CA2010083C - Cutting method and apparatus - Google Patents
Cutting method and apparatusInfo
- Publication number
- CA2010083C CA2010083C CA 2010083 CA2010083A CA2010083C CA 2010083 C CA2010083 C CA 2010083C CA 2010083 CA2010083 CA 2010083 CA 2010083 A CA2010083 A CA 2010083A CA 2010083 C CA2010083 C CA 2010083C
- Authority
- CA
- Canada
- Prior art keywords
- nozzle
- fluid
- cutting
- flow
- pressurized fluid
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 238000005520 cutting process Methods 0.000 title claims abstract description 54
- 238000000034 method Methods 0.000 title claims abstract description 29
- 239000012530 fluid Substances 0.000 claims abstract description 56
- 239000002245 particle Substances 0.000 claims abstract description 18
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 22
- 238000011144 upstream manufacturing Methods 0.000 claims description 5
- 239000002173 cutting fluid Substances 0.000 claims description 4
- 230000003247 decreasing effect Effects 0.000 claims 2
- 238000009826 distribution Methods 0.000 description 7
- 238000007796 conventional method Methods 0.000 description 4
- 239000007788 liquid Substances 0.000 description 4
- 229910052751 metal Inorganic materials 0.000 description 4
- 239000002184 metal Substances 0.000 description 4
- 238000002156 mixing Methods 0.000 description 4
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 3
- 239000012141 concentrate Substances 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 230000005764 inhibitory process Effects 0.000 description 3
- 229910010272 inorganic material Inorganic materials 0.000 description 3
- 239000011147 inorganic material Substances 0.000 description 3
- 230000007423 decrease Effects 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 229910052581 Si3N4 Inorganic materials 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 230000001154 acute effect Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000004568 cement Substances 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 239000002223 garnet Substances 0.000 description 1
- 238000000265 homogenisation Methods 0.000 description 1
- 229910003465 moissanite Inorganic materials 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 239000011435 rock Substances 0.000 description 1
- 229910010271 silicon carbide Inorganic materials 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24C—ABRASIVE OR RELATED BLASTING WITH PARTICULATE MATERIAL
- B24C5/00—Devices or accessories for generating abrasive blasts
- B24C5/02—Blast guns, e.g. for generating high velocity abrasive fluid jets for cutting materials
- B24C5/04—Nozzles therefor
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24C—ABRASIVE OR RELATED BLASTING WITH PARTICULATE MATERIAL
- B24C1/00—Methods for use of abrasive blasting for producing particular effects; Use of auxiliary equipment in connection with such methods
- B24C1/04—Methods for use of abrasive blasting for producing particular effects; Use of auxiliary equipment in connection with such methods for treating only selected parts of a surface, e.g. for carving stone or glass
- B24C1/045—Methods for use of abrasive blasting for producing particular effects; Use of auxiliary equipment in connection with such methods for treating only selected parts of a surface, e.g. for carving stone or glass for cutting
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B26—HAND CUTTING TOOLS; CUTTING; SEVERING
- B26F—PERFORATING; PUNCHING; CUTTING-OUT; STAMPING-OUT; SEVERING BY MEANS OTHER THAN CUTTING
- B26F3/00—Severing by means other than cutting; Apparatus therefor
- B26F3/004—Severing by means other than cutting; Apparatus therefor by means of a fluid jet
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- Forests & Forestry (AREA)
- Perforating, Stamping-Out Or Severing By Means Other Than Cutting (AREA)
Abstract
The present invention provides a novel method and apparatus for fluid cutting by ejecting a fluid by a Coanda spiral flow generated through a pressurized fluid. The apparatus comprises a rotatable and movable Coanda spiral flow generating nozzle having an annular slit for introducing a pressurized fluid transversely to a nozzle ejecting port and a curved wall running from said slit to said ejecting port. Cutting efficiency is greatly improved and wear resistance of a nozzle is excellent. When using hard cutting particles, they are uniformly dispersed throughout the fluid.
