EP0383556B1 - Schneidverfahren und Vorrichtung - Google Patents

Schneidverfahren und Vorrichtung Download PDF

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Publication number
EP0383556B1
EP0383556B1 EP90301539A EP90301539A EP0383556B1 EP 0383556 B1 EP0383556 B1 EP 0383556B1 EP 90301539 A EP90301539 A EP 90301539A EP 90301539 A EP90301539 A EP 90301539A EP 0383556 B1 EP0383556 B1 EP 0383556B1
Authority
EP
European Patent Office
Prior art keywords
nozzle
fluid
cutting
flow
downstream
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 - Lifetime
Application number
EP90301539A
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English (en)
French (fr)
Other versions
EP0383556A1 (de
Inventor
Kiyoshi Horii
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
E C CHEMICAL IND. CO., LTD.
Original Assignee
E C CHEMICAL IND Co Ltd
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Filing date
Publication date
Application filed by E C CHEMICAL IND Co Ltd filed Critical E C CHEMICAL IND Co Ltd
Publication of EP0383556A1 publication Critical patent/EP0383556A1/de
Application granted granted Critical
Publication of EP0383556B1 publication Critical patent/EP0383556B1/de
Anticipated expiration legal-status Critical
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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

Definitions

  • 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.
  • the liquid jet cutting method is popularly known as a water jet cutting method using high pressure water, and is widely applied for cutting steel sheet. This method is employed also in building sites where powder cannot be used for cutting or breaking rocks and concrete.
  • FIG. 3 A typical jet nozzle used for the liquid jet cutting method is illustrated in Fig. 3.
  • High pressure water is introduced from a high-pressure water inlet (B) toward 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.
  • 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. Furthermore, a cut surface is apt to be ununiform and production of burrs is inevitable. When using hard cutting particles, the nozzle inner wall suffers seriously from being worn.
  • SU-A-1 245 349 discloses a nozzle which produces a spiral jet flow which offers some improvements and the preambles of claims 1 and 5 are based on this document.
  • the present invention has an object to provide a novel jet cutting method based on a jet flow which avoids at least some of the aforementioned defects in the conventional method.
  • 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 of jet cutting performed by ejecting a fluid, comprising: transporting hard cutting particles by means of a first pressurised 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 pressurised 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 pressurised 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.
  • the pressurised fluid is introduced through an annular slit in the nozzle and the inner wall of the nozzle is convexly curved at least from where the pressurised fluid is introduced towards the nozzle exit.
  • the pressurised fluid is water and the ejected fluid contains hard cutting particles.
  • the present invention provides 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 pressurised 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.
  • the nozzle has an annular slit for introducing the pressurized fluid transversely to the nozzle ejecting port and a curved wall running from said slit to said ejecting port.
  • the upstream end of the nozzle is attached to a conduit for conveying the fluid, and the nozzle is movable and rotatable about the downstream end of the conduit, such that the ejected fluid can be directed.
  • 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 the turbulent region, unlike the laminar flow or a turbulent flow known as the conventional concept of fluid movement.
  • a method for forming the Coanda spiral flow has already been proposed also by the present inventor.
  • the Coanda spiral flow as defined herein 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.
  • a negative pressure having a strong sucking force is formed on the side opposite to the running direction of the Coanda sprial flow, and high velocity Coanda layer based on the spiral flow near the pipe inner wall is formed.
  • the present invention may perform cutting 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 and apparatus is to concentrate velocity distribution on the running axis relative to the running direction of the Coanda sprial 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.
  • Fig. 1 illustrates an embodiment of the present invention as a Coanda spiral flow generating nozzle which 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 development of the nozzle was based on the spiral flow theory.
  • the nozzle is designed with an annular slit connected to a generally conical tube. Pressurized fluid is supplied through this slit and the fluid, passing through the generally conical tube, is deformed to the spiral flow with the maximum axial flow on the axis, caused by Coanda effect and the instability of turbulence.
  • annular slit (3) for pressurizing and introducing a fluid such as water on a main tube (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.
  • 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 adjustable.
  • a distribution chamber (9), for example, may be provided for the purpose of ensuring uniform supply.
  • the inclination angle ( ⁇ ) should preferably be such that tan ⁇ is about 1/3 to 1/10.
  • pressurized water as a pressurized fluid may be introduced from the slit (3) into the main cylinder (2).
  • 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 in at least preferred embodiments 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.
  • the pressure of the fluid such as water can be appropriately set, and any of metals, inorganic materials such as alumina garnet, or the like may be used appropriately as hard cutting particles. It may not always be necessary to use those hard cutting materials.
  • Pressurized fluid may be water or other fluid or a mixed liquid.
  • the object to be cut may be any of metals, inorganic materials and other solids.
  • the nozzle shown in Fig. 1 was used.
  • An exit diameter of the nozzle was 19 mm.
  • a distance of 50 mm was provided between the nozzle exit and a sample, and a concrete wall as the sample was cut.
  • 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 with 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 the present embodiment.
  • the cut depth increased even to about 26 cm.
  • a velocity of 43 m/sec was set at a position of 4 cm from the nozzle tip, and comparison was made with the conventional water jet.
  • Velocity distributions of an embodiment 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).
  • velocity concentration is far higher in the Coanda jet of the present embodiment than the conventional jet.

