CN105537523A

CN105537523A - Method for casting double-end blind hole part at negative pressure through evanescent mode

Info

Publication number: CN105537523A
Application number: CN201610095496.4A
Authority: CN
Inventors: 项恒新; 丁崇贵
Original assignee: Jiangsu Grinka Machinery Co Ltd
Current assignee: Jiangsu Grinka Machinery Co Ltd
Priority date: 2016-02-22
Filing date: 2016-02-22
Publication date: 2016-05-04

Abstract

The invention belongs to the technical field of machining models and relates to a method for casting a double-end blind hole part at negative pressure through an evanescent mode. The method is characterized in that blind holes are filled with self-hardening sand in advance, and the bottom blind hole is tamped in advance. According to the method, the problem of molding sand flying or casting sand burning caused by uncompacted sand filling of a bottom blind hole of a product can be effectively avoided, and the workload of sand removal in the next working procedure can be greatly relieved. The method is similarly suitable for evanescent mode casting production during which sand filling is not easy to carry out due to a large hole in the bottom.

Description

The method of the blind hole type parts of Negative casting of EPC double end

Technical field

The invention belongs to processing model technical field, be specifically related to the method for the blind hole type parts of a kind of Negative casting of EPC double end.

Background technology

At present, in lost foam casting foundry goods, double end blind hole class occupies certain proportion, (the general aperture > 20mm when the footpath being in pouring position lower end blind hole is deeply larger, aperture: degree of depth > 1) part with bottom blind hole time, in the process of filling moulding, the blind hole of bottom usually can not fully be tamped, cause the foundry goods sand grains pouring into a mould out waft to cast-internal or occur the defects such as bottom scab, cause foundry goods to scrap the polishing work of Huo Geihou road and add operation easier.

Summary of the invention

The object of the invention is for solving the problem, and the method for the blind hole type parts of a kind of Negative casting of EPC double end proposed.

Main technical schemes of the present invention: the casting method of the blind hole type parts of lost foam casting double end, is characterized in that, by dosing self-hardening sand in advance in blind hole, bottom blind hole being tamped in advance.

Usually, the inventive method is mixed in proportion dry sand, polyvinyl alcohol water solution and cement, with mould, the molding sand that mixture is good is made the core of required form, core is put among the blind hole organized bottom the white mould of having gone here and there, be bonded together with running gate system evaporative pattern PUR with after white mould blind hole face compacting, put into sandbox and add sand vibration molding.

A kind of representative process method of the present invention, comprises the following steps:

1. become polyvinyl alcohol water solution for subsequent use with water by the proportions of 1:8 ~ 11 pva powder;

2. 50 ~ 70 order dry sands, polyvinyl alcohol water solution, cement are mixed in the ratio of 100:9 ~ 10:3 ~ 6, with mould, the molding sand that mixture is good is made the core of required form, be placed in dull and stereotyped upper more than natural air drying 36h or put into temperature and dry more than 24h at 40 ~ 60 DEG C of baking rooms;

3. the core outer surface of having dried is wrapped one deck and commonly use coating, put into temperature 40 ~ 60 DEG C of baking room dry for standby;

4. white mould evaporative pattern PUR bonding group of string;

5. the floating sand in core surface after removal, reconditioning oven dry and unnecessary coating, make core smooth surface to the white mould surface of not scratch, the core that reconditioning is good being dipped in upper conventional coating puts among the blind hole organized bottom the white mould of having gone here and there, after white mould blind hole face compacting, go here and there together with white mould with group and be coated with conventional coating again, and put into temperature and white mould coated oven dry at 40 ~ 60 DEG C of baking rooms;

6. the white mould after oven dry is taken out and be bonded together with running gate system evaporative pattern PUR, put into sandbox and add sand vibration molding.

The inventive method can effectively avoid blind hole bottom product to cause molding sand to hike up because back-up sand is unreal or scab problem appears in foundry goods, greatly alleviates the workload of later process sand removal.This method is suitable for equally to have with bottom and produces compared with the lost foam casting of macroscopic-void not easily back-up sand.

Accompanying drawing explanation

Fig. 1 is two blind hole schematic diagrames that in the embodiment of the present invention, part exists.

