Abrasive jet cutting head system

Abstract

An abrasive jet cutting head system (apparatus and method) is disclosed in which abrasive is introduced into a liquid jet at two or more locations and / or dispersed prior to encountering the liquid jet, resulting in a more efficient cutting head system having a longer life.

Description

[0001] Cross-reference to related applications This application does not claim priority from any other application. Technical Field

[0002] This invention relates to an abrasive jet cutting head system (apparatus and method) for use with a high-speed abrasive liquid jet cutting device. Background Technology

[0003] For many years, high-speed liquid jets filled with abrasive have been used to precisely cut a wide variety of materials. A high-speed liquid jet is formed by compressing a liquid (usually water) and forcing it through an orifice with a very small diameter, then entraining the abrasive particles within the liquid. Due to the high pressure, the need to maintain realistic edges, and heat dissipation, certain dense materials are used to define the water jet orifice; these materials are, for example, hard gemstones such as sapphire, ruby, or diamond. Abrasive jet machining (“AJM”) is also known as abrasive microjetting, pencil blasting, and microjetting, all of which are used in a variety of abrasive cutting processes.

[0004] The enhanced cutting capability achieved by entraining the abrasive into the liquid jet can be effectively used to cut a variety of particularly hard materials, such as armor plates, cast iron, steel, ceramics, and bulletproof glass.

[0005] As understood by those skilled in the art, the use of abrasive materials in high-pressure liquid jets not only creates large cutting tools but also generates significant abrasive wear on both the tool and the abrasive jet nozzle itself. This leads to a shortened tool or cutting head life and has prompted those skilled in the art to seek more effective and efficient methods for introducing abrasives into liquid jets to balance cutting performance with improved wear resistance.

[0006] Therefore, the object of embodiments of the present invention is to provide an abrasive jet cutting head system that introduces abrasive into the liquid flow more effectively and efficiently, thereby reducing tool wear, which increases nozzle life and the economic efficiency of embodiments of the present invention.

[0007] Embodiments of the present invention provide a system that replaces the prior art by introducing abrasive into a liquid jet at one location. The present invention discloses a system (apparatus and method) wherein abrasive is introduced into and / or dispersed in a liquid jet at two or more locations. These embodiments of the present invention have the advantage of providing tool life of up to 25% or more, while increasing cutting speed and reducing power requirements.

[0008] Other objects, features, and advantages of the invention will become apparent from the description, claims, and the accompanying drawings, which form a part of the description. In achieving the objects of the invention, it should be understood that its essential features are readily adaptable to changes in design and structural arrangement; therefore, only one practical and preferred embodiment is shown in the drawings as needed. Attached Figure Description

[0009] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings.

[0010] Figure 1 This is a front cross-sectional view of an embodiment of the present invention, showing an abrasive jet cutting system; Figure 2 This is a partial cross-sectional front view of an embodiment of the present invention; Figure 3 This is a partial cross-sectional front view of an embodiment of the present invention; Figure 4 This is a partial cross-sectional front view of an embodiment of the present invention; and Figure 5 This is a front cross-sectional view of an embodiment of the present invention. Detailed Implementation

[0011] Many of the fastening, connecting, manufacturing, and other devices and components used in this invention are widely known and used in the field of this invention, and their exact nature or type is not essential for those skilled in the art or science to understand and use this invention; therefore, they will not be discussed in great detail. Furthermore, various components shown or described herein for any particular application of this invention may vary or be modified as contemplated by the invention, and the practice of any particular application or embodiment of any element may be widely known or used by those skilled in the art or science; therefore, each will not be discussed in great detail.

[0012] The terms “a,” “an,” and “the” used in the claims herein are based on long-standing claims drafting practices and are not used in a restrictive manner. Unless specifically stated herein, the terms “a,” “an,” and “the” are not limited to one of these elements, but rather mean “at least one.”

[0013] In most applications, a jet of water or other suitable liquid is formed by first pressurizing a liquid (typically water) to 3,000 to 150,000 psig, and then supplying the liquid to a sharp-edged orifice through a pipe or channel constructed to facilitate the movement of the liquid. The orifice diameter is typically in the range of approximately 0.003 inches to 0.060 inches. The resulting laminar liquid jet moving from the pipe through the sharp-edged orifice converts the energy stored as pressure into a small amount of heat and kinetic energy in the flow velocity-mass. Such a flow can reach speeds exceeding three times the speed of sound, or exceeding 3,000 fpm (feet per minute).

