JPH09103960A - Negative-pressure suction blasting device and method - Google Patents

Abstract

PURPOSE: To provide a facility in which to finish the surface of a material to be polished by using a negative-pressure gas decompressed from atmospheric pressure, and ejecting and colliding a negative-pressure mixed gas flow mixed with abrasive grains toward and against the material to be polished that is located inside a closed space. CONSTITUTION: In a negative-pressure suction blasting device which comprises a decompression device 16, a dust collector 17, and a wire blasting device 18, a negative-pressure gas of about -8,000 to -1,000mmAq, produced at the decompression device 16, is supplied to the wire blasting device 18, the inside of a blast tube 9 formed by a polygonal tube is sucked by the negative-pressure gas, and abrasive grains are mixed with the flow of negative-pressure gas by an abrasive supply tube 21 attached to the blast tube 9, to form a mixed gas flow. The mixed gas flow is ejected from a blast nozzle and collided against a material to be polished that is placed inside the blast tube 9, to treat the surface of the material 14 to be polished. The abrasive grains used in the polishing are collected, separated from the negative-pressure mixed flow gas by a cyclone separator, and returned to an abrasive tank 8 for reuse.

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to sandblasting, and in particular, abrasive grains are jetted into and collided with a material to be polished by using a negative pressure gas to remove scale of oxides, plating base finish, satin finish, and rough surface finish. The present invention relates to a negative pressure suction blasting device for processing a metal surface such as a sushi and its method.

[Prior Art] A method of performing surface processing of an object to be processed by using a sandblasting method which has been conventionally called sandblasting is performed by using abrasive grains of 3.5 to 7.0 Kg / cm ^2.
A method such as spraying on the surface of these objects with a certain amount of compressed gas, or rotating the impeller etc. at high speed and tapping steel abrasive grains etc. onto the surface of the objects using centrifugal force. And, it has been widely used for sand removal of castings, deburring, scale removal, metal coating / plating base finishing, letters or pattern writing.

In this surface processing method, since compressed gas is used, the apparatus must have a pressure resistance, and therefore mechanical strength is required. In addition, drains or oils from the compressor are used as abrasive grains. It may be mixed and adversely affect the material to be polished, and equipment for removing these is required, or the method of blasting using centrifugal force also needs mechanical strength to withstand centrifugal force. It included cost-up factors such as

Various problems are also contained in the jet of gas flow and the jet of abrasive from the blast nozzle,
Regarding the gas flow, the diffusion of the injected gas flow is narrow, the diffusion of the abrasive is small, the surface to be processed is also sharp, and the pulsation of the gas flow ejected from the blast nozzle cannot be ignored, and the blast unevenness There was a defect that was likely to occur.
Also, in terms of the ejection of the abrasive from the blast nozzle, the gas flow of the high-pressure gas can be easily obtained at high speed, but the efficiency of the blast effect is lower than the energy consumption, and in addition, the object to be processed is thin. If it is configured, there is a problem that the object to be processed is deformed due to the influence of the ejected gas flow.

In addition, since silica sand, which is an abrasive, is ejected on the ejected gas flow, the ejected abrasive scatters in the work place, which adversely affects the health management of workers and causes work accidents. It had various problems such as the possibility of causing it.

[Problems to be Solved by the Invention] In the conventional sandblasting method by jetting high-pressure gas, there are various defects such as low polishing efficiency, cost up factors, and possibility of occurrence of work accidents. The negative pressure suction type sand blasting apparatus according to the present invention uses negative pressure instead of the conventional high pressure gas jet, puts abrasive grains on a gas flow flowing in from the surrounding atmosphere, and causes the grains to collide with the object to be polished. The surface pressure is small, and the gas pressure difference is small, and since the abrasive grains are ejected to the object to be processed in a closed environment of negative pressure, they do not scatter in the work space, and the efficiency is high. In order to improve the above, in combination with the structural improvement of the nozzles and guides, it is attempted to improve the defects of the conventional jet blast by high pressure gas.

