JP2003002428A - Screw conveyer device for conveying kneaded sand, and its control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a screw conveyer device for conveying kneaded sand capable of easily removing adhered sand to a trough or a screw, or for realizing a screw structure for preventing the kneaded sand from being adhered and smooth flow of the kneaded sand by loosing and conveying the kneaded sand in a simple structure. SOLUTION: In this screw conveyer device for conveying kneaded sand, a rotating shaft rotated by a motor is disposed in the trough having an input port in its upper part and a discharge port in its lower part, and a scraper is spirally mounted to the rotating shaft. Many blow nozzles for injecting compressed air are arranged in the trough at an interval, the motor is connected to an ammeter and communicated to a solenoid opening/closing valve for switching between supply and block of the compressed air to many blow nozzles, and the ammeter and the solenoid opening/closing valve are electrically interconnected via a controller.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screw for conveying kneading sand used for making a green sand mold.
The present invention relates to a conveyor device and a control method thereof.

[0002]

2. Description of the Related Art In general, kneading sand for molding a green sand mold is kneaded by adding clay as a binder, water and additives to silica sand and kneading the mixture to improve its moldability and mold retention. Therefore, the adhesiveness is high. Conventionally, a belt conveyor has been frequently used as a conveying means for such highly adhering kneaded sand, but in recent years, in order to prevent the working environment from being deteriorated, a screw conveyor in which the entire conveying passage has a closed structure. Are being used more often.

However, when the kneaded sand is conveyed by a screw conveyor, the kneaded sand adheres to the screw, and if this adherence grows, the conveying ability is significantly lowered and the conveyance becomes impossible. For this reason, a screw conveyor of powder and granules, which is intended to solve these problems, is disclosed in Japanese Patent Laid-Open No.
No. 0-71426, Japanese Utility Model Laid-Open No. 60-81918 and Japanese Patent Application Laid-Open No. 2000-233817 are known.

[0004]

However, the above-mentioned Japanese Patent Laid-Open No.
In the case of JP-A-0-71426, only the granular material below the granular material charging port is fluidized by the granular material fluidizing gas, and the effect of preventing adhesion is insufficient. In addition, the actual development 6
The method disclosed in 0-81918 is not a satisfactory solution because it has only a small clearance at the base of the screw shaft. Further, the above-mentioned JP 2000-2
The one disclosed in Japanese Patent No. 33817 prevents the clogging phenomenon of powder particles, but has a problem that the structure is complicated and the manufacturing cost becomes high.

The present invention has been made in view of the above problems, and has a screw structure in which sand adhering to troughs and screws can be easily removed, or kneading sand is less likely to adhere. An object of the present invention is to provide a kneading sand conveying screw conveyor device and a control method thereof, which can realize the flow of kneading sand by loosening and improving the flow of the kneading sand with a simple structure.

[0006]

In order to achieve the above object, a kneading sand conveying screw conveyor device according to the present invention is provided with a motor in a trough having an input port at the upper portion and an outlet port at the lower portion. It is equipped with a rotating shaft,
In a kneading sand conveying screw conveyor device in which a scraping plate is spirally attached to the rotary shaft, a large number of blow nozzles for injecting a compression air are arranged in the trough at intervals, and the blow nozzle is provided in the motor. An ammeter is connected and an electromagnetic on-off valve for switching between supply and interruption of the compression air is connected to the plurality of blow nozzles, and the ammeter and the electromagnetic on-off valve are electrically connected via a controller. Is characterized by.

Further, in the kneading sand conveying screw conveyor device according to the present invention, a rotary shaft is arranged in a trough having an input port at the upper part and an outlet port at the lower part, and a large number of supporting members are arranged on the rotary shaft. And a scraping plate is attached to the supporting member in a spiral shape in a state of being lifted up from the rotating shaft, thereby forming a space between the scraping plate and the rotating shaft, and further by rotating the rotating shaft. A large number of stirring members are arranged at intervals in front of and behind the spiral scraping plate.