[0014] Because the abrasive material is subjected to a high-speed liquid flow, the abrasive travels at extremely high speeds, making each abrasive particle a tool capable of cutting almost any material. Garnet is the most widely used abrasive material for abrasive jet applications.

[0015] A high-speed liquid jet is conveyed through a mixing chamber, which is also a Venturi tube. The Venturi tube generates a vacuum that draws the abrasive into the jet's region; this is sometimes referred to as abrasive entrainment into the liquid jet. Typically, the Venturi effect will result in a vacuum of 20 to 40 inches of mercury being applied to the abrasive supply tube.

[0016] Most abrasive jet cutting heads introduce abrasive into a liquid jet within a region commonly known as the mixing chamber. The abrasive enters the mixing chamber laterally to the jet flow and moves rapidly through the mixing chamber as it reaches the velocity required to produce a cutting action. While traveling through the mixing chamber, it then enters the abrasive jet nozzle along with the liquid jet. The abrasive flow tends to remain a single, downward flow with the liquid jet, but it follows a spiral path as it travels through the abrasive jet nozzle.

[0017] A liquid jet (carrying abrasive) enters the path through an abrasive jet nozzle, which is positioned during operation to impact some workpiece or material to be cut. The passage of the abrasive and liquid at high speed and pressure causes extreme wear on components such as the abrasive supply pipe, mixing chamber, orifice, and abrasive jet nozzle. This is done when it becomes apparent that these components have become excessively worn and must be replaced or replaced (as wear hinders the effectiveness of the abrasive jet in cutting the desired workpiece or material).

[0018] Embodiments of the present invention may use a typical abrasive jet cutting head structure that uses high-pressure water entering through an orifice to form a longitudinal binder liquid flow, into which abrasive is introduced in a region called a mixing chamber.

[0019] In some embodiments of the invention, the cutting head assembly includes novel constructions and methods for introducing abrasive into a jet stream within a mixing chamber region. In some embodiments of the invention, eliminating individual abrasive jets and dispersing the abrasive by generating multiple abrasive jets before entering the entrainment region reduces the necessary grinding rate and decreases wear on various components of the cutting head, including but not limited to nozzles, mixing chambers, conduits, or orifices. Those skilled in the art will understand that the novel constructions and methods in the embodiments of the invention will also increase cutting speed.

[0020] Embodiments of the present invention address known key factors of effectiveness and efficiency in abrasive jet cutting heads, namely, the importance of most effectively introducing abrasive material into the water jet and utilizing the water jet to introduce the abrasive material. This is demonstrated in direct jets, where the abrasive is suspended in the liquid prior to jet formation. The quality of cutting speed and cutting area is achieved by utilizing 20% ​​of the pressure of the abrasive jet.

[0021] Embodiments of the present invention may include an abrasive jet cutting head assembly having a body with a longitudinally extending through-channel extending about a longitudinal axis between upstream and downstream regions of the cutting head. A sharp-edged orifice at the inlet generates an axially centered coherent flow to deliver the length through the cutting head assembly. In the region above the entrainment region, the water jet is protected by jet protection by being conveyed through a jet protection channel. Upon exiting the protected region, the jet is introduced into the entrainment region, referred to in the present abrasive jet cutting head as a mixing chamber region, which is dispersed around the axially positioned liquid jet. The mixing chamber region is also a venturi tube to facilitate the flow of abrasive material into the liquid or water stream to be introduced.

[0022] By introducing abrasive into the jet in a dispersed manner, cutting efficiency is improved, in some cases by as much as 20% to 25% or more.

[0023] Figure 1 This is a front cross-sectional view of an embodiment of the present invention, showing an abrasive jet head cutting system 100 having a cutting head body 140 that holds or aligns the upper portion 118, the water jet guard 108, the orifice mount 101, and the lower portion 117. The entrainment area may be in the upper and / or lower portion (nozzle portion).

[0024] The lower part 117, also known as an abrasive jet nozzle, includes a longitudinal channel 103, a nozzle body 102, and a discharge port 104 at the lower end or outlet end. Figure 1Also shown are an orifice 105, a longitudinal jet channel 106, an abrasive inlet region 107, and an entrainment region 110 (which extends conically into the nozzle portion, as shown). The longitudinal jet channel 106 partially protects the water jet as it passes the abrasive inlet point, thus maintaining jet integrity. In embodiments of the invention, the water jet flows almost linearly into the longitudinal channel of the abrasive jet nozzle until it exits the working end of the abrasive jet nozzle.