[Means for Solving the Problems] The present invention is
A negative pressure device consisting of a decompression device that generates a negative pressure higher than atmospheric pressure, a dust collector that removes dust, a wire blast device that polishes the object to be polished, and an exhaust supply pipe that connects each device and supplies a negative pressure to each device. In a pressure suction blasting device, a mixed gas flow in which a negative pressure gas and polishing abrasive grains that can be varied by a polishing material supply cylinder is generated and is jetted into a blast tube forming a negative pressure closed space where an object to be polished exists. The blast tube is provided with a blast nozzle for ejecting the mixed gas flow, a blast guide for guiding the mixed gas flow, and a protector facing the blast nozzle, and this is achieved by means of ejecting and polishing the mixed gas flow onto the object to be polished. Also, the used mixed gas flow is
After passing through the blast suction pipe and the discharge suction pipe, it is separated into negative pressure gas and abrasive grains by a cyclone separator, and the abrasive grains are reused.

[Operation] While operating the device to generate a negative pressure gas, the wire or bar material to be polished is passed through the blast tube to expose the head from the other end, and at that time, the negative pressure is applied to the blast tube. When the pressure is supplied, the abrasive grains dropped on the blast receiving port and the negative pressure gas flow flowing from the atmospheric pressure inlet are mixed and ejected into the blast tube. In the blast tube, the mixed gas flow is guided by the guide to polish the material to be polished from one side.
At the same time, the inner polishing material is polished on the entire surface by the mixed gas flow ejected from four directions. At this time, if the material to be polished is moved to one side at an appropriate speed, the material to be polished is polished over the entire surface and the entire length. The abrasive grains used for polishing are collected, separated by a cyclone separator, returned to the abrasive tank, and reused.

[Example] An example of the present invention will be described with reference to the drawings. FIG. 1 is an overall configuration diagram of a negative pressure suction blasting apparatus according to an embodiment of the present invention. FIG. 2 is a perspective view showing a state in which an abrasive material supply cylinder is attached to the blast tube of the negative pressure suction blast device of the embodiment of the present invention. FIG. 3 is a cross-sectional view of the blast tube, the abrasive material supply cylinder portion, and the exhaust suction pipe portion of the negative pressure suction blasting apparatus according to the embodiment of the present invention. FIG. 4 is a vertical cross section and a horizontal cross section of the blast surface of the negative pressure suction blast tube of the embodiment of the present invention.

Normal atmospheric pressure is 1013 mbar (m
However, the atmospheric pressure of a typhoon called a large typhoon that hits Japan every year is about 950 mbar.
It is well known that a severe disaster is caused even though the negative pressure is only about 10% lower than the atmospheric pressure. Therefore, it can be easily imagined that a considerably large negative pressure energy can be obtained if the negative pressure is set to about 10% or more. Therefore, negative pressure suction gas is used instead of the jetting of high pressure gas that has been frequently used in the past. I suggest the negative pressure suction type sand blast. From the point of view of jetting gas from the nozzle, both high-pressure jet and negative-pressure jet are relative to the atmospheric pressure, and since they are negative pressure, they do not cause any inconvenience. On the contrary, there are also benefits that result from negative pressure. Based on such an idea, the negative pressure suction type sandblasting method of the present invention has been developed, and an embodiment will be described with reference to the drawings.

FIG. 1 is an overall view of a negative pressure suction sandblasting apparatus of the present invention, which is an exhaust suction for connecting a depressurizing apparatus 16, a dust collector 17, and a wire rod blasting apparatus 18 to each apparatus which is pressure-closed. It consists of a tube 25.

