JPH09142634A - Screw conveyer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the conveying pressure inside of the cylindrical part of a trough from rising and prevent the rotational load on a screw blade from increasing and choking of the material to be conveyed from taking place by setting the blade pitch of a part positioned inside of the cylindrical part of the trough of a screw blade larger than the blade pitch at a part facing to a receiving port. SOLUTION: In a screw blade 22, an inter-blade pitch P2 in a part 22b positioned inside of the cylindrical part 21a of a through 21 is set larger than an inter-blade P1 in a part 22a facing to a receiving port 27. Accordingly, an inter-blade volume at a part 22b positioned inside of the cylindrical part 21a of the through 21 is made larger than the inter-blade volume at a part 22a facing to the receiving port 27 of the screw blade 22. As the result, even though the filling rate of conveyed article at the part 22a facing to the receiving port 27 is 100%, the filling rate is reduced at the part 22b positioned inside of the cylindrical part 21a of though 21 of the screw blade. Therefore, there is neither chance of any excessive increase in rotational load on the screw blade nor chance of choking of conveyed article.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screw conveyor, and more particularly, to a screw conveyor which prevents a screw blade from being excessively loaded with rotation and a transported object to be blocked in a trough.

[0002]

2. Description of the Related Art Conventionally, screw conveyors have been widely used to convey powder, grains, earth and sand and the like. The general structure of this screw conveyor will be described with reference to FIG. 3. The screw conveyor 10 shown in FIG.
Is used to transfer the goods P stored in the hopper 1 into the bucket 2, and the cylindrical trough 11
And a screw blade 12 inserted in the trough 11. A chain 16 driven by a motor 15 having a speed reducer is wound around a sprocket 14 attached to the end of the rotary shaft 13 of the screw blade 12.

The goods P stored in the hopper 1 are shown in FIG.
It is supplied into the trough 11 via the receiving port 17 as shown in FIG. Then, when the motor 15 is operated to rotate the screw blade 12, the transported object P is displaced by the screw blade 12 and gradually moves in the trough 11 in the axial direction. Then, the transported article P that has reached the discharge port 18 drops from the trough 11 and is transferred and placed in the bucket 2.

[0004]

In the screw conveyor 10 described above, the blade pitch P of the screw blades 12 is constant over the entire length of the screw blades 12. Therefore, as shown in FIG. 4, when the material P is supplied in a state where the filling rate P is 100% at the portion 12a of the screw blade 12 facing the receiving port 17, the material P is also conveyed in the cylindrical portion 11a of the trough 11. The filling rate of the object P is 100%. Therefore, when the pressure of the transported object P in the trough 11 increases due to the pressure feeding by the screw blade 12, the transported object P adheres strongly to the inner wall surface 11b of the trough 11 when the adhesiveness of the transported object P is high. . As a result, the conventional screw conveyor 10 has problems that the rotational load of the screw blades 12 becomes excessively large and that the material P is packed inside the trough 11 to cause a so-called clogging state.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a screw conveyor in which the rotational load of the screw blades does not become excessively large and the transported object does not get stuck in the trough. Improve efficiency and prevent troubles such as equipment failure.

[0006]

In order to achieve the above object, a screw conveyor according to the present invention has a receiving port for receiving a conveyed product at one end and a discharge for discharging the conveyed product at the other end. In a screw conveyor having a cylindrical trough each provided with an outlet and a screw blade that is inserted into the trough and is driven to rotate, a portion of the screw blade located in the cylindrical portion of the trough The blade pitch is set to be larger than the blade pitch of the portion facing the receiving opening. Alternatively, the blade pitch of a portion of the screw blade located in the cylindrical portion of the trough may be set to gradually increase toward the discharge port. Good. Then, in the structure of the screw conveyor configured in this manner, the inter-blade volume of the screw blade in the portion located in the cylindrical portion of the trough is larger than the inter-blade volume in the portion facing the inlet of the screw blade,
The filling rate of the cargo in the part facing the entrance of the screw blade is 10
Even if it is 0%, the filling rate is lowered in the portion located in the cylindrical portion of the trough. Therefore, in the cylindrical portion of the trough, the conveying pressure of the conveyed goods does not rise, and the conveyed goods are stirred by the screw blades to maintain the fluidity, so that the rotational load of the screw blades becomes excessive. And the transported objects do not become clogged.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of a screw conveyor according to the present invention will be described in detail below with reference to the drawings. FIG. 1 is a sectional view showing an embodiment of a screw conveyor according to the present invention, and FIG. 2 is a view showing an operating state of the screw conveyor shown in FIG.

