JPH11130227A - Powder supplying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably supply a fixed quantity of a powder by filling the powder in a measuring part through a powder feed pipe by the vibration of a first vibration generating device, and moving a measuring plate horizontally to fall the powder down by the vibration of a second vibration generating means. SOLUTION: A first vibration generating device 4 is driven in an ultrasonic area, a powder is continuously taken in from the connecting part with a powder supplying vessel 13 by the progressive wave generated on the wall surface of a powder feed pipe 2, carried in the direction of a powder measuring mechanism 3 and pushed thereto. The powder within the powder measuring mechanism 3 is pressed and filled into a measuring part 8 provided on a measuring plate 9 by the fluidizing effect with the wall surface of the measuring part 8 by the stationary wave vibration of a second vibration generating device 6 for vibrating the powder measuring mechanism 3. A sliding base 11 prevents the powder from being fallen from the lower opening part of the measuring part 8. The position of the measuring plate 9 is moved to the left to shift the measuring part 8 from the surface of the sliding base 11, and the powder is fallen and discharged by the stationary wave vibration for vibrating the whole measuring mechanism. At this time, an upper leakage preventing plate 12 prevents the powder from being leaked from the upper opening part of the measuring part 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a powder supply apparatus, and more particularly to a powder supply apparatus which has a simple structure and can supply a small amount of powder stably and quickly.

[0002]

2. Description of the Related Art Conventionally, as a method of quantitatively supplying powder, a method of weighing using a weight sensor such as an electronic balance or a load cell, or a method of dropping powder by using its own weight due to gravity acting on the powder. A method of filling a constant volume space, grinding the upper portion, and measuring the volume has been used.

However, in a method of weighing powder using a weight sensor such as an electronic balance or a load cell, it takes time to perform averaging processing for processing variations in weighed values due to fluctuations peculiar to the weight sensor. It was difficult to supply the powder stably.

[0004] In a system in which powder falling under its own weight is charged into a constant volume space by using gravity acting on the powder and the upper part is cut off to measure the volume, the powder in the space becomes smaller when the volume space becomes smaller. It takes a long time to replace air, resulting in low production capacity, and incomplete filling may cause cavities.
There was a problem in performance and it was difficult to measure a trace amount.

[0005]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems, and the operation of uniformly filling powder into a small volume space and then discharging the powder can be repeated in a short time, and the operation is stable and constant. An object of the present invention is to provide a powder supply device for supplying an amount of powder.

[0006]

DISCLOSURE OF THE INVENTION The present invention has been made as a result of diligent studies to achieve the above object, and is provided at one end of a powder supply pipe made of a hollow pipe made of a material having a large vibration damping. A powder supply container is connected, and a through-hole is formed in the plate at the other end to form a weighing unit and to be connected to a weighing mechanism equipped with a weighing plate that can be moved laterally on a slide. A first vibration generator is mounted on the other end of the powder supply pipe, and a second vibration generator is mounted on the weighing mechanism. Filling the measuring portion of the powder measuring plate with the powder, then moving the measuring plate in the horizontal direction and dropping the powder downward by the vibration of the second vibration generator to take out a certain amount of powder. It is another object of the present invention to provide a powder supply apparatus characterized in that:

Further, the powder supply tube is provided vertically and the powder supply container is provided above the powder supply tube, and the measuring plate is provided below the powder supply tube. At the time of powder filling, the lower opening of the measuring section is located on the slide table surface to prevent powder falling, and when discharging the powder from the small space by moving the measuring plate, the upper opening of the measuring section of the measuring plate It is an object of the present invention to provide a powder feeder which is located on a powder upper leak prevention plate for preventing body from leaking upward and whose lower opening is shifted from a position of a slide table surface so that powder may drop.

The first vibration generator is a piezoelectric vibrator or a magnetostrictive vibrator and is driven at an ultrasonic frequency, and the second vibration generator is a piezoelectric vibrator, a magnetostrictive vibrator, an electromagnetic vibrator or a motor. An object of the present invention is to provide a powder supply device which is driven as an oscillator at an audible frequency.

[0009]

According to the present invention, the powder is smoothly supplied and filled into the measuring section by the first vibration generator, and the measuring mechanism is vibrated by the second vibration generator to completely fill the measuring section. The powder corresponding to the volume of the measuring section is accurately measured.

