JP2013215854A - Abrasive water jet nozzle, and abrasive water jet machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve processing precision by restricting clogging of abrasives inside a nozzle.SOLUTION: There is provided: a mixing chamber 3 formed of an air chamber, into which abrasives G are introduced from a supply port 31; a mixing nozzle 5 disposed on a downstream side against the water nozzle 4 to mix the abrasives G with a water jet WJ jetted out of the water nozzle 4 and to jet it into the mixing chamber 3 through a through hole 51; and an abrasive nozzle 6 disposed on a downstream side against the mixing nozzle 5 so as to introduce the water jet AW thereinto and so as to jet an abrasive water jet AWJ. A hole diameter D3 of the through hole 51 of the mixing nozzle 5 is formed larger than the hole diameter D1 of the water nozzle 4 so that the abrasives G inside the mixing chamber 3 are sucked together with air into a clearance δ1 formed between the water jet WJ passing through the through hole 51 and an inner peripheral surface of the through hole 51 to mix with the water jet WJ inside the through hole 51.

Description

  The present invention relates to an abrasive water jet nozzle and an abrasive water jet processing machine, and more particularly to an abrasive water jet nozzle having a mixing nozzle that sucks an abrasive material into a conduction hole and mixes it with high pressure water (water jet), and the abrasive water jet processing Related to the machine.

  Conventionally, when cutting a hard material or a thick workpiece such as a composite material such as glass, stone, synthetic resin, or carbon fiber reinforced plastic (CFRP), the high pressure water supplied at a high pressure of 200 to 400 MPa is used. 2. Description of the Related Art An abrasive water jet machining apparatus that improves cutting efficiency by spraying an abrasive water jet mixed with an abrasive (abrasive) onto the surface of a workpiece is known.

Conventionally, in the abrasive water jet machining apparatus, various means for mixing an appropriate amount of abrasive into the injected high-pressure water have been adopted in order to prevent damage to the nozzle by the abrasive and improve cutting efficiency. (For example, Patent Documents 1 and 2).
The abrasive nozzle described in Patent Document 1 generates a swirling flow of an ultra-high pressure fluid in the nozzle body by swirling flow generating means including a spiral groove, and moves the abrasive toward the center of the nozzle body to cause the abrasive to be high pressure. The water is mixed at a higher density at the center of the water.
The abrasive nozzle described in Patent Document 2 is supplied from the high-pressure water supply unit 11 to the spherical zircon beads ZB supplied from the spherical zircon bead supply unit 12a and the spherical zircon bead mixed water supplied from the recovered spherical zircon bead supply unit 12b. The high-pressure water to be injected is mixed with spherical zircon beads in the high-pressure water.

JP-A-8-1515 (paragraphs 0004 to 0008, FIG. 1) Japanese Patent No. 45633962 (paragraphs 0041-0044, FIG. 3)

However, in the conventional abrasive nozzle, the abrasive supplied to the mixing chamber is directly drawn into the high-pressure water and absorbed by injecting the high-pressure water into the mixing chamber, so that the abrasive is superimposed on the inlet of the abrasive nozzle. There is a problem that nozzle clogging and nozzle wear are likely to occur due to concentration on the nozzle. In particular, when an attempt is made to reduce the diameter of the abrasive nozzle in order to improve the cutting accuracy, the amount of abrasive is saturated inside the nozzle, and nozzle clogging is more likely to occur.
In addition, since an abrasive water jet in which abrasive is mixed with high-pressure water is sprayed onto the workpiece, there is a problem that variations in cutting accuracy and quality will occur unless machining is performed with an abrasive water jet containing an appropriate amount of abrasive. was there. Furthermore, if a partial deviation occurs in the mixing of the abrasive inside the nozzle, there is a possibility of promoting the wear of the nozzle.

  The present invention has been made in view of such a background, and an appropriate amount of abrasive is mixed in a water jet (high-pressure water) to suppress clogging of the abrasive in the nozzle, and processing accuracy and processing are improved. It is an object of the present invention to provide an abrasive water jet nozzle and an abrasive water jet processing machine capable of improving efficiency.

  In order to solve the above-mentioned problem, the invention according to claim 1 of the present invention is an abrasive water jet nozzle that injects and processes an abrasive water jet in which abrasive is mixed into high-pressure water supplied to an introduction hole, onto a workpiece. A mixing chamber comprising an air chamber into which the abrasive is sucked together with air from the supply port and introduced, a water nozzle in which the introduction hole is formed and from which the high-pressure water is ejected, and a downstream portion of the water nozzle. A mixing nozzle that mixes the abrasive into the water jet ejected from the water nozzle and ejects the water jet from the conduction hole into the mixing chamber; and the water jet disposed downstream of the mixing nozzle. An abrasive that jets the abrasive water jet onto the workpiece And the hole diameter of the conduction hole of the mixing nozzle is larger than the hole diameter of the water nozzle, and is formed between the water jet passing through the conduction hole and the inner peripheral surface of the conduction hole. The abrasive material retained in the mixing chamber in the gap is sucked together with air and mixed into the water jet in the conduction hole.