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  • 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)

Claims (6)

  1. Verfahren zum Strahlschneiden, durchgeführt durch Ausstoßen eines Fluids, umfassend:
    Fördern harter Schneidpartikel mittels eines ersten Druckfluids, das durch eine Leitung (4) mit einer konischen Düse an ihrem stromabwärtigen Ende fließt, wobei der Durchmesser der Düse in die stromabwärtige Richtung abnimmt und die Düse an ihrem stromabwärtigen Ende eine axial gerichtete Öffnung (1) zum Ausstoßen des Schneidfluids aufweist; und
    dadurch gekennzeichnet, daß es weiter umfaßt:
    Einführen von Druckfluid, das anfänglich um den Umfang eines stromaufwärtigen Endes der Düse zu der Düsenachse in die Düse fließt, um eine Tangentialkomponente zu dem Fluß des ersten Druckfluids einzuführen, wodurch ein Coandaspiralfluß aus Fluid mit einer hohen Geschwindigkeit in der stromabwärtigen Richtung mit der maximalen Stromabwärtsgeschwindigkeit auf der Achse zusammen mit einer Coandaschicht nahe der Düseninnenwand erzeugt wird.
  2. Verfahren nach Anspruch 1, in dem das anfänglich zu der Düsenachse fließende Druckfluid mittels eines Ringschlitzes (3) in der Wand (5) der Düse eingeführt wird.
  3. Verfahren nach Anspruch 1 oder 2, in dem das Druckfluid Wasser ist und harte Schneidpartikel ausgestoßen werden.
  4. Strahlschneidvorrichtung, umfassend eine konische Düse mit einer axial gerichteten Öffnung (1) zum Ausstoßen eines Schneidfluids an ihrem stromabwärtigen Ende, durch die Schneidpartikel führendes Fluid fließen kann, wobei der Düsendurchmesser in die stromabwärtige Richtung abnimmt, und dadurch gekennzeichnet, daß:
    um den Umfang eines stromaufwärtigen Endes der Düse ein Mittel (3) zum Einführen eines Druckfluids vorgesehen ist, welches anfänglich zu der Achse der Düse in das bei Verwendung durch die Düse fließende Fluid fließt, um zu dem Fluß des bei Verwendung durch die Düse fließenden Fluids eine Tangentialkomponente einzuführen, um hierdurch einen Coandaspiralfluß von Fluid mit einer hohen Geschwindigkeit in der stromabwärtigen Richtung mit der maximalen Stromabwärtsgeschwindigkeit auf der Achse in dem durch die Düse fließenden Fluid zusammen mit einer Coandaschicht nahe der Düseninnenwand zu erzeugen.
  5. Vorrichtung nach Anspruch 4, in der das Mittel (3) zum Einführen eines Druckfluids einen Ringschlitz aufweist, durch den das Druckfluid in den Fluidfluß eingeführt werden kann.
  6. Vorrichtung nach Anspruch 4 oder 5, in dem die Düse an einer Leitung (4) angebracht ist, die das bei Verwendung durch die Düse fließende Fluid zu dem stromaufwärtigen Ende der Düse fördert, wobei die Düse um das stromabwärtige Ende der Leitung beweglich und drehbar ist, wodurch das ausgeworfene Fluid ausgerichtet werden kann.
EP90301539A 1989-02-14 1990-02-14 Schneidverfahren und Vorrichtung Expired - Lifetime EP0383556B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP34492/89 1989-02-14
JP3449289A JPH02218600A (ja) 1989-02-14 1989-02-14 切削・切断方法とその装置

Publications (2)

Publication Number Publication Date
EP0383556A1 EP0383556A1 (de) 1990-08-22
EP0383556B1 true EP0383556B1 (de) 1994-08-10

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EP90301539A Expired - Lifetime EP0383556B1 (de) 1989-02-14 1990-02-14 Schneidverfahren und Vorrichtung

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EP (1) EP0383556B1 (de)
JP (1) JPH02218600A (de)
CA (1) CA2010083C (de)
DE (1) DE69011357T2 (de)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1096336C (zh) 1997-07-11 2002-12-18 水力喷射技术公司 产生高速颗粒流的方法和装置
KR100504629B1 (ko) 1997-07-11 2005-08-03 워터제트 테크놀로지 인코퍼레이티드 고속 입자 스트림을 생성하기 위한 방법 및 장치
JP2010120138A (ja) * 2008-11-21 2010-06-03 Hitachi Constr Mach Co Ltd 粒子噴射ノズル
CN102380829B (zh) * 2010-08-31 2015-11-18 鸿富锦精密工业（深圳）有限公司 喷砂装置及形成图案的方法
HUE038353T2 (hu) 2013-10-09 2018-10-29 Tomas Fernandez Szerkezet folyadéksugár létrehozására munkadarabok megmunkálásához, fõként vágásához
CN105058245B (zh) * 2015-07-23 2017-02-22 长春理工大学 一种磨粒流超精密加工装置

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SU1245349A1 (ru) * 1984-12-19 1986-07-23 Владимирский политехнический институт Сопло дл получени режущей струи жидкости

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
SOVIET INVENTIONS ILLUSTRATED, P,Q, sections, week 8710, April 22, 1987 DERWENT PUBLICATIONS LTD. London P 42 *SU-1245-349 (WLADIMIR POLY)* & SU-A-1245349 (POLY). *

Also Published As

Publication number Publication date
JPH02218600A (ja) 1990-08-31
DE69011357T2 (de) 1994-12-15
CA2010083C (en) 1996-04-23
EP0383556A1 (de) 1990-08-22
CA2010083A1 (en) 1990-08-14
DE69011357D1 (de) 1994-09-15

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