[0025] The entrainment region 110 is the area entrained in the liquid before the abrasive is carried through the longitudinal channel 103 in the abrasive jet nozzle 102. Figure 1 A high-pressure water source 133 operatively connected to orifice 105 is also schematically shown. Note that the various parts can be combined in a manner most suitable for manufacture, operation, and / or service.

[0026] Figure 2 This is a partial front sectional view of an embodiment of the present invention, showing an abrasive jet head cutting system 100, which has a cutting head body 140 ( Figure 1 (as shown), abrasive jet nozzle 102, abrasive channel 124 and discharge port 104. Figure 2 Also shown are orifice 105, jet longitudinal channel 106, abrasive inlet region 107, jet guard 108, abrasive dispersion element 112 (abrasive dispersion geometry element, ridge, thread or protrusion) and entrainment region 110. Figure 2 A further example of an embodiment of the invention is shown, which utilizes a dispersing body that disperses the abrasive flow so that the abrasive flow enters the entrainment region, the abrasive flow being distributed as uniformly as possible around an annulus serving as the entrance to the entrainment region 110. The abrasive is then entrained as uniformly as possible by liquid jets from all lateral directions.

[0027] Figure 3 This is a partial front sectional view of an embodiment of the present invention, showing an abrasive jet head cutting system 100, the system having a cutting head body 140 ( Figure 1 (as shown), abrasive jet nozzle 102 and abrasive jet discharge port 104. Figure 3 Also shown are orifice 105, jet longitudinal channel 106, abrasive inlet region 107, jet guard 108, entrainment region 110, first abrasive dispersion orifice 115, second abrasive dispersion orifice 116, and abrasive inlet 113 (which supplies / provides abrasive material to both the first abrasive dispersion orifice 115 and the second abrasive dispersion orifice 116). More of these abrasive passages, channels, or orifices can be added as needed to achieve the desired level of abrasive distribution or dispersion.

[0028] Figure 3The invention illustrates the use of multiple channels or orifices (115 and 116) to disperse the abrasive flow, which convey the abrasive from the abrasive inlet 113 to the entrainment region 110. Embodiments of the invention are not limited to two channels, passages, or orifices 115 and 116, but may include more such channels, orifices, or passages as needed.

[0029] Figure 4 These are partial cross-sectional front views and partial schematic diagrams of embodiments of the present invention, showing an abrasive jet head cutting system 100, which has a cutting head body 140 ( Figure 1 (as shown), abrasive jet nozzle 102 and abrasive jet discharge port 104. Figure 4 Further shown are the orifice 105, the jet longitudinal channel 106, the abrasive inlet region 107, the water jet guard 108, the entrainment region 110, the dispersion body 119, the abrasive passage or abrasive channel 122, the geometry or protrusion 123 in the abrasive channel 122 that promotes abrasive dispersion, and the excitation transducer 120 (which causes the dispersion body 119 to vibrate).

[0030] Figure 4 A dispersion region is shown, which uses geometry on a flexible material to hold the abrasive when the transducer 120 imparts high-frequency motion to the dispersion region. The high-frequency motion excites the abrasive to enter the entrainment region 110 in a more dispersed state.

[0031] Figure 5 This is a front cross-sectional view of another embodiment of the invention, showing an orifice 105, an abrasive jet nozzle 102, a water jet guard 108, an orifice mount 101, an entrainment region 110, a dispersion and entrainment region receiving housing 134, an abrasive inlet 139, an abrasive channel 138, a longitudinal channel 103 within the abrasive jet nozzle, and the abrasive jet nozzle comprising a mixture of abrasive and water / liquid. In this embodiment, a protrusion 131 or dispersion element 131 within the abrasive channel 138 interacts with the abrasive moving through it to produce a desired movement pattern of the abrasive.

[0032] Those skilled in the art will understand that the materials of all parts of the cutting head can be varied to achieve the desired results in operation, service life, and maintainability.

[0033] Those skilled in the art will understand that there are many embodiments of the present invention, as well as variations of the elements and components that can be used, all of which are within the scope of the present invention.

