JPS58145331A - Cooler for molding sand - Google Patents

Abstract

PURPOSE:To provide a titled device which is small in size, has good cooling efficiency and does not pollute environment by providing cooling chambers in plural pieces of cooling plates of spiral shape inscribing the outside cylinder of double cylinders and circumscribing the inside cylinder so as to cool the sand gliding on the cooling plates with said chambers. CONSTITUTION:Four pieces of cooling plates 3 are disposed spirally in tight contact with the inside wall of the outside cylinder 2 of the body of a cooler and the outside wall surface of the inside cylinder 12. The recovered sand 1 introduced through a supply port 5 is glided on the same plane thereof and is cooled with the cooling water passed into the cooling chambers in the plates 3 and a discharge pipe 8 from a supply pipe 7, whereafter the sand is removed through a discharge port 6. The molding sand disintegrated after the casting is charged through the supply port 5 for the sand 1 and is distributed past a dropping port 11 onto the plates 3 by distributing plates 10. The plates 10 regulate the spacing of the port 11 according to the temp., moisture, etc. of the sand 1 thereby regulating the layer thickness of the sand 1 slipping downward on the plates 3.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a molding sand cooling device that is small in size, has good cooling efficiency, does not deteriorate the working environment, and has little moisture fluctuation in recovered sand.

In recent mass-produced castings such as automobile parts, the amount of raw material has increased, and therefore, the mixing of foundry sand (silica sand, bentonite, sand kneaded with water and various additives, raw lidding sand) - molding - casting - sand recovery - kneading - As the molding cycle progresses, the temperature of the recovered sand rises, causing the following problems.

■ Stain on the model.

■ Out of shape. ´■ Raggedness on the surface of the mold.

■ Gas defect.

■ The above items ■ to ■ cause casting defects such as sand entrapment.

Molds for mass-produced castings are automatically molded by a series of molding plants, from mixing the foundry sand to recovering it, but conventionally, the recovered sand is cooled by aeration, which also serves to loosen sand nodules after the mold is dismantled. It was about. However, recently, various cooling devices have been developed to address the above problems, but they have the following drawbacks.

■ Projection type sand cooler Sand is projected into the cooling air and cooled by repeating this process several times.It has the following drawbacks.

(1) Poor heat transfer due to air cooling.

(2) The equipment becomes larger.

(3) Dust deteriorates the working environment.

(2) Vibratory sand cooler This type of sand cooler fluidizes the sand by vibration and cools it by blowing cold air from the bottom, and has the same drawbacks as (2) above.

(2) Stirring type sand cooler This cools the sand by blowing air into it while stirring, and has the same drawbacks as (2) above.

■Pre-kneading type cooler Cools using the heat of vaporization of water through water injection and cross-circuiting, and has the following drawbacks.

(1) The working environment deteriorates due to water vapor and dust.

(2) Moisture control of foundry sand is difficult due to moisture fluctuations.

(1) A device for cooling by sliding recovered sand (including foundry sand) over a cooling plate is known (Japanese Patent Publication No. 56-5610), as shown in Fig. 1. In FIG. 1, 1 is recovered sand, 2 is a main body outer cylinder, 3 is a cooling plate, 4 is a water cooling chamber, 5 is a sand supply port, 6 is a sand discharge port, 7 is a water supply pipe, and 8 is a drain pipe.

However, due to the shape and arrangement of the cooling plate 3, there are many empty NUs,
The equipment becomes larger.

The present invention provides a compact molding sand cooling device for green molding sand that has little moisture fluctuation in recovered sand and does not deteriorate the working environment, and has good cooling efficiency.

That is, the present invention consists of a double cylinder body consisting of an outer cylinder and an inner cylinder, and a plurality of cooling plates are spirally arranged in the space between the outer cylinder and the inner cylinder in close contact with the inner wall surface of the outer cylinder and the outer wall surface of the inner cylinder. The present invention relates to a molding sand cooling device characterized in that the cooling plate is provided with a cooling chamber in which cooling water flows.

Hereinafter, the apparatus of the present invention will be described in detail with reference to the accompanying drawings.

Figures 2 (A) to (0) are diagrams showing an embodiment of the apparatus of the present invention, in which Figure 2) is a longitudinal cross-sectional view, Figure 2) is a plan view, and Figure 2 (0) is a cross-sectional view. The A-A cross section in FIG. 2 (b) is a cross-sectional view, and FIGS. 5 and 6 are diagrams showing the cross-sectional shape of the cooling plate 3 according to the apparatus of the present invention.

In Figures 2 to 6, 1 is recovered sand, 2 is a main body outer cylinder, and 6 is a cooling plate, which is inscribed in the main body outer cylinder 2 and externally in contact with the main body inner cylinder 12, and has a cooling chamber 4 in which cooling water is passed. It has a spiral shape so that the molding sand slides down the same plane. 5 is a recovered sand supply port, 6 is a recovered sand discharge port, 7 is a cooling water supply pipe, and cooling plate 3
It is connected to the cooling chamber 4. 8 is a cooling water drain pipe, 9 is a cooling water flow rate adjustment valve, 10 is a distribution plate, 11 is a drop port, 3'
3a is a corrugated cooling plate, 3a is a fin-shaped cooling plate, and 12 is a cylinder inside the main body.