The present invention comprises a mixing chamber comprising an air chamber into which the abrasive material is sucked and introduced into the room from the supply port, and is composed of an air chamber in which water jets ejected from a water nozzle are partitioned. When passing through the room, the abrasive is sucked together with the air by the negative pressure generated by the water jet passing at high speed and stays in the mixing chamber, and the retained abrasive is efficiently mixed into the water jet.
In the description of the present invention, the terms “water” and “high-pressure water” are conventionally used. However, the term “water” is not intended to be particularly limited, but “working fluid” is widely used.

  The present invention includes a mixing nozzle that ejects the water jet that passes through the conduction hole into the mixing chamber, and is formed between the water jet that passes through the conduction hole and the inner peripheral surface of the conduction hole. The abrasive is sucked into the gap together with air and mixed so that the abrasive is absorbed by the water jet in the conduction hole of the mixing nozzle.

  For this reason, the present invention does not directly mix the abrasive material introduced into the mixing chamber into the water jet as in the prior art, but sucks the abrasive material into the mixing nozzle together with air, and within the conduction hole of the mixing nozzle. By absorbing and mixing the abrasive so as to wind up in the direction opposite to the flow of the water jet, an appropriate amount of the abrasive can be mixed into the water jet.

  Further, the present invention is provided with the mixing nozzle, so that the abrasive introduced into the mixing chamber is upstream from the opening of the mixing nozzle (the opening formed at the tip of the conduction hole) in the direction opposite to the flow of the water jet. The abrasive can be mixed into the water jet by the first mixing route that is sucked into the water jet and mixed into the water jet and the second mixing route that is mixed into the water jet ejected downstream from the opening of the mixing nozzle.

  In this way, the present invention disperses and mixes the abrasive material in the first mixing route and the second mixing route so that the abrasive material in the mixing chamber is not concentrated and drawn into the inlet of the abrasive nozzle, A uniform and uniform amount of abrasive material is mixed in the water jet to effectively suppress clogging of the abrasive material inside the abrasive nozzle.

For this reason, the abrasive water jet nozzle according to the present invention can suppress the clogging of the abrasive nozzle, thereby reducing the hole diameter of the abrasive nozzle and increasing the flow velocity of the abrasive water jet more smoothly. Consumption can be saved and machining accuracy and machining efficiency can be improved by the small diameter abrasive water jet.
Further, the present invention can improve the processing accuracy and processing efficiency with a simple configuration as well as a general abrasive water jet processing machine. It can also be suitably used in a portable abrasive water jet nozzle that is processed by holding it.

  The invention according to claim 2 is the abrasive water jet nozzle according to claim 1, wherein the hole diameter of the conduction hole of the mixing nozzle is 5 to 25 times the hole diameter of the water nozzle. .

  According to this configuration, the diameter of the conduction hole of the mixing nozzle is 5 to 25 times the diameter of the water nozzle, so that the abrasive is more efficiently put into the gap formed on the inner peripheral surface of the conduction hole. Can be sucked and mixed.

  That is, if the gap is too small, the amount of abrasive that is sucked decreases, and if the gap is too large, the negative pressure decreases and the amount of abrasive that is similarly sucked decreases. The amount of abrasive that is sucked between 5 to 25 times the hole diameter of the water nozzle is an extreme value, and it is desirable to adjust it appropriately within this range.

  The invention according to claim 3 is the abrasive water jet nozzle according to claim 1 or 2, wherein the length of the conduction hole of the mixing nozzle is determined from an opening formed at the tip of the conduction hole. It is longer than the distance to the abrasive nozzle.

  According to this configuration, the length of the second mixing route can be set short by making the length of the conduction hole of the mixing nozzle longer than the distance from the opening of the mixing nozzle to the abrasive nozzle. Therefore, the abrasive in the mixing chamber is prevented from being concentrated and drawn into the inlet of the abrasive nozzle, so that clogging of the abrasive can be more effectively suppressed, and an appropriate amount of abrasive can be mixed stably.

  In other words, the second mixing route for mixing the abrasive into the water jet ejected downstream from the opening of the mixing nozzle acts to draw the abrasive introduced into the mixing chamber into the inlet of the abrasive nozzle. However, it is concentrated at the inlet of the abrasive nozzle and the density becomes unevenly high, and it becomes easy to induce clogging of the abrasive. For this reason, it is preferable to shorten the length of the second mixing route and increase the length of the first mixing route accordingly.

