JP2653531B2 - Method and apparatus for supplying powder and granules - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for supplying a granular material for quantifying the continuous supply of the granular material, and in particular, for stabilizing the flow rate instantaneously.

[Prior art] With the increase in speed, direct connection, and non-stop of industrial machines, the demands related to the supply of powder and granules have become even more sophisticated. From a constant supply guarantee in seconds, an instantaneous constant supply guarantee in 1/10 second or 1/100 second time has been required.

The field of application of the present invention is not limited to the production of wires containing powdered particles for welding described below, but can be used in fields where constant weight supply of powdered particles is required. Hereinafter, the manufacture of a wire containing a powdered material for welding, which is one of fields in which constant weight supply of powdered material is particularly strictly required, will be described as an example.

In the process of forming a tubular shape while feeding a metal band (hoop) in the longitudinal direction thereof, the wire containing the granular material for welding supplies the granular material from an opening extending along the longitudinal direction, and opposes the edge of the opening. The surface is welded by high-frequency induction welding or the like or formed by bending, then reduced to a desired diameter and wound up to obtain a product.

In the most advanced manufacturing method at present, the above-mentioned manufacturing process is directly connected, and the speed is such that the granular material is supplied, and the edge surface of the opening is welded to form an approximately 1-inch granular material-filled tube. 30 to 40m per minute in the process. This approximately 1-inch filled powder-filled tube is reduced to an outer diameter of about 1.2 mm in order to be used as a welding wire, and is commercialized. This welding powder-filled wire is a product for welding. Uniform filling rate over the entire length of the wire to ensure uniform welding quality.

The filling ratio, which is the ratio between the powder and the shell metal, is defined as a percentage obtained by dividing the weight of the powder and the metal shell by the sum of the weight of the metal shell and the powder at a unit wire length. The rate shall be the basis of the guarantee.

For example, with a wire of 1.2 mm outside diameter, the filling rate is 12.0 ±
When 1.0% is set, when filling a granular material at a pipe speed of 30 m / min into an open pipe having an outer diameter of 22 mm and a wall thickness of 2.0 mm, the time is 1/100
The filling rate must be controlled with an accuracy of 6 mm or more in seconds and pipe length.

Therefore, in order to achieve such demands, a number of methods for instantaneously supplying a fixed amount of powder and granules have been proposed and provided, but they are roughly classified into two methods.

The first method is to directly detect the supply weight value and control the apparatus to bring the supply value closer to the target value.However, the signal processing instantaneously detects the supply weight value instantaneously and sends a control signal to the supply apparatus. However, since the supply device responding to the signal cannot follow up due to a control delay due to a response delay of a mechanical system such as a drive, the powder used for manufacturing the wire containing the powdered particles for welding is used. As a body supply device, there was a problem that it was too rough to guarantee a uniform filling rate.

The second method is a method of stabilizing the supply weight by supplying a constant volume, that is, a process of making a granular material a constant volume with a screw feeder, an auger feeder, a reciprocating feeder with a cylinder and a piston. Then, in the process of sending out the powder, the density of the granules increases and the consolidation occurs, and the volume of the granules to be sent out does not change, but the fluctuation occurs in terms of the supplied weight. There was difficulty. Further, the granular material 7 is stored in an upper storage tank 26 as shown in FIG. 4 in a constant volume feeder, and the granular material 7 is continuously connected to a disk 21 which is rotated by a motor 22 directly below a bottom plate opening of the storage tank 26. There is a table feeder which, after dropping and depositing 7, is scraped off by a scraper 25 in the outer circumferential direction of the disk and supplied through a chute 23, and is one of the feeders having the best constant weight supply in the powder and granular material supply apparatus. However, the powder and granular material supply device used for manufacturing the wire with the powder and granular material for welding also has the following problems.

[Problems to be Solved by the Invention] First, a method for evaluating the constant weight supply property of a granular material and a method for actually measuring the flow rate of the granular material will be described.

FIG. 5 shows the state of supply of general powder and granular material, with the vertical axis representing weight and the horizontal axis representing time.

In any case, in the measurement time T seconds, W _max : the maximum supply weight when actually measured every 1/100 second of the measurement cycle (g / 0.01 sec) W _min : the minimum supply weight when actually measured every 1/100 second of the measurement cycle ( g / 0.01sec) W _ave: when the simple average of the supply weight when measured for every measurement cycle 1/100 seconds and (g / 0.01sec), a quantitative index F shown by the following formula granule The constant weight supply property was evaluated.