[0010]

FIG. 1 to FIG. 1 show an embodiment of the present invention.
Explanation will be made using 0.

FIG. 1 shows a powder supply apparatus 1 of the present invention. The powder supply apparatus 1 includes a powder supply pipe 2, a powder measuring mechanism 3, a first vibration generator 4, an AC power supply 5, and a second vibration. Generator 6, AC power supply 7, weighing plate 9 having weighing unit 8, weighing plate moving device 1
0.

An upper part of the powder supply pipe 2 is provided with a powder supply container 13.
And the lower end thereof is fitted and connected to the powder inlet portion of the measuring mechanism 3 so that the powder can smoothly move from the powder supply pipe 2 to the measuring mechanism 3 without leaking to the outside during powder supply. I have. The connection method may be any of fitting, screwing, bonding and the like. The weighing mechanism 3 is connected to the powder supply pipe 2, and a plate-shaped body is provided with a through-hole below the weighing mechanism 2.
Is formed on the slide table 11 so as to be movable in the lateral direction.

A piezoelectric vibrator as a first vibration generator 4 is bonded to a powder outlet portion of the powder supply pipe 2, and a piezoelectric vibration as a second vibration generator 6 is attached to the measuring mechanism 3. Child is attached.

A piezoelectric vibrator or a magnetostrictive vibrator is used as a vibrator as the first vibration generating device 4. In the case of a piezoelectric vibrator, an AC voltage is applied by an AC power supply 5 having a peak-to-peak voltage of 0 to 100 volts. Is done. The frequency is preferably in the ultrasonic range of about 20 kHz to 100 kHz.

As a vibrator as the second vibration generator 6, a piezoelectric vibrator, a magnetostrictive vibrator, an electromagnetic vibrator, or a rotary vibrator using a motor is used. An AC voltage is applied by a volt AC power supply 7. The vibration frequency in the audible wave range is preferably about 10 to 1000 Hz, and the optimum vibration frequency can be selected in accordance with the powder physical properties such as the particle size, adhesion and specific gravity of the powder.

The application time of the piezoelectric vibrator of the first vibration generator 4 and the application time of the piezoelectric vibrator of the second vibration generator 6 may be varied in a pulsed manner.

The piezoelectric vibrator of the first vibration generator 4 is shown in FIG.
As shown in the figure (only the outer wall of the hollow nozzle is shown), it is possible to generate vibration such that the outer wall of the cross section of the powder supply pipe 2 causes radial vibration (r direction) as shown by a two-dot chain line. A bending traveling wave as shown in FIG. 3 is generated in the powder supply tube 2 excited by the piezoelectric vibrator. When a material having a large attenuation characteristic is used for the powder supply pipe 2, the bending traveling wave is attenuated as shown in FIG. Therefore, there is almost no reflected wave at the tip, and the bending traveling wave becomes a stable wave without being disturbed by the reflected wave, the powder supply power is increased, and the powder is supplied to the powder supply pipe 2.
Is sent to the measuring mechanism 3 stably.

On the other hand, the piezoelectric vibrator of the second vibration generator 6 is mounted so as to reciprocate the powder measuring mechanism 3 in the direction of gravity and in the direction of antigravity. This vibration is a low frequency with a small vibration attenuation in the audible wave region, and is repeatedly reflected on the end face of the member of the powder measuring mechanism 3, causing the entire powder measuring mechanism 3 to undergo standing wave vibration as shown in FIG. The weighing plate 9 also vibrates up and down.

The standing wave vibration generated by the powder measuring mechanism 3 is also transmitted to the powder supply pipe 2, which becomes a composite vibration of the bending traveling wave and the standing wave vibration in the powder supply pipe 2, Container 1
0 contributes to the operation of taking in the powder into the powder supply pipe 2.

As shown in FIG. 5, the piezoelectric vibrator of the first vibration generator 4 for generating the traveling wave has a thickness of 0.1 mm.
A type in which 5 to 3 mm ceramic PZT 14 is sandwiched between electrodes 15 and 15 from both sides thereof can be used. When a voltage is applied between the electrodes, expansion and contraction vibrations are excited in the inner and outer diameter directions, that is, in the r direction by the expansion and contraction force of the ceramic, and the vibrations are transmitted to the first powder supply pipe 2 to become traveling waves. . The optimum peak-to-peak voltage and frequency can be calculated from the resonance mode depending on the shape of the piezoelectric vibrator, and the oscillation frequency can be changed by changing the thickness and shape of the piezoelectric vibrator.

