JPH04308164A - Manufacture of traverse drum - Google Patents

Abstract

PURPOSE:To precisely cast a thin and lightweight traverse drum by repeating actions dipping, lifting and drying a model made of synthetic resin of a soluble material in the fire-resistant slurry of a mold material, baking a stuck and generated fire-resistant material layer, and melting the model to manufacture a hollow mold. CONSTITUTION:The right half-model 20A and the left half-model 20B are molded with area resin by compression molding in the half-model molding process A. Two half-models 20A, 20B are integrally stuck to form a hollow truncated cone-shaped model 21 in the model assembling process B. Dipping, lifting and drying actions in the slurry of a fire-resistant material 23a are repeated required times in the next mold manufacturing process C. After a fire-resistant material layer 23 is formed, it is baked, and the model 21 made of area resin is removed by thermal decomposition to form a mold 24. A molten metal 25 is cast in a void section formed after the area resin of the mold 24 is removed under vacuum or high decompression in the next filling process D.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a traversing drum used in an automatic winder for winding various yarns, and more particularly to a method for manufacturing the drum by precision casting.

0002

[Prior Art] When winding various types of threads in addition to spun yarn into bobbin or cheese shapes at high speed, a traversing drum equipped with a spiral endless groove for guiding and traversing the threads is indispensable. It is. In recent years, in response to the demand for higher efficiency in the textile industry, winding speeds are becoming increasingly faster. As a result, friction in the drum groove, which comes into contact with the yarn running at high speed for long periods of time, is becoming an increasingly serious problem.
Furthermore, reducing the weight of the drum is also an extremely important prerequisite for high-speed rotation with high precision.

Traversing drums made of aluminum alloy are lightweight but have insufficient wear resistance. On the other hand, traversing drums made of iron-based alloys are excellent in terms of wear resistance and anti-static properties, but they have a specific gravity that is about three times that of aluminum products, and in order to meet the demand for weight reduction, they must be made at 1/2 the weight of aluminum products. It is necessary to have a wall thickness of 3 or less.

[0004] In view of this situation, the present inventor has already proposed a traverse drum made of iron-based alloy that is made thinner and lighter by precision casting, and a method for manufacturing the same (Japanese Patent Laid-Open Publication No. 61-69670).

[0005]

[Problems to be Solved by the Invention] However, in the above-mentioned conventional method, it is necessary to increase the draft angle with respect to the groove when molding the model, and it is necessary to use soluble wax, etc., which has a high coefficient of thermal expansion and has poor mechanical strength, to form the original shape. In order to manufacture a product (that is, a model), it is not possible to make the width of the groove for guiding the yarn narrow enough to satisfy the winding conditions. It has been found that there is a problem that, for example, ribbon winding tends to occur. In addition, since the core is made of soluble urea resin, it is necessary to dispose of the spilled solution, and as production increases, pollution control costs become a major problem.

Therefore, the present invention does not use a core at all, and the model is made of a synthetic resin with excellent dimensional stability and mechanical strength.
For example, we provide a method for precision casting a narrow, thin-walled, lightweight iron-based alloy traversing drum by molding it with urea resin, which has low thermal expansion and a low melting point, and using this to reduce the draft angle of the groove. The purpose is to

[0007]

[Means for Solving the Problems] In order to achieve the above object, the present invention involves making a model from a soluble material, immersing it in a mold material, removing the model to make it hollow, and melting the material into the cavity. In this casting method, a synthetic resin is used as the soluble material, and two thin-walled hollow half models each having a shape divided into two parts in the axial direction of the traversing drum are formed in a mold, and then these two parts are cast. Two half-models were joined together with adhesive to form the above-mentioned model, and the operation of repeatedly dipping the model into the refractory slurry of the molding material, pulling it up, and drying it was repeated to form a fireproof material that adhered to both the inside and outside of the model. After the material layer reaches the required thickness, when firing the refractory material layer, the model sandwiched between the refractory material layers is simultaneously pyrolyzed and removed to produce a hollow mold, and then poured. It is characterized by performing various precision casting operations such as hot water and post-treatment.

In the method of the present invention, each of the half-models made of the synthetic resin is molded using a mold having a multi-segmented structure, and the joining operation is performed by forming an inner circumferential surface of the half-model in close contact with an outer circumferential surface of the half-model. One of the extremely important requirements is that the process be carried out in a bonding jig that is split into two and can be opened and closed. Another requirement is to use a urea resin with a low coefficient of thermal expansion as the synthetic resin.

