JPS6072635A - Production of casting mold - Google Patents

Abstract

PURPOSE:To prevent cracking owing to sulfur of a casting and flaking of spheroidal graphite by adding varnish consisting principally of a specific wt% of a furan resin, etc. and an oxalic acid, etc. to sand particles, kneading the mixture, molding the mixed sand and heating the mold to cure by high frequency electric power. CONSTITUTION:About 0.5-5wt% varnish consisting principally of a furan resin, phenolic resin or furan modified phenolic resin and about 0.05-1.0wt% a hardener consisting of >=1 kind among a formic acid, oxalic acid, acetic acid and propionic acid are added to sand particles and after the mixture thereof are kneaded and molded, the molding is heated to cure by about 10-100kHz high frequency. The eluted sulfur of the mold hardener is decreased to prevent cracking of the casting and the deterioration in strength owing to flaking of spheroidal graphite.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention deals with the casting of steel castings and spheroidal graphite iron Jf1 products with self-hardening@types, and the use of sulfur-containing hardening agents. Regarding the manufacturing method of sand molds provided by cranks and lead-free flaky molds, τ prevention molds and mold trays.

When molding conventional organic self-hardening sand using indoor hardening, a considerably strong acid is required, so sulfone or sulfur acid is not used.
ゐFor this reason, sulfur in the hardening agent enters into steel castings and causes cracks to develop.When melting the spheroidal graphite cast iron, the graphite shape is spherical and desulfurization is required. If there is a deposit, the graphite will penetrate into the graphite and the graphite will become flaky. Furan modified pheno
Rumi 4 fat Ojobu and Dingi varnish 0.5 to sand particles
~ 59%, and @ba, oxalic acid, acetic acid, etc. are suitable for hardening agents of at least 14 tij and 0 for sand particles.
, 05-1.0% nail polishing is added, cross-wired, and the model is filled with light, after which it is heated with high frequency power of 10-100 11z to make it harden. 〇In the present invention, high frequency power is required due to the dielectric loss of the binder and hardening agent in the sand mold) JD K! Since the power and heat are approximately 90%, the varnish can be cured with care by using an organic acid such as citric acid. This cast m
In the scene 8 when using τ, Kikucho is used to prevent the fall of Fenghu.
L7).

In addition, the acid hardener used in 1 misfire ψJ has a weak catalytic effect on the hardening of the varnish in the chamber, and the hot water temperature rises to 60 to 100°C. Since the action and effect are exhibited only in the wet state, the possible time of the sand in forming 1 is long (
, the frequency of C (Yo, the linear heating process rapidly transforms the film, so it provides an effective molding method for small-sized Koshi-Nanzeng works). 0.05 to 1. Q j
The iqo and os * firefly % are full and the hardening does not proceed even if the sword mouth is heated. Etsu λ
-The saponification reaction has not started in the first place, the time to use the mouth becomes shorter, and there is excess water in the sand! This is because the steepness is slow.

Princess of sticky varnish〃0 rough τ 0.5~5 ton approval% bound 5
If it is less than 0.05%), even if it is overcome by JO* hardening, the light stability of the sand mold will be poor.・It breaks during the first step.
The V hook proboscis vC scum defect τ96 raw with a lot of hot scum and 1j is fantastic.

Concrete VC explanation of the effect of the example λ"shows the main circle" Example 1 100 square meters (Y+) of Nrakuryu, t fortune, and a pentagonal self plane! Note 7 Enol-modified furanyl] l]t: f varnish 2 (heavy loading → and 10% Shiri Jtsusan as a hardening agent)
7ftjtt) Water f8i1+=3 fJ (AE,
+: ) and r force 1) λ and summon fij.

C sample τφ5υ 6,0OOV, H・
"Hakin 16M1lz no sieve frequency wave Kanto ke seal) fil L 7
j o t= ) iJ IJX '+ii, Cali 1-4
t) III h4r between 5, 5, 7 and 10 minutes,
When the tube (Yarima II ++ cM autumn was taken out and the trial grade student ThH was caught in the trap glare f), the pressure force was returned to the t side and the result was 0 as shown in Figure 2. The mixed sand used in Example 1 did not undergo any agitation after 12 hours at VC at 15 to 20°C.

Next, in a mold using the core τ prepared by the method of "unexploded ψ", a hot bath of porcelain black porridge was made using the same mold as the same mold (70% water bathing solution). When spheroidal graphite komagane τ was added to a mold made using ``Fran Jikyo Sumitomo Oki'' τ, VC used flaky graphite or oxalic acid on a part of the core surface. In the case where the graphite shape in the same region was spherical, it was hardened with sulfonic acid or hardened with sulfonic acid. When τ was caught *&:+mMiJ There was a problem that the shape of the graphite returned to a flaky shape in the case of people who lived in the bath. In the case of spheroidal graphite beast control, sulfurization was able to prevent flaking and cracking of spheroidal graphite and the occurrence of cracks. Short reason (, 1 wooden pattern - 〇 effective RuiJj Zhu Jing in the case of many denominations) BL is the owl-shaped Hirata 1 figure and 11411 mountain for Ya 1 Is O L allocation piece busy 1' to envy 1゛ 4) It's terrible, A0 Figure 2 carries out Seri 1's knee ゛C Molding/
This (discipline) 1 to 6 (one round of technicians, 1 to 6) is a diagram of the I tomb 1 mountain and the 1 force of Okan no Mushio.

Claims (1)

[Scope of Claims] 1. Sand particles VC7 orchid resin, phenol resin or furan-edible phenolic resin, 0.5 to 5 weights and 1 kaol, and phosphoric acid, oxalic acid to the sand particles. , acetic acid and propionic acid, a hardening agent of 40.05 to 1.0 wt.
Characteristics of heating and curing with high frequency power and method of manufacturing molds. 2. The method for manufacturing a mold according to claim 1, wherein the curing agent is oxalic acid.