  In this way, the abrasive water jet nozzle according to the present invention increases the length of the first mixing route in which the abrasive introduced into the mixing chamber is sucked and mixed upstream from the opening of the mixing nozzle. By shortening the length of the mixing route, it is possible to more effectively suppress clogging of the abrasive and stably mix an appropriate amount of abrasive.

  The invention according to claim 4 is the abrasive water jet nozzle according to any one of claims 1 to 3, wherein a hole diameter of the abrasive nozzle is smaller than a hole diameter of the mixing nozzle, and the water nozzle It is characterized by being larger than the hole diameter.

  According to such a configuration, by making the hole diameter of the abrasive nozzle smaller than the hole diameter of the mixing nozzle, it is possible to apply a small diameter abrasive nozzle, and therefore it is possible to improve processing accuracy and processing efficiency. And the clogging of an abrasive | polishing material can be suppressed by making the hole diameter of the said abrasive nozzle larger than the hole diameter of the said water nozzle.

  The invention according to Claim 5 is the abrasive water jet nozzle according to any one of Claims 1 to 4, wherein the mixing nozzle has a substantially cylindrical shape, and the outer periphery of the mixing nozzle is formed on the outer periphery of the mixing nozzle. A taper having a diameter reduced at the tip so as to go in the direction of the abrasive nozzle is formed from the position facing the supply port to the tip.

According to this configuration, since the taper is provided at the distal end portion of the outer peripheral surface of the mixing nozzle, the abrasive introduced together with air from the supply port into the mixing chamber is advanced along the outer peripheral portion of the mixing nozzle. It is sucked so that it flows smoothly to the part.
For this reason, the abrasive is efficiently sucked together with air into the gap formed on the inner peripheral surface of the conduction hole from the opening of the water jet formed at the tip of the mixing nozzle, and is introduced into the water jet in the conduction hole. Can be absorbed and mixed.

  According to a sixth aspect of the present invention, there is provided an abrasive water jet processing machine comprising: the abrasive water jet nozzle according to any one of the first to fifth aspects; and an abrasive material supply device that supplies a predetermined amount of abrasive material to the mixing chamber. The abrasive supply device is provided with a storage section in which the abrasive is stored, an outflow hole disposed in a lower portion of the storage section, and a predetermined gap provided downstream of the outflow hole. And a transport rotor that rotates around a horizontal rotation shaft, a receiving portion disposed downstream of the transport rotor, and a discharge port formed in the receiving portion. .

According to this configuration, the predetermined gap is provided downstream of the outflow hole and the conveyance rotor is provided, so that the abrasive that has flowed out of the outflow hole is conveyed by the rotation of the conveyance rotor.
In other words, by providing a predetermined gap between the outflow hole and the transfer rotor, when the transfer rotor is stopped, the abrasive remains in the gap with the transfer rotor due to the frictional resistance between the particles. become. On the other hand, when the conveying rotor is rotating, the abrasive remaining in the gap is conveyed along the outer peripheral surface of the conveying rotor, so that a new abrasive flows out again into the gap from the outflow hole. In this way, due to the rotation of the transport rotor, the abrasive that has flowed out into the gap according to the rotation speed is transported along the outer peripheral surface of the transport rotor, and is accommodated in the receiving portion of the abrasive disposed downstream. And is discharged from an outlet formed in the receiving portion.

  For this reason, the abrasive water jet processing machine according to the present invention can smoothly supply an appropriate amount of abrasive to the mixing chamber without rotation by the rotation of the transport rotor, so that the abrasive is uniformly mixed in the water jet. The clogging of the abrasive inside the nozzle can be suppressed, and the processing accuracy and processing efficiency can be improved.

The invention according to claim 7 is the abrasive water jet processing machine according to claim 6, wherein the transport rotor includes an uneven portion formed on an outer peripheral portion of the transport rotor.
According to such a configuration, by providing an uneven portion on the outer peripheral portion of the transport rotor, the abrasive that has flowed out into the gap can be held, and free fall can be suppressed and transported smoothly along the outer peripheral portion of the transport rotor. it can.

  According to the present invention, an abrasive water jet nozzle that uniformly mixes an abrasive into a water jet (high-pressure water), suppresses clogging of the abrasive inside the nozzle, and can improve processing accuracy and processing efficiency, and An abrasive water jet processing machine can be provided.

It is sectional drawing which shows typically the structure of the abrasive water jet processing machine which concerns on embodiment of this invention. 1 is a schematic cross-sectional view of an abrasive water jet nozzle according to an embodiment of the present invention. It is a figure for demonstrating the effect | action of the mixing nozzle of the abrasive water jet nozzle which concerns on embodiment of this invention. It is the elements on larger scale for demonstrating the effect | action of the abrasive | polishing material supply apparatus which concerns on embodiment of this invention.