The decompression device 16 comprises an exhaust pump 1 equipped with a silencer 2 and is installed in the soundproof room 3. The exhaust pump has a pressure of -1000 to -8000 mmA.
Since it is only necessary to obtain a pressure of about q (900 to 200 mbar), a negative pressure of this level is a pressure that can be sufficiently dealt with by an ordinary oil rotary pump or roots pump, and is not a special facility. However, since the exhaust amount is a relatively large amount of gas, a silencer 2 for silencing the exhaust noise is required, and the silencer 2 must be installed in the soundproof room 3 to insulate the surrounding work area from noise. The negative pressure obtained by the decompression device 16 is sucked into the negative pressure of the next-stage device by the exhaust suction pipe 25.

The dust collector 17 is provided to remove dust such as abrasive grains and cut polishing pieces and protects the decompression device, and exhausts dust containing dust sucked by the wire blasting device 18, Introduced from below the dust collecting filter,
Dust such as polishing abrasive grains and polishing pieces that cannot be removed by the wire rod blasting device 18 is separated from the gas flow and stored in the lower part thereof. At the lower part of the dust collecting filter section 4, there is a normally-closed dust collecting and discharging port 5, and by opening this, the dust is discharged into the dust collecting box 6.

The wire rod blasting device 18 is a main part of the present invention, and comprises a cyclone separator 7 and an abrasive tank 8 having an abrasive outlet 29 equipped with an abrasive grain adjusting orifice.
A blast tube 9 having closed ports 12 at both ends, a guide roller 11, an operation panel 13, an abrasive material supply cylinder 21 attached to the blast tube 9, and a blast suction pipe 10 connected to both ends of the blast tube 9, It is composed of a suction pipe collecting portion 32 that connects both, and a discharge suction pipe 33 that connects between the cyclone separator 7 and the suction pipe collecting portion 32, and a maximum of −8000 mmAq by the exhaust suction pipe 25.
Some negative pressure is being supplied.

The cyclone separator 7 is equipment for separating the abrasive grains after polishing the material to be polished by the blast tube 9 and the dust such as cutting pieces cut from the object to be processed from the negative pressure gas flow. Attention, cyclone separator 7,
Intermediate tank 34, four valves 351, 352, 353, 3
54 and connecting pipes 361, 36 for connecting them to each other
2 and auxiliary connecting pipes 371, 372, 373, and the separated abrasive grains are returned to the abrasive material tank 8 located at the lowermost part for reuse. An exhaust suction pipe 25 is connected to the top of the cyclone separator 7, and the maximum-8000 mmA required by the wire rod blasting device 18 is provided.
Negative pressure of about q is supplied. Further, from the rear surface near the top of the cyclone separator 7, a discharge suction pipe 33 (indicated by a dot-dash line) is connected to the suction pipe collecting portion 32 at the bottom, and a negative pressure is supplied to the blast tube 9.

The abrasive tank 8 is a tank for accommodating and storing abrasive grains for polishing the object to be polished. The abrasive grains used for polishing are steel-based shot materials, grits materials, and alumina (Al). _{The 2} O ₃ ) system includes brown alumina, white alumina, artificial emery, alumina zirconia, etc., and the silicon carbide (SiC) system includes black silicon carbide,
Other materials such as green silicon carbide include CBN, diamond, etc. The particle size and type are selected and used according to the object to be processed and its use. At the lower part of the abrasive tank 8, there is provided an abrasive outlet 29 equipped with a plurality of abrasive grain adjusting orifices.
The required amount can be naturally dropped into the blast receiving port 21 and supplied.

Under the abrasive material tank 8, an abrasive material supply cylinder 21 having a blast tube 9 and a blast receiving port 26 is provided.
However, they are arranged horizontally and so that they are orthogonal to each other, the end portion on the blast tube side of the abrasive material supply cylinder 21 is a closed mouth, and the blast branch pipe 27 branches at an angle of 45 degrees from the vicinity thereof, It is fixed to one side of the wall of the blast tube 9. As another embodiment other than this method, FIG.
As shown in (C), the abrasive supply cylinder 21 may be attached to the blast nozzle 22 at an angle of 45 degrees, instead of the blast branch pipe 27. At the end portion on the blast receiving port side, an atmospheric air inlet 30 having an opening through which the amount of gas flow can be varied is provided,
The mixing ratio of the abrasive grains and the inflowing negative pressure gas is adjusted to an appropriate amount to improve the polishing efficiency. However, even if the air inlet 30 is not specially provided,
It is also possible to obtain a mixed negative pressure gas flow with abrasive grains.

