JPH04331073A - Free abrasive grain blasting unit - Google Patents

Abstract

PURPOSE:To provide a free abrasive grain blasting unit that is made up of enabling a minute blasting job smoothly and so efficiently without entailing any fine grain receiver on a machined surface. CONSTITUTION:A suction nozzle 1 is concentrically set up in the central part of an injection nozzle 2, while a tip part of this suciton nozzle 1 is yet more projected than that of the injeciton nozzle 2. In succession, a part 13 being at the tip side of this suction nozzle 1 and adjoining to a machined surface is set down to negative pressure, through which a solid gas 2-phase jet sprayed out of the injeciton nozzle 2 and dust are sucked and then discharged to the outside.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a free particle injection processing apparatus, and more particularly to a processing apparatus which processes a workpiece by injecting a solid-gas two-phase flow of free particles and gas onto the workpiece.

0002

[Prior Art] Processing methods that perform mechanical energy processing using abrasive grains include processing methods using fixed abrasive grains and processing methods using free abrasive grains. Machining methods using fixed abrasive grains include grinding, honing, There are super finishing, abrasive paper processing, etc. On the other hand, processing using free abrasive grains includes lapping, polishing, buffing, barrel processing, ultrasonic processing, jet processing, and the like. Furthermore, a sandblasting method is known as a type of jetting process.

JP-A-63-22272 discloses a sandblasting device useful for removing rust from weathered surfaces of concrete structures such as buildings and metal structures. According to such a conventional sandblasting device, free abrasive grains are used and the abrasive grains are ejected under high pressure to remove burrs or chamfer the workpiece. Such devices were also used for decorative purposes such as engraving glass and metal. Furthermore, as disclosed in the above-mentioned publication, it is also used for paint and rust removal purposes.

0004

[Problems to be Solved by the Invention] The drawbacks of such conventional free abrasive injection machining equipment are that the particle size of the free abrasive is large;
Poor surface structure such as surface roughness or surface texture,
This made it impossible to perform high-precision surface processing such as that of semiconductor devices.

[0005] Furthermore, if the particle size of the free abrasive grains is large, there is a drawback that the edge portions are scraped and polishing sag occurs. Furthermore, the processing conditions could not be said to be good in terms of surface roughness and surface properties of slopes and inclined parts.

Therefore, conventional free abrasive jet machining devices have been used for deburring, decorative machining, or for applications where dimensions and shapes are not too strict. In other words, it could not be applied to microfabrication of semiconductors, magnetic disks, and the like. Further, with conventional abrasive jet machining devices such as sandblasting, there is a problem in that the amount of machining cannot be controlled well.

[0007] Such drawbacks are due to the fact that free abrasive grains are not made into a powder beam. In addition, the pressure distribution of the injected free abrasive grains was not uniform, and the degree of turbulence in the flow velocity distribution was large.

[0008]Furthermore, the above-mentioned technique has the problem that the resist formed on the workpiece is thick and the resolution is low. Furthermore, accumulation of loose abrasive grains on the processed surface lowers processing efficiency and adversely affects surface accuracy, surface roughness, etc.

[0009] The present invention was made in view of these problems, and it is possible to make fine particles into a powder beam and spray them with a uniform distribution, thereby making it possible to perform microfabrication of semiconductors, magnetic disks, etc. It is an object of the present invention to provide a free fine particle injection processing apparatus as described above.

0010

[Means for Solving the Problems] The present invention provides an apparatus for machining a workpiece by injecting a solid-gas two-phase flow of free particles and gas onto the workpiece. Injection nozzles are arranged so as to enclose the solid-gas two-phase flow from the injection nozzles of the injection nozzles, and a suction nozzle is arranged inside the injection nozzles, and the fine particles are discharged to the outside by the suction nozzles. It is designed to be discharged.

