JP2004058151A - Apparatus for kneading molding sand - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve kneading efficiency of kneading material wherein a kneading apparatus is unnecessary to be of large scale for molding sand and does not develop clogging with a simple modification. <P>SOLUTION: In the kneading apparatus for molding sand so as to knead and take out the kneading material with a stirring blade 3 in a cylindrical trough 1. The cylindrical trough 1 is arranged by being inclined so as to keep the leading part 1B higher than the base part. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
[Field of the Invention]
The present invention relates to a molding sand kneading apparatus for kneading molding sand such as self-hardening molding sand and a binder using a stirring blade.
[0002]
[Prior art]
Conventionally, as a device for kneading molding sand and a binder (abbreviated as a kneading material), generally, as shown in FIG. 6, a stirring blade is built in a cylindrical trough 1 and put into one end of the cylindrical trough 1. There is known a configuration in which the kneaded material is advanced while being stirred by rotation of a stirring blade and discharged from the other end. This kind of kneading device is laid so that the cylindrical trough 1 protrudes horizontally on a column in view of the fact that the device is made compact, and in particular, there are many places where the height is easily restricted at a laying site in a factory. ing.
[0003]
In this type of kneading apparatus, various devices have been proposed to increase the kneading efficiency. One of the problems is to make the cylindrical trough as short as possible without increasing the size of the apparatus. However, the point is how to improve the kneading efficiency.
[0004]
The present invention has already proposed, in Japanese Patent Application Laid-Open No. 6-254653, an improvement on a stirring blade as one means for solving such a problem. Here, in the arrangement of the stirring blades, a high-speed conveyance by the left-handed stirring blade arrangement can be performed on the upper side in the conveyance direction, and a conveyance force in the opposite direction is exerted by the right screw arrangement on the lower side in the conveyance direction. In this manner, the kneading efficiency is increased by applying the reverse conveying force and thereby performing the low-speed conveying.
[0005]
[Problems to be solved by the invention]
However, according to such a solution, the kneading efficiency can be increased by the primary kneading and the secondary kneading of the reverse kneading in the first half while the cylindrical trough is shortened and miniaturized. Is formed by forcibly developing a conveying force in the reverse direction, as well as a manufacturing problem that the base end side and the distal end side of the cylindrical trough must be reverse-threaded. The thickness of the kneading material (formed on the inner peripheral surface of the cylindrical trough at the time of stirring) fluctuates depending on the conditions of the kneading material (casting sand, binder) and various conditions such as the rotation speed of the stirring blades. In many cases, the rotational load is abnormally increased, and as a result, there is a problem that it is difficult to perform sufficient kneading efficiently.
[0006]
An object of the present invention is to increase the kneading efficiency of a kneading material without increasing the size of a foundry sand kneading apparatus, with a simple improvement, and without causing clogging.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the foundry sand kneading apparatus according to the present invention rotatably supports a rotary shaft 2 on a cylindrical trough 1 laid horizontally on a support column 5 and stirs the rotary shaft 2 at a predetermined pitch. A plurality of blades 3 are implanted along the virtual screw locus T, and the kneading material supplied from the inlet 6 of the base end 1A of the cylindrical trough 1 is kneaded and discharged from the outlet 7 of the tip 1B. Casting sand kneading device,
The cylindrical trough 1 is provided so as to be inclined such that the distal end portion 1B is located higher than the base end portion 1A.
We took the measure.
[0008]
DESCRIPTION OF THE PREFERRED EMBODIMENTS
This means of inclining the cylindrical trough 1 urges the kneading material, which is advancing upward while being agitated, to return to the base end portion 1A side by its own weight, and as a result, it takes time to advance the kneading material. This is based on the idea that the stirring action on the material is extended for a long time.There is no need to dispose the stirring blades in such a way that the backflow is positively caused in the kneaded material as in the past, and in addition to such a forced backflow, The kneading efficiency can be increased while avoiding the risk of clogging due to the occurrence.
[0009]
In the present invention, it is preferable that the cylindrical trough 1 is provided so that the angle can be freely adjusted in an angle range of 5 to 30 degrees with respect to the horizontal.