The blast tube 9 is a negative pressure closed space for polishing the material to be polished, and has a maximum of −80 due to the exhaust suction pipe 33 connected to the cyclone separator 7.
It is sucked to a negative pressure of about 00 mmAq. In the present embodiment, the blast tube 9 is described as a square cylinder, but other polygonal cylinders, cylinders, hollow cylinders, etc. may be used.
Both ends of the blast tube 9 are square cylinders that form a negative pressure closed space in which a blast suction pipe 10 is attached to the closing port 12 and a wall body in the vicinity thereof, and the diagonals thereof are positioned at an angle in the vertical and horizontal directions. It is installed on the floor.

The closing ports 12 located at both ends of the blast tube 9 have a diameter corresponding to the size of the material to be polished 14,
A street guide 1 made of a tapered superalloy or a hardened metal body with a wide inlet and a narrow outlet.
5 is firmly attached from the inside and outside of the tube wall of the blast tube 9 by means such as screwing. Since the hole portion of the passage guide 15 is an opening, the negative pressure in the blast tube 9 may draw the atmospheric pressure of the surrounding area, which may lower the polishing efficiency. It is effective to attach a pressure member 28 to prevent the inflow of atmospheric pressure.

A blast nozzle 22 is firmly attached to the wall of the blast tube 9 by means such as screwing, and a part of the tip of the blast nozzle 22 partially projects into the tube of the blast tube 9. In the nozzle 22,
Similarly, the blast branch pipe 27 is firmly attached by means such as screwing. In the illustrated example, the blast nozzle 22
Is attached to the pipe wall on the upper right side of the blast tube 9, but the blast nozzles 22 are also attached to the four pipe walls on the lower right side, the upper left side and the lower left side of the other pipe walls in the same manner. The polishing material 14 is polished from four directions. Further, as shown in FIG. 4 (B), the blast nozzle 22 is not one in one direction, but a plurality of blast nozzles 22 are arranged in parallel as shown in the drawing to further improve the polishing efficiency. In addition, the screwing stroke of the blast nozzle 22 is set to be long, and the material to be polished 1
If the distance to 4 is variable, further improvement in polishing efficiency can be expected.

Inside the blast tube 9, as shown in FIG. 4, there is arranged a material to be polished 14 which is to be ground just below the injection port of the blast nozzle 22 and in the vicinity of substantially the center of the blast tube 9. A guide space sandwiched by the blast guides 23 is formed on both sides. Blast guide 2
No. 3 is about 6 to 7 degrees on the nozzle side and about 12 to 14 on both sides.
It has a shape that is open to the blast nozzle side, and the space portions on both sides that sandwich the material to be polished 14 that follow are parallel spaces, and a mixed gas of negative pressure gas and polishing abrasive particles ejected from the blast nozzle 22. It is composed of a pair of left and right block bodies having a shape suitable for guiding the flow to the material to be polished 14.

On the tube wall of the blast tube 9 facing the blast nozzle 22, the tube wall of the blast tube 9 is protected from the mixed gas flow of the abrasive particles and the negative pressure gas jetted from the blast nozzle 22. A block-shaped protector 24 having a central portion formed in a concave groove is arranged.

In the above embodiment, the blast guide 23 and the protector 24 are described as block bodies, but a blast guide and protector made of resin or rubber may be used depending on the type of abrasive grains used.

