JPH04336963A - Suction pipe - Google Patents

Abstract

PURPOSE:To prolong the service life of a suction nozzle by preventing fine particles from colliding against the respective inner surfaces of the suction nozzle in the suction nozzle which extracts fine particles stored in a fine particle storing tank by means of suction caused by the flow of high pressure air. CONSTITUTION:The outer circumferential surface 27a of the other end section 27 of a fine particle suction pipe 24 is formed in a tapered shape in such a way as to be narrowed in diameter as it goes to the tip end of the pipe, and the inner circumferential surface 28a of the air discharge port 28 of a high pressure air supply chamber 26 is formed into a tapered shape having a gradient equivalent to that of the outer circumferential surface of the other end section of the fine particle suction pipe formed into a tapered shape, so that a narrow gap 29 is thereby formed between the outer circumferential surface of the other end section of the fine particle suction pipe and the air discharge port of the high pressure air chamber with the other end section of the fine particle suction pipe positioned close to the air discharging port of the high pressure air supply chamber.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a suction nozzle that takes out fine powder stored in a fine powder supply tank by a negative pressure suction action generated by a flow of high-pressure air.
It is an object of the present invention to provide a novel suction nozzle that can prevent fine powder from colliding with the inner surface of each part of the nozzle and can extend the life of the suction nozzle.

0002

[Prior Art] There is a fine powder injection device as a device that performs a predetermined treatment by injecting fine powder made of metal, inorganic material, etc. onto an object to be treated (hereinafter referred to as a "work") using high pressure air. For example, it is used to form minute blind holes or through holes in circuit boards.

By the way, in order to inject fine powder onto a workpiece in such a fine powder injection device, the fine powder is taken out from the fine powder supply tank in which the fine powder is stored, and the fine powder is mixed with high-pressure air. There is a need to.

[0004] A suction nozzle that utilizes negative pressure suction is used to take out the fine powder and mix it with high-pressure air.

FIG. 7 shows an example a of such a suction nozzle.

In the figure, b is a nozzle body, which has a first passage c extending in the vertical direction and a second passage d communicating with the first passage c from a direction perpendicular to the first passage c.
A high-pressure air injection nozzle e is inserted in the upper part of the passage c, and one end of the fine powder delivery pipe f is inserted in the lower part, and one end of the fine powder suction pipe g is inserted in the second passage d. section has been inserted.

The high-pressure air jetting nozzle e is connected to an air compressor (not shown) via an air pipe h, and the other end of the fine powder delivery pipe f is connected to a jetting nozzle placed in a workpiece processing chamber (not shown). The other end of the suction pipe g is connected to a take-out nozzle i that projects into a fine powder supply tank in which fine powder is stored.

j is a fine powder supply tank in which fine powder k is stored (only the lower end is shown in the drawing); l is a filter attached to close the lower end opening m of the fine powder supply tank j; , n is a powder collector disposed inside the fine powder supply tank j, o is an air supply chamber for air vibration communicating with the lower end opening m across the filter l, and the above-mentioned take-out nozzle i is a powder collector disposed inside the fine powder supply tank j. is fixed to the center of the dust collector n, and its upper end is located within a recess p formed in the lower end surface of the dust collector n.

[0009]The high pressure air jetted from the high pressure air injection nozzle e reaches the confluence q of the first passage c and the second passage d.
The flow of high-pressure air creates a negative pressure inside the fine powder suction pipe g, and this negative pressure creates a suction force at the suction port opened at the upper end of the take-out nozzle i. occurs.

The fine powder k in the fine powder supply tank j is agitated by the air vibration effect of high-pressure air that is injected from the air supply chamber o through the filter l, and a part of it is absorbed into the concave part of the powder collector n. p, is sucked into the fine powder suction pipe g from the suction port of the take-out nozzle i, is mixed with high pressure air at the confluence q of the nozzle body b, and flows into the fine powder delivery pipe f.

[0011]The suction nozzle a takes out the fine powder k from the fine powder supply tank j and mixes it with high-pressure air as described above.

0012

However, in such a suction nozzle a, the moving direction of the fine powder k exiting from the fine powder suction pipe g into the nozzle body b is the same as the direction in which high-pressure air flows. Because they intersect perpendicularly, most of the fine powder k collides with the inner circumferential surface of the first passage c and the fine powder delivery pipe f, and these inner circumferential surfaces are severely abraded, shortening the life of the nozzle body b. The problem was that it would disappear.

