JP3175192B2 - Suction nozzle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suction nozzle for taking out fine powder stored in a fine powder supply tank by a negative pressure suction effect generated by a flow of high-pressure air.
An object of the present invention is to provide a novel suction nozzle which can prolong the life of the suction nozzle without the fine powder colliding with the inner surface of each part of the nozzle.

[0002]

2. Description of the Related Art There is a fine powder injection device as a device for performing a predetermined process by injecting a fine powder made of a metal, an inorganic substance, or the like at an object to be processed (hereinafter, referred to as a "work") at a high pressure of air. For example, it is used to form minute blind holes or through holes in a circuit board.

In order to inject fine powder into a work in such a fine powder spraying apparatus, the fine powder is taken out from a 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 utilizing a negative pressure suction action 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 FIG. 1, reference numeral b denotes a nozzle body having a first passage c extending vertically and a second passage d communicating with the first passage c from a direction orthogonal to the first passage c.
A high-pressure air injection nozzle e is inserted into an upper portion of the passage c, and one end of a fine powder delivery pipe f is inserted into a lower portion thereof. One end of a fine powder suction pipe g is inserted into a second passage d. Part is inserted.

The high-pressure air ejection 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 an injection nozzle arranged in a work processing chamber (not shown). The other end of the suction pipe g is connected to an extraction nozzle i protruding into a fine powder supply tank storing fine powder.

[0008] j is a fine powder supply tank in which the fine powder k is stored (only the lower end is shown in the drawing), 1 is a filter attached so as to close the lower end opening m of the fine powder supply tank j. , N is a dust collector arranged inside the fine powder supply tank j, o is an air supply chamber for air vibrating communicating with the lower end opening m across the filter l, and the take-out nozzle i is a filter l And the upper end thereof is located in a concave portion p formed on the lower end surface of the dust collector n.

The high-pressure air ejected from the high-pressure air ejection nozzle e is supplied to a junction q between the first passage c and the second passage d.
Then, the high-pressure air flows into the fine-powder feeding pipe f, and the inside of the fine-powder suction pipe g is made to have a negative pressure. This negative pressure causes the suction port opened at the upper end of the take-out nozzle i to have a suction force. Occurs.

The fine powder k in the fine powder supply tank j is stirred by the air vibration effect of the high pressure air injected from the air supply chamber o through the filter l, and a part of the fine powder k is formed in the concave portion of the dust collector n. It is moved into p, is sucked into the fine powder suction pipe g from the suction port of the discharge nozzle i, is mixed with high-pressure air at the junction q of the nozzle body b, and flows into the fine powder delivery pipe f.

The removal of the fine powder k from the fine powder supply tank j by the suction nozzle a and the mixing with the high-pressure air are performed as described above.

[0012]

However, in such a suction nozzle a, the moving direction of the fine powder k coming out of the fine powder suction pipe g into the nozzle body b is the same as the direction in which the high-pressure air flows. Since they are perpendicular to each other, most of the fine powder k collides with the first passage c and the inner peripheral surface of the fine powder delivery pipe f, and these inner peripheral surfaces are severely worn, so that the life of the nozzle body b is short. There was a problem that it disappeared.

[0013]

In order to solve the above-mentioned problems, the suction nozzle of the present invention is formed in a tapered shape so that the outer peripheral surface of the other end of the fine powder suction pipe is reduced in diameter toward the tip. 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 in a tapered hole shape having the same gradient as that of the outer peripheral surface of the other end of the fine powder suction pipe. The other end of the fine powder suction pipe is located near the 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 is connected to the high pressure air supply pipe. A narrow gap between the air outlet of the chamber and / or the inner surface of the fine powder delivery pipe.
Forming and adjusting the cross-sectional area of the narrow gap
It is made possible .

