JP2006224205A - Powder injection nozzle device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a powder injection nozzle device for blasting which is excellent in working capability and durability at a nozzle part. <P>SOLUTION: The powder injection nozzle device has an inner tube for powder injection, an outer tube, a mixing chamber, and an accelerated fluid supply part. The outer tube is concentrically arranged outside of the inner tube in a state that the tip is axially protruded farther than the inner tube. The tip of the outer tube faces a workpiece. The mixing chamber is formed between the tip of the outer tube and that of the inner tube. The accelerated fluid supply part supplies an accelerated fluid for acceleration of powder from a gap formed by the outer periphery of the inner tube and the inner periphery of the outer tube to the mixing chamber. Then, the powder energized by the accelerated fluid in the mixing chamber is directly injected to the workpiece. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a powder injection nozzle device for blasting.

  Blasting, in which abrasive grains such as WA, SiC, and glass beads are sprayed onto a workpiece with a compressed fluid, has been conventionally used for surface roughening, pretreatment for adhesion and coating, pattern cutting, and the like. In pattern cutting by blasting, mask processing in which a mask material is applied to the work surface and abrasive grains are sprayed only on the processing area is common, but in recent years, for fine processing such as wiring patterns on inkjet heads and circuit boards. In addition, there is a demand for a direct blasting process in which abrasive grains are directly sprayed onto a workpiece without a mask.

In addition, regarding this type of blasting apparatus, Patent Document 1 discloses a hyper-type that supplies abrasive particles contained in a jetting compressed fluid (jetting fluid) to a nozzle by being urged by a compressing fluid for acceleration (acceleration fluid). The structure of the unit is disclosed.
Japanese Patent Laid-Open No. 11-300619

  The configuration of Patent Document 1 is a mixing portion of an injection fluid and an acceleration fluid, and a hose and a nozzle portion are connected to the downstream side. For this reason, in the configuration of Patent Document 1, the processing capacity and durability are reduced in proportion to the passage length due to the downstream pipe resistance. In particular, when the diameter of the flow path is reduced at the downstream nozzle part for fine processing, the resistance in the pipe to the nozzle tip becomes very large, so the processing capability and the durability of the nozzle part are greatly reduced. End up.

Further, in pattern cutting by blasting, abrasive grains may accumulate at a work site of the workpiece, and in this case, the operation must be interrupted in order to remove the abrasive grains from the workpiece, which is complicated. In general, it is difficult to accurately grasp the processing amount of blast processing, and the skill of the operator is required to obtain a desired processing amount.
The present invention is to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide a powder injection nozzle device excellent in processing capability and durability of the nozzle portion.

  Another object of the present invention is to provide a powder injection nozzle device that can easily grasp the amount of blast processing without having to interrupt the operation to remove abrasive grains from the workpiece.

  A powder injection nozzle device according to a first invention includes an inner tube for powder injection, an outer tube, a mixing chamber, and an acceleration fluid supply unit. The outer tube is disposed concentrically outside the inner tube with the tip protruding axially from the inner tube, and the tip of the outer tube faces the workpiece. The mixing chamber is formed between the distal end of the outer tube and the distal end of the inner tube. The accelerating fluid supply unit supplies the accelerating fluid for accelerating the powder from the gap formed by the outer periphery of the inner tube and the inner periphery of the outer tube toward the mixing chamber. Then, the powder urged by the accelerating fluid in the mixing chamber is directly jetted onto the workpiece.

In the first invention, the powder injected from the inner tube is mixed with the accelerating fluid in the mixing chamber formed in front of the inner tube, and the powder urged by the accelerating fluid is directly injected from the outer tube to the workpiece. The That is, the flow containing the powder is not squeezed downstream, and the flow containing the powder is accelerated near the tip of the nozzle and then sprayed directly onto the workpiece.
According to a second aspect, in the first aspect, the fuel supply pipe further includes an injection fluid supply pipe for powder injection and a powder supply pipe. One end of the jet fluid supply pipe is connected to the base end of the inner pipe, and the inner diameter thereof is set smaller than the inner diameter of the inner pipe. One end of the powder supply pipe is connected to the inner pipe in the vicinity of the connecting portion between the inner pipe and the jet fluid supply pipe.

