阅读说明：本技术 一种砂芯生产防粘模方法 (Anti-sticking method for sand core production ) 是由 李祥 成松学 陈满义 于 2020-06-17 设计创作，主要内容包括：本发明公开了一种砂芯生产防粘模方法,包括以下步骤：调整砂芯模具的排气塞的位置和大小；动模、定模喷涂脱模剂,喷嘴朝向动模、定模的成型腔喷涂脱模剂,脱模剂包括氟氯烷溶剂,每次喷涂可进行多次成型,动模移动至定模,动模上部移动到定模下方并贴合,合模后形成成型腔和进气道、排气道；射砂,提高射嘴数量,射砂部移动到定模上方压紧,射砂部的射嘴向成型腔内射覆膜砂,射芯压力取成型压力范围的下值,覆膜砂充填成型腔,气体通过排气塞或排气孔排出芯腔外；固化成型,加热一定时间,树脂和粘合剂融化将砂子固化,脱模,动模下移,顶杆将成型的砂芯脱模。本发明组合多种调节方法,脱模效果好,提高产品生产质量,降低不合格率。(The invention discloses a sand core production anti-sticking method, which comprises the following steps: adjusting the position and size of an exhaust plug of the sand core mold; spraying a release agent on the movable mold and the fixed mold, wherein a nozzle sprays the release agent towards the molding cavities of the movable mold and the fixed mold, the release agent comprises a chlorofluorocarbon solvent, multiple times of molding can be performed during each spraying, the movable mold moves to the fixed mold, the upper part of the movable mold moves to the lower part of the fixed mold and is attached, and the molding cavity, the air inlet channel and the air exhaust channel are formed after the mold is closed; shooting sand, increasing the number of nozzles, moving the sand shooting part to the upper part of the fixed die for pressing, shooting precoated sand into the molding cavity by the nozzles of the sand shooting part, taking the lower value of the molding pressure range of the core shooting pressure, filling the precoated sand into the molding cavity, and exhausting gas out of the core cavity through an exhaust plug or an exhaust hole; and (3) curing and molding, heating for a certain time, melting the resin and the adhesive to cure the sand, demolding, moving the movable mold downwards, and demolding the molded sand core by the ejector rod. The invention combines a plurality of adjusting methods, has good demoulding effect, improves the production quality of products and reduces the reject ratio.)

1. A sand core production anti-sticking method is characterized in that: the method comprises the following steps:

s1, adjusting the position and the size of an exhaust plug of a sand core mould,

the vent plugs are arranged at the positions far away from the injection ports, so that the number of the vent plugs is increased; meanwhile, the two exhaust methods of the exhaust groove and the exhaust plug are combined for use, the exhaust groove is arranged at the position of the groove dividing surface of the core box, and then the exhaust plug is arranged in the exhaust groove.

S2, spraying a release agent on the movable mold and the fixed mold,

the nozzle sprays the release agent towards the molding cavities of the movable mold and the fixed mold, the release agent comprises a chlorofluorocarbon solvent, and the molding can be carried out for a plurality of times by each spraying,

s3, moving the movable mold to the fixed mold,

the upper part of the movable mould moves to the lower part of the fixed mould and is jointed, a forming cavity, an air inlet channel and an air outlet channel are formed after mould assembly,

s4, shooting the sand,

the number of the nozzles is increased, the sand shooting part moves to the upper part of the fixed die to be compressed, the nozzles of the sand shooting part shoot precoated sand into the molding cavity, the core shooting pressure takes the lower value of the molding pressure range, the precoated sand fills the molding cavity, gas is discharged out of the core cavity through the air exhaust plug or the air exhaust hole,

s5, curing and forming are carried out,

heating for a certain time, melting the resin and the binder to solidify the sand,

s6, demoulding is carried out,

and moving the moving die downwards, and demoulding the formed sand core by using the ejector rod.

2. The sand core production release method according to claim 1, characterized in that: the spraying interval of the release agent is 30-45 times, and the release agent is formed and sprayed once.

3. The sand core production release method according to claim 1, characterized in that: and after sand shooting, injecting catalytic gas before curing and forming, moving the sand shooting part away, moving the gas supply part to the upper part of the upper forming cavity for pressing, injecting the catalytic gas into the forming part, curing the sand through adhesive reaction under the catalysis of the catalytic gas, and moving the gas supply part away after the gas supply is finished.