In FIGS. 2 to 6, the molding sand that has been disassembled after casting is loosened of lumps and then introduced into the recovered sand supply port 5. The collected sand 1 that has been thrown in is distributed by the distribution plate 10 to the plurality of cooling plates 6 through the drop openings 11, and slides down on the cooling plates 3. At this time, the distribution plate 10 adjusts the gap between the falling sand 110 depending on the temperature, moisture, etc. of the recovered sand 1, and
Adjust layer thickness. While the recovered sand 1 slides down on the cooling plate 5, it is cooled by heat exchange with the cooling plate 3, and is discharged through the recovered sand outlet 6.

In the apparatus of the present invention, the cooling plate 3Fi, as shown in FIG.
It has a cooling chamber 4 for circulation of cooling water inside, the sliding surface of the recovered sand is horizontal in the diameter direction of the main body outer cylinder 2, and the standard shape has a certain angle in the circumferential direction determined by the sliding speed of the recovered sand. shall be.

In the case of the standard shape, the cooling plate 3 is designed as shown in Fig. 4 to prevent the collected sand 1 from moving outward due to centrifugal force during downhill sliding and to prevent changes in the sand layer thickness, and to widen the cooling area. It is preferable that the outer edge of the cooling plate 3 is raised υ, and that grooves or fin-like protrusions are provided on the collecting sand sliding surface as shown in FIG.

In addition, the recovered sand 1, which is green mold sand, contains moisture, and in order to cool the moisture that evaporated during downhill sliding and return it to the recovered sand, cooling and adding water to the sand are carried out using a cooling plate 5 as shown in Fig. 6. It is also preferable to attach fin-like projections 3a to the lower surface of the .

Furthermore, in cooling the sand, the cooling effect due to heat transfer between sand grains is very small, so it is necessary to stir the sand to reduce this effect. 3
It is preferable to increase the inclination of the sand so that the recovered sand is turned over when sliding downhill, and to arrange this device in series in two or three stages above and below.

In addition, as a means of stirring the sand, it is also possible to provide a step on the cooling plate 3 near the surface of the inner cylinder 12 so that a part of the sand that slides down falls. 12
There is also the effect that the difference in inclination between the side and the outer cylinder 2 side can be reduced.

Figure 7 shows an example of applying this method to a square outer cylinder 2 (
c)) and (B). Figure 7 (body) is an M sectional view, Figure 7 (E) is a plan view, and Figure 8 shows details of the step of the cooling plate 3.

In Figure 7.8, the same symbols as in Figures 2 to 6 are 2 to 6.
The same functional product as in the figure is shown, and 13 is a cooling plate with 60 steps.

The outer circumferential side (outer cylinder 2 side) and the inner circumferential side (inner cylinder 12 side) of the cooling plate 3
If the slopes are the same, a step 13 will be formed as shown in Figure 8, and this step 13 will allow for good agitation of the sand.

According to the device of the present invention described above, the following effects can be achieved.

(1) By sliding the molding sand down on the cooling plate, it is cooled using heat transfer between the cooling plate and the molding sand, which has better cooling efficiency than heat transfer with air ( Heat transfer coefficient: 400 Kca#/m2・h・℃, Heat transfer coefficient between sand grains (transfer through air): 0.16 K (!a#/m
”h @ ℃).

(2) Since no water is added, there is no need to manage moisture due to moisture fluctuations or dry sand.

(3) Since a plurality of cooling plates for sliding the foundry sand down are fixedly arranged inside the cylinder in a spiral shape (partly in the form of steps in the case of a square cylinder), the sliding distance is long and the device can be made smaller.

(4) By attaching a fin-like cooling plate to the bottom of the cooling plate, the water that evaporated while the green mold sand is sliding down and cools is aggregated and returned to the sand, so the moisture content in the green mold sand changes. Less is.

(5) Dust scattering due to air and steam due to water addition.
No dust is generated and the working environment is improved.

(6) The structure is simple because it does not use compressed air or a vibrator.

[Brief explanation of drawings]

Figure 1 is a diagram showing an example of a molding sand cooling device using a conventional cooling plate, Figure 2) to (0) are diagrams showing an example of an embodiment of the device of the present invention, and Figure 2 (4) is a diagram showing an example of a molding sand cooling device using a conventional cooling plate. Longitudinal cross-sectional view, Figure 2 (4)
2(C) is a plan view, FIG. 2(C) is a sectional view taken along the line A-A in FIG. 2(B), FIGS. Figure (03) is a diagram showing another embodiment of the device of the present invention, and the seventh
Figure (A) is a longitudinal sectional view, Figure 7 C@ is a plan view, Figure 8 is 8.
J! FIG. 8 is a diagram for explaining the step difference in the cooling plate of the apparatus of the present invention shown in FIG. 7; Sub-agents 1) Meifuku Agent Ryo Hagiwara - 9IP13 Figure Horse Figure 7 (B) Horse Figure 8

Claims (1)

[Claims] It consists of a double cylinder body consisting of an outer cylinder and an inner cylinder, and a plurality of cooling plates are spirally arranged in the space between the outer cylinder and the inner cylinder in close contact with the inner wall surface of the outer cylinder and the outer wall surface of the inner cylinder. A molding sand cooling device characterized by being provided with a cooling chamber for circulating KFi cooling water inside a cooling plate.