JPH04322271A - Powder carrying device - Google Patents

Abstract

PURPOSE:To efficiently carry powder in a long distance by low energy by generating a traveling wave to a powder carrying member connected by a vibration absorption member by giving vibration in a radius direction by a vibration generation means. CONSTITUTION:A hollow pipe 2 is formed in a longitudinal direction by giving curvature and a piezoelectric element 3 is disposed at the plural positions of the longitudinal direction of the pipe 2. Besides, the pipe 2 between the elements 3 is connected by the vibration absorption member 5. That means, the element 3 for generating the ultrasonic vibration being the vibration generation means is disposed on the acrylic pipe 2 being the tube-like powder carrying member at regular intervals and an AC voltage is impressed on it by an AC voltage power source 4. The elongating and contracting vibration is excited in the directions of an inner diameter and an outer diameter, that means, an (r) direction by the elongating and contracting force of ceramic and such vibration is transmitted to the pipe 2 as the traveling wave. Therefore, the powder in the pipe 2 is carried in a reverse direction to the direction of the traveling wave by the traveling wave.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for conveying powder.

0002

BACKGROUND OF THE INVENTION Conventionally, the most common technique for conveying powder is the use of a screw, which is used in all types of powder conveying means. In this method, for example, powder inside a pipe is transported by rotating a screw provided inside the pipe.

0003

However, in the conventional example described above, since the screw in the pipe must be rotated by a motor, there are problems in that the power consumption is large and the rotation noise is relatively loud.

[0004] The structure also requires a relatively complicated member such as a screw and a motor, resulting in a large space and high cost.

[0005] Furthermore, if the gap between the screw and the inner wall of the pipe is large, the conveyance efficiency will decrease, and conversely, if the gap between the screw and the inner wall of the pipe is small, the conveyance efficiency will increase, but the rotation of the screw will be reduced due to the friction between the screw and the inner wall of the pipe. Another problem was that the torque increased.

Furthermore, the powder may deteriorate or break due to friction between the inner wall and the screw, or may melt due to frictional heat. In addition, since powder is generally easily charged, the powder often becomes charged during transportation and adheres to the screw, and in severe cases, there is a problem that transportation failure occurs.

Furthermore, since the screw is passed through the pipe, it is very difficult to freely change the direction of conveyance, and changing the direction of conveyance requires a means to temporarily store the powder, which complicates the equipment. There was a problem.

An object of the present invention is to solve the above-mentioned problems, and to provide a powder conveying device that has low power consumption, low noise, has good conveying efficiency, and can freely change the conveying direction. .

[0009]

[Means for Solving the Problems] According to the present invention, the above object is to provide a tubular or trough-like powder conveying member that has a curvature in the longitudinal direction and conveys powder in the longitudinal direction, and This is achieved by including vibration generating means disposed at a plurality of positions in the longitudinal direction of the vibration generating means, and a vibration absorbing member connecting the powder conveying member between the vibration generating means.

0010

According to the present invention, vibrations are generated in the radial direction of the powder conveying member by the vibration generating means disposed at a plurality of positions in the longitudinal direction of the powder conveying member having a curvature. Then,
Traveling waves are generated in both longitudinal directions around each vibration generating means. However, a vibration absorbing member is attached near one side of each vibration generating means, and the generation of a backward traveling wave traveling in the direction in which the vibration absorbing member is attached is suppressed to prevent interference between the traveling waves. Therefore, the traveling waves generated from each vibration generating means are only those traveling in the direction opposite to the direction in which the vibration absorbing member is attached, and the traveling waves are combined. In this way, the powder in the powder conveying member having the curvature is conveyed in a direction opposite to the direction of the combined traveling wave and along the curvature of the powder conveying member.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First to fifth embodiments of the present invention will be described with reference to the accompanying drawings.

<First Embodiment> First, a first embodiment of the present invention will be described with reference to FIGS. 1 to 11.

FIG. 1 shows a first embodiment of the present invention. This device is a powder conveying device that utilizes the present invention. Figure 1(A)
is a perspective view, FIG. 1(B) is a top view, and FIG. 1(C) is a side view.

In FIG. 1, 1 is a hopper for supplying powder, and 2 is an acrylic hollow pipe which is a tubular powder member. The hollow pipe 2 has an outer diameter of 15 mm and an inner diameter of 10 m.
m, it extends for a long time while changing the curvature arbitrarily in the longitudinal direction. Note that the hollow pipe 2 remains horizontal with respect to the direction of gravity.

Ultrasonic vibration generating piezoelectric elements 3 serving as vibration generating means are arranged at regular intervals in the longitudinal direction of the hollow pipe 2, and an AC voltage is applied to them by an AC power source 4.

