CN101972844A - Production process for applying expendable pattern casting technology to vermicular-iron diesel engine - Google Patents

Abstract

The invention relates to a production process for applying an expendable pattern casting technology to a vermicular-iron diesel engine, which comprises the following steps of: molding by adopting an EPS (Expanded Polystyrene) foam model; adding water to regulate the concentration of a special coating for an expendable pattern; dip-coating the foam model, a foam sprue and a foam runner with the coating; dip-coating for the second time after drying, wherein the thickness of the coating is required to be about 0.5mm; carrying out sand pre-burying processing for the sand difficultly-filled part of the model; bonding the foam sprue and the foam runner for the model, and manufacturing equipment for shaping a casting system; self-manufacturing a sandbox, and firstly filling Baozhu sand with the height of 500mm in the sandbox; placing the foam model into the sandbox; placing the sandbox on a vibration platform for vibration, drenching and adding the sand; carrying out three-dimensional jolting for 110 seconds after sand addition is finished; closing the sandbox, and connecting a vacuum system and the sandbox; starting the vacuum system to stabilize the negative pressure in the box at -0.3MPa; and casting, wherein the casting time is 35-41 seconds. The invention improves the production efficiency, lowers the production cost and improves the qualified rate of products.

Description

The lost foam casting technology production technology on the iron Diesel engine that is used to wriggle

Technical field

The invention belongs to machinery manufacturing technology field, be specifically related to a kind of lost foam casting technology be used to wriggle production technology on the iron Diesel engine.

Background technology

According to national shipping industry development plan, the central government resolves Shipbuilding of China industry made in the coming five years and is the world's strongest nation, the director Chen Bin of industry coordination department of National Development and Reform Committee represented April 7, the guiding theory of shipping industry development planning is to take positive credit facilities, stablize the shipbuilding order, greatly develop the ocean engineering equipment, implement the development strategy of ocean power.He points out that following 3 years, the shipbuilding aggregate tonnage of China strove reaching 5,000 ten thousand tons, reach 1,200 ten thousand horsepowers, the share of occupying world market 30%, wherein the boats and ships of high added value account for the share of world market 20%, and the occupation rate of market of ocean engineering reaches 10% of world market.

Marine diesel is boats and ships " hearts ", makes the first in the world shipbuilding big country, does to make the essence marine diesel of running business into strong one greatly and become the most important thing undoubtedly.All the time, owing to do not grasp core technology, lack independent brand, the serious inadequate natural endowment of China's boat diesel engine manufacturing industry.In recent years, the situation that supply falls short of demand appears in China's shipbuilding industry continuous prosperity, high-power marine diesel, however form strong contrast with it be, China's homemade diesel engine main frame localization shipment rate only is about 35%, and the shipment rate about 65% is external imported product.

Appearance along with central shipping industry development plan, first develop the supporting industrial chain of boats and ships, cultivate specialized marine diesel manufacture base, improve the production efficiency and the product quality of complete machine and auxiliary products, improve localization shipment rate and become national basic decision.

Make a general survey of industry, all adopt traditional founding technology for the complex thin-wall pieces of vermicular cast iron of similar marine diesel parts accessory.With diesel engine cylinder head for ship 3411 is example, its complicated air flue, water channel, oil circuit, finish founding and need squeeze into 13 loam cores, water channel loam core complex structure particularly, finished product loam core intensity is low, is not easy moulding, assembles fragile, position deviation very easily causes problems such as buoyancy tank easily in the assembling of water channel, air flue loam core during casting.Every professional teams and groups can only finish 1 ~ 2 every day, can't form large-scale production.

Summary of the invention

The objective of the invention is at the existing above-mentioned defective of existing foundry engieering, provide a kind of lost foam casting technology be used to wriggle production technology on the iron Diesel engine.

Production technology of the present invention comprises the step of following order:

(1) adopt any surface finish, proportion to be not more than 21 grams per liters and the moulding of uniform high-quality eps foam model;

(2) the temper concentration of disappearance mould special coating;

(3) with (2) step gained coating dip coating bubbles model, foam sprue, foam cross gate; Carry out the dip-coating second time again after the drying room oven dry, dry back paint thickness requires about 0.5mm;

(4) be difficult for filling out Sha Chu at model and do pre-buried husky the processing

(5) to the bonding foam sprue of the model that reaches the paint thickness requirement, foam cross gate, and the making frock formalizes to running gate system;

(6) self-control sandbox, specification is 1200mm*1200mm*1500mm, first packed height is 500mm in the sandbox

Mound sand;

(7) use the frock bubbles model that moulding is good to insert in the sandbox;

(8) then sandbox is positioned on the shock platforms, opens shock platforms, drench with rain and add sand;

(9) add sand and finish again three-dimensional ram-jolt 110 seconds;

(10) the sealing sandbox is connected vacuum system with sandbox;

(11) open vacuum system, negative regulation is at-0.3MPA in the guard box;

(12) casting, and the control casting time was at 35 ~ 41 seconds;

(13) casting is finished, and checks to have or not crush and other casting flaw.