[0013]

[Means for Solving the Problems] Therefore, in order to solve the above-mentioned problems, the suction nozzle of the present invention is provided by forming the outer peripheral surface of the other end of the fine powder suction pipe into a tapered shape so that the diameter decreases toward the tip. At the same time, the vicinity of the air discharge port of the high-pressure air supply chamber and/or the inner peripheral surface of the fine powder delivery pipe is formed into a tapered hole shape having approximately the same slope as the slope of the outer peripheral surface of the other end of the tapered fine powder suction pipe. Then, the other end of the fine powder suction pipe is located near the air outlet of the high-pressure air supply chamber and/or near the inner circumferential surface of the fine powder delivery pipe, and the other end of the fine powder suction pipe and the high-pressure air A narrow gap is formed between the air outlet of the supply chamber and/or the inner peripheral surface of the fine powder delivery pipe.

[0014]

[Operation] Therefore, according to the suction nozzle of the present invention, in the region where fine powder is mixed with high-pressure air, high-pressure air flows into the flow channel from the outer circumference, and fine powder flows into the flow channel from approximately the center thereof. Therefore, the fine powder does not collide with the inner circumferential surface of the flow path, and therefore the air discharge port of the high-pressure air supply chamber and the inner circumferential surface of the fine powder delivery pipe are not scraped off by the fine powder. The life of the suction nozzle can be extended.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the suction nozzle of the present invention will be explained below according to the embodiments shown in the accompanying drawings.

In the embodiment shown in the drawings, the suction nozzle of the present invention is applied to a suction nozzle for taking out fine powder from a fine powder supply tank in a fine powder injection device 1.

First, an overview of the fine powder injection device will be explained (
(See Figures 1 and 2).

The fine powder injection device 1 includes a fine powder supply tank 4 having a storage chamber 3 in which fine powder 2 is stored, a fine powder replenishing section 5 that replenishes the fine powder 2 to the storage chamber 3 in a timely manner, and a workpiece. a processing chamber 8 provided with an injection nozzle 7 that injects the fine powder 2 toward the storage chamber 3; and a suction nozzle 9 that is fixed to the lower surface of the fine powder supply tank 7 and sucks and takes out the fine powder 2 from within the storage chamber 3.
, an air compressor 10 that supplies high-pressure air to the suction nozzle 9 and the storage chamber 3, and a collection section (not shown) that collects the fine powder 2 in the processing chamber 8.

The fine powder supply tank 4 has a substantially cylindrical shape that is short in the axial direction relative to its diameter, and the upper half of the storage chamber 3 is cylindrical, and the lower half has a diameter that decreases as it goes downward. The upper part of the fine powder supply tank 4 is closed by a top plate 11, and the opening at the lower end is closed by a disc-shaped filter 13.

Reference numeral 14 denotes a rotating shaft located on the axis of the storage chamber 3, and a powder collector 15 in the shape of a bullet that is elongated in the vertical direction is fixed to the lower end of the rotating shaft. 16 is located near the lower end opening 12 of the fine powder supply tank 4,
A circular recess 16a is formed in the lower end surface 16.

Reference numeral 17 denotes a stirring plate attached to the outer peripheral surface of the powder collector 15, the lower end of which extends close to the filter 13.

Reference numeral 18 denotes a motor, and the rotating shaft 14 is rotated by the motor 18, thereby rotating the powder collector 15 and the stirring plate 17 in the direction around the axis.

19, 19, . . . are bimorph diaphragms disposed along the inner peripheral surface of the lower half of the storage chamber 3, and each bimorph diaphragm 19 extends along the inner peripheral surface in the axial direction. It is formed into a substantially fan-like shape as if it were divided.

The fine powder replenishing section 5 consists of a hopper 20 disposed at the upper part of the fine powder supply tank 4 and storing the fine powder 2, and a valve body 21 etc. disposed at the lower part of the hopper 20. The fine powder 2 stored in the valve body 20 is thrown into the storage chamber 3 at appropriate times by opening and closing the valve body 21, so that a substantially constant amount of the fine powder 2 is always stored in the storage chamber 3.

Reference numeral 22 denotes an air inflow recess formed in the upper end surface of the suction nozzle 9, and the filter 13 is located between the upper surface of the air inflow recess 22 and the lower end opening 12 of the fine powder supply tank 4. .