Such an angle is adjusted in accordance with the type of foundry sand, but a natural return to the base end 1A side of the cylindrical trough 1 can be expected due to slippage due to its own weight, and the kneading material is accordingly increased. This increases the residence time and increases the kneading efficiency.
[0010]
Further, the stirring blades 3 of the rotary shaft 2 are arranged at a predetermined pitch L1 in the direction of the rotary shaft core 2A along a predetermined virtual screw locus T, and at the tip 1B side of the cylindrical trough 1, With reference to the specific stirring blade 3A, the next stirring blade 3B to be positioned at the predetermined pitch L1 of the virtual screw locus T moves a plurality of pitches in the circumferential direction of the rotary shaft 2 while keeping the position advanced by the predetermined pitch L1. Preferably, the arrangement is advanced.
[0011]
As a result, at the base end portion 1A to which the kneading sand is sequentially supplied, the kneading sand is rapidly advanced by the feeding action of the stirring blades 2 arranged at a predetermined position, and then, at the tip end portion 1B side, the stirring blades in a toothless state are formed. 2, the smooth transfer of the kneading material is intentionally interrupted, and the kneading material in the meantime slips back to the base end 1A due to its own weight, resulting in prolonging the residence time and increasing the kneading efficiency. It is.
[0012]
Further, the stirring blades 3 are arranged along the predetermined screw trajectory at a pitch of 60 degrees around one rotation of the rotating shaft 2, and the stirring blades 3 adjacent to the tip end 1 </ b> B of the cylindrical trough 1 are adjacent to each other. It is preferable that the irregular arrangements of 3A and 3B are set at intervals of 120 degrees (one tooth skipping state). Actually, such an arrangement of the stirring blades 2 maximizes the stirring efficiency without causing clogging of the kneading material.
The kneading material can be applied not only to molding sand as a self-hardening molding sand and a binder (resin, catalyst), but also to various molding sands requiring kneading.
[0013]
【Example】
Hereinafter, a preferred embodiment of a casting sand kneading apparatus according to the present invention will be described in detail with reference to the drawings.
As shown in FIG. 1 as a front view of the entire casting sand kneading apparatus, and FIG. 2 as a partially cutaway sectional view of a main part thereof, the apparatus is horizontally mounted on a support column 5 fixed to a factory floor. A rotating shaft 2 is rotatably mounted on the cylindrical trough 1, and a plurality of stirring blades 3 are implanted on the rotating shaft 2 at a predetermined pitch along a virtual screw locus T (see FIG. 5). The kneading material supplied from the inlet 6 of the base 1A is kneaded and discharged from the outlet 7 of the distal end 1B.
[0014]
1 and 2, reference numeral 8 denotes an electric motor for driving the rotating shaft 2, which is driven to rotate at 750 to 1800 rpm. Reference numeral 9 denotes a hopper for charging the kneading material, which is connected to the entrance 6 of the base end 1A. The other overall configuration of the kneading apparatus is not different from the conventional configuration, and thus the detailed description is omitted here.
[0015]
And the said cylindrical trough 1 is provided so that the front-end | tip part 1B may incline so that it may be located higher than the base-end part 1A. Here, the inclination is provided at 10 degrees (variable) with respect to the horizontal as the most preferable angle, but the object of the present invention can be achieved even when the inclination is adjusted in the range of 5 degrees to 30 degrees. it can. Although not shown, the adjustment of the inclination is such that the cylindrical trough 1 is rotatable around the horizontal axis on the support column 5 and is fixed by bolting. However, another inclination adjusting means may be used as appropriate.
[0016]
Further, as shown in FIGS. 3 to 5, the stirring blades 3 of the rotating shaft 2 are arranged at a predetermined pitch L1 in the direction of the rotating shaft core 2A along a predetermined virtual screw locus T, and On the tip end 1B side of the trough 1, the next stirring blade 3B to be positioned at the predetermined pitch L1 of the virtual screw trajectory with respect to the specific stirring blade 3A, The irregular arrangement is advanced a plurality of pitches in the circumferential direction of the rotating shaft 2.
