JPH07289942A - Screw conveyor - Google Patents

Abstract

PURPOSE:To provide a structure for forming an assembly of a lining tile and a tip to be manufactured easily and eliminating the fear of dropping off the tip regarding a wear-resistant component at a helical blade end of a screw conveyor particularly for a decanter type centrifugal separator. CONSTITUTION:A screw conveyor is desirably constituted of a lining tile 1 formed by a material of the same kind as that of a helical blade, a tip composed of a wear-resistant material bonded with the tile 1 and a mounting piece 3, and the lining tile is provided with a horizontal channel 11 fitted with a projected line section 21 on the lower section of tip, a vertical channel 12 fitted with the mounting piece 3, while the tip is provided with a recessed section 22 continuing to the vertical channel of the lining tile on the rear face of the projected line section 21, and the mounting piece is fitted into the vertical channel 12 and the recessed section 22 and fixed therein. It is desirable that the tile, tip and mounting piece are bonded one another, and the vertical channel 12 is fitted to the mounting piece 3 by dovetail joint.

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 an improvement of a wear-resistant member at a tip of a spiral blade of a screw conveyor of a decanter type centrifugal separator.

[0002]

2. Description of the Related Art In screw conveyors, especially screw conveyors of a decanter type centrifugal separator, in order to reduce the wear of the surface of the spiral blade, an attempt is made to attach a wear resistant tip such as tungsten carbide or ceramic to the tip of the spiral blade. Has been done. Welding or adhering the tip directly to the spiral blade is problematic in terms of thermal effect on the tip, reliability of mounting, etc., and it is desirable to use a mounting member made of the same material as the spiral blade and the chip. Has been proposed, and a method of welding the mounting member to the spiral blade has been proposed.

For example, in Japanese Utility Model Laid-Open No. 59-166852, a mounting member having an engaging portion for the tip extending in the circumferential direction of the conveyor is welded to the tip of the spiral blade and the base of the tip for mounting the tip. It has been proposed to mount the chip by forming a dovetail groove along the surface of the spiral blade and then inserting and engaging an engaging portion provided on the chip into the dovetail groove from the side surface of the mounting member. However, this method is difficult to manufacture because the two members need to be welded separately so as to form a dovetail groove having a correct size for the chip.

In Japanese Patent Publication No. 51-41707, this mounting member is formed as a backing tile, and it is proposed to braze or adhere parallel plate-shaped chips to the backing tile and weld the backing tile. ing.

Further, in Japanese Patent Publication No. 59-15032, which is proposed as an improvement thereof, in order to prevent the chips from coming off due to the brazing or the peeling of the adhesive, a dovetail-shaped groove extending along the spiral blade surface on the backing tile. The engaging groove is provided so as to be substantially perpendicular to the centrifugal force, and the engaging portion provided on the chip is inserted into and engaged with the dovetail groove from the side surface of the backing tile. However, in this structure, it is necessary to provide an engaging part for the dovetail groove extending from the chip body at an acute angle, and stress concentration occurs here, so it is necessary not only when handling the chip individually but also after mounting it on the screw body. However, when the chip is subjected to impact, such as when the screw body is placed on the floor during disassembly or during manufacturing, this part may be damaged in the chip having low toughness. Further, in the case of manufacturing by precision casting, there is a problem that a sag occurs at an acute angle portion and a repair work is indispensable for accurate mounting. Further, in the type in which the engaging portion is inserted into the dovetail groove from the side, when the force that causes the lateral displacement of one chip is applied or the chip is damaged, the chips may be displaced from each other one after another. There were problems such as causing it.

[0006]

SUMMARY OF THE INVENTION The present invention provides a backing tile / chip assembly that has a simple shape for both the backing tile and the chip, is easy to manufacture and assemble, and does not cause the chip to fall off. It seeks a structure to obtain.

[0007]

[Means for Solving the Problems] To achieve the above object,
The backing tile and tip assembly of the present invention, as shown in FIG. 1, comprises a backing tile 1, preferably of the same material as the spiral blade, with a tip 2 of wear resistant material adhered thereto and an attachment. The backing tile 1 consists of pieces 3.
A lateral groove 11 extending in the circumferential direction along the surface of the spiral blade is provided at a portion contacting the lower portion of the chip (a side closer to the center of rotation of the helical blade), and a longitudinal groove extending in the radial direction of the helical blade is provided at the lower center of the groove. The chip 2 has a groove 12, and the chip 2 has a ridge portion 21 that engages with the lateral groove 11 of the backing tile, and a recess 22 continuing from the vertical groove 12 of the backing tile at the lower end of the back surface thereof. 3 has a shape to be fitted into the vertical groove 12 and the concave portion 22.