_{F = (W max -W min)} / W ave × 100 (%) Next, the measured flow rate of the particulate material used was an apparatus FIG. 6. The granular material b discharged from the granular material supply device a is once applied to the inclination measuring plate c, and the collision force at that time is rated at 3 kg.
The measurement was recorded on the analyzing recorder f via the converter e for 80 seconds in a 1/100 second measurement cycle using the load cell d. The surface of the measurement plate c was coated with Teflon so that the powder did not adhere to the plate surface and flowed down in a rectified state, and was inclined at 60 degrees. In addition, for the effect of the eccentric load of the load cell,
The error when loading% was within 0.02% R.0. Therefore, the main component is rutile, and the filled and dried welding flux (granule) having the particle size distribution shown in Table 1
Using a table feeder shown in Fig. 4 which is a conventional powder feeder with the best constant weight feedability,
As a result of examining the actual supply weight at a supply speed of 0.01 sec, the conventional table feeder method has the following problems.

That is, as shown in FIG. 7, the change in weight is 46.1% in the quantitativeness index F, and the fluctuation width of the instantaneous supply weight (difference between the maximum value and the minimum value) is large. Then, the present inventors have examined the relationship between the supply volume and the supply weight in detail, and as a result, have found that the change in the volume is very small and only the supply weight fluctuates greatly. The range of this variation is that the powder pressure of the powder
It was concluded that the greatest cause was that the compaction was caused by the influence of the powder pressure when deposited on 21 and the density of the granular material was increased. In other words, although the upper storage tank is provided for the purpose of reducing the influence of the powder pressure of the granular material, it has been found that the conventional method and apparatus cannot achieve a constant supply weight instantaneously.

Accordingly, an object of the present invention is to provide a method and an apparatus which enable a highly accurate instantaneous level constant weight supply.

[Means for Solving the Problems] According to the method for supplying a granular material of the present invention, the granular material is dropped and deposited continuously from a bottom plate opening of an upper storage tank to a rotating disk below, and then the rotating disk is rotated. In the method of supplying the granular material which is substantially horizontally scraped off the upper part of the granular material deposited on the accumulation surface of the rotating disk, the granular material is scraped in the outer peripheral direction of the rotating disk and discharged, While adjusting the amount of fall so as to reach the set stacking height, the powder and granules are dropped from directly below the bottom plate opening on the inclined surface inclined toward the stacking surface of the rotating disk,
The method is characterized in that the compacted powdery material by sliding down the inclined surface is dispersed, averaged and supplied to the rotating disk.

Further, the powder and granular material supply device of the present invention continuously drops and deposits the powder and granular material from the bottom plate opening of the upper storage tank to the rotating disk below, and scrapes and discharges the powder to the outer peripheral direction of the rotating disk. In a supply device for a granular material, a storage tank provided with an agitator that rakes the granular material to an opening portion, and a slope that guides and regulates a granular material that is directly under the opening portion and that can adjust an inclination angle. A rotating disk disposed below the plate and the inclined plate and having a stacking surface, a detector for detecting the height of the granular material deposited on the stacking surface, and the number of rotations of the agitator in the upper storage tank based on an output signal of the detector A drive control device for increasing or decreasing the diameter, a replaceable outer guide fixed to the outer periphery of the rotating disk, a cutter for cutting the upper portion of the accumulated powder substantially horizontally, and an outer periphery of the rotating disk for the worn powder It is characterized by comprising a scraper that scrapes in the direction.

The amount of powder dropped from the bottom plate opening of the upper storage tank is adjusted by the accumulation height of the accumulation surface, and when the accumulation height is detected and exceeds the set amount, the rotation speed of the agitator is reduced or stopped, When it falls below, the number of rotations is increased so that the deposition height is always within the set range.

A more preferable result is obtained when the set range of the deposition height is a height exceeding the worn thickness and the surplus height is minimized.