Further, in the kneading sand conveying screw conveyor device according to the present invention, a rotary shaft rotated by a motor is provided in a trough having an input port at the upper portion and an outlet port at the lower portion, and the rotary shaft is provided. A large number of support members are arranged at a distance to the support member, and the scraping plate is spirally attached to the support member in a state of being lifted up from the rotating shaft, so that a space is provided between the scraping plate and the rotating shaft. In addition, a large number of stirring members are arranged at intervals in the front and rear positions of the spiral scraping plate on the rotating shaft, and a plurality of blow nozzles for injecting compression air are also arranged at intervals in the trough. An ammeter is connected to the motor and an electromagnetic on-off valve for switching between supply and cutoff of the compression air is communicated with the plurality of blow nozzles to connect the ammeter and the electromagnetic on-off valve. Electrically connected through Characterized in that it was.

In order to achieve the above object, the method of controlling the kneading sand conveying screw conveyor device according to the present invention is a step of measuring the current value of the motor when the motor for rotating the screw is in operation. If the current value during measurement exceeds the desired reference current value, the compression air is discharged from the blow nozzle.
And a step of stopping the injection of the compression air from the blow nozzle when the current value during measurement falls below the desired reference current value.

The control method of the kneading sand conveying screw conveyor device according to the present invention comprises a step of measuring a current value of the motor when the motor for rotating the screw is in operation.
When the current value during measurement exceeds the desired reference current value, the kneading sand supply to the trough is stopped while the screw is still rotating, and this state is maintained for a predetermined time and remains in the trough. The step of discharging the kneaded sand, the step of discharging the kneaded sand from the trough, and the step of injecting the compression air from the blow nozzle, and the time point when the current value during the measurement falls below the desired reference current value. Then, the compression air from the blow nozzle
And the step of restarting the supply of the kneading sand into the trough.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. First, trough and screw
A kneading sand transfer screw conveyor device and a control method therefor capable of easily removing sand adhering thereto will be described with reference to FIG. 1 as a first embodiment. In FIG. 1, a rotary shaft 5a rotated by a motor 4 is disposed in a trough 3 having an inlet 1 at an upper portion and an outlet 2 at a lower portion. A plate-shaped scraping plate 5b is spirally attached to the rotary shaft 5a, and the rotary shaft 5a and the scraping plate 5 are attached.
The screw 6 is formed by b.

Further, blow nozzles 7 and 7 which are inclined in the kneading sand conveying direction are provided on the bottom portion and the inclined side surface portion of the trough 3.
Are arranged at intervals, and compression air is jetted from the blow nozzles 7, 7. And, the plurality of blow nozzles 7, 7 are
A pipe 8 is connected to the air pipe 8, and an electromagnetic opening / closing valve 9 is attached to the base end of the air pipe 8. An ammeter 11 for measuring the current value of the motor 4 is connected to the power line 10 of the motor 4, and the ammeter 11 and the electromagnetic opening / closing valve 9 are connected via a controller 12. It is electrically connected by the control line 12a. The current value of the motor 4 is constantly measured by the ammeter 11 when the motor 4 is operating, and the controller 12 is preset with a desired reference current value. .

In the thus constructed device, the screw 6 is first rotated by the motor 4. Then, the kneading sand is introduced into the trough 3 from the introduction port 1, is conveyed in the direction of the ejection port 2 by the scraping plate 5b of the screw 6 and is ejected from the ejection port 2. If this operation is continued, the kneading sand will adhere to the trough 3 and the screw 6, and the adhesion will gradually grow to lower the kneading sand transport efficiency, and the rotation resistance of the screw 6 will be proportional to the amount of the kneading sand attached. Increase.

At this time, as the rotation resistance of the screw 6 increases, the motor 4 is constantly measured by the ammeter 11.
However, if the current value exceeds the desired reference current value preset in the controller 12, the kneaded sand in the trough 3 is kept in the state where the screw 6 is still rotated. Stop the supply. Then, when a predetermined time elapses in this state, the kneading sand remaining in the trough 3 is discharged. The predetermined time at this time is preset by a timer (not shown).