[0008]

In the present invention, the chip is fitted from the front side of the backing tile so that the projecting ridge portion 21 of the chip 2 is fitted into the lateral groove 11 of the backing tile, or is projected into the lateral groove 11 from the side. The ridge 21 is slid and inserted, and the attachment piece 3 is fitted and fixed in the groove formed by the vertical groove 12 of the backing tile and the concave portion 22 of the chip. With such a structure, the centrifugal force acting on the chip can be received by the engaging portion between the lateral groove 11 and the protruding portion 21. Further, in the chip, the recess 22 at the lower part of the chip prevents the protrusion 21 from being detached from the lateral groove 11 by the mounting piece 3, and the mounting piece 3 is fitted in the recess 22 at the lower end of the chip. It will be held so that there is no left-right deviation with respect to.
Moreover, each groove and ridge has a simple shape and is not only easy to manufacture and assemble, but also it is possible to reduce the manufacturing error and to have a strong bonding strength when bonding. Have.

[0009]

EXAMPLES Examples of the present invention will be shown below. FIG. 1 is a development view showing respective shapes and relationships of a backing tile, a chip, and a mounting piece which constitute an assembly of the present invention, and FIG. 2 is a perspective view showing a state after completion of assembly. Desirably, the backing tile 1, which is made of the same material as the spiral blade, for example stainless steel, is welded to the spiral blade with its rear projection 13 and lower part 14 like a conventional tile.
The backing tile of the present invention may be such that the backing tile 1 is first welded and then the chips 2 are glued, as is apparent from its shape, or it may be welded to the spiral blade as the assembly 10 shown in FIG. You may.

On the front surface of the backing tile 1, a flat surface portion 15 that abuts on and adheres to the chip 2 extends to the tip of the chip 2, and at the lower end thereof along the spiral blade surface in the circumferential direction. A lateral groove 11 extending in the direction of the chip 2 is provided, and the lateral groove 11 is fitted into the ridge 21 of the chip 2. The fitting between the groove and the ridge portion may be a dovetail groove. However, the fitting is held by the mounting piece 3 and there is no risk of disengagement. In order to avoid damage of the chip due to stress concentration on the acute angle portion, as shown in the figure, the upper and lower surfaces of the lateral groove 11 are formed on the front flat surface portion. It may be right-angled or slightly obtuse.

If the recess 22 on the front surface of the chip 2 has the same width as the vertical groove 12 of the backing tile 1 as shown in the drawing, the shape of the mounting piece 3 is simple, but it is not always required to be the same. If the side walls of the vertical grooves 12 and 22 formed by fitting the backing tile 1 and the chip 2 are formed by a surface perpendicular to the chip surface, the mounting piece 3 is fitted into this groove from the front surface. Can be fixed by gluing or welding to the backing tile. However, it is desirable that the vertical groove 12 and the mounting piece 3 be fitted with each other by a groove. In this case, after the backing tile and the chip are fitted, the mounting piece 3 is inserted and fixed from below the vertical groove 12. At this time, the attachment piece 3 is bonded to ensure sufficient holding strength.

[0012]

Since the screw conveyor according to the present invention has the above-mentioned structure, not only does each of the backing tile and chip assemblies have a structure against the centrifugal force and peeling force acting on the chip, The lateral displacement of the chip is also prevented. Moreover, each member has a simple shape, and it is easy to obtain high processing accuracy, and the adhesive layer can be thinned to obtain strong adhesive strength. In addition, even if the chip is damaged or comes off, it can be replaced very easily.

[Brief description of drawings]

FIG. 1 is a development view showing the structure of a wear resistant member of a screw conveyor according to the present invention.

FIG. 2 is a perspective view of an assembly of wear resistant members of the screw conveyor of the present invention.

[Explanation of symbols]

1 Backing tile 2 Chips 3
Mounting piece 10 Assembly 11 Lateral groove 1
2 Vertical groove 13,14 Welded portion 21 Protruded portion 2
2 recess

Claims (5)

[Claims] 1. A backing tile, wherein a wear-resistant member attached to a tip of a spiral blade of a screw conveyor of a centrifuge comprises a backing tile, and chips and a mounting piece of a wear-resistant material fixed to the backing tile. Has a lateral groove extending in the circumferential direction along the surface of the spiral blade at the portion contacting the lower portion of the chip (the side closer to the center of rotation of the spiral blade), and extending in the radial direction of the spiral blade at the lower center of the groove. The chip has a vertical groove, and the chip has a ridge on its lower part that engages with the lateral groove of the backing tile, and a recess on its back surface that follows the vertical groove of the backing tile. The screw conveyor is shaped to be fitted into the vertical groove of the backing tile and the concave portion of the chip. 2. The screw conveyor according to claim 1, wherein the vertical groove of the backing tile is a dovetail groove. 3. The screw conveyor according to claim 1, wherein the backing tile and the chip are adhered to each other. 4. The screw conveyor according to claim 1, wherein the mounting piece is inserted into the dovetail groove and is bonded to at least the backing tile. 5. The screw conveyor according to claim 1, wherein the attachment piece is inserted into the dovetail groove and welded to the backing tile.