Further, the bottom plate of the storage tank is appropriately replaced with a bottom plate having a different opening diameter depending on the target supply amount, properties, particle size configuration, and the like of the granular material. Immediately below the bottom plate opening of the upper storage tank, there is provided an inclined plate for guiding and rectifying the particles whose tilt angle can be adjusted, and the particles are dropped toward the inclined surface. The surface is such that the powder particles smoothly slide down in a rectified state and hardly adhere thereto, for example, a surface treated with Teflon coating. Further, the inclination angle is adjusted by the target supply amount, the property, the particle size configuration, and the like of the granular material. The change of the supply amount is usually performed by changing the rotation speed because the rotation of the rotating disk is an independent speed change drive, and is performed by changing the accumulation height and / or width of the granular material as necessary.

[Action] The powder and granules stored in the upper storage tank are dropped toward the inclined surface immediately below the opening of the storage tank bottom plate according to the level of the accumulation surface of the rotating disk, and the slope is slid down, and then the rotating disk And the upper surface of the deposited powder is scraped off and further scraped in the outer peripheral direction of the disk to discharge and supply.

That is, even in the case of a granular material that has been compacted during storage in the upper storage tank, the granular material is dispersed and averaged in the process of falling from the opening and sliding down the inclined surface. In addition, the impact of the powder pressure can be almost ignored because the height of the deposited granules is regulated, and it is cut off as it is and discharged and supplied by a scraper. Is extremely small. Therefore, the constant-weight supply property of the supplied granular material at a moment is dramatically improved.

[Example] Hereinafter, an example in which the present invention is applied to the production of a wire containing a powdered material for welding will be described.

FIG. 2 is a structural view of a main part of the wire manufacturing apparatus, and FIG. 1A is a longitudinal sectional view showing one embodiment of the apparatus of the present invention.

As shown in FIG. 2, forming roll groups 2a are sequentially arranged along the feeding direction of the tube 1. The powder supply device 3 is arranged between the forming rolls 2a. At the welding position, a high-frequency current is applied to the work coil 5 to generate an induced current in the tube 1, and the tube 1 is heated and welded by the squeeze roll 4. The welded pipe 1 is reduced in diameter to a desired diameter by a diameter reducing roll 2b.

As shown in FIG. 1A, the granular material supply device 3 stores the granular material 7 in an upper storage tank 6 and a bottom plate 6a of the storage tank 6 having a hole diameter.
An opening 6b of 20 mm is provided.

On the other hand, the agitator 8 which rakes the granular material 7 in the upper storage tank 6 toward the opening 6b is independently steplessly shifted by a stepless speed change motor 9 at 0 to 20 RPM according to the height of the stacking surface 11a. Then, the powder 7 is swept up to the opening 6b. FIG. 1B is a plan view of the agitator 8. Below the opening 6b, there is provided an inclined plate 10 for guiding a granular material having a smooth inclined surface, and a deposition surface 11a of the granular material 7 dropped through the inclined plate 10, and has a stepless speed-change motor 12. Rotating disk 11 that rotates independently
Is arranged. FIG. 1C is a plan view of the rotating disk 11. FIG. An outer periphery guide 13 is provided on the outer periphery of the rotating disk 11 so that the accumulation surface 11a becomes a valley with respect to the inclined plate 10. The fallen granular material slides down the slope of the inclined plate 10 and forms a valley.
deposited on a. Level detector 1 detects the height of the deposited powder
7 (for example, a capacitance type), a level signal is transmitted, and the number of rotations of the agitator 8 is increased / decreased via the controller 18 based on the level signal, thereby controlling the amount of the granular material falling. Due to the rotation of the stacking surface 11a, the granular material is cut off by the cutter 14 on its upper surface, further rotated and scraped off by the scraper 15, and supplied to the valley of the tube 1 being formed via the chute 16. You.

Here, a description will be given of the result of manufacturing the welding wire containing the granular material for welding manufactured by the apparatus of the present invention configured as described above.

Steel hoop material with outer diameter 22.0mm, wall thickness 2.2mm, pipe feed speed 30m
The tube was molded at a rate of / min. During the molding, the powders shown in Table 1 were filled at a target filling rate of 12.0 ± 1.0%. Feed rate 0.8
3g / 0.01sec, the agitator rotation speed is 6RPM, the storage amount of the granular material in the upper storage tank is 160kg, the rotation speed of the rotating disk is 30RPM, the pile height is 30 ~ 50mm, the cutting height is 10mm, the cutting width
20 mm. The fluctuation of the supply weight was detected by using the apparatus for measuring the flow rate of the granular material shown in FIG. 6, and the granular material flowing from the measuring plate, that is, the chute, was directly supplied to the valley of the pipe 1 during the molding. The output signal from the load cell d was connected to an analyzing recorder f having a resolution of 1/100 second via a converter e, and continuously measured for 80 seconds.

