cavitation bubbles according to the present invention has the following (a) to (a).
(C). (A) A nozzle hole (22) for ejecting a liquid (b) A diameter-expanded columnar space portion (28) having a diameter larger than that of the nozzle hole (22) and provided at the front side of the nozzle hole (22) and opening at the front end. (C) A circumferential groove (30) formed in the peripheral portion of the expanded columnar space (28) so as to extend in the circumferential direction of the expanded columnar space (28).

The circumferential groove (30) is used as a concept including not only the spiral groove (30) but also any groove extending in the circumferential direction of the expanded diameter columnar space portion (28) such as a circumferential groove and an annular groove. There is.

The liquid is expanded from the injection hole (22) into a columnar space portion (28) having a diameter increased.
The fuel is injected into the inside of the expanded diameter columnar space portion (28) and then forwards, and exits forward from the expanded diameter columnar space portion (28). Expanded columnar space (28)
Inside, a large relative velocity difference occurs between the high-pressure jet liquid from the injection hole (22) and the liquid around it. Especially the circumferential groove (30)
The liquid in the inside is the flow direction of the high-pressure jet liquid due to its side wall,
That is, since the axial movement of the expanded columnar space (28) is suppressed, the relative speed difference with the liquid outside the circumferential groove (30) is increased, and the liquid inside the circumferential groove (30) is also increased. Will locally reduce the pressure. Thus, cavitation bubbles
(36) are efficiently generated in the circumferential groove (30).

Another submerged nozzle device (10) for producing cavitation bubbles according to the present invention further has the following element (d). (D) A circumferential groove (3
Guide groove (32) extending in the axial direction of the expanded diameter columnar space (28) across (0)

The cavitation bubbles (36) generated in the circumferential groove (30) pass through the lead-out groove (32) and the expanded columnar space (2).
8) is moved in the axial direction, is caught in the high-pressure jet liquid, and exits forward from the expanded diameter columnar space (28). Due to the lead-out groove (32),
The efficiency of generation of the cavitation bubbles (36) by the circumferential groove (30) can be increased, and the discharge of the cavitation bubbles (36) from the expanded diameter columnar space (28) can be facilitated.

Another submerged nozzle device (10) for producing cavitation bubbles according to the present invention further has the following elements (e) and (f). (E) Orifice (22) which is the injection hole (22) and this orifice
Nozzle member (14) provided with a taper portion (20) connected to the back of (22) and gradually reducing the diameter toward the orifice (22) (f) A pipe body (12) provided with a diameter-expanded columnar space portion (28) A screwing member (16) for mounting the nozzle member (14) on the front end portion of the conduit (12) while screwing on the front end portion of the

Since the screw member (16) is screwed to the front end portion of the pipe body (12), the screw member (16) can be separated from the pipe body (12) as appropriate. Therefore, by removing the screwing member (16) from the conduit body (12) and replacing the nozzle member (14), and in some cases also replacing the screwing member (16), the injection hole (22 ), The diameter of the orifice (22) and the taper angle of the taper portion (20) can be easily changed as appropriate.
The combination of these values with the diameter of the expanded diameter columnar space portion (28) can be easily changed as appropriate.

According to another submerged nozzle device (10) for producing cavitation bubbles of the present invention, the circumferential groove (30) is a spiral groove.
(30).

The high pressure jet liquid from the injection hole (22) causes the spiral groove (3
The liquid in 0) is increased in relative velocity difference with respect to the high-pressure jet liquid, and the pressure is locally reduced, so that cavitation bubbles (36) are efficiently generated in the spiral groove (30). Since the spiral groove (30) is easy to process, the manufacturing of the circumferential groove (30) can be simplified. Further, since the spiral groove (30) is appropriately inclined with respect to the direction of the high pressure jet liquid from the injection hole (22), the cavitation bubbles (36) in the spiral groove (30) are It is possible to efficiently move to the lead-out groove (32) along the inclination of the spiral groove (30) with respect to the direction.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a vertical cross-sectional view of the front end portion of the submersible nozzle device 10, and FIG. 2 is a view of the front end portion of the submersible nozzle device 10 as seen from the axial direction. The lance 12 extends linearly, the nozzle tip 14 is applied to the front end surface of the lance 12, and the cap 16 is inserted into the nozzle tip 14 from the lance 12 side while being inserted into the thread groove 24 of the front end portion of the lance 12. The thread groove 26 is screwed together and mounted on the front end portion of the lance 12 together with the nozzle tip 14. The passage 18 is formed in the lance 12 along the center line of the lance 12. The nozzle tip 14 has a rear end connected to the front end of the passage 18 and a taper portion 20 that gradually decreases in diameter toward the front, and a nozzle tip 14 that opens to the front end surface of the nozzle tip 14 and connects the rear end to the front end of the taper portion 20. An orifice 22 as a cylindrical hole is provided. The expanded cylindrical hole 28 has a diameter slightly smaller than the diameter of the nozzle tip 14 and sufficiently larger than the diameter of the orifice 22,
The spiral groove 30 is spirally formed around the center line of the cap 16 in the peripheral portion of the expanded cylindrical hole 28. 3 cross grooves 32 in total
Indicates that the expanded cylindrical holes 28 are arranged at equal angular intervals in the circumferential direction of the expanded cylindrical holes 28.
It is formed in the peripheral part of, and goes straight to the spiral groove 30,
It extends over the entire axial range of 28. As seen in FIG. 2, the transverse groove 32 is formed slightly deeper than the spiral groove 30.