[0011] It is preferable that the suction nozzle disposed within the injection nozzle is coaxial with the injection nozzle, and the tip of the suction nozzle is approximately the same as the tip of the injection nozzle or slightly protrudes in the axial direction. It is preferable to let The tip of the suction nozzle inserted into the injection nozzle is maintained at negative pressure so as to effectively suction the fine particles.

0012

[Operation] Therefore, a solid-air two-phase flow of free abrasive grains and gas becomes a jet and is injected onto the workpiece from the injection port of the injection nozzle, which is arranged so as to almost surround the processing position of the workpiece. It turns out. The injected fine particles and dust are sucked by the suction nozzle disposed within the jet nozzle and discharged to the outside, so that no fine particle accumulation occurs on the surface of the workpiece.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a particulate injection processing apparatus according to an embodiment of the present invention, and this apparatus is equipped with an injection nozzle 2 for injecting a solid-gas two-phase flow containing particulates. The injection nozzle 2 has a cylindrical shape, and a cylindrical suction nozzle 1 for discharging dust containing fine particles is inserted coaxially inside the injection nozzle 2 .

In order to fix the suction nozzle 1 to the injection nozzle 2, an upper cover 3 is fixed to the upper part of the nozzle 2 by welding or brazing so as to close the upper end of the injection nozzle 2. A concave-shaped supply pipe 4 for forming a solid gas two-phase flow supply pipe is connected to the outer periphery of the injection nozzle 2, and the upper part of the supply pipe 4 is connected to an extension of the upper lid 3. (See Figure 2). Note that the extended portion of the upper lid 3 and the upper end of the supply pipe line 4 are both fixed by welding or brazing.

In this embodiment, the suction nozzle 1, the injection nozzle 2, the upper cover 3, and the supply pipe line 4 are all made of stainless steel, and their joints are joined by welding to integrate them.

As shown in FIG. 1, the suction nozzle 1 and the injection nozzle 2 are arranged coaxially. Further, as shown in FIG. 3, the supply pipe line 4 is joined to the injection nozzle 2 so as to extend in the tangential direction of the injection nozzle 2.

Next, the operation of such a free particle injection processing apparatus will be explained.

The workpiece 7 is movable on the mounting and moving table 8 in each of the X-axis direction, Y-axis direction, and Z-axis direction. Note that this moving mechanism is controlled by a computer. And moving platform 8
The workpiece 7 mounted thereon is here a mold,
A narrow inclined groove 9 is formed. Note that this inclined groove 9
Both side surfaces are composed of inclined surfaces 10.

The inclined groove 9 of the mold 7 is machined using a long and thin taper end mill. Alternatively, the inclined grooves 9 may be formed by groove machining by electrical discharge machining.

Generally, the mold 7 is then polished by a hand tool to complete the mold 7. The material for this mold 7 is S.
KD and WC (cemented carbide) are used.

[0021] If the polishing for finishing the inclined grooves 9 of the mold 7 is performed using conventional techniques, it will take too much time. Furthermore, as the shape of the mold 7 becomes more complex, sophisticated polishing techniques are required. Further, when the inclined grooves 9 are formed by electric discharge machining, it is difficult to remove the discharge hardened layer on the surface of the grooves. Furthermore, according to the conventional technique, the edges of the inclined grooves 9 will sag.

In order to solve the problems of the prior art, a free particle injection processing apparatus as shown in FIG. 1 is used. That is, the mold 7 is placed on the movable table 8 so that the inclined groove 9 of the mold 7 faces the injection port 5 of the injection nozzle 2 .

A solid-gas two-phase flow 11 containing fine particles is supplied to the injection nozzle 2 . In this case, in the case of rough polishing or removal of the discharge-altered layer, fine particles having a particle size of 50 to 100 μm are used. In the case of medium-smooth polishing, fine particles with a particle size of 15 to 50 μm are used. For final polishing, 1
Fine particles with a particle size of ~15 μm are used. In addition, materials for the free abrasive grains constituting the fine particles include Al2O3, S
iC etc. are used. The injection pressure of the solid-gas two-phase flow is 3 to 10 kg/cm2.