Fig. 2 is white module string schematic diagram in embodiment method.

Fig. 3 is the core enlarged diagram prepared in embodiment method.

Fig. 4 is that the core for preparing in embodiment method and white module connect schematic diagram.

Fig. 5 is white module bunch schematic diagram in embodiment method.

Detailed description of the invention

Below in conjunction with embodiment and accompanying drawing, the present invention is described in detail.

Embodiment

There are two blind holes (as Fig. 1) in this part, put into box moulding process after group bunch (as a Fig. 5) completes, bottom blind hole is not easily tamped.

Implementation step:

1. become glue for subsequent use with water by the proportions of 1:1:8 ~ 11 pva powder;

2. sand (50 ~ 70 order), glue, cement are mixed in the ratio of 100:9 ~ 10:3 ~ 6, with mould, the molding sand that mixture is good is made the core (as shown in Figure 4) of required shape, be placed in dull and stereotyped upper more than natural air drying 36h or put into temperature and dry more than 24h at 40 ~ 60 DEG C of baking rooms;

3. the core surface of having dried is wrapped the conventional coating of one deck, again put into temperature and dry at 40 ~ 60 DEG C of baking rooms;

4. will scheme shown in white mould evaporative pattern PUR bonding group of string shown in (1) to figure (2);

5. the white mould of group having been gone here and there and the core of having dried carry out group and connect: the floating sand in core surface after the oven dry of A reconditioning sand and unnecessary coating, make the core smooth surface extremely white mould exterior view (3) of not scratch; The core that reconditioning is good is dipped in upper conventional coating and puts among the blind hole of the white mould bottom diagram (1) completed shown in group string figure (2), after white mould blind hole face compacting by B; The C group white mould of having gone here and there and the core of having dried carry out group and meet rear figure (4), then are coated with conventional coating, and put into temperature and dry at 40 ~ 60 DEG C of baking rooms;

6. the white mould after oven dry is taken out and be bonded together (as shown in Figure 5) with running gate system PUR, put into sandbox and add sand vibration molding.

Adopting said method can avoid blind hole bottom product to occur scab problem effectively, can alleviate the workload of rear road sand removal, and this method is suitable for equally to have with bottom and produces compared with the lost foam casting of macroscopic-void not easily back-up sand.

Claims

1. the method for the blind hole type parts of Negative casting of EPC double end, is characterized in that, by dosing self-hardening sand in advance in blind hole, feature bottom blind hole being tamped in advance.

2. method according to claim 1, dry sand, polyvinyl alcohol water solution and cement is it is characterized in that to mix in proportion, with mould, the molding sand that mixture is good is made the core of required form, core is put among the blind hole organized bottom the white mould of having gone here and there, be bonded together with running gate system evaporative pattern PUR with after white mould blind hole face compacting, put into sandbox and add sand vibration molding.

3. method according to claim 1, is characterized in that comprising the following steps: 1) become polyvinyl alcohol water solution for subsequent use with water by the proportions of 1:8 ~ 11 pva powder; 2) 50 ~ 70 order dry sands, polyvinyl alcohol water solution, cement are mixed in the ratio of 100:9 ~ 10:3 ~ 6, with mould, the molding sand that mixture is good is made the core of required form, be placed in dull and stereotyped upper more than natural air drying 36h or put into temperature and dry more than 24h at 40 ~ 60 DEG C of baking rooms; 3) the core outer surface of having dried is wrapped one deck and commonly use coating, put into temperature 40 ~ 60 DEG C of baking room dry for standby; 4) Bai Mo evaporative pattern PUR bonding group of string; 5) the floating sand in core surface after removal, reconditioning oven dry and unnecessary coating, make core smooth surface to the white mould surface of not scratch, the core that reconditioning is good being dipped in upper conventional coating puts among the blind hole organized bottom the white mould of having gone here and there, after white mould blind hole face compacting, go here and there together with white mould with group and be coated with conventional coating again, and put into temperature and white mould coated oven dry at 40 ~ 60 DEG C of baking rooms; 6) the white mould taking-up after oven dry is bonded together with running gate system evaporative pattern PUR, puts into sandbox and add sand vibration molding.