Blast nozzle 22 and blast guide 23
In addition, since the protector 24 is constantly subjected to the same polishing action as that of the material to be polished 14 by the mixed gas flow of the polishing abrasive particles and the negative pressure gas, its wear is so great that these parts can be easily replaced. It must have a structure that can be easily attached and detached by means such as screwing. Blast tube 9
Since the same effect is exerted on the blast tube 9, it is desirable to construct the blast tube 9 not by a single cylinder but by an assembly method such as fixing an iron plate with a screw.

A blast suction pipe 10 is connected near both ends of the blast tube 9, and a suction pipe collecting portion 32 is provided.
Connected to the cyclone separator 7 through the discharge suction pipe 33, and the maximum inside of the blast tube 9 is -8000.
A negative pressure of about mmHg is supplied. In this embodiment,
Although a method of supplying a negative pressure into the blast tube 9 by using the blast suction tube 10 and the suction tube collecting portion 32 is described, the discharge suction tube 33 is connected to approximately the center of the blast tube 9 and the negative pressure is applied. It does not matter even if it supplies a system.

Guide rollers 11 are attached to both outer frames of the wire blasting device 18, which horizontally supports the material 14 to be polished by the blast tube 9 and cooperates with the guides 15 as described above. The blast tube has a function of smoothly feeding the material 14 to be polished.

The operation of the blast device of the present invention will be described with reference to the drawings. Prior to carrying out the polishing, the wire material or the bar material of the material to be polished 14 is inserted into the blast tube 9 through the guide roller 11 and the passage guide 15 from one side of the apparatus, and its head is exposed from the other end. When the preparation is completed, the operation panel 13 is operated to activate the decompression device 16 to generate a negative pressure of about -8000 mmAq at the maximum. The generated negative pressure is made negative through the exhaust suction pipe 25, the discharge suction pipe 33, and the blast tube 9 to the location of the atmospheric pressure inlet 30 of the abrasive material supply cylinder 21.

At this time, the operation panel 13 is operated to discharge a required amount of abrasive grains from the abrasive material discharge port 29, and the blast receiving port 2
When it is naturally dropped toward No. 6, the abrasive grains are supplied to the abrasive supply tube 2
While falling into the inside 1, the mixture is mixed with the gas flow flowing in from the atmospheric pressure inlet 30 into a negative pressure mixed gas flow, passes through the blast branch pipe 27, and is ejected from the blast nozzle 22 into the blast tube 9. The jetted negative-pressure mixed gas flow is guided by the blast guide 23, collides with the negative-pressure mixed gas flow jetted from the four directions, and collides with the material to be polished 14 to be polished.
Polish.

The material 14 to be polished is pulled from left to right or vice versa by a pulling device (not shown) to guide the roller 1.
1. Move from left to right through the closing port 12 having the passage guide 15, and be polished by the negative pressure mixed gas flow ejected in the meantime. When the polishing of the workpiece 14 is completed, the operation panel 1
3 is operated to close the abrasive material discharge port 29, and then the decompression device 16 is stopped to release all negative pressure. Next, a new material to be polished 14 is attached, and new polishing is started by the above procedure.

The mixed gas flow of the abrasive grains and the negative pressure gas used during polishing is collected by the blast suction pipes connected to both ends of the blast tube 9, and the suction pipe collecting portion 32 and the discharge suction pipe 33 are collected. After that, it is returned to the cyclone separator 7,
Here, the abrasive grains and the negative pressure gas are separated, and the abrasive grains are returned to the abrasive tank 8 for reuse. A mixed gas flow of abrasive grains and a negative pressure gas passing through the exhaust suction pipe 33 is guided from the back surface into the cyclone separator 7, where the mixed gas flow is wider than the narrow exhaust suction pipe 33. Since it is discharged into the separator 7, the flow velocity of the mixed gas flow sharply decreases according to Bernoulli's theorem, so that the abrasive grains fall downward due to their own weight, and are separated from the negative pressure gas flow to form a cyclone. Accumulates at the bottom of the separator 7.