Description
`~ 1 2010083 CUTTING METHOD AND APPARATUS
F IELD OF THE INVENTION
The present invention relates to a method for cutting and an apparatus for the application thereof.
More particularly, the present invention relates to a method for jet cutting and an apparatus for the application thereof, which are excellent in cutting efficiency with a uniform cut surface and permit inhibition of production of burrs.
DESCRIPTION OF PRIOR ART
For cutting a metal object, a high temperature gas melting-cutting method using combustion flame of gas and a liquid jet cutting method adopted under conditions not permitting use of flame in taking a tank for storage of an oily material have conventionally been known.
For example, the liquid jet cutting method is popularly known as a water jet cutting method using high pressure water, and widely applied for cutting a steel sheet. This method is employed also in building sites where powder cannot be used for cutting or breaking rocks and concrete.
SUMMARY OF THE INVENTION
The present invention has an object to provide a novel jet cutting method based on a jet flow which eliminates the aforementioned defects in the conventional method.
Furthermore, the present invention has another object to provide a new apparatus for the application of said jet cutting method.
The present invention provides a method for jet cutting comprising performing cutting by ejecting a fluid by a Coanda spiral flow generated through introduction of a pressurized fluid.
A~
F IELD OF THE INVENTION
The present invention relates to a method for cutting and an apparatus for the application thereof.
More particularly, the present invention relates to a method for jet cutting and an apparatus for the application thereof, which are excellent in cutting efficiency with a uniform cut surface and permit inhibition of production of burrs.
DESCRIPTION OF PRIOR ART
For cutting a metal object, a high temperature gas melting-cutting method using combustion flame of gas and a liquid jet cutting method adopted under conditions not permitting use of flame in taking a tank for storage of an oily material have conventionally been known.
For example, the liquid jet cutting method is popularly known as a water jet cutting method using high pressure water, and widely applied for cutting a steel sheet. This method is employed also in building sites where powder cannot be used for cutting or breaking rocks and concrete.
SUMMARY OF THE INVENTION
The present invention has an object to provide a novel jet cutting method based on a jet flow which eliminates the aforementioned defects in the conventional method.
Furthermore, the present invention has another object to provide a new apparatus for the application of said jet cutting method.
The present invention provides a method for jet cutting comprising performing cutting by ejecting a fluid by a Coanda spiral flow generated through introduction of a pressurized fluid.
A~
Furthermore, as an apparatus for the application of the present method, the present invention provides an apparatus for jet cutting comprising a rotatable and movable Coanda spiral flow generating nozzle having an annular slit for introducing a pressurized fluid transversely to a nozzle ejecting port and a curved wall running from said slit to said ejecting port.
According to a still further broad aspect of the present invention, there is provided a method of jet cutting performed by ejecting a fluid. The method comprises transporting hard cutting particles by means of a first pressurized fluid flowing through a conduit having a conical nozzle at the downstream end thereof.
The diameter of the nozzle decreases in the downstream direction and the nozzle has an axially directed opening at its downstream end for the ejection of cutting fluid. The method is characterized in that pressurized fluid flowing initially towards the nozzle axis is introduced to the nozzle around the periphery of an upstream end of the nozzle to introduce a tangential component to the flow of the first pressurized fluid whereby a Coanda spiral flow of fluid having a high velocity in the downstream direction with the maximum downstream velocity on the axis, together with a Coanda layer near the nozzle inner wall, is produced.
According to a still further broad aspect of the present invention, there is provided a jet cutting apparatus comprising a conical nozzle having an axially directed opening for the ejection of cutting fluid at its downstream end through which fluid carrying cutting particles can flow. The nozzle diameter decreases in the downstream direction. The apparatus is characterized in that means is provided for introducing a pressurized fluid which flows initially towards the axis of the nozzle into the fluid flowing in use through the nozzle to introduce a tangential component A
_ _ 3 _ 2010~83 to the flow of fluid flowing in use through the nozzle provided around the periphery of an upstream end of the nozzle, thereby to generate a Coanda spiral flow of fluid having a high velocity in the downstream direction with the maximum downstream velocity on the axis in the fluid flowing through the nozzle, together with a Coanda layer near the nozzle inner wall.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a sectional view illustrating an embodiment of the nozzle of an apparatus of the present invention;
Figs. 2(a) and (b) are drawings illustrating velocity distributions of the jet flow in a method of the present invention and the conventional method, respectively; and Fig. 3 is a sectional view illustrating a conventional water jet cutting nozzle.