W _max , W _min , and _Wave were calculated by the analyzing recorder f, and a quantitative index F was obtained based on the result.

FIG. 3 shows the supply results of the powder and granules, and Table 2 shows the measurement results of the filling rate of the filled tubes.

As is clear from FIG. 3, the quantitativeness index F was 46.1% according to the conventional method, but was 25.7% according to the present invention, which is a dramatic improvement. Further, as can be seen from FIG. 3, the supply state has a small fluctuation range, and it has been proved that the supply state is extremely stable.

Furthermore, the result of measuring the filling rate of the filled pipes shows that the target filling rate (12.0 ± 1.0%) was out of the target filling rate of 10.7 to 13.8%, which was the conventional value.
It was confirmed that all of 1.5 to 12.8% were within the range of the target filling rate (12.0 ± 1.0%).

[Effects of the Invention] According to the present invention, the compaction of the granular material is prevented in the supply of the granular material, and the cutout supply is performed while keeping the volume and the density constant, so that even in the instant of 1/100 second, A constant supply of the weight of the granular material can be achieved. The filling rate of the welding wire containing the granular material for welding manufactured by using the method and the apparatus for supplying the granular material of the present invention can be kept within the range of the target filling rate (12.0 ± 1.0%), and the dispersion is extremely small. It becomes a stable wire.

[Brief description of the drawings]

FIG. 1A is a longitudinal sectional view showing one embodiment of the apparatus of the present invention, FIG.
Figure is a plan view of the agitator, Figure 1C is a plan view of the rotating disk,
FIG. 2 is a view showing a main part of an apparatus for manufacturing a wire containing a powder for welding, and FIG. 3 is a view showing a state of supply of powder by a powder supply apparatus of the present invention, and FIG. FIG. 5 is a perspective view showing a granular material supply device, FIG. 5 is a view showing a general state of supplying granular material, FIG. 6 is a flow rate measuring device for granular material, and FIG. 7 is a conventional granular material supply device. It is a figure which shows the supply state of the granular material by. 1 ... pipe, 3 ... powder and granular material supply device, 6, 26 ... tank, 7
…… Powder and granules, 8 …… Agitator, 10 …… Slope plate, 11,21
…… Rotating disk, 13 …… Outer circumference guide, 14 …… Cutter, 1
5,15… Scraper, 16,23 …… Shoot, 17 …… Level detector.

Claims (2)

(57) [Claims] After the particles are continuously dropped and deposited on a rotating disk below from an opening of a bottom plate of an upper storage tank, the upper part of the particles deposited on the deposition surface of the rotating disk is made substantially horizontal. Wear,
In the method of supplying the granular material, which scrapes the granular material in the outer circumferential direction of the rotating disk and discharges the material, the bottom plate is opened while adjusting the drop amount so as to have a predetermined deposition height from the bottom plate opening of the upper storage tank. The powder and granules are dropped on the inclined surface that is inclined from just below the hole toward the deposition surface of the rotating disk, and the inclined surface is slid down to disperse and consolidate the powdered particles, averaged and supplied to the rotating disk. The method of supplying the granular material. 2. An apparatus for supplying a granular material which continuously drops and deposits a granular material from a bottom plate opening of an upper storage tank onto a rotating disk below, and scrapes and discharges the granular material in an outer peripheral direction of the rotating disk. In the above, a storage tank having an agitator that rakes the granular material to the opening, an inclined plate that is located immediately below the opening and guides and regulates the granular material having an adjustable inclination angle, and an inclined plate. A rotating disk disposed below and having a stacking surface, a detector for detecting the height of the granular material deposited on the stacking surface, and a drive control for increasing or decreasing the rotation speed of the agitator in the upper storage tank based on an output signal of the detector Equipment and
An exchangeable outer peripheral guide fixed to the outer periphery of the rotating disk, a cutter that cuts the upper part of the accumulated powder substantially horizontally, and a scraper that scrapes the worn powder toward the outer periphery of the rotating disk An apparatus for supplying a granular material, comprising: