JPH02160140A - Lost foam pattern casting device - Google Patents

Abstract

PURPOSE:To prevent drastical lowering of temp. of cast molten metal caused by contact with lost foam pattern and to stably produce a high quality casting by making hollow shape of a feeding head pattern arranged at runner in molding sand or including exothermic material in the feeder head pattern in a lost foam pattern casting device. CONSTITUTION:The lost foam pattern 5 formed with foam polystyrene resin is embedded into the molding sand ina flask 1 and on the way of a runner 11 for the molten metal 9 to be cast, the hollow shape feeder head pattern 13 is set at front or rear of the pattern 5 and the exothermic material 21 is included therein. The molten metal 9 in a cap 7 is caused to flow into the foaming polystyrene-made lost foam pattern 5 through the runner 11, and the pattern 5 is lost with heat of the molten metal to cast the molten metal into the pattern 5. In this case, at intermediate between the runner 11 and the pattern 5 or at rear of the pattern 5, the hollow shape feeder head pattern 13 is laid and as the molten metal 9 temp. is not lowered in the feeder head pattern 13, but contrarily, raised with the exothermic material, the molten metal 9 temp. is not remarkably lowered in spite of the reaction with the lost foam pattern 5 and further, as the feeder head pattern is hollow shape, the casting having only a little contamination of carbon, etc., caused by decomposition of foaming styrene at this part is cast at good dimensional accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to an investment model casting apparatus, and particularly to an apparatus with an improved feeder structure.

(Prior Art) One of the casting methods is the vanishing model casting method, which eliminates the need for cutting out a model.

Therefore, the above-described vanishing model casting method will be explained with reference to FIGS. 4 and 5.

FIG. 4 is a sectional view showing the configuration of a casting apparatus for carrying out the disappearing model casting method. The flask 101 is filled with sand 103, and a product model 105 is placed within the sand 103. The product model 105 is made of a vanishing material, such as expanded polystyrene resin, and is vanishable by hot water.

On the other hand, a sprue cup 107 is attached above the flask 101, and hot water 109 is supplied from the sprue cup 107 through a runner 111 disposed within the sand 103 and made of vanishing material. It is introduced into the product model 105. By supplying the hot water 109, the product model 105 gradually disappears, and the disappeared portion is filled with hot water 109. This allows the product to be cast.

A riser model 113 is arranged in the runner 111 on the primary side of the product model 105. This feeder model 113 is also made of a vanishing material, and gradually vanishes as hot water 109 is supplied, and the vanishing part is filled with a sprue 109.

By the way, the hot water 109 filled in the product model 105
When it solidifies, a shrinkage phenomenon is observed. This shrunken portion is replenished by the hot water 1d9 filled in the portion of the riser model 113 already described, and this is the riser.

A vacuum chamber 115 is formed in the lower part of the flask 101, and a reduced pressure state is maintained by suctioning the suction port 117 using a vacuum pump (not shown).

The casting apparatus shown in FIG. 5 has a riser model 113 disposed on the secondary side of the product model 105, and the other configuration is the same as that shown in FIG. 4.

(Problems to be Solved by the Invention) The conventional configuration described above has the following problems. That is, in the case of the apparatus shown in FIG. 4, the hot water 109 first causes the feeder model 113 to disappear, and then is supplied to the product model 105.

Therefore, since a large amount of heat is consumed for the riser model 113 to disappear, there is a problem in that the temperature of the hot water 109 drops significantly.

In addition, since foamed polystyrene resin has benzene rings, even if it disappears, it does not completely gasify, and carbon residue (soot) and gas are mixed into the hot water 109, reducing the quality of the hot water 109. However, there was a problem in that defects occurred on the surface of the product.

In addition, in the case of the apparatus shown in FIG. 5, the feeder model 113
is placed on the secondary side of the product model 105, so the hot water 1
Although there are no problems such as a drop in the temperature of 09 or a drop in the quality of the hot water 109, there is a problem in that the temperature of the hot water 109 filled in the feeder model 113 portion decreases. Therefore, the volume of the feeder model 113 has to be expanded, and the supplied hot water 1
There was a problem that the amount of 09 and the yield between products decreased.