An abrasive water jet processing machine 100 according to an embodiment of the present invention will be described in detail with reference to the drawings as appropriate.
The abrasive water jet processing machine 100 is a processing apparatus that cuts a workpiece (not shown) by mixing abrasive G into high-pressure water Q supplied at a high pressure of 200 to 400 MPa and injecting abrasive water jet AWJ. . And since the abrasive water jet processing machine 100 can inject the abrasive water jet AWJ at a speed higher than the speed of sound, even if it is a hard material such as glass or a relatively soft material such as a synthetic resin, Even a composite material composed of many kinds of materials such as a hard material and a soft material can perform high-quality shape cutting.

  As shown in FIG. 1, the abrasive water jet processing machine 100 includes an abrasive water jet nozzle 1 that injects an abrasive water jet AWJ mixed with abrasive G, and high-pressure water Q from a high-pressure pipe 102 to the abrasive water jet nozzle 1. A high-pressure water supply device 101 for supplying and an abrasive material supply device 8 for supplying an appropriate amount of the abrasive material G to the abrasive water jet nozzle 1 are provided.

  In the present embodiment, in FIG. 1, the abrasive water jet processing machine 100 is illustrated with the jet direction of the abrasive water jet AWJ downward, but the present invention is not limited to this, and the horizontal direction and the jet direction can be freely set. It may be a portable abrasive water jet processing machine that is mounted on the tip of a robot arm that changes to a hand or that is held by a worker.

  As the abrasive G, a general material such as garnet, sapphire, cemented carbide or the like can be appropriately used according to the type of workpiece. The abrasive G has a particle size appropriately set according to the type and application of the workpiece, but a fine one or a coated one can also be used.

  As shown in FIG. 2, the abrasive water jet nozzle 1 includes a nozzle body 2, a mixing chamber 3 formed in the nozzle body 2, and a water nozzle that is formed with an introduction hole 41 and ejects high-pressure water (water jet WJ). 4 and a mixing nozzle 5 for generating a water jet AW (hereinafter simply referred to as “water jet AW”) in which the abrasive G is mixed in the water jet WJ ejected from the water nozzle 4 and the abrasive is mixed. And an abrasive nozzle 6 for injecting an abrasive water jet AWJ for machining a workpiece (not shown).

  In FIG. 2, for example, the relationship between the diameter of the water nozzle 4 and the diameter of the water jet WJ is simplified from the viewpoint of visibility for the convenience of explanation. Also, it is assumed that the diameter of the jet jet is small. In FIG. 1 and FIG. 2, the particle size of the abrasive G is exaggerated and shows a state in which the abrasive G floats and flows in the air in the mixing chamber 3. Shows a state where the granular material flows and is conveyed.

  The nozzle body 2 is composed of an upper body 21 and a lower body 22, and is a member for positioning and disposing each constituent member such as the water nozzle 4 and the mixing nozzle 5 with high accuracy. 3 is formed.

Note that the configuration of the nozzle body 2 is illustrated with the mixing nozzle 5 embedded in order to clarify the layout of each nozzle portion and the like for convenience of explanation, but from the viewpoint of manufacturability and the like, the nozzle body 2 (upper body 21) is shown. ) And the mixing nozzle 5 are generally configured as a single unit.
On the other hand, by making the mixing nozzle 5 detachable from the upper body 21, it becomes easy to change the size and material of the mixing nozzle 5. In the present embodiment, the upper body 21 and the lower body 22 are separated from each other. However, the upper body 21 and the lower body 22 may be integrally formed.

  The mixing chamber 3 has a substantially cylindrical shape, and is arranged so that the mixing nozzle 5 enters the central portion of the mixing chamber 3, and the high pressure water (water jet WJ) ejected from the water nozzle 4 through the mixing nozzle 5. ) Passes through the mixing chamber 3 and is introduced into the abrasive nozzle 6.

  The mixing chamber 3 includes a supply port 31 into which the abrasive G is introduced. The abrasive G discharged from the abrasive supply device 8 (see FIG. 1) is sucked together with air from the supply port 31 and introduced into the mixing chamber 3. Further, the mixing chamber 3 is a space that is composed of partitioned air chambers, in which the introduced abrasive G can be sufficiently decelerated and accumulated in the room. For this reason, the abrasive G introduced into the mixing chamber 3 is mixed into the water jet WJ, and an abrasive water jet AWJ in which the abrasive G is mixed is generated. The abrasive supply device 8 (see FIG. 1) is configured to discharge an appropriate amount of the abrasive G toward the supply port 31.

  Note that the “mixing chamber consisting of air chambers” means a space partitioned so as to stagnate the abrasive in the mixing chamber, for example, a vacuum that supplementarily generates a negative pressure during piercing. It is not limited to a sealed airtight space in which an opening or the like for mounting other accessory devices such as a suction device is not formed.