The suction nozzle 9 includes a take-out nozzle 23 located coaxially with the powder collector 15, a fine powder suction pipe 24, a fine powder delivery pipe 25, a high-pressure air supply chamber 26, and the like.

The take-out nozzle 23 is provided so as to pass through the center of the filter 13 and its upper end is located within the recess 16 a of the powder collector 15 . The upper end is in communication.

Most of the fine powder suction pipe 24 is located within the high pressure air supply chamber 26, and its lower end 24 is located within the high pressure air supply chamber 26.
The outer circumferential surface 27a of No. 7 is formed in a tapered shape whose diameter decreases toward the lower end.

The lower part of the high-pressure air supply chamber 26 is formed with an air outlet 28 in the form of a tapered hole whose diameter decreases as it goes downward, and the tapered inner surface of the air outlet 28 is connected to the lower end of the fine powder suction pipe 24. The lower end of the air discharge port 28 and the upper end of the fine powder delivery pipe 25 are communicated with each other.

The lower end 2 of the fine powder suction pipe 24
7 is located within the air outlet 28, and a narrow gap 29 is formed between the lower end outer circumferential surface 27a of the fine powder suction pipe 24 and the inner circumferential surface 28a of the air outlet 28.

The injection nozzle 7 is disposed inside the processing chamber 8, and a collecting member 30 having a substantially funnel shape is provided at the bottom of the processing chamber 8.
is arranged, and the tip of a collection pipe 31 extending from the bottom top of the collection member 30 is connected to a fine powder collection section (not shown) equipped with air exhaust and dust removal functions.

The end of the fine powder delivery pipe 25 on the anti-fine powder suction pipe 24 side is connected to the injection nozzle 7 directly or via a relay pipe.

The blow pipe 32 extending from the air compressor 10 has two branch pipes 32a and 32 in the middle.
The tip of one branch pipe 32a is connected to an air supply hole 22a communicating with the air inflow recess 22, and the tip of the other branch pipe 32b is connected to an air supply hole 26a extending horizontally to supply high-pressure air. It communicates with the chamber 26.

The air supply hole 26a communicating with the high pressure air supply chamber 26 is provided so as to point away from the center of the high pressure air supply chamber 26 (see FIG. 3).
reference).

A part of the high pressure air discharged from the air compressor 10 is transferred from the branch pipe 32a to the air supply hole 22a.
Air is injected from the bottom of the storage chamber 3 through the air inflow recess 22 and filter 13 in this order, and this injection is performed intermittently at regular intervals.

The fine powder 2 stored in the storage chamber 3, especially the fine powder 2 located at the bottom of the storage chamber 3, is collected by the powder collector 15.
The mixture is stirred by the rotation of the stirring plate 17 which is rotated integrally with the filter, the vibration of the bimorph diaphragms 19, 19, etc. which are vibrated at a high frequency, and the air vibration effect of the high pressure air taken in through the filter 13. At the same time, a part of the powder is moved into the recess 16a of the powder collector 15.

Another part of the high pressure air discharged from the air compressor 10 flows into the high pressure air supply chamber 26 through the branch pipe 32b and the air supply hole 26a.

At this time, the high-pressure air flowing into the high-pressure air supply chamber 26 is rotated around the axis because its air supply hole 26a is directed away from the center of the high-pressure air supply chamber 26. .

The high-pressure air rotated within the high-pressure air supply chamber 26 flows into the fine powder delivery pipe 25 through the narrow gap 29, and the high-pressure air flowing into the fine powder delivery pipe 25 sucks the fine powder. pipe 24
A negative pressure is generated inside the take-out nozzle 23 which is communicated with the take-out nozzle 23.

The fine powder 2 that has moved into the recess 16a of the powder collector 15 is sucked into the take-out nozzle 23 through its upper opening, and is taken out through the fine powder suction pipe 24 to the fine powder delivery pipe 25, where it is taken out. The mixture is mixed with high-pressure air and fed under pressure to the injection nozzle 7, from which it is injected toward the workpiece 6.

[0041] As a result, the workpiece 6 is subjected to predetermined processing.

[0042] As the fine powder 2, it is desirable to use a material having a hardness corresponding to the hardness of the workpiece 6. For example, if the workpiece 6 is a circuit board or the like, alumina, glass, silicon dioxide, silicon carbide, etc. Fine powders made of ceramic materials such as iron, nickel, chromium, etc. are used.

Next, details of the suction nozzle 9 will be explained.

33 is a casing of the suction nozzle 9;
The casing 33 consists of a fixed block fixed to the lower surface of the fine powder supply tank 4 and a movable block coupled to the fixed block in a position adjustable manner.

Reference numeral 34 denotes a fixed block, and the fixed block 34 has an outer diameter that is approximately the same as the outer diameter of the lower end of the fine powder supply tank 4, and is approximately short in the axial direction relative to its diameter. It has a cylindrical shape, and a deep recess 35 (hereinafter referred to as "space forming recess") with a circular cross section is formed in its lower end surface, and from the center of the upper surface of the space forming recess 35. A cylindrical fine powder suction pipe 24 projects downward, and the lower end of the fine powder suction pipe 24 ends slightly higher than the lower end surface of the fixed block 34.

The fine powder suction pipe 24 is formed integrally with the fixed block 34, and as described above, the outer circumferential surface 27a of the lower end 27 is tapered so that the diameter decreases as it goes downward. ing.

An air inlet recess 22 having a circular cross section is formed in the center of the upper end surface of the fixed block 34, and the upper end 36a of the hole 36 of the fine powder suction pipe 24 is larger than the remaining part. The upper end portion 36a has a top surface opened at the bottom surface of the air inflow recess 22.

The fixed blocks 34 are arranged at equal intervals in the circumferential direction at positions near the outer circumferential surface of the fixed blocks 34 .
Four holes 37, 37, . . . are formed vertically through the holes 37, 37, .
A, . . . are formed to have a slightly larger diameter than the upper half portions 37b, 37b, .

The fixed block 34 has the holes 37,
37,... from below the bolts 38, 38,...
are inserted, and the tips of the bolts 38, 38, . . . are inserted into the screw holes 4a, 4 formed in the bottom surface of the fine powder supply tank 4.
a, . To position.

The filter 13 is fitted into the upper end of the air inflow recess 22 so as to cover it, and the fixing block 34 is attached to the fine powder supply tank 4 to open the lower end of the fine powder supply tank 4. 12 is occluded by filter 13.

A part of the outer peripheral surface of the fixed block 34 is formed as a flat surface 34a, and the air supply holes 22a and 26a are respectively formed between the flat surface 34a and the air inflow recess 22 and the space forming recess 35. It is formed.

The fixed block 34 has screw holes 39, 39 opened at its lower end surface and located between the holes 37, 37, . . .
,... are formed.

Reference numeral 40 designates a movable block of the casing 33, which includes a disk portion 41 having an outer diameter substantially the same as the outer diameter of the fixed block 34, and a disk portion 41 that protrudes from the upper surface of the disk portion 41. and a cylindrical insertion part 42 which is coaxial and has an outer diameter one size smaller than this, and the insertion part 42 has an outer diameter approximately equal to the inner diameter of the space forming recess 35 of the fixed block 34. The height of the insertion portion 42 is equal to the space forming recess 35.
The length is approximately half of the length in the axial direction.

A generally trumpet-shaped recess 43 whose diameter decreases toward the center is formed on the upper surface of the insertion portion 42, and a portion below the upper surface of the recess 43 is the air outlet. The lower end of the air outlet 28 extends to a position slightly below the center of the movable block 40 in the height direction, and the inner circumferential surface 28a
The diameter of the hole decreases toward the lower end, and is formed into a tapered hole shape as described above.

Reference numeral 44 denotes a sleeve fitting recess formed at the center of the bottom surface of the movable block 40, and its cross section is circular with a diameter larger than the diameter of the lower end opening of the air discharge port 28. The lower end of the outlet 28 is opened at the upper surface of this sleeve fitting recess 44 .

Reference numeral 45 denotes a buffer sleeve that is fitted almost exactly into the sleeve fitting recess 44, and is made of a material having rubber elasticity, such as urethane rubber, and has a relatively thick cylindrical peripheral wall. A substantially upper half portion 46a (hereinafter referred to as the "tapered portion") of the hole 46 is formed into a tapered hole shape whose diameter increases upwardly, and the upper end of the tapered portion 46a is located at the inner periphery of the air outlet 28. It is continuous with the lower end of the surface 28a.

The portion of the disc portion 41 near the outer periphery has four through holes 47, 47, . . . spaced apart at equal intervals in the circumferential direction.
are formed, and four spring receiving recesses 48, 48, . . . are formed on the upper surface of the disc portion 41 at positions between the insertion holes 47, 47, .