DESCRIPTION OF PRIOR ART
Referring to Fig. 3, there is illustrated a typical jet nozzle used for the liquid jet cutting method. High pressure water is introduced from a high-pressure water inlet (B) towards a nozzle exit (A), while introducing hard particles from a cutting particles inlet (C) provided transversely, and cutting is conducted by means of a jet flow ejected from the nozzle exit (A). Hard cutting particles may be omitted in this case.
While the jet cutting method is very useful as a cutting method applicable under conditions making it difficult to use fire, the conventional method and apparatus have several points to be improved.
More specifically, in the conventional method, the jet flow ejected from the nozzle exit (A) shown in Fig. 3 rapidly diffuses so that it is difficult to concentrate the jet flow onto the portion to be cut.
~`A
- 3a - 201 0083 Furthermore, a cut surface is apt to be uniform and production of burrs is inevitable. When using hard cutting particles, the nozzle inner wall suffers from seriously being worn.
These defects are inevitable in the generation of a jet flow based on the introduction of high-pressure water, and this naturally limits the applicability of the liquid jet cutting method. There has, therefore, been a strong demand for improvement of cutting efficiency, homogenization of a cut surface, inhibition of occurrence of burrs, and reduction of nozzle wear.
DETAILED DESCRIPTION OF THE INVENTION
The Coanda spiral flow used in the present invention was discovered by the present inventor as a state of movement different from a turbulent flow while being under the conditions of movement of a fluid belonging to the turbulent region, unlike the laminar flow or a turbulent flow known as the conventional ~ ;~010083 concept of fluid movement. A method for forming the Coanda spiral flow has already been proposed also by the present inventor.
More particularly, the Coanda spiral flow is a flow of a fluid which runs at a high velocity in the pipe direction while forming a spiral, and can be formed by adding a vector in the pipe radial direction to the flow vector of the fluid introduced in the pipe direction. In this case, a negative pressure having a strong sucking force is formed on the side opposite to the running direction of the Coanda spiral flow, and high velocity Coanda layer based on the spiral flow near the pipe inner wallis formed.
The present invention is to perform cuttlng of a metal, an inorganic material, cement or other solids by the use of the features of such a Coanda spiral flow. One of the most important things in using the present method is to concentrate velocity distribution on the running axis relative to the running direction of the Coanda spiral flow. This concentration is never observed in a conventional jet flow based on a turbulent flow. This concentration of velocity distribution permits improvement of cutting efficiency with a uniform cut surface and inhibition of burr occurrence.
Now, the present invention is described with reference to following.
Fig. 1 illustrates an embodiment of the present invention as a Coanda spiral flow generating nozzle.
The nozzle has bee developed for use in efficient mixing `-~ 2~ 083 of abrasive and for improved focusing of water jet streams in high pressure abrasive water ~et cutting applications. The development of the nozzle was based on the spiral flow theory.
To obtain a focused jet flow, the nozzle is designed with an annular slit connected to a conical cylinder. Pressurized fluid is supplied through this slit and the fluid, passing through the conical cylinder, is deformed to the spiral flow with the maximum axial flow on the axis, caused by Coanda effect and the instability of turbulence.
- In the embodiment shown in Fig. 1, for example, an annular slit ~3) for pressurizing and introducing a fluid such as water on a main cylinder (2) directed toward a nozzle exit (1), and this slit (3) is provided with a supply pipe (7) for supplying a pressurized fluid.
The main cylinder (2~ has a diameter becoming similarly and gradually larger from the nozzle exit (1) toward the slit (3) and a wall surface (5) of the main cylinder (2) is formed to be smoothly curved. The end opposite to the nozzle exit (1) is provided with an auxiliary cylinder (4) with an inlet (6) for a mixed flow of a fluid, or a fluid and hard cutting particles.