In the second invention, the inner pipe is supplied with the injection fluid from the injection fluid supply pipe and is supplied with the powder from the powder supply pipe. When the jet fluid flows toward the inner pipe, a negative pressure is generated in the powder supply pipe due to the expansion of the pipe diameter at the connecting portion between the jet fluid supply pipe and the inner pipe. Due to this negative pressure, the powder is sucked out from the powder supply pipe into the inner pipe (ejector effect), and the powder flows into the mixing chamber together with the jet fluid.
According to a third aspect, in the first or second aspect, the first control unit that controls the powder injection of the inner tube, and the second control unit that controls the amount of acceleration fluid supplied to the acceleration fluid supply unit Have. The first control unit provides an injection stop time and intermittently performs powder injection from the tip of the inner tube, while the second control unit continuously supplies the acceleration fluid to the acceleration fluid supply unit.

  In the third aspect of the invention, since the accelerating fluid that does not contain powder is ejected from the tip of the outer tube to the workpiece during the ejection stop time, the powder accumulated at the work site of the workpiece is removed by the accelerating fluid. Moreover, if the processing amount by one powder injection is set equal, the processing amount of the workpiece can be easily grasped by the number of times of powder injection.

In the present invention, the flow containing powder is not squeezed on the downstream side, and the flow containing powder is accelerated near the tip of the nozzle and then blown directly onto the workpiece. Is greatly improved.
In addition, when accelerating fluid is continuously supplied while the powder is intermittently ejected from the tip of the inner tube, abrasive grains can be removed from the workpiece being worked on, and the amount of blasting can be reduced. It is also easy to grasp.

(Configuration of this embodiment)
FIG. 1 is a sectional view of an assembled state of the powder injection nozzle device of the present embodiment, and FIG. 2 is an exploded view of the powder injection nozzle device. FIG. 3 is an enlarged view of a main part of the nozzle portion of FIG.
The powder injection nozzle device includes an abrasive tank 10 and a fixing ring 11, a nozzle unit 12, an injection fluid control unit 13, and an acceleration fluid control unit 14.

  The abrasive tank 10 has a cylindrical tip portion, and a stepped portion 10a is formed on the inner periphery of the tip portion. Further, a male thread is engraved on the outer periphery of the tip of the abrasive tank 10 in order to mount the fixing ring 11. On the inner periphery of the fixing ring 11, a female screw that is screwed into the male screw of the abrasive grain tank 10 is formed, and an annular protrusion 11a for locking the nozzle portion 12 is formed at the back of the female screw.

  The nozzle unit 12 includes three nozzle blocks (20, 21, and 22), a processing nozzle 23, an injection nozzle 24, and an air pipe 25. The nozzle portion 12 is disposed at the tip of the abrasive tank 10, and the nozzle portion 12 is positioned by being sandwiched between the stepped portion 10 a of the abrasive tank 10 and the annular protrusion 11 a of the fixing ring 11 when the apparatus is assembled. In addition, the nozzle part 12 is fixed to the abrasive grain tank 10 using an adhesive agent at the time of apparatus assembly.

  The first nozzle block 20 of the nozzle portion 12 is formed in a cylindrical shape, and the outer diameter thereof is set slightly smaller than the inner diameter of the tip portion of the abrasive grain tank 10. When the apparatus is assembled, the first nozzle block 20 is disposed closest to the abrasive grain tank 10 among the nozzle blocks, and the base end side surface of the first nozzle block covers the opening of the abrasive tank 10 tip. An annular protrusion 20a is formed on the outer periphery of the first nozzle block 20 so as to be engaged with the stepped portion 10a of the abrasive tank 10, and the first nozzle block 20 is attached to the abrasive tank 10 after the device is assembled. It is designed not to fall inside.

A jet fluid inlet 20b is opened at the center of the first nozzle block 20 at the center of the block, and an abrasive grain inlet 20c and an acceleration fluid inlet 20d are provided around the jet fluid inlet 20b. It is penetrating. These intakes (20 b, 20 c, 20 d) are provided so as to penetrate to the front end side facing the axial direction of the first nozzle block 20.
The second nozzle block 21 is formed in a cylindrical shape having substantially the same diameter as the protrusion 20 a of the first nozzle block 20. When the apparatus is assembled, the first nozzle block 20 is disposed on the distal end side of the second nozzle block 21, the third nozzle block 22 is disposed on the proximal end side, and the second nozzle block 21 is sandwiched between the two nozzle blocks. It becomes a state.

  The second nozzle block 21 is provided with an injection nozzle insertion hole 21a along the central axis of the block. The second nozzle block 21 is formed with an abrasive supply path 21b and an acceleration fluid supply path 21c. The inlet of the abrasive grain supply path 21b is connected to the abrasive grain inlet 20c of the first nozzle block 20 at the time of assembling the apparatus, and the outlet is connected to the injection nozzle insertion hole 21a in a T shape inside the second nozzle block 21. Yes. On the other hand, the inlet of the accelerating fluid supply path 21c is connected to the accelerating fluid inlet 20d of the first nozzle block 20 at the time of assembling the apparatus, and the outlet is formed on the tip side of the second nozzle block 21 through the block.

The distal end side of the third nozzle block 22 is formed in a substantially conical shape, and an annular protrusion 22a is formed on the proximal end side. When the apparatus is assembled, the proximal end side of the third nozzle block 22 is adjacent to the distal end side of the second nozzle block 21, and the protrusion 22 a of the third nozzle block 22 is locked to the annular protrusion 11 a of the fixing ring 11. .
The third nozzle block 22 is provided with a machining nozzle insertion hole 22b along the central axis. An acceleration fluid inflow chamber 22c is formed concentrically with the machining nozzle insertion hole 22b on the proximal end side of the third nozzle block 22. When the apparatus is assembled, the acceleration fluid inflow chamber 22c is connected to the outlet of the acceleration fluid supply path 21c of the second nozzle block 21.

The processing nozzle 23 is inserted into the processing nozzle insertion hole 22 b of the third nozzle block 22. The length of the processing nozzle 23 is set to be substantially the same as the distance from the tip of the third nozzle block 22 to the bottom surface of the acceleration fluid inflow chamber 22c.
The injection nozzle 24 is inserted into the injection nozzle insertion hole 21 a of the second nozzle block 21. The length of the injection nozzle 24 is set to be slightly longer than the distance from the base end of the second nozzle block 21 to the bottom surface of the accelerating fluid inflow chamber 22c when the apparatus is assembled. Further, the outer diameter of the injection nozzle 24 is set smaller than the inner diameter of the processing nozzle 23.

  The base end of the injection nozzle 24 is aligned with the base end of the second nozzle block 21 when the apparatus is assembled. That is, when the apparatus is assembled, the injection nozzle 24 is concentrically disposed inside the processing nozzle 23, and a gap is formed between the inner periphery of the processing nozzle 23 and the outer periphery of the injection nozzle 24. Further, the tip of the processing nozzle 23 protrudes in the axial direction from the tip of the injection nozzle 24, and a mixing chamber is formed between the tip of the processing nozzle 23 and the tip of the injection nozzle 24.

The injection nozzle 24 has a slit 24a at a position corresponding to the abrasive supply path 21b. Therefore, when the apparatus is assembled, the slit 24a of the injection nozzle 24 matches the outlet of the abrasive supply path 21b, and the abrasive grains of the abrasive tank 10 reach the injection nozzle 24 through the abrasive intake 20c and the abrasive supply path 21b. It is supposed to be.
The outer diameter of the air pipe 25 is set to be substantially the same as the inner diameter of the injection nozzle 24. The distal end of the air pipe 25 is inserted into the proximal end side of the injection nozzle 24 with an interference fit. The front end of the air pipe 25 is inserted to the front of the slit 24a of the injection nozzle 24, and the slit 24a is positioned downstream of the front end of the air pipe 25 when the apparatus is assembled.