While the wire blasting device 18 is stopped, the valve 35
When the openings 1, 352 are opened, the polishing abrasive particles accumulated in the bottom of the cyclone separator 7 are returned to the polishing material tank 8 through the connecting pipe 361, the valve 351, the intermediate tank 34, the valve 352 and the connecting pipe 362. When the wire blasting device 18 is operating, first, the valve 353 is opened to make the intermediate tank 34 a negative pressure, and then the valve 351 is opened to transfer the abrasive grains accumulated at the bottom of the cyclone separator 7 to the intermediate tank 34. To do.
After that, if the valves 351 and 353 are closed and the valve 354 is opened, the inside of the intermediate tank 34 becomes normal pressure, and if the valve 352 is opened, the abrasive grains pass through the connecting pipe 362 and are returned to the abrasive tank 8. In this way, the abrasive grains can be returned to the abrasive tank 8 regardless of whether the wire blasting device 18 is operating or stopped.

Although the embodiments of the present invention have been described by polishing wire rods, bar members, etc., they can be used for other materials or applications without departing from the spirit of the invention. Instead of polishing as in the present embodiment, it is also possible to suction paint a negative pressure gas flow with a paint or a chemical, and to paint the surface of the object or clean the surface with the chemical. In this case, since the chemicals, paints, etc. used are confined in the negative pressure closed space, they do not scatter in the workplace, and have a great effect on the conservation of the workplace environment. Further, the shape of the blast tube is not limited to the square tube as in the present embodiment, but other polygonal tubes are possible, and the blast tube is formed of, for example, a sphere, and the negative pressure mixed gas flow with the polishing abrasive grains is arranged in a staggered arrangement. It is also possible to polish the object to be polished by ejecting it into the sphere from the blast nozzle. Not only can the object be polished, but it can also be expected to be used for degreasing the surface of the object and removing the lubricant that has adhered during the wire drawing process.

[Advantages of the Invention] As described in detail above as the embodiments, the negative pressure suction type wire rod blasting apparatus of the present invention has many advantages. Since it is a negative pressure suction type, there is no chance that the drain, oil, etc. generated by the pump will mix into the polishing abrasive grains, and the polishing target material is always polished with clean abrasive grains, so the polishing target material is contaminated. It has a great effect on improving the finished quality of the product.

The negative pressure used in the apparatus is -8000 to -100.
Since it is a negative pressure of about 0 mmAq, there is no need to give special consideration to the internal pressure and mechanical strength of the equipment, and normal equipment can be used, so the manufacturing cost is low, there is no cost up factor, and the conventional equipment There is also a merit that can reduce the range of self-damage and elimination. In addition, since a gas flow that is depressurized to about 1/2 is usually used to flow from the atmospheric pressure area into the negative pressure space, the gas pressure difference and the pressure fluctuation range are also small, and if the depressurization is about 1/3 to 1/4, it is thin. Even if the object is blasted, the rate of deformation of the object is small.

Since negative pressure is utilized, it is necessary to form a negative pressure closed space around the object to be processed. Therefore, the abrasive grains do not scatter in the workplace, and the occupational disease caused by the abrasive grains is caused. Since there is no occurrence of occupational accidents such as, there is no need to install special equipment in the workplace. Since the polishing abrasive grains can also be collected and reused in the negative pressure space, there are many advantages that the material cost can be reduced and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a negative pressure suction blasting device according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a state in which an abrasive material supply cylinder is attached to a blast tube in the negative pressure suction blast device according to the embodiment of the present invention.

FIG. 3 is a cross-sectional view of a blast tube and an abrasive material supply cylinder portion in the negative pressure suction blast device according to the embodiment of the present invention.

FIG. 4 is an enlarged view of the blast surface cross section of the blast tube in the negative pressure suction blast device according to the embodiment of the present invention.