4. The sand core production release method according to claim 1 or 2, characterized in that: the release agent also comprises siloxane and a solid lubricant, wherein the fluochloroalkane solvent accounts for 79-89% by mass, the siloxane accounts for 16-20% by mass, and the rest is the solid lubricant.

5. The sand core production release method according to claim 1, characterized in that: the number of the exhaust plugs is determined according to the size of the sand core, and the area of the exhaust plugs accounts for 20% -35% of the area of the part far away from the injection opening.

Technical Field

The invention belongs to the field of mold processing, and particularly relates to a mold sticking preventing method for sand core production.

Background

The sand core is molded by a core shooter, and the injection-compression molding machine is used for uniformly injecting molding sand into a sand box by utilizing compressed air for pre-compaction, then applying pressure for compaction, and waiting for the molding sand to be cooled and molded. The sand core is solidified by heating, and once the core shooter is operated by mistake in the core making process, the mold sticking condition is easy to occur in the manufacturing process. This causes problems such as the sand core falling out of the meat, difficulty in mold stripping, and the like.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a sand core production anti-sticking method, which avoids the problems of meat falling, difficult mold stripping and the like caused by the mold sticking phenomenon in the sand core production process.

In order to achieve the purpose, the invention adopts the following technical scheme: a method for preventing a sand core from being stuck in a mold comprises the following steps:

the position and the size of an exhaust plug of the sand core mould are adjusted,

the vent plugs are arranged at the positions far away from the injection ports, so that the number of the vent plugs is increased; meanwhile, the two exhaust methods of the exhaust groove and the exhaust plug are combined for use, the exhaust groove is arranged at the position of the groove dividing surface of the core box, and then the exhaust plug is arranged in the exhaust groove.

Spraying a release agent on the moving die and the fixed die,

the nozzle sprays the release agent towards the molding cavities of the movable mold and the fixed mold, the release agent comprises a chlorofluorocarbon solvent, and the molding can be carried out for a plurality of times by each spraying,

the movable mold moves to the fixed mold,

the upper part of the movable mould moves to the lower part of the fixed mould and is jointed, a forming cavity, an air inlet channel and an air outlet channel are formed after mould assembly,

the sand-shooting is carried out,

the number of the nozzles is increased, the sand shooting part moves to the upper part of the fixed die to be compressed, the nozzles of the sand shooting part shoot precoated sand into the molding cavity, the core shooting pressure takes the lower value of the molding pressure range, the precoated sand fills the molding cavity, gas is discharged out of the core cavity through the air exhaust plug or the air exhaust hole,

curing and forming are carried out, and then,

heating for a certain time, melting the resin and the binder to solidify the sand,

and (4) demoulding the mixture,

and moving the moving die downwards, and demoulding the formed sand core by using the ejector rod.

Furthermore, the spraying interval of the release agent is 30-45 times of molding and spraying once.

Furthermore, after sand shooting, catalytic gas is injected before solidification and molding, the sand shooting part is moved away, the gas supply part is moved to the upper part of the upper molding cavity to be compressed, the catalytic gas is injected into the molding part, the sand is solidified by the reaction of the adhesive under the catalysis of the catalytic gas, and after the gas supply is finished, the gas supply part is moved away.

Further, the release agent also comprises siloxane and a solid lubricant, wherein the fluochloroalkane solvent accounts for 79-89% by mass, the siloxane accounts for 16-20% by mass, and the rest is the solid lubricant.

Further, the number of the exhaust plugs is determined according to the size of the sand core, and the area of the exhaust plugs accounts for 20% -35% of the area of the part far away from the injection opening.

The invention has the beneficial effects that:

1. the sand core production anti-sticking method provided by the invention combines methods such as setting of the vent plug, using of the release agent, adjusting of the core shooting pressure and the like, has a good release effect, improves the production quality of products, and reduces the reject ratio;

2. the vent plug combines two exhaust methods of an exhaust groove and the vent plug for use, gas is exhausted, sand grains, a core cavity and a groove form a compact sand core, the sand grains are prevented from being adhered to the exhaust hole, and the demolding efficiency is improved;

3. the invention selects proper release agent, is suitable for manufacturing sand cores with different shapes and types, is particularly suitable for producing the sand cores of the engine cylinder cover air flue with complex structure determined by structure and sand grain specification, and can reduce the using amount of the release agent and the spraying times.

Drawings

FIG. 1 is a schematic step diagram of a sand core production release method of the present invention.

Detailed Description

The details of the present invention are described below with reference to the accompanying drawings and specific embodiments.

As shown in fig. 1, the method for preventing the sand core from being stuck in the mold comprises the following steps:

s1, adjusting the position and the size of an exhaust plug of a sand core mould,

the vent plugs are arranged at the positions far away from the injection ports, so that the number of the vent plugs is increased; meanwhile, the two exhaust methods of the exhaust groove and the exhaust plug are combined for use, the exhaust groove is arranged at the position of the groove dividing surface of the core box, and then the exhaust plug is arranged in the exhaust groove.

S2, spraying a release agent on the movable mold and the fixed mold,

the nozzle sprays the release agent towards the molding cavities of the movable mold and the fixed mold, the release agent comprises a chlorofluorocarbon solvent, and the molding can be carried out for a plurality of times by each spraying,

s3, moving the movable mold to the fixed mold,

the upper part of the movable mould moves to the lower part of the fixed mould and is jointed, a forming cavity, an air inlet channel and an air outlet channel are formed after mould assembly,

s4, shooting the sand,

the number of the nozzles is increased, the sand shooting part moves to the upper part of the fixed die to be compressed, the nozzles of the sand shooting part shoot precoated sand into the molding cavity, the core shooting pressure takes the lower value of the molding pressure range, the precoated sand fills the molding cavity, gas is discharged out of the core cavity through the air exhaust plug or the air exhaust hole,

s5, curing and forming are carried out,

heating for a certain time, melting the resin and the binder to solidify the sand,

s6, demoulding is carried out,

and moving the moving die downwards, and demoulding the formed sand core by using the ejector rod.

In practical application, the spraying interval of the release agent is 30-45 times of molding and spraying once.

In practical application, after sand shooting, the catalytic gas is injected before solidification and molding, the sand shooting part is moved away, the gas supply part is moved to the upper part of the upper molding cavity to be compressed, the catalytic gas is injected into the molding part, the sand is solidified by the reaction of the adhesive under the catalysis of the catalytic gas, and after the gas supply is completed, the gas supply part is moved away.

In practical application, the release agent also comprises siloxane and a solid lubricant, wherein the chlorofluoroalkane solvent accounts for 79-89% by mass, the siloxane accounts for 16-20% by mass, and the rest is the solid lubricant.

In practical application, the number of the exhaust plugs is determined according to the size of the sand core, and the area of the exhaust plugs accounts for 20% -35% of the area of the part far away from the injection port.

The working principle of the invention is as follows:

the sticking mould of the core shooter is divided into a plurality of good types, and the types of sticking moulds caused by different reasons can be different. The energy type die sticking is easy to occur, and the main reason is that the sand shooting pressure of the core shooting machine is large, so that solidified molding sand is left on the surface of a core box, and in the condition, the sand shooting pressure of the core shooting machine is adjusted. The exhaust hole blocking type sticking is easy to occur, the exhaust area is reduced due to the fact that the molding sand is adhered to the exhaust holes, operators want to relieve the sand shooting pressure, the error is achieved, if the sand shooting pressure is improved blindly, the core shooter is not only loose in sand shooting and not solid in sand blowing, and the sticking problem is also caused. This is actually related to the position and size of the core mold vent plug, and it is better to note the position and size when designing.

Secondly, it is also noted that the design of the core box and the selection of proper binder and the reasonable control of the adding amount of the binder in the core sand are both beneficial to preventing the mucosa, but for a certain core box tool design and the core sand, a simple and effective mold release method is to use a proper release agent. The invention selects the release agent mainly comprising the chlorofluorocarbon solvent for demoulding and lubricating, and can produce 30-45 sand cores by spraying once, thereby improving the quality and the production efficiency of the sand cores.

In conclusion, the invention combines the methods of setting the vent plug, using the release agent, adjusting the core shooting pressure and the like, has good release effect, improves the production quality of products and reduces the reject ratio.

The foregoing illustrates and describes the principles, general features, and advantages of the present invention. It should be understood by those skilled in the art that the foregoing embodiments are merely illustrative of the technical spirit and features of the present invention, and the present invention is not limited thereto but may be implemented by those skilled in the art.