Although only one piezoelectric vibrator is shown in FIG. 5, a plurality of sandwich types (multi-layer type) as shown in FIG. The bending traveling wave also increases and the pumping force increases.
Further, a metal plate may be interposed between the piezoelectric vibrators to be multilayered.

As the piezoelectric vibrator of the second vibration generator 6, as shown in FIG. 7, a ceramic PZT 14 having a thickness of 0.2 to 1 mm is sandwiched between the electrodes 15 from both sides and a thickness of 0.1 to 0 mm. .3 mm metal plate 16
Can be used as a single plate (unimorph). When a voltage is applied between the electrodes, the ceramic expands and contracts. However, since one side is adhered to the metal plate 16, the shrinkage of the adhered surface is suppressed, and as shown in FIGS. By repeating the warping motion, vibration of the audible wave region frequency is generated.

In FIG. 7, only one piezoelectric vibrator is used. However, as shown in FIG. 9, two sandwich types (bimorph type) sandwiching a metal plate 16 can further increase the amount of excitation vibration. The vibration transmitted to the plate 9 is also increased, and the filling efficiency can be increased.

The material of the powder supply pipe 2 is made of a material that has a large attenuation in frequency vibrations in the ultrasonic range and a small attenuation in frequency vibrations in the audible range, that is, a polyacrylate ester.
Plastic materials such as nylon, Freon resin, polycarbonate, polypropylene, and polystyrene are preferable. In addition to plastic, a material with large attenuation is glued to a part of the metal member, or a groove is made to a part of the metal member, etc.
A material with low attenuation can be made in the audible frequency oscillation.

The powder supply pipe 2 is particularly preferably made of polyacrylic acid ester. The polyacrylic acid ester pipe has a part in which the bending traveling wave of the vibration in the ultrasonic region frequency applied to a part thereof is attenuated by the member itself. However, the vibration in the audible frequency range has a small attenuation.

As a member of the measuring mechanism 3, it is preferable to use hard plastic, metal or glass which has a small attenuation of frequency vibration in the audible wave region.

The powder supply pipe 2 may be installed in an inclined state with the powder outlet side downward, but when it is set vertically,
The gravitational force of the powder itself is added to the pumping force by the bending traveling wave, and the pumping effect is improved.

The powder outlet of the powder supply pipe 2 and the powder measuring mechanism 3
It is preferable that the central portion of the connecting portion with the powder inlet is aligned, but if the powder can be moved and the powder does not flow out to the outside at the connecting portion, the central axis is not necessarily aligned. good.

Further, the cross section of the powder supply pipe 2 does not necessarily have to be circular, and any structure having no opening other than the end face may be used. The powder supply pipe 2 is preferably a straight pipe in order to reduce the flow resistance of the powder, but may be a curved pipe.

The powder outlet of the powder supply pipe 2 and the powder measuring mechanism 3
The connection with the powder inlet may be performed by pressing and pressing via packings to prevent the powder from flowing out, and a connection method that is easy to attach and detach.

When a predetermined amount of powder is to be taken out by the apparatus of the present invention, the powder supply tube 2 connected to the upper portion of the powder supply container 13 is connected to the powder measuring mechanism 3 and the measuring plate 9 of the measuring mechanism 3 is connected.
Is moved rightward to position the measuring section 8 below the powder supply pipe 2.

In this state, when the first vibration generator 4 is driven in the ultrasonic range, the powder supply pipe 2 is placed in the powder supply container 13 side, that is, in the powder inlet direction by the vibration absorption of the pipe member itself. An advancing bending wave that attenuates is generated. In addition, the second vibration generator 6 generates a standing wave vibration in the powder measuring mechanism 3 that causes the entire powder measuring mechanism to vibrate.

The powder is continuously taken in from the connection portion with the powder supply container 13 by the traveling wave generated on the wall surface of the powder supply pipe 2, and the first powder has a first direction opposite to the traveling direction of the bending traveling wave.
, Ie, in the direction of the connected powder measuring mechanism 3. Since the powder supply pipe 2 is hollow, the powder in the pipe has no escape route in the radial direction, is brought into a pressure feeding state by the powder taken in one after another, and is pushed into the powder measuring mechanism 3.