[0034] For example, in one embodiment, an abrasive jet cutting head may be provided, comprising: a body having a first internal longitudinally extending through channel between an upstream region and a downstream region about the longitudinal axis; a water jet forming orifice member within the channel for generating a generally axially aligned water jet when the channel upstream of the orifice is connected to a high-pressure fluid source; an abrasive supply device for allowing abrasive material to enter the channel through an inlet pipe, and the abrasive being entrained by the water jet longitudinally downstream of the abrasive inlet in the entrainment region; means for preventing the abrasive from contacting the water jet or interfering with its longitudinal direction before reaching the entrainment region; and means for axially and longitudinally fixing an abrasive jet nozzle at a lower position in the longitudinal channel to guide the abrasive jet to a workpiece to be processed.

[0035] In addition to the embodiments disclosed above, the present invention may also include: means for dispersing abrasive material around a channel before it is entrained by a water jet and upstream of the entrainment region; a cutting head, wherein the inlet axis is located at any lateral position of the longitudinal central axis of the cutting head and can enter at any angle from horizontal to vertical, and can be accessed by means of a fixed or replaceable fitting, to which an abrasive carrying conduit can be attached to supply abrasive material to the cutting head; the cutting head including an abrasive dispersion region of a cone manufactured in a generally conical shape, the cone having dispersion members positioned around the conical surface; wherein the dispersion region uses a plurality of channels or pathways to disperse the abrasive material before it enters the entrainment region; wherein the dispersion region is made of a material to which high-frequency vibrations can be applied to excite the abrasive material into the dispersion region, causing the abrasive material to disperse before entering the entrainment region; and / or wherein the vibrations induced in the dispersion region create a fluidized bed of abrasive material before it enters the entrainment region.

[0036] Another embodiment may provide an abrasive jet cutting head with a device for protecting the water jet from external forces or materials; or an abrasive jet cutting head having a longitudinally entrained region before the abrasive jet nozzle and after the area where the water jet is protected from interference.

[0037] In yet another embodiment, an abrasive jet cutting head may be provided that can fix a nozzle with an inner diameter of 0.004 to 0.100 inches, which is laterally and longitudinally aligned with a water jet formed by an orifice longitudinally fixed in front of the nozzle.

[0038] In accordance with regulations, the structural and methodological features of the present invention have been described, more or less, in detail. However, it should be understood that the invention is not limited to the specific features shown and described, as the means disclosed herein include preferred forms for carrying out the invention. Therefore, the invention claims protection for any form or modification within the appropriate scope of the appended claims, as properly interpreted under the doctrine of equivalents.

Claims

1. An abrasive jet cutting head, the abrasive jet cutting head comprising: A cutting head body having an upper part and a lower part, the cutting head body having a longitudinally oriented channel extending through the interior of the cutting head body, the channel including an inlet region, a clamping region and a nozzle outlet region; The water jet forming orifice component within the channel is used to generate a generally axially aligned water jet when the channel upstream of the orifice is connected to a high-pressure liquid source. A water jet shield is disposed within the body of the cutting head to shield the water jet upstream of the entrainment area; An abrasive source is configured to supply abrasive to an abrasive channel in the cutting head body, the abrasive channel facilitating the delivery of the abrasive to the entrainment region; The abrasive channel includes at least one dispersing geometry element therein to radially disperse the abrasive entering the entrainment region; and The lower part of the cutting head body is configured to deliver a water jet carrying abrasive material through an outlet.

2. The abrasive jet cutting head of claim 1 wherein, The at least one dispersed geometry element is a protrusion, thread, or ridge.

3. An abrasive jet cutting head, the abrasive jet cutting head comprising: A cutting head body having an upper part and a lower part, the cutting head body having a longitudinally oriented channel extending through the interior of the cutting head body, the channel including an inlet region, a clamping region and a nozzle outlet region; The water jet forming orifice component within the channel is used to generate a generally axially aligned water jet when the channel upstream of the orifice is connected to a high-pressure liquid source. A water jet shield is disposed within the body of the cutting head to shield the water jet upstream of the entrainment area; An abrasive source is configured to supply abrasive to an abrasive channel in the cutting head body, the abrasive channel facilitating the delivery of the abrasive to the entrainment region; The abrasive channel consists of two or more channels for conveying abrasive in a dispersed manner to the entrainment region; The abrasive channel includes at least one dispersing protrusion to radially disperse the abrasive entering the entrainment region; and The lower part of the cutting head body is configured to deliver a water jet carrying abrasive material through the outlet.

Images