[0009]

[Operation] In order to form a half model, the above-mentioned mold consists of a male mold and a female mold, each of which is assembled by assembling a plurality of mold parts divided in the axial direction so as to form a semi-cylindrical shape as a whole. A gap to be filled with synthetic resin is formed between male and female molds. If the synthetic resin is urea resin,
The prepolymer powder is filled into the void and compression molding is performed, and after the resin has cooled, each mold part of the female mold is removed in the centrifugal direction, and the male mold is removed in the centripetal direction.

[0010] Also, a soluble core is not used, and therefore, unlike conventional methods, the female mold is made by leaving a gap around the core, which has poor dimensional stability and is prone to partial deformation or breakage during handling. Since it is not necessary to perform the difficult operation of arranging the pores, the method of the present invention allows a gap of a predetermined size to be formed with high accuracy. Therefore, the wall thickness of a model that is directly manufactured without a core using a synthetic resin with good dimensional stability and mechanical strength can be made sufficiently thin, and it is also excellent in terms of dimensional accuracy. Moreover, the width of the groove formed in the peripheral surface of the model, that is, the recess that serves as a yarn guiding guide in the traversing drum after finishing, can be made sufficiently narrow based on the molding conditions.

[0011] When joining two half models, the above-mentioned two
When using a split opening/closing type jig, by bringing the outer circumferential surface of the half model into close contact with the inner circumferential surface of the jig, there is no risk of relative displacement of the two abutted half models.
They are joined to form a perfect circle in any cross section.

A layer of refractory material is formed on both the inner and outer surfaces of the truncated cone-shaped or cylindrical thin-walled hollow half model thus produced by dipping as described above, but the firing temperature of the refractory material layer is set to a temperature higher than that of organic matter. It is much higher than the melting temperature of the synthetic resin, such as urea resin. Therefore, since the model can be automatically removed at the same time as firing, there is no need for the conventional wax elution operation using an autoclave before firing.

[0013]

EXAMPLES Examples of the present invention will be described below with reference to the drawings, but the method of the present invention is not limited to these examples.

First, the traversing drum 1 after completion will be outlined with reference to FIG. It comes into contact with the circumferential surface of the bobbin, etc. that is being wound. The drum is indirectly or directly supported by a drive shaft 6 via a cover 4 on the large diameter side and a cover 5 on the small diameter side, both end faces of which are closed. These covers 4
, 5 are screwed into screw holes 7 on the end face of the drum, respectively. The bearing 9 supports the cylindrical body 8 on the drum large diameter side of the drive shaft 6 so as to be relatively rotatable, and the bearings 11 and 12 are for relatively rotatably supporting the housing 10 fitted onto the cylindrical body 8. It is something. In other words, the drum 1 which receives the driving force on the small diameter side is rotatably supported by the drive shaft 6 via the housing 10 and the cylindrical body 8 on the large diameter side.

The traversing drum 1 manufactured by the method of the present invention has, for example, a diameter (d) of about 90 mm and a length (
l) is approximately 150 mm, and the thickness (t) of the cylindrical portion 3 is approximately 1.0.
The included angle α of the opposing side wall surface of the yarn guiding groove 2 is about 5°, and the width of the groove 2 is about 3 mm on the outside.
,It has become. The weight of drum 1 with this specification is approximately 1.2
kg. In contrast, the conventional method shown in FIG.
In the drum 1A, the thickness of the cylindrical portion 3A is approximately 1.5 to 2.5 mm, and the included angle β of the opposing side wall surface of the yarn guiding groove 2A is
is approximately 15°, the width of the groove is approximately 5 mm on the outside, and the weight of the drum is approximately 1.5 kg.

Next, the method of the present invention will be explained step by step with reference to FIG. First, a half model forming step A is performed, and the right half model 20A and the left half model 20B are formed by compression molding of urea resin, the details of which will be described later with reference to FIGS. 3 to 6. . Next, a model assembly process B is performed, in which the two half models 20A and 20B are bonded and integrated to form a hollow truncated conical model 21. The details will be described later with reference to FIGS. 7 and 8. Furthermore, in the next mold manufacturing step C, a short cylindrical urea resin sprue 22 is attached concentrically to the small diameter side end of the model 21, and the operations of dipping the refractory material 23a into the slurry, pulling it up, and drying are repeated the required number of times. After the refractory material layer 23 is formed, this is fired and the model 21 made of urea resin and the sprue 22 are removed by thermal decomposition to form a mold 24.
This will be described later with reference to FIG.