An O-ring 26 is disposed around the outer periphery of the first nozzle block 20, around each inlet on the tip side of the first nozzle block 20, and around the acceleration fluid inflow chamber 22 c on the base end side of the third nozzle block 22. The compressed fluid or the like is configured not to leak into other flow paths.
The jet fluid control unit 13 and the acceleration fluid control unit 14 incorporate a solenoid valve for adjusting the flow rate of the compressed fluid. One end of each flow path of each control part 13 and 14 is connected to the compressor which is not illustrated. The other end of the flow path of the jet fluid control unit 13 is connected to the jet fluid intake port 20b via the tube 15 and the joint 16. On the other hand, the other end of the flow path of the accelerating fluid control unit 14 is connected to the accelerating fluid intake 20 d via the tube 15 and the joint 16.

(Operation of this embodiment)
The powder injection nozzle device of the present embodiment is configured as described above, and the operation thereof will be described below.
When the solenoid valve of the jet fluid control unit 13 is opened, the compressed fluid (jet fluid) flows from the compressor into the jet fluid inlet 20b. The jet fluid from the jet fluid inlet 20 b flows from the air pipe 25 to the jet nozzle 24. At this time, a negative pressure is generated on the downstream side of the connecting portion between the air pipe 25 and the injection nozzle 24 due to a change in the pipe diameter between the air pipe 25 and the injection nozzle 24 (ejector effect).

With this negative pressure, the abrasive grains in the abrasive grain tank 10 are sucked into the injection nozzle 24 from the slit 24a via the abrasive grain intake 20c and the abrasive grain supply path 21b. The abrasive particles sucked into the injection nozzle 24 are injected into the mixing chamber of the processing nozzle 23 by the injection fluid.
On the other hand, when the solenoid valve of the acceleration fluid control unit 14 is opened, the compression fluid (acceleration fluid) flows from the compressor into the acceleration fluid intake 20d. The accelerating fluid flows into the accelerating fluid inflow chamber 22c through the accelerating fluid inlet 20d and the accelerating fluid supply path 21c. The accelerating fluid in the accelerating fluid inflow chamber 22 c passes through the gap between the processing nozzle 23 and the injection nozzle 24 and flows into the mixing chamber of the processing nozzle 23. Therefore, the flow of abrasive grains ejected from the ejection nozzle 24 and the accelerating fluid 23 merge in the mixing chamber.

The abrasive grains urged by the accelerating fluid in the mixing chamber are ejected from the tip of the machining nozzle 23 to cut the workpiece w. Note that the processing amount of the workpiece w can be adjusted by controlling the flow rate of the jet fluid in the jet fluid control unit 13 or controlling the flow rate of the acceleration fluid in the processing fluid control unit 14.
Here, when the workpiece w is continuously ground by deep hole machining or the like, abrasive grains may gradually accumulate in a portion of the workpiece w to be processed, resulting in a reduction in processing efficiency. In this case, it is preferable to set so that the ejection fluid control unit 13 intermittently supplies the ejection fluid, while the acceleration fluid control unit 14 continuously supplies the acceleration fluid.

  When the solenoid valve of the injection fluid control unit 13 is closed while the solenoid valve of the acceleration fluid control unit 14 is opened, the injection of abrasive grains from the injection nozzle 24 is stopped, and only the acceleration fluid is injected from the processing nozzle 23. The abrasive grains at the portion to be processed of w are removed (see FIG. 4). Therefore, if the abrasive grain injection stop time is periodically provided by controlling the electromagnetic valve of the jet fluid control unit 13, the machining surface of the workpiece w is cleaned and blasting can be performed efficiently. Moreover, if the machining amount by one injection is set equal in such control, the machining amount of the workpiece w can be easily grasped by the number of injections.