When the timer expires, the electromagnetic on-off valve 9 is opened, the compression nozzles 7 and 7 inject the compression air, and the kneaded sand adhering to the trough 3 and the screw 6 is blown. Then, the removed adhered sand is conveyed toward the discharge port 2 and discharged. During this period, the current value of the motor 4 being measured by the ammeter 11 is the controller 1
When the value falls below the desired reference current value preset to 2, the electromagnetic on-off valve 9 is closed, the work of removing the adhering sand by the air blower is stopped, and the supply of the kneading sand into the trough 3 is restarted. .

It should be noted that the time from the stop of the supply of the kneading sand to the restart of the supply is monitored by a timer or the like, and an abnormality is displayed when the supply cannot be resumed even after a lapse of a predetermined time or more after the stop of the supply of the kneading sand You may

Next, a kneading sand conveying screw conveyer device which can realize a kneading sand having a screw structure in which the kneading sand is unlikely to adhere and a kneading sand that is conveyed while being loosened to improve the flow of the kneading sand can be realized with a simple structure. Will be described as a second embodiment with reference to FIG. In FIG. 2, in a trough 15 having an inlet 13 at the top and an outlet 14 at the bottom,
A rotating shaft 16a is provided which is rotated by a motor (not shown).

A plurality of round rods 16b and 16b as support members are spirally arranged at intervals on the rotary shaft 16a, and the plurality of round rods 16b and 16b are scraped in a plate shape. The plate 16c is attached in a spiral shape in a state of being lifted from the rotary shaft 16a, and thus the scraping plate 16c
Spaces 17, 17 are formed between the bottom of the shaft and the rotary shaft 16a. A large number of round rods 16d and 16d as stirring members are arranged at intervals in front of and behind the spiral scraping plate 16c on the rotary shaft 16a. 16a and round bar 16b, 1
A screw 18 is formed by 6b and the scraping plate 16c.

In the thus constructed device, the screw 18 is first rotated by a motor (not shown). Then, the kneading sand is charged into the trough 15 through the charging port 13,
The scraping plate 16c of the screw 18 conveys it toward the discharge port 14 and discharges it from the discharge port 14.

At this time, the scraping plate 16c is attached to the rotary shaft 1
By being spirally attached to a large number of round bars 16b, 16b in a state of being lifted from 6a, and by forming space portions 17, 17 between the bottom portion of the scraping plate 16c and the rotary shaft 16a, The kneading sand does not easily adhere to the screw-18. Further, a large number of round bars 16 are provided at the front and rear positions of the spiral scraping plate 16c on the rotary shaft 16a.
Since d and 16d are arranged at intervals,
Even if a part of the kneading sand is supplied as a condensed lump of sand, since the lump of sand is crushed and stirred by the large number of round bars 16d, 16d, the flow of the kneading sand is improved. can do.

In the embodiment of the present invention, the first embodiment and the second embodiment have been described, but in the first embodiment, the screw 6 of the second embodiment is used instead of the screw 6 of the first embodiment. When No. 18 is applied, the adhering sand to the trough and the screw can be easily removed, and the kneading sand is made to have a screw structure in which the adhering sand is less likely to adhere, and the kneading sand is conveyed while being unraveled to flow the kneading sand It is more preferable because it can be achieved with a simple structure.

[0022]

As is apparent from the above description, the present invention provides a rotary shaft which is rotated by a motor in a trough having an inlet at the upper portion and an outlet at the lower portion. In a kneading sand conveying screw conveyor device in which a scraping plate is spirally attached, a large number of blow nozzles for injecting a compression air are arranged at intervals in the trough, and an ammeter is provided in the motor. Since a solenoid opening / closing valve for switching between supplying and shutting off the compression air is connected to the plurality of blow nozzles while being connected, and the ammeter and the electromagnetic opening / closing valve are electrically connected through the controller, the trough and the It is possible to easily remove the sand adhering to the screw. Also,
A rotating shaft is provided in a trough having an inlet at the upper part and an outlet at the lower part, a large number of supporting members are arranged at intervals on the rotating shaft, and a scraping plate is provided on the supporting member. Attach it in a spiral shape with it lifted up from
Since a space is formed between the scraping plate and the rotary shaft, and a large number of stirring members are arranged at the front and rear positions of the spiral scraping plate on the rotary shaft at intervals, the screw to which the kneading sand does not easily adhere There are various effects such as the structure and the fact that the kneading sand can be conveyed while being loosened to improve the flow of the kneading sand with a simple structure.