At the oppoiste side of the wall surface (5) opposite to the slit (3), a wall surface (8) of the auxiliary cylinder (4) is bent at right angles or at an acute angle.
The interval of the slit (3) may be ad~ustable. There is no particular limitation on the structure of the supply pipe (~) ~upplying a pressurized fluid. Furthermore, a distribution chamber (9), for example, may be provided for the purpose of 2~10083 ensuring uniform supply.
For the main cylinder (2), the inclination angle (~) should preferably be such that tan ~ is about 1/3 to 1/10.
In the Coanda spiral flow generating nozzle, a typical embodiment of which has been described above, pressurized water as a pressurized fluid may be introduced from the slit (3) into the main cylinder (2). This permits synthesis of the motion vector of the pressurized water and the motion vector of the fluid such as water and air from the inlet (6), thus forming a spiral motion (10). This spiral motion (10) brings about concentration of fluid velocity in the running axis direction, forming a high velocity concentrated flow, Since a Coanda layer is formed in the main cylinder (2), wear of the nozzle inner wall is inhibited even when hard cutting particles are mixed in a pressurized fluid. When mixing particles such as alumina, SiC, Si3N4, BN, WC, etc., their dispersion is homogenized.
The nozzle has been developed for use in efficient mixing of abrasive and for improved focusing of water jet streams in high pressure abrasive water jet cutting applications.
The jet stream is more stable and concentrates the particles to the axial area of the jet flow caused by the characteristics of a spiral jet. That is the maximum axial flow on the axis and a rotational flow around the axis.
In cutting, the pressure of the fluid such as water can be appropriately set, and any of metals, inorganic materials as alumina garnet, or the like may be used appropriately as hard cutting particles. It may not always be necessary to use those . _ . . . . .
2(~1008;~
hard cutting materials.
Pressurized fluid may be water or other fluid or a mixed li-quid. The object to be cut may be any of metals, inorganic materials and other solids.
Now, the present invention is described in more detail by means of examples as follows.
EXAMPL~ 1 The nozzle shown in Fig. 1 was used. An exit diameter of the nozzle was 19 m/m.
A distance of 50 m/m was provided between the nozzle exit and a sample, and a concrete wall as the sample was cut. In this case, water pressurized at 400 kgf/cm2 was ejected, without the use of hard cutting particles.
The sample was cut to a depth of 18 cm. Cutting was conducted by the conventional water jet method under the same conditions. The sample was cut only to a depth of 10 cm. The cut surface was rough and innumerous fine burrs occurring on it.
The cut width was more than twice as large as in the cutting by the Coanda spiral flow of lthe prsent invention.
Additionaly, when mixing of alumina particles, the cut depth increasedeven to about 26 m/m.
Velocity distribution of a jet flow from a nozzle of 8 mm was evaluated.
A velocity of 43 m/sec was set at a position of 4 cm from the nozzle tip, and comparison wa~ made with the conventional water jet.
Z~1008~
~_ .
Velocity distributions of the Coanda jet with pressurized water of 4.8 kgf/cm2 and the conventional water jet are shown in Figs. 2 (a) and (b).
As is clear from the comparison of velocity distribu-tion of 20 m/sec, i.e., expanses (~) of the velocity velocity concentration is far higher in the Coanda jet of the present invention than the conventional jet.
According to the present invention, as described above in detail, the following effects are available when performing cutt-ing with the use of a jet flow based on a Coanda spiral flow:
1) Since diffusion of the jet is smaller and the energy exerts its effect concentrically in the running direction, the cutting efficiency may be largely improved.
2) Wear resistance of the nozzle may be excellent.
3) Hard cutting particles may be uniformly dispersed throughout the fluid.
For these advantages, it may be possible to achieve far more useful method and apparatus for cutting than the conventional ones.
According to a still further broad aspect of the present invention, there is provided a method of jet cutting performed by ejecting a fluid. The method comprises transporting hard cutting particles by means of a first pressurized fluid flowing through a conduit having a conical nozzle at the downstream end thereof.
The diameter of the nozzle decreases in the downstream direction and the nozzle has an axially directed opening at its downstream end for the ejection of cutting fluid. The method is characterized in that pressurized fluid flowing initially towards the nozzle axis is introduced to the nozzle around the periphery of an upstream end of the nozzle to introduce a tangential component to the flow of the first pressurized fluid whereby a Coanda spiral flow of fluid having a high velocity in the downstream direction with the maximum downstream velocity on the axis, together with a Coanda layer near the nozzle inner wall, is produced.
According to a still further broad aspect of the present invention, there is provided a jet cutting apparatus comprising a conical nozzle having an axially directed opening for the ejection of cutting fluid at its downstream end through which fluid carrying cutting particles can flow. The nozzle diameter decreases in the downstream direction. The apparatus is characterized in that means is provided for introducing a pressurized fluid which flows initially towards the axis of the nozzle into the fluid flowing in use through the nozzle to introduce a tangential component A
_ _ 3 _ 2010~83 to the flow of fluid flowing in use through the nozzle provided around the periphery of an upstream end of the nozzle, thereby to generate a Coanda spiral flow of fluid having a high velocity in the downstream direction with the maximum downstream velocity on the axis in the fluid flowing through the nozzle, together with a Coanda layer near the nozzle inner wall.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a sectional view illustrating an embodiment of the nozzle of an apparatus of the present invention;
Figs. 2(a) and (b) are drawings illustrating velocity distributions of the jet flow in a method of the present invention and the conventional method, respectively; and Fig. 3 is a sectional view illustrating a conventional water jet cutting nozzle.
DESCRIPTION OF PRIOR ART
Referring to Fig. 3, there is illustrated a typical jet nozzle used for the liquid jet cutting method. High pressure water is introduced from a high-pressure water inlet (B) towards a nozzle exit (A), while introducing hard particles from a cutting particles inlet (C) provided transversely, and cutting is conducted by means of a jet flow ejected from the nozzle exit (A). Hard cutting particles may be omitted in this case.
While the jet cutting method is very useful as a cutting method applicable under conditions making it difficult to use fire, the conventional method and apparatus have several points to be improved.
More specifically, in the conventional method, the jet flow ejected from the nozzle exit (A) shown in Fig. 3 rapidly diffuses so that it is difficult to concentrate the jet flow onto the portion to be cut.
~`A
- 3a - 201 0083 Furthermore, a cut surface is apt to be uniform and production of burrs is inevitable. When using hard cutting particles, the nozzle inner wall suffers from seriously being worn.
These defects are inevitable in the generation of a jet flow based on the introduction of high-pressure water, and this naturally limits the applicability of the liquid jet cutting method. There has, therefore, been a strong demand for improvement of cutting efficiency, homogenization of a cut surface, inhibition of occurrence of burrs, and reduction of nozzle wear.
DETAILED DESCRIPTION OF THE INVENTION
The Coanda spiral flow used in the present invention was discovered by the present inventor as a state of movement different from a turbulent flow while being under the conditions of movement of a fluid belonging to the turbulent region, unlike the laminar flow or a turbulent flow known as the conventional ~ ;~010083 concept of fluid movement. A method for forming the Coanda spiral flow has already been proposed also by the present inventor.
More particularly, the Coanda spiral flow is a flow of a fluid which runs at a high velocity in the pipe direction while forming a spiral, and can be formed by adding a vector in the pipe radial direction to the flow vector of the fluid introduced in the pipe direction. In this case, a negative pressure having a strong sucking force is formed on the side opposite to the running direction of the Coanda spiral flow, and high velocity Coanda layer based on the spiral flow near the pipe inner wallis formed.
The present invention is to perform cuttlng of a metal, an inorganic material, cement or other solids by the use of the features of such a Coanda spiral flow. One of the most important things in using the present method is to concentrate velocity distribution on the running axis relative to the running direction of the Coanda spiral flow. This concentration is never observed in a conventional jet flow based on a turbulent flow. This concentration of velocity distribution permits improvement of cutting efficiency with a uniform cut surface and inhibition of burr occurrence.
Now, the present invention is described with reference to following.
Fig. 1 illustrates an embodiment of the present invention as a Coanda spiral flow generating nozzle.
The nozzle has bee developed for use in efficient mixing `-~ 2~ 083 of abrasive and for improved focusing of water jet streams in high pressure abrasive water ~et cutting applications. The development of the nozzle was based on the spiral flow theory.
To obtain a focused jet flow, the nozzle is designed with an annular slit connected to a conical cylinder. Pressurized fluid is supplied through this slit and the fluid, passing through the conical cylinder, is deformed to the spiral flow with the maximum axial flow on the axis, caused by Coanda effect and the instability of turbulence.
- In the embodiment shown in Fig. 1, for example, an annular slit ~3) for pressurizing and introducing a fluid such as water on a main cylinder (2) directed toward a nozzle exit (1), and this slit (3) is provided with a supply pipe (7) for supplying a pressurized fluid.
The main cylinder (2~ has a diameter becoming similarly and gradually larger from the nozzle exit (1) toward the slit (3) and a wall surface (5) of the main cylinder (2) is formed to be smoothly curved. The end opposite to the nozzle exit (1) is provided with an auxiliary cylinder (4) with an inlet (6) for a mixed flow of a fluid, or a fluid and hard cutting particles.
At the oppoiste side of the wall surface (5) opposite to the slit (3), a wall surface (8) of the auxiliary cylinder (4) is bent at right angles or at an acute angle.
The interval of the slit (3) may be ad~ustable. There is no particular limitation on the structure of the supply pipe (~) ~upplying a pressurized fluid. Furthermore, a distribution chamber (9), for example, may be provided for the purpose of 2~10083 ensuring uniform supply.
For the main cylinder (2), the inclination angle (~) should preferably be such that tan ~ is about 1/3 to 1/10.
In the Coanda spiral flow generating nozzle, a typical embodiment of which has been described above, pressurized water as a pressurized fluid may be introduced from the slit (3) into the main cylinder (2). This permits synthesis of the motion vector of the pressurized water and the motion vector of the fluid such as water and air from the inlet (6), thus forming a spiral motion (10). This spiral motion (10) brings about concentration of fluid velocity in the running axis direction, forming a high velocity concentrated flow, Since a Coanda layer is formed in the main cylinder (2), wear of the nozzle inner wall is inhibited even when hard cutting particles are mixed in a pressurized fluid. When mixing particles such as alumina, SiC, Si3N4, BN, WC, etc., their dispersion is homogenized.
The nozzle has been developed for use in efficient mixing of abrasive and for improved focusing of water jet streams in high pressure abrasive water jet cutting applications.
The jet stream is more stable and concentrates the particles to the axial area of the jet flow caused by the characteristics of a spiral jet. That is the maximum axial flow on the axis and a rotational flow around the axis.
In cutting, the pressure of the fluid such as water can be appropriately set, and any of metals, inorganic materials as alumina garnet, or the like may be used appropriately as hard cutting particles. It may not always be necessary to use those . _ . . . . .
2(~1008;~
hard cutting materials.
Pressurized fluid may be water or other fluid or a mixed li-quid. The object to be cut may be any of metals, inorganic materials and other solids.
Now, the present invention is described in more detail by means of examples as follows.
EXAMPL~ 1 The nozzle shown in Fig. 1 was used. An exit diameter of the nozzle was 19 m/m.
A distance of 50 m/m was provided between the nozzle exit and a sample, and a concrete wall as the sample was cut. In this case, water pressurized at 400 kgf/cm2 was ejected, without the use of hard cutting particles.
The sample was cut to a depth of 18 cm. Cutting was conducted by the conventional water jet method under the same conditions. The sample was cut only to a depth of 10 cm. The cut surface was rough and innumerous fine burrs occurring on it.
The cut width was more than twice as large as in the cutting by the Coanda spiral flow of lthe prsent invention.
Additionaly, when mixing of alumina particles, the cut depth increasedeven to about 26 m/m.