[0058] Such a movable block 40 is
The insertion portion 42 is the space forming recess 35 of the fixed block 34.
After inserting the adjustment bolts 49, 49, . . . from below into the insertion holes 47, 47, .・
screw holes 39, 39, which are opened in the bottom of the fixing block 34;
It is coupled to the fixed block 34 by being screwed into...

At this time, the fine powder suction pipe 24
The outer circumferential surface 27a of the lower end portion 27 is located at the inner circumferential surface 28a of the air discharge port 28 with an appropriate gap around its axis, and this gap becomes the narrow gap 29.

Furthermore, the space forming recess 3 of the fixed block 34
5 and the insertion portion 42 of the movable block 40 define the high pressure air supply chamber 26, and the high pressure air supply chamber 26 is located so as to surround most of the fine powder suction pipe 24.

50, 50, . . . are lower half portions 37a, 37a, . . . of the holes 37, 37, .
It is a coil spring arranged in the holes 37, 37, .
The heads of the bolts 38, 38 inserted through the upper half portions 37b, 37b, . . . and the spring receiving recess 48 of the disc portion 41
, 48, . . . , and the movable block 40 is constantly urged to move downward by the elastic force of these coil springs 50, 50, .

Therefore, when the adjusting bolts 49, 49, . . . are turned in the screwing direction, the movable block 40
When the movable block 40 moves upward against the elastic force of the coil springs 50, 50, . . . and turns the adjusting bolts 49, 49, . Moves downward due to force.

Furthermore, when the movable block 40 moves as described above, the gap between the inner peripheral surface 28a of the air discharge port 28 and the outer peripheral surface 27a of the lower end 27 of the fine powder suction pipe 24, that is, the narrow gap 29, is reduced. The cross-sectional area changes; for example, when the movable block 40 moves upward, the cross-sectional area of the narrow gap 29 becomes smaller, and when the movable block 40 moves downward, the cross-sectional area of the narrow gap 29 becomes larger.

Reference numeral 51 denotes an O-ring for keeping the space between the inner circumferential surface 35a of the space-forming recess 35 and the outer circumferential surface 42a of the insertion portion 42 airtight.

Reference numeral 52 denotes a joint consisting of a socket 53 and a spigot 54 screwed into the socket 53.

The socket 53 consists of a cylindrical portion 53a having a threaded groove formed on its inner peripheral surface and a flange 53b protruding outward from the upper end of the cylindrical portion 53a. flange 5 so that it is located coaxially with
3b is fixed to the bottom surface of the movable block 40 by screwing.

Further, the spigot 54 has a substantially cylindrical shape, and a spiral groove is formed in the upper half of its outer peripheral surface.

The fine powder delivery pipe 25 is made of the same material as the buffer sleeve 45, and has a flange 25a formed near one end thereof.
The first end of the buffer sleeve 45 is fitted substantially snugly into the lower part of the hole 46 of the buffer sleeve 45, and the flange 25a is positioned within the cylindrical portion 53a of the socket 53 of the joint 52.

The spigot 54 of the joint 52 is screwed into the cylindrical portion 53a of the socket 53 with the fine powder delivery pipe 25 inserted into the hole, so that the fine powder delivery pipe 25 is connected to its flange. 25 a is held between the lower surface of the buffer sleeve 45 and the upper end of the spigot 54 and fixed to the center of the lower surface of the movable block 40 .

[0070] Thus, the one end 25b of the fine powder delivery pipe 25 is located so as to complement the lower part of the hole 46 of the buffer sleeve 45, and its inner peripheral surface has no level difference with the tapered part 46a of the hole 46. Continuous.

Reference numeral 55 denotes a rubber tube, which is fitted almost snugly into the hole 36 of the fine powder suction pipe 24, and a flange 55a formed at the upper end of the tube 55 is attached to the upper end 3 of the hole 36.
6a.

The take-out nozzle 23 is composed of a nozzle main part 56 and a nozzle tip 57, and the nozzle main part 56 includes a disk-shaped mounting seat 56a and a relatively large hole protruding upward from the center of the mounting seat 56a. Thin cylindrical nozzle pipe 56b
The lower end of the hole of the nozzle pipe 56b is opened at the lower surface of the mounting seat 56a, and the nozzle pipe 56
The lower end of the nozzle chip 57 is press-fitted into the upper end of b.