The submersible nozzle device 10 is submerged in water together with a work to be chipped and deburred. The high-pressure water pumped from the high-pressure pump is tapped from the passage 18.
After entering the nozzle 20, the flow cross-sectional area in the tapered portion 20 is reduced, the velocity is increased, and the fuel is injected forward through the orifice 22 into the enlarged diameter cylindrical hole 28 along the center line of the orifice 22. FIG. 3 is a diagram showing a generation state of cavitation bubbles 36 in the spiral groove 30. A indicates the direction of high-pressure jet water jetted from the orifice 22 into the expanded diameter cylindrical hole 28. The water in the spiral groove 30 is restricted from moving in the A direction by the ridge portion 38 serving as a partition of the spiral groove 30, the relative speed difference with respect to the high pressure jet water is increased, and the pressure is locally reduced. Thereby, the cavitation bubbles 36 are efficiently generated in the valley portions 34 of the spiral groove 30.

FIG. 4 shows a state in which the cavitation bubble 36 is led out by the transverse groove 32. In the transverse groove 32, a water flow in the A direction is generated by the high pressure jet water, and the valley portion of the spiral groove 30 is generated.
The cavitation bubbles 36 in the 34 move from the trough 34 to the transverse groove 32 so as to be caught in the flow thereof, pass through the transverse groove 32, are entrained in the high pressure jet water, and are discharged in front of the enlarged diameter cylindrical hole 28. It has become so. The spiral groove 30 is slightly inclined with respect to the direction orthogonal to the direction A, and the cavitation bubbles 36 in the spiral groove 30 are transverse grooves along the inclination of the spiral groove 30.
The movement of the cavitation bubble 36 from the spiral groove 30 to the transverse groove 32 is facilitated. In FIG. 4, in the transverse groove 32, an arrow indicates
Two of the expanded cylindrical holes 28 are drawn substantially forward and the other is expanded substantially backward. With the discharge of the high-pressure jet water from the expanded cylindrical hole 28 forward, water flows into the expanded cylindrical hole 28 from the front, and this inflow water flows backward in the expanded cylindrical hole 28, but faces backward. The arrow indicates a cross groove 32 in this inflow.
It is shown that some of the cavitation bubbles 36 in the inside are trapped and move.

The work arranged in front of the submersible nozzle device 10 in water is subjected to high-pressure jet water accompanied by the cavitation bubbles 36 from the submersible nozzle device 10 to clean and chip by the erosion effect of the cavitation bubbles 36. , Peeling,
Alternatively, deburring or the like is efficiently performed.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a front end portion of an underwater nozzle device.

FIG. 2 is a view of the front end portion of the submersible nozzle device as seen from the axial direction.

FIG. 3 is a diagram showing how cavitation bubbles are generated in a spiral groove.

FIG. 4 is a diagram showing how cavitation bubbles are led out by a transverse groove.

[Explanation of symbols]

10 Submerged Nozzle Device (Submerged Nozzle Device for Cavitation Bubble Generation) 12 Lance (Pipe) 14 Nozzle Tip (Nozzle Member) 16 Cap (Screw Member) 20 Tapered Part 22 Orifice (Injection Hole) 28 Expanded Cylindrical Hole ( Expanded columnar space) 30 Spiral groove (circumferential groove) 32 Transverse groove (outlet groove) 36 Cavitation bubble

Claims (4)

[Claims] 1. (a) Injection holes (22) for ejecting liquid, (b)
A diameter-expanded columnar space portion (2) that has a diameter larger than that of the injection hole (22) and is provided on the front side of the injection hole (22) and opens at the front end.
8), and (c) a circumferential groove (30) formed in the peripheral part of the expanded diameter columnar space (28) so as to extend in the circumferential direction of the expanded diameter columnar space (28). A submerged nozzle device for generating cavitation bubbles, characterized in that 2. (d) A lead-out groove formed in the peripheral portion of the expanded diameter columnar space portion (28) and extending in the axial direction of the expanded diameter columnar space portion (28) across the circumferential groove (30). 32), The submerged nozzle device for generating cavitation bubbles according to claim 1, characterized in that: 3. (e) Orifice (2) which is said injection hole (22)
2) and behind this orifice (22)
(22) A nozzle member (14) having a taper portion (20) whose diameter is gradually reduced toward (22), and (f) A screw member provided at the front end portion of the conduit body (12) having the enlarged diameter columnar space portion (28). Cavitation bubble generation according to claim 1 or 2, further comprising: a screwing member (16) for mounting the nozzle member (14) on the front end of the conduit body (12) while wearing the same. Liquid submerged nozzle device. 4. The submerged nozzle device for generating cavitation bubbles according to claim 1, wherein the circumferential groove (30) is a spiral groove (30).