The present invention is owing to adopt the foamed plastics of very easily gasification to make model, need not to take out moulding mould (as wooden model) before the casting, no die joint, no core, so product non-trimming burr, no pattern draft has reduced the scale error that causes owing to the core combination, and the dimensional accuracy of foundry goods and surface roughness are near precision-investment casting.Simultaneously, because adopt dry moulding, eradicated the casting defect of bringing owing to water, binding agent, additives in the molding sand, the casting wasted product rate significantly descends.In addition, this new technology is less demanding to technical level of operators, has avoided because of operating personnel's technical merit is unbalanced product quality being caused bad influence.Process of the present invention has improved the production efficiency of the complex thin-wall pieces of vermicular cast iron of similar marine diesel greatly, has reduced production cost, has improved product percent of pass.

The specific embodiment

The present invention is further detailed explanation below in conjunction with specific embodiment.

The process of the test of present embodiment is as follows:

1, adopting any surface finish, proportion is 19 grams per liters and the moulding of uniform high-quality EPS marine diesel cylinder head bubbles model;

2, a certain amount of water mediation of adding good fortune Cisco disappearance mould special coating fully stirred 2 hours, adjusted concentration;

3, use coating dip coating bubbles model, foam sprue, the foam cross gate that a step is become reconciled;

4, carry out the dip-coating second time again after the drying room oven dry, dry back paint thickness requires about 0.5mm;

5, pre-buried mound sand processing is done at cylinder head model water channel place;

6,, make frock running gate system is formalized to the bonding foam sprue of the model that reaches thickness requirement, foam cross gate;

7, self-control sandbox, specification is 1200mm*1200mm*1500mm, first filling mound sand in the sandbox, ram-jolt, it highly is about 500mm;

8, use the frock bubbles model that moulding is good to insert in the sandbox;

9, sandbox is positioned on the shock platforms, opens shock platforms, drench with rain and add sand;

10, add sand and finish after, three-dimensional ram-jolt 110 seconds;

11, the sealing sandbox is connected vacuum system with sandbox;

12, open vacuum system, negative regulation is at-0.3MPA in the guard box;

13, flowing full casting was finished in 37 seconds;

14, casting is finished.

Through check, essentially no crush and other casting flaw, yield rate are 98%.

The principle and the characteristics of process of the present invention are:

1,, select the bubbles model of best bright finish essential for improving the quality of products because lost foam casting product directly reacts the surface of bubbles model.

2, gasify behind the pre-high temperature of foam, low density foam significantly reduces the gas forming amount of gasification, reduces the product defects risk.

3, special-purpose Fox's lost foam paint, dry strength is good, and good permeability improves the quality of products greatly.

4, adopt CAD/CAM system modeling Simulation casting cycle, design suitable casting system, improved product percent of pass and production efficiency greatly.

5, do sand in the better consolidation sandbox of three-dimensional bumper, avoid crush, situations such as displacement occur.

6, the negative pressure pressure of determining through test of many times better guarantees the collection of waste gas in the cavity filling process, and negative regulation in the guard box improves product percent of pass.

7, stablize casting time, quantize casting cycle.

8, product percent of pass is more than 98%, and production efficiency is tens of times of traditional handicraft.

Claims (1)

1. the lost foam casting technology production technology on the iron Diesel engine that is used to wriggle is characterized in that comprising the step of following order:

(1) adopt any surface finish, proportion to be not more than 21 grams per liters and the moulding of uniform high-quality eps foam model;

(2) the temper concentration of disappearance mould special coating;

(3) with (2) step gained coating dip coating bubbles model, foam sprue, foam cross gate; Carry out the dip-coating second time again after the drying room oven dry, dry back paint thickness requires about 0.5mm;

(4) be difficult for filling out Sha Chu at model and do pre-buried husky the processing

(5) to the bonding foam sprue of the model that reaches the paint thickness requirement, foam cross gate, and the making frock formalizes to running gate system;

(6) self-control sandbox, specification is 1200mm*1200mm*1500mm, first packed height is 500mm in the sandbox

Mound sand;

(7) use the frock bubbles model that moulding is good to insert in the sandbox;

(8) then sandbox is positioned on the shock platforms, opens shock platforms, drench with rain and add sand;

(9) add sand and finish again three-dimensional ram-jolt 110 seconds;

(10) the sealing sandbox is connected vacuum system with sandbox;

(11) open vacuum system, negative regulation is at-0.3MPA in the guard box;

(12) casting, and the control casting time was at 35 ~ 41 seconds;

(13) casting is finished, and checks to have or not crush and other casting flaw.