The present invention has been made based on the above points, and its purpose is to improve the function of the feeder, improve the quality of products, and improve the yield. It is about providing.

(Means for Solving the Problems) In order to achieve the above object, a vanishing model casting apparatus according to the first aspect of the present invention includes a casting flask filled with sand, and a casting flask disposed within the sand in the flask to remove vanishing material. A product model that is formed and disappears by the supply of hot water and fills the disappearing portion with hot water, a runner placed in the sand that introduces hot water supplied from a sprue into the product model portion, and a runner that is placed in the sand and introduces hot water supplied from a sprue into the product model portion, and and a riser model which is disposed on the primary side or secondary side of the product model in the direction of hot water flow, is formed from a vanishing material, disappears when hot water is supplied, and fills the vanishing portion with hot water. In the vanishing model casting device, the shrinkage of the hot water filled in the product model part is replenished by the hot water filled in the feeder model part, characterized in that the feeder model has a hollow shape. Furthermore, the vanishing model casting apparatus according to the second claim is the vanishing model casting apparatus according to claim 1, characterized in that a heat generating agent is accommodated in the hollow part of the feeder model. It is.

(Function) First, in the case of the disappearance model casting device according to the first claim,
The riser model has a hollow shape.

Due to the hollow shape, the amount of vanishing material is significantly reduced, the contact area with the hot water is reduced, and a drop in the temperature of the hot water can be suppressed.

Furthermore, the amount of soot, gas, etc. mixed into the hot water is significantly reduced, making it possible to prevent the quality of the hot water from deteriorating and the resulting defects from occurring on the surface of the product.

In the case of the vanishing model casting apparatus according to the second aspect, a heat generating agent is housed in the hollow part of the hollow riser model.

The above exothermic agent starts generating heat when it comes into contact with hot water, thereby suppressing the temperature drop of the feeder and effectively exerting its function as a feeder (Example). A first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view showing a casting apparatus for carrying out the disappearance model casting method.

A casting flask 1 is filled with sand 3, and a product model 5 is placed within this sand 3. This product model 5 is made of a vanishing material, for example, expanded polystyrene resin,
It is thermally decomposed by hot water and disappears.

On the other hand, a sprue cup 7 is installed above the flask 1, and the hot water 9 supplied from the sprue cup 7 is fed to the sand 3.
The product model 5 is introduced into the product model 5 through a runner 11 disposed inside and made of vanishing material.

Due to this supply of hot water 9, the product model 5 gradually disappears, and the disappeared portion is filled with hot water 9.

This allows the product to be cast.

In the runner 11 on the primary side of the product model 5, there is a riser model 13.
is located. This feeder model 13 is also made of a vanishing material, and gradually vanishes as hot water 9 is supplied, and the vanishing portion is filled with hot water 9. Further, a vacuum chamber 15 is formed in the lower part of the flask 1, and a reduced pressure state is maintained by suctioning a suction port 17 using a vacuum pump (not shown).

The feeder model 13 will be explained in more detail. As shown in the figure, the feeder model 13 is hollow and has a cylindrical shape with a bottom, and a lid 19 is adhered to the upper end thereof. By making it hollow in this way, the amount of vanishing material is significantly reduced, and the contact area with the hot water 9 is reduced, thereby suppressing the temperature drop of the hot water 9 and preventing the mixing of impurities into the hot water 9. It also suppresses

A powder exothermic agent 21 is accommodated in the hollow portion of the feeder model 13. The exothermic agent 21 starts generating heat when it comes into contact with the hot water 9, and has the function of suppressing a drop in temperature of the riser that is filled after the riser model 13 has disappeared.

The operation will be explained based on the above configuration. When hot water 9 is supplied from the sprue cup 7, the cough water 9 is introduced into the riser model 13 via the runner 11. At this point, a part of the feeder model 13 disappears, and filling of the riser is thereby started. This will later function as a riser.

On the other hand, hot water 9 is also provided to the product model 5, and the product model 5 gradually disappears, after which hot water 9 is filled and the product is cast.

The hot water 9 filled after the product model 5 disappears contracts while solidifying. This shrinkage is replenished by a riser filled after the riser model 13 and maintained at a high temperature.