The piezoelectric element 3 has an outer diameter 3 as shown in FIG.
0mm, inner diameter 15mm, thickness 2mm ceramic PZT
It is a type that is sandwiched between electrodes from both sides.

By applying a voltage between the electrodes, as shown in FIG. 3, the expansion and contraction force of the ceramic excites expansion and contraction vibrations in the inner and outer diameter directions, that is, in the r direction, and the vibrations are transmitted to the hollow pipe 2 as traveling waves. be done. The powder in the hollow pipe is transported by the traveling wave generated by the piezoelectric element 3 in a direction opposite to the direction of the traveling wave (direction of arrow A in FIG. 1). In addition, in the above embodiment, the peak-to-peak voltage 1
An alternating current voltage of 00 V and a frequency of 50 KHz is applied. This is a value calculated from the resonance mode depending on the shape of the piezoelectric element, and the resonance frequency can be changed by changing the thickness and shape of the piezoelectric element. In addition, in this example, the piezoelectric element is only one layer, but if a multiple sandwich type (multilayer type) is used as shown in Fig. 4, the amount of excited vibration can be further increased, and the traveling wave transmitted to the hollow pipe will also be larger. The powder conveying force also increases. Further, as shown in FIG. 5, electrodes may be provided around the circumference of the piezoelectric element. Furthermore, by subdividing the electrodes of the piezoelectric element and changing the polarity of the applied voltage, it is possible to obtain various vibration modes. Specifically, the electrode arrangement shown in FIG. 6 is used to create a 1 mode called the ((1,1)) mode shown in FIG.
Axisymmetric vibration can be excited.

Furthermore, if the electrode division is subdivided as shown in FIG. 8, parallel vibration of the central axis called the ((2,1)) mode can be excited as shown in FIG. Furthermore, by shifting the phase of the AC voltage applied to these electrodes by 90 degrees, a rotational mode of vibration is also possible.

[0019] In this way, many vibration modes can be excited by subdividing the electrodes and shifting the phase of the voltage applied to each electrode, and by utilizing these various modes, it is possible to control the characteristics of various powders. By selecting the most suitable excitation mode for each powder, you can obtain sufficient transport force for each powder.

[0020] This is because the mass, specific gravity, slipperiness, adhesion, and chargeability of powder vary, and even if the hollow pipe is the same, the transportability of powder strongly depends on the characteristics of the powder itself. be. The same thing can be said even if the material, surface properties, and chargeability of the hollow pipe are changed.

Furthermore, since the traveling wave excited by the piezoelectric element propagates while vibrating on the inner wall surface of the hollow pipe, it can propagate without any problem even if the curvature of the hollow pipe is arbitrarily changed.

However, when a plurality of piezoelectric elements are provided, a problem arises in that their traveling waves interfere with each other. Therefore, when connecting multiple piezoelectric elements to the same long hollow pipe to transport powder over a long distance, the hollow pipe between the piezoelectric elements is divided as shown in Figure 1, and the movement generated by each piezoelectric element is The vibration absorbing member 5 may be interposed so that the waves do not interfere with traveling waves generated by other piezoelectric elements.

In order to explain the action of this vibration absorbing member, FIG. 10(B) shows a schematic diagram of each traveling wave generated by the piezoelectric element.

As shown in FIG. 10, the traveling wave transmitted through the hollow pipe 2 is attenuated by the vibration absorbing member 5, and the traveling wave is not transmitted to the adjacent hollow pipe 2.

FIG. 10C shows the vibration of the traveling wave excited in the hollow pipe 2 after combining the respective traveling waves.

[0026] By cutting the hollow pipe 2 in which the backward traveling waves occur and interposing a vibration absorbing member between them, the influence of the backward traveling waves can be suppressed to a small level, and powder conveyance as shown in FIG. 10(C) can be achieved. It becomes possible to have the magnitude and direction of force.

[0027] Here, for the sake of simplicity, the case where they are arranged in a straight line has been explained, but there is no difference even if they have a curvature.

As is clear from this, the effective powder conveying force acts in a fixed direction, and as shown in FIG.
Powder is strongly conveyed in this direction. That is, by shifting the position of the vibration absorbing member from the midpoint between adjacent piezoelectric elements, powder can be transported in the opposite direction to the shifting direction, and the closer it is to the piezoelectric elements, the more the transport force increases.

Furthermore, the vibration width at the end of the hollow pipe 2 in contact with the vibration absorbing member 5 is 1/1 of the vibration width at the piezoelectric element portion.
If it is not attenuated to 2 or less, the influence of the reflected wave at the end becomes large, and the attenuation of the carrier force of the traveling wave becomes large, which is not preferable.

The vibration absorbing member 5 is made of vibration isolating rubber (NBR) 5B and silicone adhesive 5A as shown in FIG.
A hollow acrylic pipe was connected.

[0031] As a result, the powder could be smoothly conveyed over a long distance of 2 m without clogging. When one-component magnetic toner having an average particle size of 12 μm was used as powder, the powder conveying force was 500 g/min.

[0032] Further, the powder was made into glass beads with an average particle size of 60 μm.
It has been found that a conveying force similar to that of the magnetic toner can be obtained even when using powders with a ferrite carrier average particle size of 60 μm and a non-magnetic toner average particle size of 8 μm, and a mixture thereof.

At this time, the amount of powder conveyed changed in proportion to the voltage applied to the piezoelectric element, making it possible to control the amount of powder conveyed.

Incidentally, in this embodiment, AC voltages of the same phase and voltage (peak-to-peak voltage 100V, frequency 50K) are used.
Hz) was applied continuously, but each piezoelectric element became an independent event due to the vibration absorbing member, and even if the phase, application time, and applied voltage of each voltage element were changed, the other voltage elements were not affected. The powder conveying force of the voltage element can be controlled.

[0035] Furthermore, if the material used for the powder conveying member has a relatively large attenuation coefficient, and the amplitude of the generated excitation is less than 1/2 at the end, the influence of reflected waves will be reduced. It was found that the conveyance ability was excellent. According to experiments, acrylic, nylon, POM (polyacetal), A
BS, polypropylene, polystyrene, etc. are suitable.

[0036] Also, NBR, urethane rubber, Si rubber, EKDM, gel resin, Si rubber adhesive, etc. are most suitable as vibration absorbing members, and by reducing the hardness of the rubber, almost 100% of traveling wave vibrations can be absorbed. It is possible. Furthermore, experiments have shown that when the vibration absorption rate is 50%, if the amplitude of the traveling wave propagating through the vibration absorbing member is attenuated to 1/2 or less, the traveling wave generated from the adjacent hollow pipe and piezoelectric element will be hardly affected and the It was also found that body transport was carried out smoothly.

As described above, since there is no conveying member such as a screw inside the hollow pipe, the powder can be efficiently conveyed without deterioration, destruction, melting, etc. in a long hollow pipe whose curvature can be arbitrarily changed. became possible.

<Second Embodiment> Next, a second embodiment of the present invention will be described based on FIG. 12. Note that the same reference numerals are given to the same parts as in the first embodiment, and the explanation thereof will be omitted.

This embodiment differs from the first embodiment in that the piezoelectric element is installed obliquely to the hollow pipe as shown in FIG. This embodiment can also achieve the same effects as the first embodiment.

[0040] Furthermore, when the inner diameter of the hollow pipe changes, the load resistance for conveying the powder changes, so optimal conveyance can be maintained by changing the distance between the piezoelectric elements and the applied voltage. In this way, this embodiment can also achieve the same effects as the first embodiment.

<Third Embodiment> Next, a third embodiment of the present invention will be described with reference to FIGS. 13 and 14. Note that the same reference numerals are given to the same parts as in the first embodiment, and the explanation thereof will be omitted.

This embodiment differs from the first embodiment in that a groove-shaped distorted conveying member 2 is used instead of the hollow pipe 2, as shown in FIG. In this embodiment as well, acrylic is used for the conveying member.

The transport principle is the same as that of the first embodiment, and the AC power supply 4
The powder is conveyed in the long groove by applying a voltage to the piezoelectric elements 3 and using a vibration prevention member 5 to prevent the traveling waves of the respective piezoelectric elements from interfering with each other.

[0044] Since this is not a hollow pipe but has an open top, it has the advantage that powder can be easily replenished through the groove opening.

Further, as shown in FIG. 14, the same effect can be achieved even if the distorted powder conveying member 2 is shaped like a gutter.

<Fourth Embodiment> Next, a fourth embodiment of the present invention will be described using FIG. 15. Note that the same reference numerals are given to the same parts as in the first embodiment, and the explanation thereof will be omitted.

In this embodiment, as shown in FIG.
This embodiment differs from the first embodiment in that it is fixed to the lower part of the distorted hollow pipe 2. This is a method in which a plate-shaped piezoelectric element such as a laminated piezoelectric element is vibrated and a part of the hollow pipe is struck by the piezoelectric element to generate a traveling wave from a part and transport the powder, and is similar to the other embodiments. Sufficient conveying force is generated. Furthermore, although the vibration preventing member 5 is inserted in the direction perpendicular to the axis of the hollow pipe, it may be provided at an angle or may be asymmetrical with respect to the axis of the hollow pipe. When traveling waves are generated from a part of the cylindrical pipe, the shape of the vibration prevention member 5 may be changed in consideration of the influence of reflected waves.