As shown in each figure, the screw conveyor 2
Reference numeral 0 is used to transfer the transported material P such as powder, grain, or earth and sand stored in the hopper 1 into the bucket 2. The cylindrical trough 21 and the trough 21 are inserted into the trough 21. And the screw blade 22 is formed. A chain 26 driven by a motor 25 having a speed reducer is wound around a sprocket 24 attached to the end of the rotary shaft 23 of the screw blade 22. This allows
When the motor 25 is operated to rotate the screw blade 22,
The cargo P supplied from the receiving port 27 into the trough 21 is
The trough 21 is displaced laterally by the screw blades 22.
Gradually move in the axial direction. Then, the conveyed product P that has reached the discharge port 28 drops from the inside of the trough 21 and is transferred into the bucket 2.

The pitch between the screw blades 22 differs depending on the axial position of the screw blades 22.
That is, as shown in FIG.
The pitch 22 between the blades of the portion 22a that faces 7 is P1, whereas the pitch P2 between the blades of the portion 22b located inside the cylindrical portion 21a of the trough 21 is P2.
2 is set to be larger than the value of the pitch P1.

As a result, as shown in FIG. 1, the inter-blade volume at the portion 22b of the screw blade 22 located inside the cylindrical portion 21a of the trough 21 is at the portion 22a facing the receiving port 27 of the screw blade 22. Since the volume becomes larger than the inter-blade volume, even if the filling rate of the transported material P in the portion 22a of the screw blade 22 facing the receiving port 27 is 100%, the screw blade 22
A portion 22 of the trough 21 located within the cylindrical portion 21a of the trough 21.
In b, the filling rate decreases.

Therefore, the cylindrical portion 21a of the trough 21 is
In the inside, since the conveying pressure of the conveyed object P does not rise, even if the conveyed object P has high adhesiveness, the conveyed object P firmly adheres to the surface of the screw blade 22 and the inner wall surface 21b of the trough 21. Never. Also, the cylindrical portion 21 of the trough 21
In the inside of a, since the transported article P is sequentially scratched by the screw blades 22, the fluidity of the transported article P can be maintained. As a result, in the screw conveyor 20 of the present embodiment, the rotational load of the screw blades does not become excessively large, and the transported material P does not get stuck in the trough 21, so that the transport amount per hour can be kept constant.

Although the screw conveyor according to the present invention has been described above, it is needless to say that the present invention is not limited to the above embodiment and various modifications can be made. For example, in the above-described embodiment, the blade pitch P2 of the portion 22b of the screw blade 22 located inside the cylindrical portion 21a of the trough 21 is fixed to a constant value. It may be set so as to gradually increase toward 28. In this case, since the inter-blade volume of the screw blades 22 gradually increases toward the discharge port 28, the filling rate gradually decreases, and the dimension H representing the position of the upper surface of the conveyed article P shown in FIG.
The value of gradually decreases. As a result, the transported material P never adheres to the inner wall surface of the upper portion of the discharge port 28 of the trough 21, and when it reaches the discharge port 28, it is quickly dropped and discharged, and the transport efficiency is further improved.

[0013]

As is apparent from the above description, in the screw conveyor of the present invention, the blade pitch of the screw blade located in the cylindrical portion of the trough is smaller than the blade pitch of the portion facing the receiving port. Since it is set to a large value, even if the filling rate of the conveyed material in the portion facing the inlet of the screw blade is 100%, the filling rate is reduced in the portion located in the cylindrical portion of the trough of the screw blade. Therefore, the conveying pressure of the conveyed goods does not rise in the cylindrical portion of the trough, and the conveyed goods are stirred by the screw blades to maintain the fluidity, so that the rotational load of the screw blades becomes excessive, The cargo does not get jammed.

[Brief description of the drawings]

FIG. 1 is a vertical cross-sectional view of an embodiment of a screw conveyor according to the present invention.

FIG. 2 is a diagram illustrating an operating state of a screw conveyor.

FIG. 3 is a vertical sectional view of a conventional screw conveyor.

FIG. 4 is a diagram illustrating an operating state of a conventional screw conveyor.

[Explanation of symbols]

 1 Hopper 2 Bucket 20 Screw Conveyor 21 Trough 22 Screw Blade 23 Rotating Shaft 24 Sprocket 25 Drive Motor 26 Chain 27 Supply Port 28 Discharge Port P

Claims (2)

[Claims] 1. A cylindrical trough provided with a receiving port for receiving a transported material at one end and a discharge port for discharging the transported material at the other end, and a trough inserted into the trough. In a screw conveyor provided with a rotationally driven screw blade, a blade pitch of a portion of the screw blade located inside the cylindrical portion of the trough is set to be larger than a blade pitch of a portion facing the receiving port. The screw conveyor is characterized by 2. The screw conveyor, wherein a blade pitch of a portion of the screw blade located in the cylindrical portion of the trough is set to gradually increase toward the discharge port. .