In the next pouring step D, molten metal 25 (for example, superalloy steel) is poured into the void of the mold 24 where the urea resin has been removed under vacuum or high reduced pressure, and the details will be described later with reference to FIG.

Among these steps, half model forming step A;
The model assembly process B and the mold manufacturing process C are the characteristic parts of the method of the present invention, and the pouring process D is a process that has been devised as described later in this embodiment, but the subsequent slow cooling process E and the take-out and post-treatment steps F may be carried out in accordance with conventionally known precision casting methods, but may be carried out by appropriately selecting a titanium nitride coating or the like to increase the hardness of the drum surface and impart wear resistance.

Hereinafter, steps specific to the present invention and embodiments will be explained. As shown in FIGS. 3 and 4, in the half model forming process A, a male mold part 30 consisting of multi-divided male mold parts 30a, 30b, and 30c so as to have a thick semi-cylindrical shape as a whole, and a hollow A central extraction rod 36 that fills the core portion is set on the stand 34. The female mold 3 is placed at a predetermined distance K from the outer peripheral surface of the male mold 30, for example, about 1.5 mm.
The female mold part 3 is also multi-divided so that the inner peripheral surfaces of the parts 1 and 1 face each other.
1a and 31b are also assembled, and the main body part 33 (small piece 33a
, 33b), and the female mold 31 and main body portion 33 are also set on the stand 34. 32 in the figure is a female mold 32 in order to accurately form a particularly thin part of the thread guiding groove.
This is a thin plate piece that protrudes inward from the male mold 30 and fits into a slightly wide groove on the surface of the male mold 30.

In the mold thus assembled (see FIG. 3), urea resin is filled (arrow Y) into the cavity of the above-mentioned interval K from the resin supply hole 35 at the top of the main body portion 33, and the mold is filled with urea resin for about 11 hours.
After compression molding at 0° and cooling, first remove the central extraction rod 36 as shown in Figure 3.
After that, the male parts 30a, 3 are removed.
0b and 30c are each pulled out in the centripetal direction of the arrow Z direction (FIG. 4). Next, the main body portion 33 is opened and the internal male portions 31a, 31b are removed in the direction of arrow X, that is, in the centrifugal direction. As a result, a hollow semi-cylindrical right half model 20A as shown in FIG. 5 is obtained. Perform the same operation using another symmetrical mold to create the left half model 20.
B is also molded as shown in FIG. Urea resin with a low coefficient of thermal expansion has a shrinkage rate of 1/10 when cooled from molding temperature to room temperature.
00, sufficient dimensional accuracy can be obtained.

In the model assembly step B, a suitable adhesive is applied to the bonded surfaces of the pair of left and right half models 20A and 20B, and the half models are butted together and set in the bonding jig 40 shown in FIGS. 7 and 8. The jig 40 includes a two-piece holder 41 having an inner peripheral surface shape that can be brought into close contact with the outer peripheral surfaces of the half models 20A and 20B.
, 42 are openably and closably connected by a hinge 43, and a nut 44b is screwed onto a screw shaft 44a fixed to one of the holders 41 to set it in the closed state. Then, the air between the outer surfaces of the half models 20A, 20B and the inner surfaces of the holders 41, 42 is removed from the intake hole 45 as shown by the arrow V, and the inner surfaces are brought into close contact. Compressed air is introduced into the mold and the set state is maintained for a sufficiently long period of time, for example several times the time required for half-model molding. Therefore, it is desirable to install several adhesive jigs for one molding machine and use them one after another.

After the adhesion is completed, the holders 41 and 42 are opened as shown by the arrow W in FIG. 7, and the model 21 is taken out from inside. At this time, since even a slight depression in the joint part causes the formation of microscopic dents in the cast product, it is essential to perform the eye coating operation with the adhesive.

In the mold manufacturing process C, a layer 23 of refractory material 23a is formed in the peripheral wall so as to cover the model 21 and the sprue 22 connected thereto, as shown in FIG. may be appropriately selected and used from those commonly used in precision casting. And the refractory material layer 23
After forming, it is sufficiently dried and then fired at 900 to 1100°C. Since the urea resin used as the model material melts at temperatures around 200° C., as shown in FIG. 10, a mold 24 in which the resin traces form cavities 24a is obtained all at once in this step.