[0014]

Therefore, according to the suction nozzle of the present invention, at the portion where the fine powder is mixed with the high-pressure air, the high-pressure air flows into the flow channel from the outer peripheral portion thereof, and the fine powder flows into the flow channel from the substantially central portion thereof. Therefore, the fine powder does not collide with the inner peripheral surface of the flow path, and therefore, the inner peripheral surface of the air discharge port of the high-pressure air supply chamber or the fine powder delivery pipe is not scraped off by the fine powder, The life of the suction nozzle can be extended.
Also, the cross-sectional area of the narrow gap can be adjusted.
The strength of the negative pressure generated in the fine powder suction pipe
Can be set arbitrarily to adjust the suction amount of fine powder.
Can be

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the suction nozzle of the present invention will be described below with reference 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 a fine powder from a fine powder supply tank in the fine powder injection device 1.

First, the outline of the fine powder injection device will be described (see FIGS. 1 and 2).

The fine powder injection device 1 includes a fine powder supply tank 4 having a storage chamber 3 for storing the fine powder 2, a fine powder supply unit 5 for replenishing the storage chamber 3 with the fine powder 2 in a timely manner, 6, a processing chamber 8 provided with an injection nozzle 7 for injecting the fine powder 2 and a suction nozzle 9 fixed to the lower surface of the fine powder supply tank 7 for sucking and extracting the fine powder 2 from the storage chamber 3.
And an air compressor 10 for supplying high-pressure air to the suction nozzle 9 and the storage chamber 3 and the like, and a collection unit (not shown) for collecting 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 for its diameter, and the storage chamber 3 has a cylindrical upper half and a smaller diameter as the lower half goes downward. The upper portion of the fine powder supply tank 4 is closed by a top plate 11, and the lower end opening is closed by a disk-shaped filter 13.

Reference numeral 14 denotes a rotary shaft positioned on the axis of the storage chamber 3, and a vertically long, substantially bullet-shaped dust collector 15 is fixed to the lower end thereof, and the lower end face of the dust collector 15 is fixed. 16 is located near the lower end opening 12 of the fine powder supply tank 4,
A circular recess 16 a is formed in the lower end surface 16.

Reference numeral 17 denotes a stirring plate attached to the outer peripheral surface of the dust collector 15, and its lower end extends to near the filter 13.

Reference numeral 18 denotes a motor, and the rotary shaft 14 is rotated by the motor 18, whereby the dust collector 15 and the stirring plate 17 are rotated in the direction around the axis.

Are bimorph diaphragms disposed along the inner peripheral surface of the lower half of the storage chamber 3, and each of the bimorph diaphragms 19 extends around the inner peripheral surface in the direction around the axis. It is formed in a substantially fan shape as if divided.

The fine powder supply section 5 comprises a hopper 20 provided above the fine powder supply tank 4 and storing the fine powder 2, a valve element 21 provided below the hopper 20, and the like. The fine powder 2 stored in the container 20 is charged into the storage chamber 3 at an appropriate time by opening and closing the valve body 21, and the fine powder 2 is always stored in the storage chamber 3 in a substantially constant amount.

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, a fine powder suction pipe 24, a fine powder delivery pipe 25, and a high-pressure air supply chamber 26, which are located coaxially with the dust collector 15.

The take-out nozzle 23 penetrates the center of the filter 13 and is provided such that the upper end thereof is located in the concave portion 16a of the dust collector 15. The lower end of the take-out nozzle 23 and the fine powder suction pipe 24 The upper end is in communication.

Most of the fine powder suction pipe 24 is located in the high-pressure air supply chamber 26 and has a lower end 2.
The outer peripheral surface 27a of 7 is formed in a tapered shape whose diameter decreases toward the lower end.

The lower portion of the high-pressure air supply chamber 26 is formed with an air discharge port 28 having a tapered hole shape whose diameter decreases as going downward, and the tapered inner surface of the air discharge port 28 is formed at 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 communicate with each other.

The lower end 2 of the fine powder suction pipe 24
7 is located in the air discharge port 28, and a narrow gap 29 is formed between the outer peripheral surface 27 a of the lower end portion of the fine powder suction pipe 24 and the inner peripheral surface 28 a of the air discharge port 28.

The injection nozzle 7 is disposed in the processing chamber 8, and the collection member 30 having a substantially funnel shape is provided at the bottom thereof.
The tip of a collection pipe 31 extending from the top of the bottom of the collection member 30 is connected to a not-shown fine powder collection unit having a function of exhausting and removing dust.

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

The blower pipe 32 extending from the air compressor 10 has two branch pipes 32a and 32
b, one end of the branch pipe 32a is connected to an air supply hole 22a communicating with the air inflow recess 22, and the other end of the branch pipe 32b is connected to an air supply hole 26a extending in the horizontal direction 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 be directed to a position off the center of the high-pressure air supply chamber 26 (FIG. 3).
reference).

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

The fine powder 2 stored in the storage chamber 3, in particular, the fine powder 2 located at the bottom of the storage chamber 3,
The vibrating plates 19, 19,... Vibrated at a high frequency vibrate at a high frequency, and the high-pressure air taken in through the filter 13 is stirred by the rotation of the stirring plate 17 that is integrally rotated. At the same time, a part thereof is moved into the concave portion 16a of the dust 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 that has flowed into the high-pressure air supply chamber 26 is rotated around the axis because the air supply hole 26a is directed to a position off the center of the high-pressure air supply chamber 26. .

The high-pressure air rotated in 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
And, a negative pressure is generated inside the take-out nozzle 23 connected to it.

The fine powder 2 having moved into the concave portion 16a of the dust collector 15 is sucked by the take-out nozzle 23 from the upper end opening thereof, taken out through the fine-powder suction pipe 24 and taken out to the fine-powder delivery pipe 25. The mixture is mixed with high-pressure air and sent to the injection nozzle 7 under pressure, and is injected from the injection nozzle 7 toward the work 6.

Thus, a predetermined process is performed on the work 6.

As the fine powder 2, it is desirable to use one having a hardness corresponding to the hardness of the work 6. For example, when the work 6 is a circuit board or the like, alumina, glass, silicon dioxide, silicon carbide or the like is used. A fine powder made of a ceramic material such as, or a fine powder made of a metal material such as iron, nickel, and chromium is used.

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

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

Numeral 34 denotes a fixed block. The fixed block 34 has an outer diameter substantially equal to the outer diameter of the lower end of the fine powder supply tank 4 and is short in the axial direction for its diameter. A deep concave portion 35 (hereinafter, referred to as a “space forming concave portion”) having a columnar shape and a circular cross section is formed at a lower end surface thereof. A cylindrical fine powder suction pipe 24 projects downward, and the lower end of the fine powder suction pipe 24 ends at a position 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. As described above, the outer peripheral surface 27a of the lower end portion 27 is formed in a tapered shape so that the diameter decreases as it goes downward. ing.

An air inflow recess 22 having a circular cross section is formed in the center of the upper end surface of the fixed block 34. The upper end 36a of the hole 36 of the fine powder suction pipe 24 is formed.
Is formed to have a larger diameter than the remaining portion.
Is opened at the bottom of the air inflow recess 22.

At a position near the outer peripheral surface of the fixed block 34, the fixed blocks 34 are arranged at regular intervals in the circumferential direction.
Are formed, and the lower half portions 37a, 37 of the holes 37, 37,.
are formed slightly larger in diameter than the upper half portions 37b, 37b,.

The fixing block 34 is provided with the hole 37,
37, ... bolts 38, 38, ... from below
Are screwed into the screw holes 4a, 4b formed in the bottom surface of the fine powder supply tank 4.
are fixed to the lower surface of the fine powder supply tank 4 by being screwed into the fine powder supply tank 4, respectively, so that the fine powder suction pipe 24 is located below and coaxial with the fine powder supply tank 4. To position.

The filter 13 is fitted over the upper end of the air inflow recess 22 so as to cover the same, and the fixed block 34 is attached to the fine powder supply tank 4 so that the lower end opening of the fine powder supply tank 4 is opened. 12 is closed by the 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 separately provided between the flat surface 34a and the air inflow concave portion 22 and the space forming concave portion 35. Is formed.

The fixing block 34 has an opening at the lower end surface thereof and screw holes 39, 3 at positions between the holes 37, 37,.
9 are formed.

Reference numeral 40 denotes a movable block of the casing 33, a disk portion 41 having an outer diameter substantially the same as the outer diameter of the fixed block 34, a protruding portion from the upper surface of the disk portion 41, and a disk portion 41. And an insertion portion 42 having a columnar shape having an outer diameter slightly smaller than the coaxial portion is integrally formed, and the insertion portion 42 has an outer diameter substantially equal to the inner diameter of the space forming recess 35 of the fixed block 34. The height of the insertion part 42 is the same as that of the space forming recess 35 described above.
Is formed in approximately half of the length in the axial direction.

The upper surface of the insertion portion 42 is formed with a substantially trumpet-shaped concave portion 43 whose diameter decreases toward the center thereof. The lower end of the air discharge port 28 extends to a position slightly lower than the center in the height direction of the movable block 40, and has an inner peripheral surface 28a.
Has a diameter which decreases as it goes to the lower end, and is formed in 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 has a circular shape having 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 the sleeve fitting recess 44.

Reference numeral 45 denotes a cushioning sleeve which is fitted almost exactly into the sleeve fitting concave portion 44, and is formed of a material having rubber elasticity, for example, urethane rubber, and its peripheral wall is formed in a relatively thick cylindrical shape. A substantially upper half portion 46 a (hereinafter, referred to as a “tapered portion”) of the hole 46 is formed in a tapered hole shape such that the diameter increases as going upward, and the upper end of the tapered portion 46 a is formed on the inner periphery of the air discharge port 28. It is continuous with the lower end of the surface 28a.

At a portion near the outer peripheral edge of the disk portion 41, four insertion holes 47, 47,.
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,.

Then, such a movable block 40
The insertion portion 42 is inserted into the space forming recess 35 of the fixed block 34.
Are inserted into the insertion holes 47, 47,... Formed in the disk portion 41 from below, and then the adjustment bolts 49, 49,.・
Are screw holes 39, 39, which are opened on the bottom surface of the fixing block 34.
Are connected to the fixed block 34 by screwing.

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

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

.. Are lower holes 37a, 37a,.
And the holes 37, 37,.
.. the heads of the bolts 38, 38 in which the upper halves 37b, 37b,.
, 48,...
Are always urged downward by the elastic force of these coil springs 50, 50,....

When the adjusting bolts 49, 49,... Are turned in the screwing direction, the movable block 40
When the adjusting bolts 49, 49,... Are turned upward in the screw-back direction against the elastic force of 0, 50,. It moves downward by vibrating force.

When the movable block 40 moves as described above, a gap between the inner peripheral surface 28 a of the air discharge port 28 and the outer peripheral surface 27 a of the lower end 27 of the fine powder suction pipe 24, that is, the narrow gap 29 is formed. The cross-sectional area changes. For example, when the movable block 40 moves upward, the cross-sectional area of the narrow gap 29 decreases, and when the movable block 40 moves downward, the cross-sectional area of the narrow gap 29 increases.

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

Reference numeral 52 denotes a joint comprising a receiving port 53 and a spigot 54 screwed into the receiving port 53.

The receiving port 53 comprises a cylindrical portion 53a having a thread groove formed on the inner peripheral surface thereof and a flange 53b projecting 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.

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

The fine powder delivery pipe 25 is formed of the same material as the buffer sleeve 45, and has a flange 25a formed at a position near one end thereof.
One end of the joint 52 is fitted almost exactly in the lower part of the hole 46 of the buffer sleeve 45, and the flange 25 a is located in the cylindrical portion 53 a of the socket 53 of the joint 52.

The spigot 54 of the joint 52 is screwed into the cylindrical portion 53a of the receiving port 53 in a state where the fine powder delivery pipe 25 is inserted through the hole. 25 a is sandwiched between the lower surface of the buffer sleeve 45 and the upper end of the spigot 54 and is fixed to the center of the lower surface of the movable block 40.

The one end 25b of the fine powder delivery pipe 25 is positioned so as to complement the lower part of the hole 46 of the buffer sleeve 45, and the inner peripheral surface thereof has no step with the tapered portion 46a of the hole 46. In succession.

Numeral 55 denotes a rubber tube, which is fitted almost exactly in the hole 36 of the fine powder suction pipe 24, and a flange 55a formed at the upper end thereof has an upper end 3 of the hole 36.
6a.

The take-out nozzle 23 is composed of a nozzle main portion 56 and a nozzle tip 57. The nozzle main portion 56 has a disc-shaped mounting seat 56a and a relatively protruding upward from the center of the mounting seat 56a. Nozzle tube 56b having a thin cylindrical shape
The lower end of the hole of the nozzle tube 56b is opened at the lower surface of the mounting seat 56a.
The lower end of the nozzle tip 57 is press-fitted into the upper end of b.

The take-out nozzle 23 is positioned coaxially with the fine powder suction pipe 24 and has its mounting seat 56a.
Is fixed to the bottom surface of the air inflow recess 22, and the nozzle tube 56
b and the nozzle tip 57 project upward through an insertion hole 13a formed in the center of the filter 13,
The upper end of the nozzle tip 57 is in the concave portion 16a of the dust collector 15.
Is located within.

The tube 55 has its flange 55
The position is fixed by the mounting seat 56a being overlapped from above with a.

Reference numeral 58 denotes a substantially cylindrical nozzle holder, which is attached to the center of the filter 13 so as to penetrate it, and an intermediate portion of the nozzle tip 57 is formed on the upper surface of the nozzle holder 58. The nozzle tip 57 is inserted through the hole, whereby the attitude and position of the nozzle tip 57 are firmly held.

The suction nozzle 9 is configured as described above.

Then, the high-pressure air supplied to the high-pressure air supply chamber 26 passes through the narrow gap 29 and passes through the fine powder delivery pipe 2.
5 and through the narrow gap 29 the pressure is increased and a substantially downward direction is given.

The high-pressure air flowing into the high-pressure air supply chamber 26 from the air supply hole 26a is directed to a position eccentric to the center of the high-pressure air supply chamber 26, so that the high-pressure air supply In the chamber 26, the fine powder suction pipe 24 is provided with a swirling property in the direction around the axis and becomes a vortex. When the fine powder suction pipe 24 flows into the fine powder delivery pipe 25 with such a swirling property, the fine powder delivery pipe 25 Is a stable flow that does not generate pulsation or the like.

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 communicates with the fine powder delivery pipe 25. The inside of the pipe 24 and the take-out nozzle 23 is made to have a negative pressure, and this negative pressure is extremely stable without fluctuation by the stable flow of the high-pressure air in the fine powder delivery pipe 25 as described above. Becomes

Then, 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 discharge nozzle 23 and is moved straight down inside the discharge nozzle 23 and the fine powder suction pipe 24. With narrow gap 29
When it comes below the lower end of the nozzle, it rides on the high-pressure air discharged from the narrow gap 29 without changing its moving direction, and is mixed with the high-pressure air and fed to the injection nozzle 7 by pressure.

Therefore, the fine powder 2 hardly collides with the inner peripheral surface of the fine powder delivery pipe 25 when riding on the high-pressure air, so that the fine powder delivery pipe 25 is not worn.

As the fine powder delivery pipe 25, a pipe having rubber elasticity is used, and a rubber tube 55 is fitted in the hole 36 of the fine powder suction pipe 24.
Since the buffer sleeve 45 having rubber elasticity is also arranged at the connecting portion between the narrow gap 29 and one end of the fine powder delivery pipe 25, the fine powder 2 is formed on the inner peripheral surface of the fine powder delivery pipe 25, the fine powder suction pipe 24 and the like. Even if a collision occurs, the impact force is considerably alleviated by the elasticity of the inner peripheral surface, whereby the progress of wear can be considerably slowed down.
Since the sleeve 5 and the cushioning sleeve 45 are detachably provided, even if these members are worn, they need only be replaced.

Then, as described above, the adjustment bolt 4
By turning 9, 49,..., The cross-sectional area of the narrow gap 29 can be adjusted, whereby the suction force by the extraction nozzle 23 can be adjusted according to the size and mass of the fine powder 2. .

[0084]

As is apparent from the above description, the suction nozzle of the present invention surrounds the fine powder suction pipe having one end connected to the fine powder supply tank and 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 extending from the air discharge port of the high-pressure air supply chamber and positioned substantially coaxially with the fine powder suction pipe; It is formed in a tapered shape so as to be diameter, and
The inner peripheral surface of the air discharge port of the high-pressure air supply chamber and / or the fine powder delivery pipe is formed in a tapered hole shape having substantially the same gradient as the outer peripheral surface of the other end of the tapered fine powder suction pipe. The other end of the fine powder suction pipe is located near the air discharge port of the high pressure air supply chamber and / or near the inner peripheral surface of the fine powder delivery 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 , and the cross-sectional area of the narrow gap is adjusted.
It is characterized by being able to do.

Therefore, according to the suction nozzle of the present invention, at the portion where the fine powder is mixed with the high-pressure air, the high-pressure air flows into the flow channel from the outer peripheral portion, and the fine powder flows into the flow channel from the substantially central portion. Therefore, the fine powder does not collide with the inner peripheral surface of the flow path, and therefore, the inner peripheral surface of the air discharge port of the high-pressure air supply chamber or the fine powder delivery pipe is not scraped off by the fine powder, The life of the suction nozzle can be extended. It can also adjust the cross-sectional area of the narrow gap
The negative pressure generated in the fine powder suction pipe.
The strength can be set arbitrarily, and the suction amount of fine powder can be adjusted.
Can be adjusted.

[0086]

Further, the shapes and structures of the respective parts shown in the above-mentioned embodiments are merely examples for embodying the present invention, and these limit the technical scope of the present invention. Should not be interpreted.

Particularly, in the above embodiment, a narrow gap is formed by the inner peripheral surface of the air discharge port of the high-pressure air supply chamber and the outer peripheral 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 the inner peripheral surface of the air discharge port of the high-pressure air supply chamber and the fine powder delivery. The inner peripheral surface of the pipe may be formed as a continuous tapered surface, and the narrow gap may be formed by the tapered surface and the outer peripheral surface of the lower end portion of the fine powder suction pipe.

[Brief description of the drawings]

FIG. 1 shows an embodiment of a suction nozzle of the present invention,
It is a front view which shows the whole fine powder injection apparatus provided with the suction nozzle by notching partially.

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

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

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

FIG. 5 is an enlarged perspective view showing a main part of the suction nozzle in a disassembled state and a part cut away.

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

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

[Explanation of symbols]

 Reference Signs List 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 fine powder suction pipe) 28 Air discharge port 29 Narrow gap

Claims (1)

(57) [Claims] 1. A fine powder suction pipe having one end connected to a fine powder supply tank; a high pressure air supply chamber surrounding the other end of the fine powder suction pipe and supplied with high pressure air; A fine powder delivery pipe extending from the air discharge port and positioned substantially coaxially with the fine powder suction pipe, so that the outer peripheral surface of the other end of the fine powder suction pipe is reduced in diameter toward the tip. The inner peripheral surface of the air discharge port of the high-pressure air supply chamber and / or the fine powder delivery pipe is substantially the same as the slope of the other outer peripheral surface of the tapered fine powder suction pipe. The other end of the fine powder suction pipe is formed near the air discharge port of the high-pressure air supply chamber and / or near the inner peripheral surface of the fine powder delivery pipe. High-pressure air with the outer peripheral surface of the other end of the body suction pipe 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 ,
And the cross-sectional area of the narrow gap can be adjusted.
Suction nozzle, characterized in that there was Unishi.