SU1407657A1 - Method of determining the extraction capability of cores and moulds - Google Patents

Abstract

The invention relates to the field of foundry and can be used in the manufacture of casting cores and molds. The purpose of the invention is to obtain reliable data on the structural and technological characteristics of real rods and shapes, cured in a heated and cold snap. The sample is removed from the equipment after curing with simultaneous recording of the extraction force applied to the sample through the tool's ejector system, and the recoverability is judged by the ratio between the strength of the sample during extraction and the specific extraction force. 2 tab.

Description

ate

The invention relates to foundry manufacture and can be used in the manufacture of casting molds and cores.

The purpose of the invention is to obtain reliable data on the design and technological characteristics of real rods.

and forms.

i

According to the method, which includes filling the equipment with a mixture of known strength and removing the test sample from the extract, the sample is removed after curing with simultaneous recording of the extraction force applied to the sample through the tool’s ejector system, and the recoverability is judged by the ratio of the sample strength during extraction and specific extraction force.

Winner Create a device for testing the proposed method. It includes a sanding machine with a knot for

15

The results indicate the impossibility of extracting samples from the tooling after 30 seconds due to insufficient strength in the hot state — the sample is stitched by pushers due to the thin thickness of the final mixture.

After 60 seconds of curing, the sample is removed with difficulty, in some cases cracks are observed.

The second mixture contains 100 wt.% Sand, 2.1 wt.% Phenol alcohol composition and 5.8 wt.% (On composition) ferric chloride (Table 2).

Samples are removed from the tooling under all curing conditions without cracking.

A comparison of the results of testing the two mixtures leads to the following conclusions regarding their structural and technological properties. First, if the ratio between the strength in a hot state and

blowing specimens from the mixtures and heated by 20 specific extraction force for the first equipment with an ejector system. If the mixes are 2.0-2.2 depending on the curing time, then for the second mixture these values vary between 2.5-5.9. Thus, since the safety margin of a mixture with ferric chloride is much larger than that of the first mixture, it is possible to make rods and shapes of a more complex configuration from it.

The neva mixture is inflated into the heated equipment, cured, and the sample is pushed out of the equipment with the help of pushers. An extraction force is then recorded on the manometer. The extracted sample is placed in the grips of the bursting mashina, where it is subjected to stretching to destruction, and the strength of the mixture is determined.

Thus, almost simultaneously

but two characteristics are determined: the specific tensile force (the extraction force attributed to the surface of the sample contact with the snap) and the tensile strength of the sample, in this case in a hot condition.

Using the device, the conditions for the manufacture and extraction of samples by the proposed method are reproduced. The duration of the filling equipment with a mixture of 0.6 seconds. Compressed air pressure during inflation of 0.5 MPa. The equipment in which the samples are cured is steel. Molding slope of AOR, roughness RX 20. Splitter composition is applied to the surface of the equipment in the form of an aqueous solution of an organosilicon emulsion KE-6009. The temperature of the tooling is 240 ° C, the curing time varies from 30 to 180 s.

Test two mixtures. The first mixture consists of 100% by weight of sand, 4.0% by weight of the phenol-alcohol composition (phenol-alcohol with 20% technical urea).

In tab. 1 shows the test results of this mixture.

0

five

The results indicate the impossibility of extracting samples from the tooling after 30 seconds due to insufficient strength in the hot state — the sample is stitched by pushers due to the thin thickness of the final mixture.

After 60 seconds of curing, the sample is removed with difficulty, in some cases cracks are observed.

The second mixture contains 100 wt.% Sand, 2.1 wt.% Phenol alcohol composition and 5.8 wt.% (On composition) ferric chloride (Table 2).

Samples are removed from the tooling under all curing conditions without cracking.

A comparison of the results of testing the two mixtures leads to the following conclusions regarding their structural and technological properties. First, if the ratio between the strength in a hot state and

0 specific extraction force for the first

the specific extraction force for the first

mixtures of 2.0-2.2, depending on the duration of curing, for the second mixture these values vary from 2.5 to 5.9. Thus, since the safety margin of a mixture with ferric chloride is much larger than that of the first mixture, it is possible to make rods and shapes of a more complex configuration from it.

Secondly, the ability to produce high-quality rods and molds over a shorter curing time allows an increase in the productivity of the process equipment.

The test results show that the use of a mixture containing ferric chloride is preferable from the standpoint of evaluating the structural and technological properties of the rods and shapes.

Claims (1)

Invention Formula The method for determining the recoverability of rods and molds produced in heated or cold tooling in mass production, including filling the equipment with a mixture, curing the mixture, removing the sample mixture from the equipment while determining the specific extraction force, determining the strength of the sample, characterized in that data on the structural and technological characteristics of real rods and shapes, the recoverability is determined by the ratio between the strength of the sample and the specific force Removing the. Table 1 30 60 90 120 150 180 0.17 0.20 0.22 0.25 0.27 0.34 0.48 0.56 0.58 0.80 30 60 90 120 150 180 0.08 0.15 0.17 0.19 0.20 0.22 0.20 0.56 0.74 0.98 1.18 0.93 table 2