(Effect of this embodiment)
In this embodiment, since the flow including the abrasive grains of the injection nozzle 24 is accelerated in the mixing chamber of the processing nozzle 23, the processing capability of blast processing is greatly improved. Further, the flow containing abrasive grains is blown directly onto the workpiece w without being squeezed in the downstream mixing chamber. Therefore, in this embodiment, since the in-pipe resistance acting on the flow is small, a relatively high processing capability can be secured even if the flow rate of the compressed fluid is small, and the durability of the nozzle portion 12 can be expected to be improved. Furthermore, since the flow containing abrasive grains does not flow back to the injection nozzle by the acceleration fluid, the relationship between the flow rates of the compressed fluid and the acceleration fluid can be freely set.

  Further, in the present embodiment, the abrasive grains are sucked by the ejector effect, so that the responsiveness is high as compared with the structure in which the abrasive grains 10 are pressurized and the abrasive grains are pushed out, and the injection amount of the abrasive grains is controlled. Is also easier. In addition, in the configuration in which the abrasive grains are sucked by the ejector effect, it is not necessary to seal the abrasive tank 10 during the operation. Therefore, it is possible to add the abrasive grains from an abrasive supply port (not shown) even during the operation.

Further, when the abrasive fluid is intermittently ejected from the ejection nozzle 24 and the accelerating fluid is continuously supplied, the abrasive grains can be removed from the work w in operation, and the blasting process can be performed depending on the number of shots. The processing amount can be easily grasped.
(Correspondence between Claims and Embodiments)
Here, the correspondence between the claims and the embodiment is shown. Note that the correspondence shown below is an interpretation given for reference only, and does not limit the technical scope of the present invention.

  The injection nozzle 24 corresponds to the “inner pipe”. The processing nozzle 23 corresponds to the “outer tube”. The “mixing chamber” is formed between the front end of the processing nozzle 23 and the front end of the injection nozzle 24 inside the processing nozzle 23. The “acceleration fluid supply unit” corresponds to the flow path of the acceleration fluid from the compressor to the mixing chamber. The air pipe 25 corresponds to the “jet fluid supply pipe”. The “powder supply pipe” corresponds to the abrasive grain inlet 20c and the abrasive grain supply path 21b. The jet fluid control unit 13 corresponds to the “first control unit”. The acceleration fluid control unit 14 corresponds to the “second control unit”.

Sectional drawing of the powder injection nozzle apparatus of this embodiment Exploded view of powder injection nozzle device of this embodiment Enlarged view of the main part of the nozzle part of FIG. The figure which shows the state which supplied the injection fluid intermittently and supplied the acceleration fluid continuously

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Abrasive grain tank 11 Fixed ring 12 Nozzle part 13 Injection fluid control part 14 Acceleration fluid control part 20 1st nozzle block 21 2nd nozzle block 22 3rd nozzle block 23 Processing nozzle 24 Injection nozzle 25 Air pipe w Workpiece

Claims (3)

An inner tube for powder injection;
An outer tube that is arranged concentrically on the outer side of the inner tube in a state in which the tip protrudes in the axial direction from the inner tube, and the tip is opposed to the workpiece;
A mixing chamber formed between the tip of the outer tube and the tip of the inner tube;
An accelerating fluid supply unit that supplies an accelerating fluid for accelerating powder toward the mixing chamber from a gap formed by the outer periphery of the inner tube and the inner periphery of the outer tube;
A powder injection nozzle device, wherein the powder energized by the acceleration fluid in the mixing chamber is directly injected onto the workpiece. One end of the inner pipe is connected to the base end, and an inner diameter is set to be smaller than the inner diameter of the inner pipe.
The powder injection nozzle device according to claim 1, further comprising: a powder supply pipe having one end connected to the inner pipe in the vicinity of a connecting portion between the inner pipe and the jet fluid supply pipe. A first control unit that controls powder injection of the inner pipe, and a second control unit that controls an acceleration fluid supply amount to the acceleration fluid supply unit;
The first control unit provides an injection stop time and intermittently injects powder from the tip of the inner tube, while the second control unit continuously supplies acceleration fluid to the acceleration fluid supply unit. The powder injection nozzle device according to claim 1 or 2, wherein the powder injection nozzle device is provided.

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