Under these conditions, the solid-gas two-phase flow 11 containing fine particles is supplied from the upstream side of the injection nozzle 2 through the supply pipe 4. As shown in FIG. 3, since the supply line 4 is connected tangentially to the injection nozzle 2, the solid air 2
The phase flow flows at high speed toward the injection port 5 side of the injection nozzle 2 while swirling within the nozzle 2 as shown by an arrow 11.

The tip of the suction nozzle 1 disposed within the injection nozzle 2 is approximately equal to or slightly protrudes from the tip of the injection nozzle 2. Since the suction port tip 13 on the tip side of the suction nozzle 1 is under negative pressure, a solid gas two-phase jet 12 is generated from the injection port 5 as shown in FIG.
As shown in the figure, it becomes a powder beam and extends from 40 to 100 meters.
The liquid is injected into the inclined groove 9 of the mold 7 at a high speed of /s.

Fine particles colliding with the inclined grooves 9 of the mold 7 and dust generated by processing are sucked through the suction port 6 of the suction nozzle 1, flow in the direction shown by the arrow 14, and are discharged to the outside. Thereafter, the fine particles are collected by a collection device, and the dust is collected by an exhaust fan.

Although the mold 7 is shown as being fixed in FIG. 1, the mold 7 may be moved while being moved by the movable table 8 during processing. Further, the nozzle 2 may be provided with movable devices in the X, Y, and Z directions.

The distance h in the height direction between the tip of the injection nozzle 2 and the workpiece 7 is suitably in the range of 1 to 20 mm. According to this device, it is possible to reduce the polishing time of the mold 7 to about one-third of the conventional polishing time. Moreover, the surface roughness can now be on the micron order.

A feature of the free particle injection processing apparatus according to this embodiment is that there is no accumulation of particles or dust on the surface of the inclined groove 9 of the mold 7, which is the processed surface. Furthermore, the flow of the solid-gas two-phase jet 12 becomes smoother, and the inclined groove 9 of the mold 7
The machining efficiency of the machined surface has been improved.

Furthermore, machining of slopes and sloped parts of the workpiece 7 has become easier. That is, etching processes such as grinding, polishing, and cutting, and deposition processes are facilitated. Further, deep groove machining such as machining of the inclined groove 9 of the mold 7 has become easier. Furthermore, the processed surface structure, that is, the dimensional accuracy and roughness of the surface is improved, and the surface quality is also improved.

[0031]

As described above, the present invention arranges an injection nozzle so as to almost surround the processing position of a workpiece, and injects a solid-gas two-phase flow from the injection port of the injection nozzle. A suction nozzle is disposed within the injection nozzle, and the fine particles are discharged to the outside by this suction nozzle. Therefore, there is no accumulation of particles or dust on the processing surface, and the flow of the solid-gas two-phase jet becomes smooth, making it possible to process the workpiece with good processing efficiency.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a free fine particle injection processing apparatus according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line II-II in FIG. 1;

FIG. 3 is a sectional view taken along the line III-III in FIG. 1;

[Explanation of symbols]

1 Suction nozzle 2 Injection nozzle 3 Top lid 4 Supply pipeline 5 Injection port 6 Suction port 7 Workpiece 8　Moving platform 9 Slanted groove 10　Slope surface 11 Solid-gas two-phase flow 12 Solid gas two-phase jet flow 13 Suction port tip (negative pressure part) 14 Arrow

Claims (1)

[Claims] 1. An apparatus for machining a workpiece by injecting a solid-gas two-phase flow of free particles and gas onto the workpiece, wherein an injection nozzle is arranged to substantially surround the machining position of the workpiece. The solid-gas two-phase flow is injected from the injection port of the injection nozzle, and a suction nozzle is disposed within the injection nozzle, and the fine particles are discharged to the outside by the suction nozzle. Free particle injection processing equipment.