[0073] Such a take-out nozzle 23 is located coaxially with the fine powder suction pipe 24, and its mounting seat 56a
is fixed to the bottom surface of the air inflow recess 22, and the nozzle pipe 56
The upper part of b and the nozzle tip 57 are projected upward through the insertion hole 13a formed in the center of the filter 13,
The upper end of the nozzle tip 57 is the recess 16a of the powder collector 15.
located within.

Note that the tube 55 has a flange 55
The position is fixed by overlapping the mounting seat 56a on the mounting seat 56a from above.

Reference numeral 58 denotes a substantially cylindrical nozzle holder, which is attached to the center of the filter 13 so as to pass through it, and the middle part of the nozzle chip 57 is formed on the upper surface of this nozzle holder 58. The nozzle tip 57 is inserted through the hole, thereby firmly maintaining the posture and position of the nozzle tip 57.

The suction nozzle 9 is constructed as described above.

Therefore, the high pressure air supplied to the high pressure air supply chamber 26 passes through the narrow gap 29 to the fine powder delivery pipe 2.
5 and passes through the narrow gap 29, increasing the pressure and giving it a substantially downward direction.

Furthermore, the high pressure air flowing into the high pressure air supply chamber 26 from the air supply hole 26a is oriented at a position eccentric to the center of the high pressure air supply chamber 26, so that the high pressure air is supplied to the high pressure air supply chamber 26. In the chamber 26, the fine powder suction pipe 24 is given a swirling property in the direction around its axis to form a vortex, and when it flows into the fine powder delivery pipe 25 with such swirling property, the inside of the fine powder delivery pipe 25 flows. The flow of high-pressure air becomes a stable flow that does not cause pulsations or the like.

Furthermore, since the high-pressure air flowing through the fine powder delivery pipe 25 sucks the air inside the fine powder suction pipe 24 and the take-out nozzle 23, which are in communication with the fine powder delivery pipe 25, these fine powder suction The inside of the pipe 24 and the take-out nozzle 23 are made to have a negative pressure, and this negative pressure is extremely stable without fluctuation due to the stable flow of high-pressure air in the fine powder delivery pipe 25 as described above. becomes.

[0080] Due to this negative pressure, the fine powder 2 in the fine powder supply tank 4 is sucked from the upper end opening of the take-out nozzle 23 and moved straight downward inside the take-out nozzle 23 and the fine powder suction pipe 24. With narrow gap 29
When the air reaches below the lower end of the narrow gap 29, it rides on the high-pressure air discharged from the narrow gap 29 without changing its direction of movement, mixes with it, and is forced into the injection nozzle 7.

[0081] Therefore, when the fine powder 2 is carried by high-pressure air, it hardly collides with the inner peripheral surface of the fine powder delivery pipe 25, so that the fine powder delivery pipe 25 is not worn out.

Further, as the fine powder delivery pipe 25, one having rubber elasticity is used, and a rubber tube 55 is fitted into the hole 36 of the fine powder suction pipe 24, and further,
Since the buffer sleeve 45 having rubber elasticity is also disposed at the connecting portion between the narrow gap 29 and one end of the fine powder delivery pipe 25, the fine powder 2 is transferred to the inner peripheral surface of the fine powder delivery pipe 25, the fine powder suction pipe 24, etc. Even if there is a collision, the impact force is considerably alleviated by the elasticity of the inner peripheral surface, which can considerably slow down the progress of wear.
Moreover, since the fine powder delivery pipe 25, tube 55, and buffer sleeve 45 are provided in a detachable manner, even if these members wear out, it is only necessary to replace them.

Then, as mentioned above, the adjustment bolt 49
, 49, . . . , the cross-sectional area of the narrow gap 29 can be adjusted, so that the suction force by the take-out nozzle 23 can be adjusted according to the size and mass of the fine powder 2.