In the next pouring step D, a pouring device 50 as shown in FIG. 10 is used. This device stores molten iron-based alloy 25 in a tank 51 that is sealed except for the intake and exhaust ports 52,
Above the liquid level, a tank-shaped mold support 53 provided with an exhaust port 54 is installed so as to be movable up and down. The mold 24 is attached to the mold support 53 in an inverted position with the sprue 22 facing down, the lower end of the mold 24 is raised slightly above the liquid level, and the air is evacuated from the intake/exhaust hole 52 as shown by arrow R to drain the tank. The internal pressure of 51 is lowered to a level close to vacuum. after that,
The mold support 53 is gradually lowered as shown by the arrow S, and when the lower end of the mold 24, that is, the lower end of the sprue 22, is slightly submerged in the liquid level, it is moved into the tank 51 from the intake/exhaust hole 52 in the opposite direction of the arrow R. When air is supplied to the chamber, the hot water 25 flows into the cavity 24a due to the pressure difference.
The liquid slowly rises in the direction of arrow T, filling the entire cavity 24a. If necessary, the mold 24 may be lowered more slowly following the lowering of the liquid level.

[0025] Unlike the conventional gravity-type pouring, this embodiment pours hot water into the cavity 24a of the mold 24 in an inverted position, so that the hot water is poured rapidly and locally. There is no risk of non-uniform pouring, and therefore non-uniformity of the metallographic structure between the various parts of the traversing drum, which is a cast product, does not occur.

After pouring, the mold 24 is removed from the pouring device 50, the inner and outer refractory layers 23 are crushed to expose the cast product, the sprue is cut, the surface is buffed, and the rotational imbalance is corrected. It is then subjected to treatments such as adjustment and solution heat treatment, and is then subjected to a hardening finish such as titanium nitride coating as described above to produce a finished product.

Various modifications can be made, such as using melamine resin instead of urea resin in the above embodiments, or performing upright pouring instead of inverted pouring if the situation permits.

[0028]

[Effects of the Invention] As explained above, according to the present invention,
In particular, it is possible to form a narrow groove by reducing the slope of the opposing side wall surface of the yarn guiding groove, which not only makes it possible to significantly reduce the groove width, but also reduces costs for pollution control measures since no soluble wax is used. can. Furthermore, there is no need for an autoclave in the dewaxing process, which was essential in the past, and there is no need to spend a long time dissolving the wax, so the working process time can be shortened. Furthermore, since it is possible to provide a lightweight drum with a wall thickness that is significantly thinner than conventional products, it is easy to increase the number of rotations of the drum, and the power cost for driving the drum can be reduced.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of a traversing drum manufactured by the method of the present invention.

FIG. 2 is a process diagram in an example of the method of the present invention.

FIG. 3 is a longitudinal sectional view of a mold for molding a half model.

FIG. 4 is a plan view showing the operation of opening the mold.

FIG. 5 is a perspective view of the right half model after molding.

FIG. 6 is a perspective view of the left half model.

FIG. 7 is a plan view of an adhesive jig for model assembly.

FIG. 8 is a front view of the same.

FIG. 9 is a cross-sectional view of a state in which a refractory material layer is formed on the inner and outer surfaces of the model in the mold manufacturing process.

FIG. 10 is a longitudinal sectional view of a pouring device used in a pouring process.

FIG. 11 is a longitudinal cross-sectional view of a traverse drum manufactured by a conventional method.

[Explanation of symbols]

1. Twill drum 20A half model 20B Half model 21 Model 22 Sprue 23 Fireproof material layer 23a Fireproof material 24 Mold 25 Molten metal 50　Pouring device

Claims (3)

[Claims] Claim 1. A casting method in which a model is made of a soluble material, the model is immersed in a mold material, the model is removed to form a hollow cavity, and a molten metal is poured into the cavity to form a product. Using synthetic resin, two thin-walled, hollow half-models that are divided into two in the axial direction of the traversing drum are molded in a mold, and then these two half-models are joined with adhesive to form the above-mentioned model. By repeatedly dipping the model into the refractory slurry of the mold material, pulling it up and drying it, the refractory layer deposited on both the inner and outer surfaces of the model reaches the required thickness, and then the refractory layer is removed. When firing, the model sandwiched between the refractory material layers is simultaneously melted and removed to produce a hollow mold, and then various precision casting operations such as pouring and post-treatment are performed. A method of manufacturing a traverse drum. 2. Each of the half-models made of the synthetic resin is molded using a mold with a multi-segment structure, and the joining operation is performed by molding the half-models made of synthetic resin into two-part molds each having an inner circumferential surface that is shaped closely to the outer circumferential surface of the half-model. 2. The method of manufacturing a traversing drum according to claim 1, wherein the manufacturing method is carried out in a bonding jig that can be opened and closed. 3. The method for manufacturing a traversing drum according to claim 1, wherein urea resin is used as the synthetic resin.