The powder pressed into the powder measuring mechanism 3 reduces the frictional resistance between the powder and the inner wall due to the flow effect of the standing wave vibration of the powder measuring mechanism 3 on the wall surface of the measuring section 8. In this state, the powder is press-fitted into the measuring section 8 provided on the measuring plate 9 by the pressing force and the gravity applied from the powder supply pipe 2 to the powder.

When the measuring section 8 of the weighing plate 9 is filled with powder, the lower opening of the weighing section 8 of the weighing plate 9 has a sliding table 1 for preventing powder from falling.
1 is provided so that the powder does not fall.

Next, the position of the weighing plate 9 is moved to the left, the weighing section 8 is shifted from the surface of the slide table 11, and the powder is dropped and discharged by standing wave vibration which vibrates the entire weighing mechanism. At that position, the upper leakage prevention plate 12 for preventing the upward leakage of the powder from the upper opening of the measuring portion 8 of the measuring plate 9 is provided, so that the powder does not leak upward due to vibration, Drop and discharge.

In the case of a powder having a high fluidity, the filling in the measuring section 8 is performed only by the powder measuring mechanism 3.
In the case of a powder having strong adhesive and cohesive properties or a light powder having a low bulk density, the powder supply pipe 2 is simultaneously driven to perform efficient filling. If the applied power and the excitation frequency of the first vibration generator and the second vibration generator are kept constant, the bulk density of the filled powder in the measuring section 8 can be maintained even if charging and discharging are repeated. , Is kept constant every time, and the weight conversion value is also constant.

The measuring plate 9 is connected to the slide 11 and the upper leakage preventing plate 1.
Repeating reciprocating movement while sliding between two,
When the powder is filled or discharged, the smaller the adhesion between the face wall of the measuring portion 8 of the measuring plate 9 and the powder, the smoother the movement of the powder is. Therefore, the measuring plate 9, the slide table 11, and the upper leakage prevention plate The member 12 is preferably made of a material having low friction and good slip, such as CFC resin, stainless steel, or glass.

A slippery sheet or packing is interposed between the weighing plate 9, the slide table 11, and the upper leakage prevention plate 12, and
Leakage of the powder from the surfaces between the plates may be prevented.

[0040]

EXAMPLE An apparatus shown in FIG. 1 was manufactured in which the powder supply pipe 2 was a plastic pipe made of polyacrylate and the powder measuring mechanism 3 was a plastic plate made of polyacrylate. The powder supply pipe 2 has an outer diameter of 15 mm and an inner diameter of 9
The first vibration generating device 4 of the ultrasonic region frequency vibration generating means has an end portion of 100 mm and a length of 100 mm.
And an inverted conical powder supply container 13 was adhesively connected to the other end. The powder inlet of the powder measuring mechanism 3 has an outer diameter of 22 mm, an inner diameter of 16 mm, and a length of 2 mm.
The thickness was set to 0 mm, and the piezoelectric vibrator of the second vibration generating device 6 of the audible wave frequency vibration generating means was bonded to the bottom of the powder measuring mechanism 3.

The powder outlet of the powder supply pipe 2 is inserted into the powder inlet of the powder measuring mechanism 3 and connected as shown in FIG. Was set vertical so that gravity acted on the powder.

The weighing plate 9 was 3 mm thick, a hole having a diameter of 3 mm was drilled and processed, and an experiment of filling the weighing portion 8 with a volume of 21.2 cubic millimeters was performed.
The experiment used a powder of 82 percent aluminum oxide having an average particle size of 10 microns.

One filling time is 5 seconds, and a discharging time is 1
In seconds, the first vibration generator 4 is set to 50 kHz excitation, the second vibration generator 6 is set to 200 Hz excitation, and both the vibration generators are used at the same time and the filling is performed when the vibration generator is not used. Each discharge was performed 100 times continuously, and the filling weights were compared.

When the vibration generator was not used, the maximum filling amount was 0.02 g, the minimum filling amount was 0.00 g, and the average filling amount was 0.005 g.

