JP5722059B2 - Water jet cutting equipment - Google Patents

Description

  The present invention relates to a water jet cutting device that cuts a pressurized water flow onto a material to be cut.

  An apparatus for injecting and cutting a pressurized water flow onto a material to be cut is known as a water jet cutting apparatus. This water jet cutting device cuts only water as a jet water flow (pressurized water flow) if the object to be cut is a soft material, and cuts a water mixed with an abrasive as a jet water flow if it is a hard material. Yes. Such a water jet cutting apparatus is described in Patent Document 1.

  In the water jet cutting device described in Patent Document 1, a nozzle for injecting high-pressure water mixed with an abrasive is inclined from the normal direction to the surface of the material to be cut, and one side of the flow of high-pressure water injected from the nozzle It describes that the material to be cut can be cut so that the side of the product becomes a product, so that the cut surface of the product can be cut at right angles to the surface.

Japanese Unexamined Patent Publication No. 2000-117637

  However, in the conventional water jet cutting apparatus, if the material to be cut is a hard material, the abrasive is mixed with the pressurized water flow ejected from the nozzle, so that the cut surface becomes rough. Moreover, there is a problem that the abrasive is attached to the cut surface. When the abrasive material adheres to the cut surface, it is difficult for the abrasive material to enter the uneven surface of the cut surface and to wash away, and a great deal of time and expense is required for processing and recovery of the abrasive material.

  Therefore, the present invention provides a water jet cutting device capable of performing a high-quality cutting process at low cost by being able to cut without using an abrasive even if the material to be cut is a hard material. With the goal.

The water jet cutting device of the present invention comprises a bubble generating device that generates fine bubbles, and a nozzle that injects a pressurized water flow containing the fine bubbles generated by the bubble generating device onto a material to be cut. And
The water jet cutting device according to the present invention includes a material to be cut due to the impact force of the pressurized water flow and the impact force generated when the fine bubbles are crushed by including micro bubbles such as micro bubbles or nano bubbles in the pressurized water flow. Even if it is a hard material, it can be cut without mixing the abrasive.

  The nozzle is connected to the narrow pipe for introducing a pressurized water flow in the axial direction, and water containing fine bubbles generated by the bubble generating device is connected to the main body through a water guide pipe from the direction orthogonal to the axial direction. A mixing tube that mixes with the pressurized water flow, and a needle portion that injects mixed water of the water containing the fine bubbles from the mixing tube and the pressurized water flow along the axis, and the water guide tube includes an inner portion of the main body. It is desirable to arrange at a position eccentric from the axis of the main body so that water flows along the circumferential direction of the peripheral wall.

  In the nozzle, the pressurized water flow introduced from the narrow tube and the water containing fine bubbles introduced from the water conduit are mixed by the main body of the mixing tube. At this time, the pressurized water flow flows in the axial direction, and the water containing fine bubbles is introduced from the direction orthogonal to the axial direction. Since the water guide pipe is arranged at a position eccentric from the axis of the main body so that the water flow flows along the circumferential direction of the inner peripheral wall of the main body, the water containing the fine bubbles becomes a swirling flow around the pressurized water flow. be introduced. Therefore, since the microbubbles surround the pressurized water flow and the super cavitation phenomenon occurs, the flow of the pressurized water flow can be further accelerated, so that the pressurized water flow having a higher impact force can be jetted from the needle portion. it can.

  If the inner diameter of the water conduit is equal to or less than the length obtained by subtracting the radius of the narrow tube from the radius of the mixing tube, water containing fine bubbles introduced from the water conduit is along the circumferential direction of the inner peripheral wall of the main body. When flowing, it does not interfere with the pressurized water flow introduced by the width of the inner diameter of the narrow tube. Therefore, the pressurized water flow vigorously flows along the axis, and the water containing the fine bubbles can be introduced between the pressurized water flow and the inner peripheral wall of the main body to be a swirling flow rotating at high speed.

  If the inner diameter of the narrow tube is smaller than the inner diameter of the needle portion, a space for flowing water containing fine bubbles that have turned into a swirling flow around the pressurized water flow that flows through the needle portion with the width of the inner diameter of the thin tube is to be in a super cavitation state. It can be secured as a space.

  The bubble generator includes: a water tank in which water is stored; a fine bubble generator that is disposed in the water tank and discharges fine bubbles into water; a suction device that takes in water containing fine bubbles; and the fine bubble generator It is desirable to provide a funnel-shaped suction pipe that is disposed in front and captures fine bubbles and feeds them together with water to the suction device. The fine bubbles released into the water tank are taken together with the water by the suction device, but the funnel-shaped suction pipe is arranged in front of the fine bubble generator, so that the fine bubbles are captured without missing from the fine bubble generator. be able to.

  According to the present invention, it is possible to obtain a high-quality product by obtaining a mirror-finished cut surface by being able to cut without mixing an abrasive with a pressurized water flow. In addition, since no abrasive is used, it is not necessary to process or collect the abrasive, so that the cutting process can be made inexpensive.

It is a figure showing a water jet cutting device concerning an embodiment of the invention. It is a figure which shows the microbubble generator of the water jet cutting device shown in FIG. 1, (A) is sectional drawing along a water flow direction, (B) is AA sectional drawing of (A). It is sectional drawing which shows the nozzle of the water jet cutting device shown in FIG. It is sectional drawing for demonstrating the nozzle shown in FIG. It is a horizontal sectional view which shows the water inlet and the water pipe of the nozzle shown in FIG. 4, (A) is a figure for demonstrating a shape, (B) is a figure for demonstrating a use condition. It is a figure for demonstrating the use condition of the nozzle shown in FIG. It is the A section enlarged view of FIG.

A water jet cutting device according to an embodiment of the present invention will be described with reference to FIGS. In FIG. 1, a moving device that moves a nozzle that injects a high-pressure water flow (pressurized water flow), a table that moves a material to be cut, and an NC control device that controls them are omitted.
As shown in FIG. 1, the water jet cutting device 1 includes a bubble generation device 2, a storage tank 3, a high-pressure water flow supply device 4, and a nozzle 5.

  The bubble generator 2 has a function of generating bubbles called nanobubbles having a bubble diameter of 1 μm to 10 μm. The bubble generating device 2 includes a generation tank 21, a water pump 22, an air pump 23, a microbubble (MB) generator 24, a suction pipe 25, and a vortex turbo mixer 26. The generation tank 21 is a water tank in which water is stored and bubbles are generated therein. The water supply pump 22 supplies pressurized water that circulates the water in the generation tank 21 through the circulation path 27. The air supply pump 23 supplies pressurized air to the microbubble generator 24. The microbubble generator 24 is disposed in the generation tank 21 and has a function of generating bubbles called microbubbles having a bubble diameter of 50 μm or less.

Here, the microbubble generator 24 will be described in detail with reference to FIG.
As the microbubble generator 24, for example, the one shown in FIG. 2 can be used. In the microbubble generator 24 shown in FIG. 2, a mixing tube 24b formed with a smaller tube diameter than the generator body 24a is fitted between a generator body 24a composed of two front and rear tubes. The mixing tube 24b has a tubular body formed of a porous circular tube, and an orifice 24c is provided at the base end. A suction port 24d is provided above the mixing tube 24b. A suction chamber 24f is provided on the outer periphery of the mixing tube 24b by closing a gap between the tubes of the generator body 24a with a sealing member 24e.

A circulation path 27 through which pressurized water from the water supply pump 22 is supplied is connected to the rear end of the generator main body 24a, and the microbubble generator 24 is connected to the trunk (suction port 24d) of the generator main body 24a. A pipe through which air from the air pump 23 is supplied is connected.
In the present embodiment, the microbubble generator 24 shown in FIG. 2 is used, but a commercially available microbubble generator may be purchased and used.

Returning to FIG. 1, the suction tube 25 is disposed in front of the microbubble generator 24. The suction pipe 25 is formed in a funnel shape, and its tip passes through the generation tank 21 and is connected to the vortex turbomixer 26.
The vortex turbomixer 26 sucks the water containing the microbubbles generated by the microbubble generator 24 and agitates it to shear the microbubbles into fine bubbles to the size of the nanobubbles, and sucks the water that is sent to the storage tank 3. Device. Further, the vortex turbomixer 26 is provided with an electromagnetic valve 26 a for mixing the air taken from the outside with the pressurized water containing the microbubbles from the microbubble generator 24. Further, on the output side of the vortex turbomixer 26, an electromagnetic valve 26b that opens and closes a water passage through which pressurized water containing nanobubbles flows to the storage tank 3 is provided.

  The storage tank 3 is a tank that temporarily stores water containing fine bubbles in order to continuously perform the cutting process. From the storage tank 3, a drain pipe 31 for returning overflowed water to the generation tank 21 is provided. The high-pressure water flow supply device 4 has a function of sending a high-pressure water flow to the nozzle 5. As the nozzle 5, an ultra-high pressure nozzle head serving as a discharge port for injecting a high-pressure water flow containing nanobubbles onto the material to be cut W can be used.

Here, the nozzle 5 will be described in detail with reference to FIG.
As shown in FIG. 3, the nozzle 5 is connected to a connector 52 for connecting a water pipe from the high-pressure water flow supply device 4 to the base end side of the mixing holder 51. In the central part of the mixing holder 51, a water inlet 53 for connecting a water pipe from the storage tank 3 is provided. A needle portion 54 that mixes the high-pressure water flow from the high-pressure water flow supply device 4 and the water containing nanobubbles from the storage tank 3 and injects the water into the material to be cut is disposed at the tip of the mixing holder 51.

The operation and use state of the water jet cutting device according to the embodiment of the present invention configured as described above will be described with reference to the drawings.
As shown in FIG. 1, first, the water pump 22 is started, and the air pump 23 is started. Further, the vortex turbo mixer 26 is started.
When the water pump 22 is started, the water in the generation tank 21 starts to circulate through the microbubble generator 24. As shown in FIG. 2, the pressurized water from the water supply pump 22 that circulates in the circulation path 27 is rapidly depressurized by passing through the orifice 24 c from the base end of the generator body 24 a, and the suction chamber 24 f is supplied from the air supply pump 23. And mixed with the pressurized air that has entered the mixing tube 24b. At this time, a circulating vortex is generated in the mixing tube 24b, whereby the pressurized air is sheared into microbubbles. The pressurized water containing the microbubbles is discharged from the microbubble generator 24 into the generation tank 21.

  Pressurized water containing microbubbles, which are fine bubbles released from the microbubble generator 24, is sent from the suction pipe 25 shown in FIG. 1 to the vortex turbomixer 26 disposed outside the generation tank 21. In the vortex turbomixer 26, the microbubbles are sheared by stirring and become nanobubbles that are finer bubbles. The pressurized water containing nanobubbles is stored in the storage tank 3.

  At this time, when the microbubbles generated by the microbubble generator 24 are insufficient, air is taken in by the vortex turbomixer 26, and the nanobubbles are mixed by stirring and mixing with the water stream containing the microbubbles from the microbubble generator 24. It is also possible to increase the amount.

  Water containing nanobubbles stored in the storage tank 3 (hereinafter, water containing fine bubbles is referred to as nanobubble water) is jetted from the nozzle 5 to the workpiece W together with the high pressure water flow from the high pressure water flow supply device 4. The material to be cut W is cut. By including microbubbles in the high-pressure water stream, the material to be cut W can be cut by the impact force generated when the high-pressure water stream is impacted and the microbubbles are crushed. Therefore, the material to be cut W can be cut without mixing the abrasive, and the cut surface of the material to be cut W can be mirror-finished, so that a high-quality product can be obtained. In addition, since no abrasive is used, it is not necessary to process or collect the abrasive, so that the cutting process can be made inexpensive.

  Further, in the present embodiment, the fine bubbles from the microbubble generator 24 are further sheared by the vortex turbomixer 26 to form fine bubbles up to the nanobubble level. 3 and can be left without disappearing while moving to the nozzle 5. Therefore, bubbles can be effectively ejected from the nozzle 5 instead of the abrasive.

Further, since the amount of nanobubbles that are insufficient can be increased by the vortex turbomixer 26, the amount of bubbles necessary to cut the workpiece W can be adjusted. The swirl turbo mixer 26 may be omitted if the amount of microbubbles generated by the microbubble generator 24 is sufficient and pressurized water containing microbubbles can be supplied to the nozzle 5 before the microbubbles disappear. Is possible.
Further, since the funnel-shaped suction pipe 25 is disposed in front of the microbubble generator 24, the microbubbles can be captured from the microbubble generator 24 without being missed and sent to the vortex turbomixer 26.

  Next, a nozzle serving as a discharge port for injecting a high-pressure water flow containing nanobubbles onto the material to be cut will be described in detail. 4 to 7, the same components as those in FIG. 3 are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 4, the nozzle 5 has a high-pressure water flow (pressurized water flow) injected from the connector 52 in the axial direction of the nozzle 5 and fine bubbles injected from the introduction port 53 in a direction orthogonal to the axial line. A mixing tube 55 is provided which joins water containing nanobubbles and flows to the needle portion 54. At the base end of the mixing tube 55, a narrow tube 56 is provided to be interposed between the connector 52. The thin tube 56, the mixing tube 55, and the needle portion 54 are connected by the same axis.

The body portion of the mixing tube 55 is provided with a water conduit 55 b that connects the water conduit 53 to the main body 55 a of the mixing tube 55. The distal end portion of the mixing tube 55 is formed so that the tube diameter gradually decreases, and the proximal end of the needle portion 54 is connected to the distal end of the mixing tube 55.
The water guide pipe 55b is disposed at a position eccentric from the axis of the main body 55a so that a water flow flows through the main body 55a of the mixing pipe 55, which is a cylindrical pipe, along the circumferential direction of the inner peripheral wall of the main body 55a (see FIG. 5 (A)). In particular, it is desirable to arrange so that the axis of the water conduit 55b is parallel to the tangent to the inner peripheral wall of the main body 55a.

  As shown in FIG. 4, the narrow tube 56 is a straight tube having the same inner diameter from the proximal end to the distal end, but the inner diameter D1 of the narrow tube 56 is smaller than the inner diameter D2 of the connector 52, and the proximal end of the mixing tube 55 (main body 55a). It is smaller than the inner diameter D3 of the portion, and further smaller than the inner diameter D4 of the needle portion 54. Further, as shown in FIG. 5A, the inner diameter D5 of the water guide pipe 55b is changed from the radius r1 of the inner diameter D3 of the mixing pipe 55 (main body 55a) to the radius r2 of the inner diameter D1 of the narrow pipe 56 that becomes the diameter of the high-pressure water flow. It is formed so as to be less than or equal to the subtracted length L.

  In the nozzle 5 according to the second embodiment, for example, the inner diameter D1 of the thin tube 56 is φ0.45 mm, the inner diameter D2 of the connector 52 is φ4 mm, the inner diameter D3 of the proximal end of the mixing tube 55 is φ4 mm, and the inner diameter D4 of the needle portion 54. Can be φ0.65 mm, and the inner diameter D5 of the water conduit can be φ1.6 mm.

The usage state of the nozzle 5 configured as described above will be described with reference to the drawings.
As shown in FIG. 4, the high-pressure water flow flows into the narrow tube 56 through the connector 52. Since the inner diameter D <b> 1 of the narrow tube 56 is smaller than the inner diameter of the connector 52, the high-pressure water flow is accelerated when proceeding to the narrow tube 56.
When the accelerated high-pressure water flow passes through the narrow tube 56, it proceeds to the mixing tube 55 while maintaining a substantially equal width to the inner diameter of the narrow tube 56.

As shown in FIG. 5A and FIG. 5B, the nanobubble water from the water inlet 53 proceeds to the main body 55a via the water guide pipe 55b of the mixing pipe 55. In the main body 55a, since the inner diameter D3 of the mixing tube 55 is larger than the inner diameter D1 of the thin tube 56, a high-pressure water flow flows through the central portion (axis) with substantially the same width as the inner diameter D1 of the thin tube 56.
The water guide pipe 55b is disposed at a position eccentric from the axis of the main body 55a, and the inner diameter D5 of the water guide pipe 55b is equal to or less than a length L obtained by subtracting the radius r2 of the narrow pipe 56 from the radius r1 of the mixing pipe 55. Since the nanobubble water flows between the high-pressure water flow and the inner peripheral wall of the main body 55a, the swirl that flows along the circumferential direction of the inner peripheral wall of the main body 55a without obstructing the flow of the high-pressure water flow. It becomes a flow.
The nanobubble water flows along with the high-pressure water flow that travels along the axis of the mixing tube 55 and travels toward the tip of the mixing tube 55. Since the tip of the mixing tube 55 is formed so that the inner diameter gradually decreases, the flow of the swirling flow is accelerated. The nanobubble advances to the needle portion 54 while flowing between the high-pressure water flow and the inner peripheral wall of the main body 55a by the centrifugal force generated by the swirling flow.

  Since the inner diameter D1 of the narrow tube 56 is smaller than the inner diameter D4 of the needle portion 54, in the needle portion 54, a high-pressure water flow flows through the central portion (axis) with substantially the same width as the inner diameter D1 of the narrow tube 56. As described above, a gap is formed between the high-pressure water flow and the inner peripheral wall of the needle portion 54 through which the nanobubble water that has become a swirling flow flows. The swirling flow that flows between the high-pressure water flow and the inner peripheral wall of the needle portion 54 rotates slowly as it moves from the high-pressure water flow toward the inner peripheral wall. Therefore, the nanobubbles contained in the nanobubble water have a higher distribution density near the high-pressure water flow and gradually become discrete as they move toward the inner peripheral wall.

  A phenomenon called super cavitation occurs around the high-pressure water flow because the nanobubbles are biased so as to surround the high-pressure water flow. In other words, the resistance of the nanobubble water to the high pressure water flow is reduced by ensuring the space in which the swirling nano bubble water flows between the high pressure water flow and the inner peripheral wall of the needle portion 54 as a space for making the super cavitation state. Become. Accordingly, the high-pressure water stream is further accelerated at high speed, and the high-pressure water stream becomes an ultra-high-pressure water stream and is ejected from the needle portion 54. This injection speed can be accelerated more than the speed of the high-pressure water flow from the narrow tube 56 because nanobubble water is introduced from the water introduction port 53 and merged with the high-pressure water flow introduced from the narrow tube 56 to increase the amount of flowing water.

  The mixed water of nano-bubble water and high-pressure water jet sprayed in this way is made of a hard material due to the impact force of the high-pressure water stream flowing in the super cavitation state and the impact force generated when the bubbles of fine bubbles collapse. Even it can be cut. Accordingly, the material to be cut can be cut without mixing the abrasive, and the cut surface of the material to be cut can be mirror-finished, so that a high-quality product can be obtained. In addition, since no abrasive is used, it is not necessary to process or collect the abrasive, so that the cutting process can be made inexpensive.

  When the high-pressure water flow is further accelerated in the super cavitation state, the rotation speed of the nanobubble water that becomes the swirl flow is further increased, so that a stronger super cavitation state can be generated. Accordingly, the acceleration of the high-pressure water flow can be further promoted, so that the impact force due to the injection from the nozzle 50 can be improved. Thus, the cutting ability can be further improved by the synergistic effect of the nanobubble water and the high-pressure water flow.

  In the present embodiment, the mixing pipe 55 is provided with one water guide pipe 55b, but a plurality of water guide pipes 55b may be provided. Even if a plurality of conduit pipes are provided in the mixing pipe 55, the nanobubble water that has entered from the plurality of conduit pipes is arranged so that the water flow flows along the circumferential direction of the inner wall surface of the main body 55a of the mixing pipe 55. That's fine. In particular, when two water conduits are provided, it is desirable that they are installed on the same plane that intersects at right angles to the axis and are positioned in opposite directions.

  Since the present invention can eliminate the need for abrasives even if it is not only soft but also a hard material to be cut, it is suitable for a water jet cutting device that cuts steel materials such as rods, plates, and irregular shapes. .

DESCRIPTION OF SYMBOLS 1 Water jet cutting device 2 Bubble generator 21 Generation tank 22 Water supply pump 23 Air supply pump 24 Micro bubble generator 24a Generator main body 24b Mixing tube 24c Orifice 24d Suction port 24e Sealing member 24f Suction chamber 25 Suction tube 26 Vortex turbo mixer 26a, 26b Solenoid valve 27 Circulation path 3 Storage tank 31 Drain pipe 4 High-pressure water flow supply device 5 Nozzle 51 Mixing holder 52 Connector 53 Water inlet 54 Needle part 55 Mixing pipe 55a Main body 55b Water guiding pipe 56 Narrow pipe W Material to be cut

Claims (4)

A bubble generating device for generating fine bubbles;
A nozzle that injects and cuts a pressurized water stream containing fine bubbles generated by the bubble generating device to a material to be cut ;
The nozzle is
A narrow tube for introducing a pressurized water flow in the axial direction;
A mixing tube connected by the same axis as the thin tube and introducing water containing fine bubbles generated by the bubble generating device from a direction perpendicular to the axial direction into the main body by a water conduit and mixing with a pressurized water stream;
A needle portion for injecting water containing fine bubbles from the mixing tube and water mixed with a pressurized water flow along an axis;
The water jet cutting device according to claim 1, wherein the water guide pipe is disposed at a position eccentric from an axis of the main body so that a water flow flows along a circumferential direction of an inner peripheral wall of the main body . The inner diameter of the water conduit, said less than or equal to the length of that from the radius of the mixing tube minus the radius of the capillary claim 1 water jet cutting device according. The inner diameter of the thin tube is smaller than the inner diameter claim 2 Symbol placement of the water jet cutting apparatus of the needle portion. The bubble generator is
A water tank in which water is stored, a fine bubble generator that is disposed in the water tank and discharges fine bubbles into the water, a suction device that takes in water containing fine bubbles, and a fine bubble generator that is disposed in front of the fine bubble generator. The water jet cutting device according to any one of claims 1 to 3 , further comprising a funnel-shaped suction pipe for capturing bubbles and feeding the water together with water to the suction device.

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