FIG. 5 is an explanatory view of a closing opening portion of the blast tube in the negative pressure suction blasting apparatus according to the embodiment of the present invention.

FIG. 6 is a system diagram for collecting abrasive grains using a cyclone separator in a negative pressure suction blasting apparatus according to an embodiment of the present invention.

[Explanation of symbols]

1: Exhaust pump 2: Silencer 3: Soundproof chamber 4: Dust collection filter 5: Dust collection discharge port 6: Dust collection box 7: Cyclone separator 8: Abrasive tank 9: Blast tube 10: Blast suction pipe 11: Guide roller 12 : Closed port 13: Operation panel 14: Material to be polished 15: Passage guide 16: Decompression device 17: Dust collector 18: Wire rod blasting device 21: Abrasive material supply cylinder 22: Blast nozzle 23: Blast guide 24: Protector 25: Exhaust suction pipe 26: Blast receiving port 27: Blast branching pipe 28: Pressure preventive material 29: Abrasive material discharging port 30: Atmospheric pressure inlet port 31: Guide opening part 32: Suction pipe collecting part 33: Discharging suction pipe 34: Intermediate tanks 351 to 354 : Valves 361-362;
Connection pipe 371-373: Auxiliary connection pipe

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[Procedure amendment]

[Submission date] October 9, 1996

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] All figures

[Correction method] Change

[Correction contents]

FIG.

FIG. 4

[Fig. 2]

[Figure 3]

FIG. 6

[Figure 5]

Claims (7)

[Claims] 1. A pressure reducing device for generating a negative pressure higher than atmospheric pressure,
A dust collector that removes dust, a wire blasting device that polishes the material to be polished, and a negative pressure suction blasting device that connects each device and supplies a negative pressure to each device. An abrasive material supply cylinder for generating a negative pressure mixed gas flow in which a variable negative pressure gas and polishing abrasive particles are mixed, and a blast nozzle for ejecting the negative pressure mixed gas flow, which is provided on the cylinder wall of the negative pressure closed space. A negative pressure suction blasting device having a blast guide for guiding a negative pressure mixed gas flow and a blaster facing a blast nozzle and polishing a material to be polished. 2. A blast suction pipe provided at both ends or a central portion of the blast tube, and a discharge suction pipe connected to a cyclone separator from a suction pipe collecting portion, and polished from the used negative pressure mixed gas flow. The negative pressure suction blasting apparatus according to claim 1, wherein the abrasive grains and the negative pressure gas are separated and the polishing abrasive grains are reused. 3. The opening facing the blast nozzle is 12 to 1.
The negative pressure blasting device according to claim 1, wherein the negative pressure blasting device has an opening of about 4 degrees, and the polishing portion has a blast guide which is a parallel space. 4. A negative pressure suction blast apparatus according to claim 1, wherein a concave protector is arranged at a position facing the blast nozzle. 5. The negative pressure suction blast apparatus according to claim 1, wherein the blast nozzle, the blast guide, the protector, and the wall of the blast tube have a structure capable of being assembled and disassembled. 6. A pressure reducing device for generating a negative pressure higher than atmospheric pressure,
A dust collector for removing dust, a wire rod blasting device for polishing a material to be polished, and a negative pressure suction blasting device including an exhaust suction pipe that connects each device and supplies a negative pressure to each device,
The negative pressure mixed gas flow generated by the abrasive supply cylinder and the negative pressure mixed gas flow with the abrasive grains are guided into the blast tube, and the negative pressure mixed gas flow induced by the blast guide is blasted to the material to be polished. A negative pressure suction blasting method, which comprises ejecting from a nozzle and polishing. 7. A blast suction pipe provided at both ends or a central portion of the blast tube, and a discharge suction pipe connected to a cyclone separator from a suction collecting portion,
The negative pressure suction blasting method according to claim 6, wherein the polishing abrasive grains and the negative pressure gas are separated from the used negative pressure mixed gas flow and the polishing abrasive grains are reused.