At this time, the temperature drop in the feeder is suppressed due to the exothermic action of the exothermic agent 21, so that effective feeding is achieved.

According to this embodiment, the following effects can be achieved. First, since the feeder model 13 has a hollow shape, the amount of vanishing material used is significantly reduced and the contact area with the hot water 9 is reduced, thereby suppressing the temperature drop of the hot water 9. The mixing of impurities into the hot water 9 can be controlled.

Therefore, in order to improve the quality of products, especially
It is possible to prevent defects from occurring on the product surface.

Further, a heat generating agent 21 is housed in the hollow part of the feeder model 13, and this heat generating agent 21 can suppress the temperature drop of the feeder, so that the feeder function can be effectively performed. Can be done.

Next, a second embodiment will be described with reference to FIG.

In this embodiment, the riser model 13 is placed on the secondary side of the product model 5, and the other configurations are the same as in the first embodiment.

Therefore, similarly to the first embodiment, it is possible to achieve the effect of suppressing the temperature drop in the feeder. In particular, the exothermic agent 21 more effectively eliminates problems caused by the riser model being located on the secondary side of the product model, that is, the drop in temperature of the hot water.

Next, a third embodiment will be described with reference to FIG.

This is done by placing the exothermic agent 21 in the hollow part of the riser model 13,
It is equipped with an adjustment mechanism so that it can be installed in any position.

In other words, the timing at which the exothermic agent 21 functions is closely related to the timing at which the feeder function is performed, and therefore, the timing at which the exothermic agent 21 generates heat must be adjusted so that the feeder function is performed most effectively. If so, the feeder function will be more effectively exerted.

Therefore, the exothermic agent (the one shown in the figure is a tablet type, not a powder type, but any type will do) is placed in a dragon-shaped container 23.
The height of the heated container 23 can be adjusted so that the exothermic agent 21 is positioned at a desired level by fitting the heated container 23 so as to be able to slide up and down along the inner surface 25 of the hollow part of the riser model 13. It is composed of As already mentioned, the exothermic agent 21 starts generating heat when it comes into contact with hot water, and the contact time is adjusted depending on the height of the cup-shaped container 23. Therefore, it is possible to more effectively perform the feeder function than in the first and second embodiments. This adjustment mechanism is exemplified by the one described above, but is not limited to this, and can be configured such that the basket-like container 23 is placed on a stand and the height of this stand is adjusted. .

(Effects of the Invention) As detailed above, according to the vanishing model casting apparatus according to the present invention, the feeder model is made hollow, which greatly reduces the amount of vanishing material used and reduces the contact area with the hot water. As a result, problems such as a drop in the temperature of the hot water and the mixing of impurities into the hot water can be alleviated, and the boiler function can be effectively utilized, thereby making it possible to obtain high-quality products.

Further, since the heat generating agent can suppress a drop in temperature of the feeder, an effective feeder function can also be provided.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of an extinguishable model casting apparatus according to a first embodiment of the present invention, FIG. 2 is a cross-sectional view of an extinguishable model casting apparatus according to a second embodiment of the present invention, and FIG. A cross-sectional view of a riser model showing the third embodiment, and FIGS. 4 and 5 are cross-sectional views of a conventional vanishing model casting apparatus. ■... Casting flask, 3... Sand, 5... Product model, 7...
・Spout cup, 9...hot water, 11...spring path, 13...
・Riser model, 21... exothermic agent. Applicant's agent Patent attorney Tatsuhiko Ishigaki

Claims (2)

[Claims] (1) A casting flask filled with sand, a product model placed in the sand in the flask, formed from a vanishing material, which vanishes when hot water is supplied, and the vanishing part is filled with hot water; a runner disposed in the sand for introducing hot water supplied from a sprue into the product model portion; and a riser model that disappears when hot water is supplied and fills the disappeared part with hot water, and the shrinkage of the hot water filled in the product model part is replenished by the hot water filled in the riser model part. A vanishing model casting device characterized in that the riser model has a hollow shape. (2) The vanishing model casting apparatus according to claim 1, wherein a heat generating material is accommodated in the hollow part of the riser model.