[0017]
In this embodiment, as can be seen from FIG. 5 shown as a developed view, the stirring blades 3 are arranged along the predetermined screw locus T around the rotation shaft 2 at a pitch of 60 degrees. On the tip 1B side of the cylindrical trough 1, the irregular arrangement of the adjacent stirring blades 3A, 3B is spaced at 120 degrees. In FIG. 5, the X mark at the position of the predetermined pitch L1 indicates the position of the stirring blade 2 when regularly arranged on the base end 1A side.
[0018]
【The invention's effect】
According to the foundry sand kneading apparatus of the present invention, the cylindrical trough is inclined at a predetermined angle so that the tip end side where the kneaded material is discharged faces upward from the base end side thereof. The simple improvement means that the backflow naturally flows toward the base end side due to its own weight can increase the kneading efficiency by increasing the residence time of the kneading material.
[0019]
Further, in the case where the arrangement of the stirring blades is stopped at the tip end side of the cylindrical trough and the irregular arrangement of the toothless state is stopped, the continuous propulsion force application to the kneading material is interrupted. Thereby, there is an advantage that the backflow by the own weight is further promoted, and the residence time is lengthened as a whole, and the kneading efficiency can be increased.
[0020]
Other specific advantages of the present invention are as detailed in the above-described embodiments and examples of the present invention.
[Brief description of the drawings]
FIG. 1 is a front view of an entire casting sand kneading apparatus according to the present invention.
FIG. 2 is a partially cutaway front view of a main part of the foundry sand kneading apparatus according to the present invention.
FIG. 3 is a vertical sectional side view at a base end of a cylindrical trough of the foundry sand kneading apparatus according to the present invention.
FIG. 4 is a vertical sectional side view of a tip end of a cylindrical trough of the foundry sand kneading apparatus according to the present invention.
FIG. 5 is a development view showing an arrangement of stirring blades of the foundry sand kneading apparatus according to the present invention.
FIG. 6 is an overall front view of a foundry sand kneading apparatus according to the prior art.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Cylindrical trough 1A Base end 1B Tip 2 Rotation axis 2A Rotation axis 3 Stirrer blade 5 Supporting column 6 Inlet 7 Exit T Virtual screw locus L1 Predetermined pitch

Claims (4)

A rotary shaft 2 is rotatably supported on a cylindrical trough 1 laid horizontally on a support column 5, and a plurality of stirring blades 3 are implanted on the rotary shaft 2 at a predetermined pitch along a virtual screw locus T. A molding sand kneading device configured to knead the kneading material supplied from an inlet 6 of a base end portion 1A of the trough 1 and discharge the kneaded material from an outlet 7 of a distal end portion 1B,
The cylindrical trough 1 is provided so as to be inclined such that the distal end portion 1B is located higher than the base end portion 1A.
Foundry sand kneading equipment. The cylindrical trough 1 is provided so as to be freely adjustable in an angle range of 5 to 30 degrees with respect to the horizontal.
The molding sand kneading apparatus according to claim 1. The stirring blades 3 of the rotary shaft 2 are arranged at a predetermined pitch L1 in the direction of the rotary shaft core 2A along a predetermined virtual screw locus T, and at a tip portion 1B side of the cylindrical trough 1, With reference to the stirring blade 3A, the next stirring blade 3B to be positioned at the predetermined pitch L1 of the virtual screw trajectory T advances a plurality of pitches in the circumferential direction of the rotary shaft 2 while keeping the position advanced by the predetermined pitch L1. It is considered an irregular arrangement,
The casting sand kneading apparatus according to claim 1 or 2. The stirring blades 3 are arranged along a predetermined screw locus at one pitch around the circumference of the rotary shaft 2 at intervals of 60 degrees. On the tip end 1B side of the cylindrical trough 1, the stirring blades 3A adjacent to each other are arranged. The irregular arrangement of 3B is set at intervals of 120 degrees,
The molding sand kneading apparatus according to claim 4.

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