The supply port 31 is located at an appropriate position with respect to the opening 53 of the mixing nozzle 5 and the abrasive nozzle 6, for example, upstream of the opening 53 of the mixing nozzle 5 with respect to the jet direction of the water jet WJ. It is arranged.
That is, the supply port 31 is related to the diameter, but if the position of the supply port 31 is too high with respect to the opening 53 of the mixing nozzle 5, the abrasive G is not smoothly supplied to the opening 53 and When the abrasive G is easily clogged in the vicinity and the position of the supply port 31 is too low with respect to the opening 53 of the mixing nozzle 5 (for example, downstream of the water jet WJ in the ejection direction of the water jet WJ). Since the abrasive nozzle 6 is likely to be clogged, it is set to an appropriate aperture and adjusted to an appropriate position.

In this way, when high-pressure water (water jet WJ) ejected from the water nozzle 4 passes through the mixing chamber 3, an appropriate amount of abrasive G is supplied by the negative pressure generated by the water jet WJ passing at high speed. The air is preferably sucked from the mouth 31 together with air. For this reason, clogging of the abrasive G in the vicinity of the supply port 31 can be effectively avoided.
Then, the abrasive G sucked from the supply port 31 floats and stays in the airflow, and is drawn into the water jet WJ in the mixing chamber 3 and mixed, and an appropriate amount of abrasive G is mixed. A water jet AW is generated.

The water nozzle 4 includes a body portion 42 embedded and disposed in an upstream portion (upper portion in FIG. 2) of the upper body 21, and a nozzle portion 43 embedded in the body portion 42, and is introduced from the high-pressure pipe 102. This is a member that ejects the high-pressure water Q supplied to the hole 41 from the nozzle portion 43 into the mixing nozzle 5.
For this reason, the hole diameter D1 of the water nozzle 4 (nozzle portion 43) is set smaller than the hole diameter D3 of the mixing nozzle 5 and the hole diameter D2 of the abrasive nozzle 6.

The mixing nozzle 5 is disposed in the downstream portion of the water nozzle 4 and has a substantially cylindrical shape. The mixing nozzle 5 is formed in the outer peripheral surface with a conduction hole 51 through which high-pressure water (water jet WJ) ejected from the water nozzle 4 passes. And the opening 53 that ejects the water jet WJ that has passed through the conduction hole 51 into the mixing chamber 3.
The mixing nozzle 5 is a member in contact with the abrasive G, so there is also a balance with the supply amount of the abrasive, but it may be made of a material harder than the abrasive G, and the inner peripheral portion is coated to be durable. Further, the wear resistance can be improved.

  In the present embodiment, the mixing nozzle 5 is cylindrical, but the outer peripheral portion may be polygonal.

<First mixed route>
In the mixing nozzle 5, high pressure water (water jet WJ) ejected from the water nozzle 4 passes through the conduction hole 51 and is ejected from the opening 53, thereby generating a negative pressure in the conduction hole 51. The abrasive G is sucked together with air from the opening 53 into a gap δ1 formed between the water jet WJ passing through and the inner peripheral surface of the conduction hole 51 (see arrow R1 in FIG. 2).

  In this way, the mixing nozzle 5 sucks the abrasive G into the conduction hole 51 to the height H3 from the opening 53, and then mixes the abrasive G into the water jet WJ in the conduction hole 51 (first mixing). Route R1). Although the height H3 from the opening 53 that sucks the abrasive G is related to the gap δ1, the amount of the abrasive G mixed tends to increase as the height H3 increases.

The outer periphery of the mixing nozzle 5 is formed with a taper 52 whose tip is reduced in diameter toward the abrasive nozzle 6, and this taper 52 extends from a position facing the supply port 31 to the tip of the mixing nozzle 5. Is formed.
With this configuration, the abrasive G introduced into the mixing chamber 3 from the supply port 31 along with the air flows smoothly to the opening 53 at the tip along the shape of the taper 52 formed on the outer periphery of the mixing nozzle 5. Sucked into.

In the present embodiment, the taper 52 is formed. However, the present invention is not limited to this, and the cross section may be a polygonal shape, and the polygonal shape may be reduced toward the tip, or from the upstream side. The polygonal shape may be gradually reduced by providing a level difference while going to the tip. Further, the outer periphery of the mixing nozzle 5 may have a straight shape without providing the taper 52. In the case of a straight outer peripheral portion, the diameter of the outer peripheral portion is reduced so that the abrasive G introduced into the mixing chamber 3 from the supply port 31 with the air reaches the opening 53 at the tip of the mixing nozzle 5. It can be made to flow smoothly.
In the present embodiment, the taper 52 is formed on the outer peripheral portion of the mixing nozzle 5, but the present invention is not limited to this, and the inner peripheral portion can be tapered as well as the outer peripheral portion.

<Setting of gap δ1>
The abrasive water jet nozzle 1 suitably uses an appropriate amount of abrasive G for the water jet WJ by appropriately setting the size of the gap δ1 formed between the water jet WJ and the inner peripheral surface of the conduction hole 51. Can be mixed. Hereinafter, the gap δ1 will be described with reference to FIG. FIG. 3 is a graph showing the relationship between the gap δ1 and the piercing time with the ratio of the hole diameter D3 of the mixing nozzle 5 to the hole diameter D1 of the water nozzle 4 (D3 / D1) on the horizontal axis and the piercing time on the vertical axis. It is.

  The piercing process is an abrasive water jet process performed as a pre-processing of the cutting process in the abrasive water jet process. By measuring the piercing process time with the water jet WJ pressure kept constant, In order to verify that an amount of abrasive G has been mixed, this is a standard for measuring the processing efficiency in the abrasive water jet processing.

The hole diameter D3 of the conduction hole 51 of the mixing nozzle 5 is preferably set to be 5 to 25 times the hole diameter D1 of the water nozzle 4.
Here, since δ1 = (D3−D1) / 2, when D3 / D1 = 5,
δ1 = (5D1−D1) / 2 = 2D1.
When D3 / D1 = 25,
δ1 = (25D1-D1) / 2 = 24D1 / 2 = 12D1.
That is, the gap δ1 formed in the conduction hole 51 is set to 2 to 12 times the hole diameter D1 of the water nozzle 4 on one side.

The gap δ1 is related to the flow velocity and pressure of the water jet WJ and the diameter D1 of the water nozzle 4, but if it is too small, the amount of abrasive G to be sucked will decrease, and if it is too large, the negative pressure will decrease. It shows a tendency that the amount of the abrasive G sucked decreases. As shown in FIG. 2, the amount of the abrasive G mixed therein increases as the height H3 at which the abrasive G is sucked upstream increases.
In order to verify that the amount of the abrasive G sucked and mixed in the water jet WJ is appropriate, the relationship between the piercing time and the gap δ1 will be described with reference to FIG. If the flow rate of the abrasive water jet AWJ is constant, generally, if the amount of the abrasive G mixed is large, the processing efficiency is improved and the processing time is shortened. If the amount of the abrasive G mixed is small, the processing is performed. Shows a tendency to increase in time.

As shown in FIG. 3, for example, when the pressure of the water jet WJ is set to 300 MPa and the hole diameter D1 of the water nozzle 4 is set to 0.1 to 0.15, D3 / D1 is about 13 times and processing efficiency is extremely high. And the amount of the mixed abrasive G is estimated to be maximized.
Actually, since various conditions such as the flow velocity and pressure of the water jet WJ and the hole diameter D1 of the water nozzle 4 are taken into account, D3 / D1 is appropriately set within a range of 5 to 25 times across this extreme value. It is preferable.

<Second mixed route>
On the other hand, the water jet WJ ejected into the mixing chamber 3 from the opening 53 of the mixing nozzle 5 also generates a negative pressure when passing from the opening 53 of the mixing nozzle 5 in the mixing chamber 3 to the abrasive nozzle 6. Therefore, the abrasive G is mixed (see arrow R2 in FIG. 2).

<Relationship between the first route and the second route>
The opening 53 of the mixing nozzle 5 is disposed at the tip of the mixing nozzle 5 and is disposed at a predetermined height H1 from the abrasive nozzle 6.
The height H1 from the abrasive nozzle 6 to the opening 53 of the mixing nozzle 5 is set to be smaller than the length H2 of the conduction hole 51 of the mixing nozzle.

  That is, the second mixing route for mixing the water jet AW ejected downstream from the opening 53 of the mixing nozzle 5 acts to draw the abrasive G introduced into the mixing chamber 3 into the inlet of the abrasive nozzle 6. The abrasive G concentrates at the inlet of the abrasive nozzle 6 and the density is unevenly increased, so that the abrasive G is easily clogged. For this reason, it is preferable to shorten the length H1 of the second mixing route and increase the length H3 of the first mixing route accordingly.

The abrasive nozzle 6 is disposed in the downstream portion of the mixing nozzle 5. The abrasive nozzle 6 is a member that introduces the water jet AW mixed with the abrasive G from the first mixing route R1 and the second mixing route R2 and injects the abrasive water jet AWJ onto a work (not shown).
The hole diameter D2 of the abrasive nozzle 6 is generally set to about 0.3 to 0.5 mm, but is set to be smaller than the hole diameter D3 of the mixing nozzle 5 and larger than the hole diameter D1 of the water nozzle 4. Is desirable.
That is, by making the hole diameter D2 of the abrasive nozzle 6 smaller than the hole diameter D3 of the mixing nozzle 5, the small diameter abrasive nozzle 6 can be set, so that the processing accuracy and the processing efficiency can be improved. Then, by making the hole diameter D2 of the abrasive nozzle 6 larger than the hole diameter D1 of the water nozzle 4, an effect of suppressing clogging of the abrasive G in the abrasive nozzle 6 is expected.