Velocity distribution of a jet flow from a nozzle of 8 mm was evaluated.
A velocity of 43 m/sec was set at a position of 4 cm from the nozzle tip, and comparison wa~ made with the conventional water jet.
Z~1008~
~_ .
Velocity distributions of the Coanda jet with pressurized water of 4.8 kgf/cm2 and the conventional water jet are shown in Figs. 2 (a) and (b).
As is clear from the comparison of velocity distribu-tion of 20 m/sec, i.e., expanses (~) of the velocity velocity concentration is far higher in the Coanda jet of the present invention than the conventional jet.
According to the present invention, as described above in detail, the following effects are available when performing cutt-ing with the use of a jet flow based on a Coanda spiral flow:
1) Since diffusion of the jet is smaller and the energy exerts its effect concentrically in the running direction, the cutting efficiency may be largely improved.
2) Wear resistance of the nozzle may be excellent.
3) Hard cutting particles may be uniformly dispersed throughout the fluid.
For these advantages, it may be possible to achieve far more useful method and apparatus for cutting than the conventional ones.
Claims (6)
1. A method of jet cutting performed by ejecting a fluid, comprising:
transporting hard cutting particles by means of a first pressurized fluid flowing through a conduit having a conical nozzle at the downstream end thereof, the diameter of the nozzle decreasing in the downstream direction and the nozzle having an axially directed opening at its downstream end for the ejection of cutting fluid; and characterized in that it further comprises:
introducing pressurized fluid flowing initially towards the nozzle axis into the nozzle around the periphery of an upstream end of the nozzle to introduce a tangential component to the flow of the first pressurized fluid, whereby a Coanda spiral flow of fluid having a high velocity in the downstream direction with the maximum downstream velocity on the axis, together with a Coanda layer near the nozzle inner wall, is produced.
transporting hard cutting particles by means of a first pressurized fluid flowing through a conduit having a conical nozzle at the downstream end thereof, the diameter of the nozzle decreasing in the downstream direction and the nozzle having an axially directed opening at its downstream end for the ejection of cutting fluid; and characterized in that it further comprises:
introducing pressurized fluid flowing initially towards the nozzle axis into the nozzle around the periphery of an upstream end of the nozzle to introduce a tangential component to the flow of the first pressurized fluid, whereby a Coanda spiral flow of fluid having a high velocity in the downstream direction with the maximum downstream velocity on the axis, together with a Coanda layer near the nozzle inner wall, is produced.
2. A method as claimed in claim 1, wherein the pressurized fluid flowing initially towards the nozzle axis is introduced by means of an annular slit in the wall of the nozzle.
3. A method as claimed in claim 1 or 2, wherein the pressurized fluid is water and hard cutting particles are ejected.
4. Jet cutting apparatus comprising a conical nozzle having an axially directed opening for the ejection of cutting fluid at its downstream end through which fluid carrying cutting particles can flow, the nozzle diameter decreasing in the downstream direction;
and characterized in that:
means for introducing a pressurized fluid which flows initially towards the axis of the nozzle into the fluid flowing in use through the nozzle to introduce a tangential component to the flow of fluid, flowing in use through the nozzle is provided around the periphery of an upstream end of the nozzle, thereby to generate a Coanda spiral flow of fluid having a high velocity in the downstream direction with the maximum downstream velocity on the axis in said fluid flowing through said nozzle, together with a Coanda layer near the nozzle inner wall.
and characterized in that:
means for introducing a pressurized fluid which flows initially towards the axis of the nozzle into the fluid flowing in use through the nozzle to introduce a tangential component to the flow of fluid, flowing in use through the nozzle is provided around the periphery of an upstream end of the nozzle, thereby to generate a Coanda spiral flow of fluid having a high velocity in the downstream direction with the maximum downstream velocity on the axis in said fluid flowing through said nozzle, together with a Coanda layer near the nozzle inner wall.
5. Apparatus as claimed in claim 4, wherein the means for introducing a pressurized fluid comprises an annular slit through which said pressurized fluid can be introduced into said fluid flow.