[0084]

[Effects of the Invention] As is clear from the above description, the suction nozzle of the present invention includes a fine powder suction pipe whose one end is connected to a fine powder supply tank, and which surrounds the other end of the fine powder suction pipe. a high-pressure air supply chamber to which high-pressure air is supplied;
A fine powder delivery pipe extends from the air discharge port of the high-pressure air supply chamber and is positioned approximately coaxially with the fine powder suction pipe, and the outer circumferential surface of the other end of the fine powder suction pipe contracts as it approaches the tip. It is formed into a tapered shape so that the diameter is
The air outlet of the high-pressure air supply chamber and/or the inner circumferential surface of the fine powder delivery pipe are formed into a tapered hole shape having approximately the same slope as the outer circumferential surface of the other end of the tapered fine powder suction pipe. and the other end of the fine powder suction pipe is located near the air outlet of the high-pressure air supply chamber and/or near the inner peripheral surface of the fine powder delivery pipe, and the other end of the fine powder suction pipe is located near the outer peripheral surface of the fine powder suction pipe. A narrow gap is formed between the air discharge port of the high-pressure air supply chamber and/or the inner peripheral surface of the fine powder delivery pipe.

Therefore, according to the suction nozzle of the present invention, in the region where fine powder is mixed with high-pressure air, high-pressure air flows into the flow channel from the outer circumference, and fine powder flows into the flow channel from approximately the center thereof. Therefore, the fine powder does not collide with the inner circumferential surface of the flow path, and therefore the air discharge port of the high-pressure air supply chamber and the inner circumferential surface of the fine powder delivery pipe are not scraped off by the fine powder. The life of the suction nozzle can be extended.

In the above embodiment, the cross-sectional area of the narrow gap can be adjusted, but by doing so, the strength of the negative pressure generated in the fine powder suction pipe can be set arbitrarily. The suction amount of fine powder can be adjusted.

[0087] Furthermore, the shapes and structures of each part shown in the above embodiments are merely examples of embodiments of the present invention, and the technical scope of the present invention is not limited by these. shall not be construed as

In particular, in the embodiment described above, a narrow gap was formed between the inner circumferential surface of the air outlet of the high-pressure air supply chamber and the outer circumferential surface of the lower end of the fine powder suction pipe. For example, it may be formed by the outer peripheral surface of the lower end of the fine powder suction pipe and the inner peripheral surface of the fine powder delivery pipe, or may be formed by the inner peripheral surface of the air discharge port of the high-pressure air supply chamber and the fine powder delivery pipe. The inner peripheral surface of the pipe may be formed into a continuous tapered surface, and the narrow gap may be formed by the tapered surface and the outer peripheral surface of the lower end of the fine powder suction pipe.

[Brief explanation of the drawing]

FIG. 1 shows an example of the implementation of the suction nozzle of the present invention,
FIG. 2 is a partially cutaway front view of the entire fine powder injection device including a suction nozzle.

FIG. 2 is a central vertical sectional view showing an enlarged lower end portion of a fine powder supply tank and a suction nozzle of the fine powder injection device shown in FIG. 1;

FIG. 3 is a sectional view taken along line III-III in FIG. 2;

FIG. 4 is an enlarged perspective view of the portion shown in FIG. 2 with a portion thereof cut away.

FIG. 5 is an enlarged perspective view showing the essential parts of the suction nozzle in an exploded and partially cutaway manner.

FIG. 6 is a central vertical sectional view showing an enlarged main part of the suction nozzle.

FIG. 7 is a sectional view showing an example of a conventional suction nozzle.

[Explanation of symbols]

4 Fine powder supply tank 9 Suction nozzle 24 Fine powder suction pipe 25 Fine powder delivery pipe 26 High pressure air supply chamber 27 Other end (of the fine powder suction pipe) 28 Air discharge port 29 Narrow gap

Claims (1)

[Claims] 1. A fine powder suction pipe whose one end is connected to a fine powder supply tank, a high pressure air supply chamber surrounding the other end of the fine powder suction pipe and to which high pressure air is supplied, and the high pressure air supply chamber. a fine powder delivery pipe extending from the air discharge port and positioned substantially coaxially with the fine powder suction pipe;
The outer circumferential surface of the other end of the fine powder suction pipe is tapered so that the diameter decreases toward the tip, and the inner circumferential surface of the air discharge port of the high-pressure air supply chamber and/or the fine powder delivery pipe is The other end of the fine powder suction pipe formed in the tapered shape is formed into a tapered hole shape with approximately the same slope as the outer peripheral surface, and the other end of the fine powder suction pipe is an air discharge port of the high pressure air supply chamber. and/or near the inner peripheral surface of the fine powder delivery pipe, and the other end outer peripheral surface of the fine powder suction pipe and the air outlet of the high pressure air supply chamber and/or the inner peripheral surface of the fine powder delivery pipe. A suction nozzle characterized in that a narrow gap is formed between the suction nozzles.