  In the present embodiment, the first mixing route R1 and the second mixing route R2 have been described in a simplified manner for easy understanding of the present invention. Since the abrasive G to be mixed also exists, it does not mean that all the abrasive G supplied to the mixing chamber 3 is mixed into the water jet from the first mixing route and the second mixing route. Further, in the first mixing route R1, a swirling flow may be generated when the abrasive G is wound upstream, and such swirling flow may affect the length H3 of the first mixing route R1.

<Abrasive supply device>
As shown in FIG. 1, the abrasive supply device 8 includes a storage portion 81 in which the abrasive G is stored, an outflow hole 82 disposed below the storage portion 81, and a predetermined gap below the outflow hole 82. A conveyance rotor 83 that is provided with δ2 (see FIG. 4) and that rotates around a horizontal rotation shaft 83a, a motor 84 that rotates the conveyance rotor 83, and a control device that controls the rotation of the motor 84. (Not shown), a receiving portion 85 disposed below the transport rotor 83, and a discharge port 86 formed in the receiving portion 85.

As shown in FIG. 4, the transport rotor 83 includes a convex portion 83 b that is a concavo-convex portion formed on the outer peripheral portion, and a wall portion 83 c formed in the circumferential direction. The protrusions 83b are formed in a straight line along the axial direction, and a plurality of protrusions 83b are formed at equal intervals in the circumferential direction, such as blades of a water turbine. The wall portion 83c is formed in a bowl shape so as to protrude in the radial direction from both edge portions of the outer peripheral portion.
With this configuration, the conveying rotor 83 holds the abrasive G flowing out from the outflow hole 82 so as not to be scattered, and can convey the necessary amount of abrasive G to the receiving portion 85 at an appropriate timing. .

  In this embodiment, the convex portion 83b is provided on the outer peripheral portion of the transport rotor 83. However, the shape is not particularly limited as long as the abrasive G can stay on the outer peripheral portion for a predetermined amount of time. However, it may be a concave portion, may be constituted by a concave portion and a convex portion, and such an uneven portion may not be formed.

  As shown in FIG. 1, the abrasive material supply device 8 causes a predetermined amount of the abrasive material G to flow downward from an outflow hole 82 disposed in the lower portion of the storage portion 81, and the abrasive material G that has flowed out of the outflow hole 82. Is transported to the receiving portion 85 by the transport rotor 83, and the abrasive G is supplied from the discharge port 86 formed in the receiving portion 85 to the supply port 31 of the mixing chamber 3.

  As shown in FIG. 4, the abrasive supply device 8 provides a predetermined gap δ2 between the outflow hole 82 and the transfer rotor 83, so that when the transfer rotor 83 is stopped, the abrasive supply device 8 is in this gap. G can be held in a state of staying between the conveying rotor 83 due to frictional resistance between particles (see FIG. 4A).

  On the other hand, when the abrasive material supply device 8 rotates the conveyance rotor 83, the abrasive material G remaining in the gap δ <b> 2 is conveyed along the outer peripheral surface of the conveyance rotor 83, so that a new abrasive material G is discharged from the outflow hole 82. It flows out again into the gap (see FIG. 4C).

In this way, as shown in FIG. 1, the abrasive supply device 8 causes the abrasive G that has flowed out into the gap δ <b> 2 along the outer peripheral surface of the transfer rotor 83 according to the rotation speed of the transfer rotor 83. The abrasive G is supplied from the discharge port 86 formed in the receiving portion 85 to the supply port 31 of the mixing chamber 3.
The abrasive material supply device 8 supplies the appropriate amount of abrasive material G to the mixing chamber 3 smoothly and at an appropriate timing by appropriately controlling the rotational speed of the transport rotor 83 by a control device (not shown). Can do.

The abrasive water jet processing machine 100 equipped with the abrasive water jet nozzle 1 according to the present embodiment configured as described above has the following effects.
The abrasive water jet nozzle 1 has a first mixing route for sucking the abrasive G introduced into the mixing chamber 3 upstream from the opening 53 of the mixing nozzle 5 and mixing it with the water jet WJ (see H3 in FIG. 2). The second mixing route to be mixed with the water jet WJ ejected downstream from the opening 53 of the mixing nozzle 5 (see H1 in FIG. 2) can be dispersed and mixed.
For this reason, the abrasive water jet nozzle 1 prevents the abrasive G in the mixing chamber 3 from being concentrated and drawn into the inlet of the abrasive nozzle 6, so that a uniform and uniform amount of abrasive G is supplied to the water jet WJ. It mixes and the clogging of the abrasive G inside the abrasive nozzle 6 is effectively suppressed.

  The abrasive water jet processing machine 100 can smoothly supply an appropriate amount of the abrasive G to the mixing chamber 3 without any deviation by the abrasive supply device 8, so that the abrasive G is uniformly mixed in the water jet WJ. The clogging of the abrasive G inside the abrasive nozzle 6 can be more effectively suppressed, and the processing accuracy and processing efficiency can be improved.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and can be implemented with appropriate modifications.
For example, in the present embodiment, the abrasive material supply device 8 that supplies the abrasive material G with the transport rotor 83 is used. However, the present invention is not limited to this, and the diameter of the outflow hole 82 is adjusted with a movable needle valve. Thus, the supply amount of the abrasive G can also be controlled.

  In the present embodiment, the case where one supply port 31 is provided in the mixing chamber 3 has been described. However, a plurality of supply ports 31 may be provided, and a plurality of abrasive supply devices 8 are provided corresponding to the plurality of supply ports 31. May be.

DESCRIPTION OF SYMBOLS 1 Abrasive water jet nozzle 2 Nozzle body 3 Mixing chamber 4 Water nozzle 5 Mixing nozzle 6 Abrasive nozzle 8 Abrasive supply device 31 Supply port 41 Introduction hole 51 Conduction hole 52 Taper 53 Opening part 81 Reservoir part 82 Outlet hole 83 Conveyor rotor 83a Rotation Shaft 83b Convex part (concave part)
83c Wall portion 84 Motor 85 Receiving portion 86 Discharge port 100 Abrasive water jet processing machine AW Water jet mixed with abrasive AWJ Abrasive water jet D1 Water nozzle hole diameter D2 Abrasive nozzle hole diameter D3 Mixing nozzle hole diameter G Abrasive material Q High pressure water R1 First mixing route R2 Second mixing route WJ Water jet (high pressure water)

Claims (7)

An abrasive water jet nozzle that injects and processes an abrasive water jet in which abrasive is mixed into high-pressure water supplied to an introduction hole,
A mixing chamber composed of an air chamber in which the abrasive is sucked and introduced into the room through a supply port;
A water nozzle for forming the introduction hole and ejecting the high-pressure water;
A mixing nozzle disposed downstream of the water nozzle, mixing the abrasive into a water jet ejected from the water nozzle, and ejecting the water jet from a conduction hole into the mixing chamber;
A mixing nozzle that ejects the water jet into the mixing chamber from a conduction hole through which the water jet ejected from the water nozzle passes, and mixes the abrasive into the water jet;
An abrasive nozzle disposed downstream of the mixing nozzle to introduce the water jet and inject the abrasive water jet onto the workpiece,
A hole diameter of the conduction hole of the mixing nozzle is formed larger than a hole diameter of the water nozzle, and a gap formed between a water jet passing through the conduction hole and an inner peripheral surface of the conduction hole is formed in the mixing chamber. An abrasive water jet nozzle, wherein the retained abrasive is sucked together with air and mixed into the water jet in the conduction hole.   The abrasive water jet nozzle according to claim 1, wherein a hole diameter of the conduction hole of the mixing nozzle is 5 to 25 times a hole diameter of the water nozzle.   3. The abrasive according to claim 1, wherein a length of the conduction hole of the mixing nozzle is longer than a distance from an opening formed at a tip of the conduction hole to the abrasive nozzle. Water jet nozzle.   4. The abrasive water jet nozzle according to claim 1, wherein a hole diameter of the abrasive nozzle is smaller than a hole diameter of the mixing nozzle and larger than a hole diameter of the water nozzle. 5. The mixing nozzle has a substantially cylindrical shape,
The tip of the outer peripheral surface of the mixing nozzle is formed with a taper having a diameter reduced at the tip so as to go in the direction of the abrasive nozzle from the position facing the supply port to the tip. The abrasive water jet nozzle according to any one of claims 1 to 4. The abrasive water jet nozzle according to claim 1,
An abrasive water jet processing machine having an abrasive supply device for supplying a predetermined amount of abrasive to the mixing chamber,
The abrasive supply device
A reservoir in which the abrasive is stored;
An outflow hole disposed in the lower portion of the reservoir,
A conveying rotor that is disposed below the outflow hole with a predetermined gap and is driven to rotate around a horizontal rotation axis;
A receiving portion disposed below the transfer rotor;
A discharge port formed in the receiving portion;
Abrasive water jet processing machine characterized by comprising   The abrasive water jet processing machine according to claim 6, wherein the transport rotor includes an uneven portion formed on an outer peripheral portion of the transport rotor.

Images