[0048] With such a configuration, it is possible to realize powder conveyance in a simple and compact manner, which is advantageous in terms of pipe replacement, cost, etc.

<Fifth Embodiment> Next, a fifth embodiment of the present invention will be described based on FIG. 16. Note that the same reference numerals are given to the same parts as in the first embodiment, and the explanation thereof will be omitted.

This embodiment differs from the first embodiment in that, as shown in FIG. 16, a method of spirally winding a hollow pipe is used.

Powder transport according to the present invention is traveling wave transport that utilizes the frictional resistance between the powder and the inner wall of the hollow pipe, so if the inclination increases to a certain extent with respect to the direction of gravity, the frictional force decreases and transport becomes impossible. Sometimes.

However, according to this embodiment, the frictional force is maintained and the powder can be easily transported upstream in the direction of gravity against gravity.

[0053]

[Effects of the Invention] As explained above, according to the present invention,
Since a traveling wave is generated by applying vibration in the radial direction by the vibration generating means to the powder conveying member connected by the vibration absorbing member, the powder can be efficiently conveyed over a long distance with less energy. Further, the powder can be transported quietly and smoothly without deterioration, damage, or melting. Furthermore, the conveyance direction can be freely set.

[Brief explanation of drawings]

FIG. 1: (A) is a perspective view showing a schematic configuration of a device according to a first embodiment of the present invention, (B) is a top view of (A), and (C) is a top view of (A).
FIG.

FIG. 2 is a perspective view showing a schematic configuration of vibration generating means of the device shown in FIG. 1;

FIG. 3 is a diagram showing changes in the outer wall of the powder conveying member of the apparatus in FIG. 1;

FIG. 4 is a perspective view showing a schematic configuration when the means of FIG. 2 are stacked.

5 is a perspective view showing a schematic configuration of the means shown in FIG. 2 in which electrodes are provided around the circumference; FIG.

FIG. 6 is a diagram showing a ((1,1)) mode electrode arrangement of the means of FIG. 2;

7 is a diagram showing changes in the outer wall of the powder conveying member in the case of the arrangement shown in FIG. 6. FIG.

8 is a diagram showing a ((2,1)) mode electrode arrangement of the means of FIG. 2; FIG.

9 is a diagram showing changes in the outer wall of the powder conveying member in the case of the arrangement shown in FIG. 8. FIG.

10: (A) is a diagram showing the state of powder inside the powder conveying member of the apparatus shown in FIG. 1; (B) is a diagram illustrating traveling waves generated within the powder conveying member of the apparatus shown in FIG. 1; C) is (
B) It is a figure explaining the traveling wave after combining each traveling wave.

11 is a diagram showing a schematic configuration of a vibration absorbing member of the device shown in FIG. 1. FIG.

FIG. 12 is a diagram showing a schematic configuration of a device according to a second embodiment of the present invention.

FIG. 13 is a diagram showing a schematic configuration of a device according to a third embodiment of the present invention.

FIG. 14 is a diagram showing a case where the powder conveying member of the apparatus shown in FIG. 13 is formed into a gutter shape.

FIG. 15 is a diagram showing a schematic configuration of a device according to a fourth embodiment of the present invention.

FIG. 16 is a diagram showing a schematic configuration of a device according to a fifth embodiment of the present invention.

[Explanation of symbols]

2 Powder conveyance member (hollow pipe) 3 Vibration generating means (piezoelectric element) 5 Vibration absorbing member

Claims (6)

[Claims] 1. A tubular or trough-like powder conveying member having a curvature in a longitudinal direction and conveying powder in the longitudinal direction; and vibration generating means disposed at a plurality of positions in the longitudinal direction of the powder conveying member. , and a vibration absorbing member connecting the powder conveying members between the respective vibration generating means. 2. The powder conveying member is configured so that the amplitude of the powder conveying member excited by the vibration generating means is 1/2 or less at the connection portion between the powder conveying member and the vibration absorbing member. The powder conveying device according to claim 1. 3. The powder conveying device according to claim 1, wherein a vibration absorbing member is used in which the amplitude of the traveling wave propagating through the powder conveying member is 1/2 or less. 4. The powder conveying device according to claim 1, wherein the vibration generating means uses a piezoelectric element. 5. The powder conveying device according to claim 1, wherein the powder conveying member is a hollow pipe. 6. The powder conveying device according to claim 1, wherein the vibration absorbing member uses a resin or a rubber adhesive.