6. Apparatus as claimed in claim 4 or S, wherein the nozzle is attached to a conduit which conveys the fluid flowing in use through the nozzle to the upstream end of the nozzle, the nozzle being movable and rotatable about the downstream end of the conduit, whereby the ejected fluid can be directed.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3449289A JPH02218600A (en) | 1989-02-14 | 1989-02-14 | Grinding/cutting method and device thereof |
| JP34,492/1989 | 1989-02-14 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2010083A1 CA2010083A1 (en) | 1990-08-14 |
| CA2010083C true CA2010083C (en) | 1996-04-23 |
Family
ID=12415745
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2010083 Expired - Fee Related CA2010083C (en) | 1989-02-14 | 1990-02-14 | Cutting method and apparatus |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0383556B1 (en) |
| JP (1) | JPH02218600A (en) |
| CA (1) | CA2010083C (en) |
| DE (1) | DE69011357T2 (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100504629B1 (en) | 1997-07-11 | 2005-08-03 | 워터제트 테크놀로지 인코퍼레이티드 | Method and apparatus for producing a high-velocity particle stream |
| DE69809053T2 (en) * | 1997-07-11 | 2003-06-18 | Waterjet Technology, Inc. | METHOD AND DEVICE FOR GENERATING A HIGH-SPEED PARTICLE FLOW |
| JP2010120138A (en) * | 2008-11-21 | 2010-06-03 | Hitachi Constr Mach Co Ltd | Particle blasting nozzle |
| CN102380829B (en) * | 2010-08-31 | 2015-11-18 | 鸿富锦精密工业（深圳）有限公司 | The method of sand blasting unit and formation pattern |
| EP2859996B1 (en) | 2013-10-09 | 2017-11-15 | Tomás Fernández | Device for producing a liquid jet for machining workpieces, especially for cutting |
| CN105058245B (en) * | 2015-07-23 | 2017-02-22 | 长春理工大学 | An abrasive flow ultra-precision machining device |
-
1989
- 1989-02-14 JP JP3449289A patent/JPH02218600A/en active Pending
-
1990
- 1990-02-14 DE DE1990611357 patent/DE69011357T2/en not_active Expired - Fee Related
- 1990-02-14 CA CA 2010083 patent/CA2010083C/en not_active Expired - Fee Related
- 1990-02-14 EP EP90301539A patent/EP0383556B1/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| DE69011357D1 (en) | 1994-09-15 |
| EP0383556A1 (en) | 1990-08-22 |
| EP0383556B1 (en) | 1994-08-10 |
| DE69011357T2 (en) | 1994-12-15 |
| CA2010083A1 (en) | 1990-08-14 |
| JPH02218600A (en) | 1990-08-31 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101835561B (en) | For cutting head and the cutting nozzles of liquid/abrasive jet cutter sweep | |
| US4253610A (en) | Abrasive blast nozzle | |
| US6283833B1 (en) | Method and apparatus for producing a high-velocity particle stream | |
| US4648215A (en) | Method and apparatus for forming a high velocity liquid abrasive jet | |
| US6168503B1 (en) | Method and apparatus for producing a high-velocity particle stream | |
| US5184434A (en) | Process for cutting with coherent abrasive suspension jets | |
| EP1702735A1 (en) | Method and apparatus for fluid jet formation | |
| CA1231235A (en) | Method and apparatus for forming a high velocity liquid abrasive jet | |
| JPH04260427A (en) | Dispersion in pipe of gas into liquid | |
| CA2010083C (en) | Cutting method and apparatus | |
| JP3343371B2 (en) | Cavitation injection device | |
| CA1199799A (en) | High pressure abrasive-fluid jet mixing and accelerating nozzle for cutting and drilling hard material | |
| JPH054199A (en) | Chopping/cutting method and device | |
| JPH071398A (en) | Machining and cutting method and device thereof | |
| JPS62251075A (en) | Method and device for blasting by coanda slit flow | |
| MXPA00000434A (en) | Method and apparatus for producing a high-velocity particle stream |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKLA | Lapsed |