[Brief description of drawings]

FIG. 1A is a vertical cross-sectional front view showing a first embodiment of the present invention. (B): It is an AA arrow line view in (a).

FIG. 2A is a vertical cross-sectional front view showing a second embodiment of the present invention. (B): It is an AA arrow line view in (a). (C): It is a partially cutaway enlarged view of (A).

[Explanation of symbols]

1 13 input port 2 14 outlet 3 15 trough 4 motors 5a 16a rotating shaft 5b 16c scraping board 6 18 screw 7 blow nozzle 9 solenoid valve 11 ammeter 12 controller 16b support member 16d stirring member 17 Space Department

Claims (5)

[Claims] 1. A kneading sand in which a rotary shaft rotated by a motor is provided in a trough having an input port in the upper part and an outlet port in the lower part, and a scraping plate is spirally attached to the rotary shaft. In the transport screw conveyor device of
A large number of blow nozzles for injecting air are provided in the trough at intervals, an ammeter is connected to the motor, and an electromagnetic on-off valve for switching the supply and interruption of the compression air is connected to the plurality of blow nozzles. A kneading sand transfer screw conveyor device characterized in that the ammeter and the electromagnetic on-off valve are electrically connected to each other through a controller. 2. A rotary shaft is provided in a trough having an inlet at the upper part and an outlet at the lower part, and a large number of supporting members are arranged at intervals on the rotating shaft and scratched on the supporting member. The plate is attached in a spiral shape in a state of being lifted from the rotating shaft, so that a space is formed between the scraping plate and the rotating shaft, and a large number of them are provided at the front and rear positions of the spiral scraping plate on the rotating shaft. A kneading sand conveying screw conveyor device, wherein stirring members are arranged at intervals. 3. A rotary shaft rotated by a motor is provided in a trough having an inlet at the upper portion and an outlet at the lower portion, and a large number of supporting members are provided at intervals on the rotational shaft. Then, the scraping plate is attached to the supporting member in a state of being floated from the rotating shaft in a spiral shape, so that a space is formed between the scraping plate and the rotating shaft, and further, the spiral scraping on the rotating shaft is performed. A large number of agitating members are arranged at the front and rear positions of the plate at intervals, and a large number of blow nozzles for injecting the compression air are also arranged at intervals at the trough.
An ammeter is connected to the controller and an electromagnetic on-off valve for switching between supplying and shutting off the compression air is connected to the plurality of blow nozzles, and the ammeter and the electromagnetic on-off valve are electrically connected via a controller. A kneading sand conveying screw conveyor device characterized by the above. 4. A step of measuring a current value of the motor during operation of the motor for rotating the screw, and a step of measuring the current value of the motor from the blow nozzle when the current value during measurement exceeds a desired reference current value. A step of injecting a compression air, and a step of stopping the injection of the compression air from the blow nozzle when the current value during measurement falls below the desired reference current value. Method for controlling kneading sand transport screw conveyor device. 5. A step of measuring a current value of the motor during operation of the motor for rotating the screw, and rotating the screw when the current value during measurement exceeds a desired reference current value. Stop the supply of the kneading sand into the trough while keeping it in that state, maintain this state for a predetermined time, and discharge the kneading sand remaining in the trough; and after discharging the kneading sand from the trough, -A step of injecting compression air from a nozzle,
When the current value during measurement falls below the desired reference current value, the step of stopping the injection of the compression air from the blow nozzle and restarting the supply of the kneading sand into the trough are included. Kneading sand transfer screw characterized by
Conveyor device control method.