Next, a filling experiment was conducted when the first and second vibration generators were used simultaneously. In this case, the maximum filling amount was 0.05 g, the minimum amount was 0.03 g, and the average filling amount was 0.046 g.

[0046]

As described above, according to the present invention, a powder supply device in which a powder supply pipe and a powder measuring mechanism are connected is provided with a vibration generator in an ultrasonic range and a vibration generator in an audible range, respectively. Thus, the powder is excited at a constant power and a constant frequency, the powder is pumped, and filling and discharging are repeated, so that a constant amount of powder can be supplied quickly, stably and efficiently.

[Brief description of the drawings]

FIG. 1 is a partially cutaway side view of a first embodiment of the present invention.

FIG. 2 is an explanatory view of an ultrasonic region vibration of an outer wall of a powder supply pipe.

FIG. 3 is an explanatory diagram showing an ultrasonic attenuated traveling wave generated in a powder supply pipe.

FIG. 4 is an explanatory diagram of frequency oscillation in an audible wave range of the powder weighing mechanism.

FIG. 5 is a partially cutaway perspective view showing an example of an ultrasonic piezoelectric vibrator.

FIG. 6 is a partially cutaway perspective view showing another example of the ultrasonic piezoelectric vibrator.

FIG. 7 is a longitudinal sectional view showing an example of the audible wave piezoelectric vibrator.

FIGS. 8A and 8B are explanatory diagrams of warping vibration of an audible acoustic wave piezoelectric vibrator. FIGS.

FIG. 9 is a longitudinal sectional view showing another example of the audible wave piezoelectric vibrator.

FIG. 10 is a cross-sectional view showing a state where a weighing plate of the powder weighing mechanism is moved.

[Explanation of symbols]

 1: powder supply device 2: powder supply tube 3: powder measurement mechanism 4: first vibration generator for generating ultrasonic vibration 5: AC power supply for generating ultrasonic frequency 6: for generating audible wave vibration Second vibration generator 7: AC power supply for generating audible wave frequency 8: Measuring unit 9: Weighing plate 10: Weighing plate moving device 11: Slide table 12: Upper leakage prevention plate 13: Powder supply container 14: Ceramic PZT 15: Electrode 16: Metal plate

Claims (5)

[Claims] 1. A powder supply container consisting of a hollow tube formed of a material having a large vibration damping is connected to a powder supply container at one end, and a through hole is formed in a plate at the other end to measure. The first vibration generating device is attached to the other end of the powder supply pipe while being connected to a weighing mechanism provided with a weighing plate that can form a portion and can be moved laterally on the slide table. Second in the mechanism
The vibration is generated by the first vibration generator, and the powder is supplied from the powder supply pipe into the measuring portion of the powder measuring plate by the vibration of the first vibration generating device. A powder supply device characterized in that a certain amount of powder is taken out by dropping the powder downward by the vibration of a vibration generator. 2. The powder supply pipe drives a first vibration generator to generate a traveling wave traveling toward the powder supply container.
The powder supply device according to claim 1, wherein the second vibration generator is driven by the weighing mechanism to generate standing wave vibration. When the powder supply tube is vertically connected, a powder supply container is connected to the upper part, a measuring plate is provided horizontally below the powder supply tube, and the measuring part of the measuring plate is filled with powder. The upper opening of the measuring unit is located below the powder supply pipe, the lower part of the measuring unit is located on the slide table surface, and when the powder is discharged, the measuring plate moves laterally and the upper opening of the measuring unit 3. The powder feeder according to claim 1, wherein the powder feeder is positioned below the powder upper leakage prevention plate, and the lower opening is displaced from the slide table surface so that the powder drops. 4. The vibration given by the first vibration generator is a bending traveling wave that is attenuated by the absorption of vibration by the pipe member of the powder supply pipe, and the vibration given by the second vibrator causes the entire weighing mechanism to vibrate. 4. The powder supply device according to claim 1, wherein the powder supply device generates a standing wave vibration. 5. The first vibration generator is a piezoelectric vibrator or a magnetostrictive vibrator and is driven at an ultrasonic frequency, and the second vibration generator is a piezoelectric vibrator, a magnetostrictive vibrator, an electromagnetic vibrator or a motor. The powder supply device according to any one of claims 1 to 4, wherein the powder supply device is a vibrator driven at an audible wave region frequency.