CN100391650C

CN100391650C - Cold core

Info

Publication number: CN100391650C
Application number: CNB2006100961216A
Authority: CN
Inventors: 杨林龙
Original assignee: SUZHOU INDUSTRIAL PARK MINGZHI CASTING EQUIPMENT Co Ltd
Current assignee: Suzhou Mingzhi Technology Co Ltd
Priority date: 2006-09-18
Filing date: 2006-09-18
Publication date: 2008-06-04
Anticipated expiration: 2026-09-18
Also published as: CN1923406A

Abstract

The invention relates to a coil core, which comprises sand core main body. Wherein, it is formed by upper and lower cores whose edges are compressed; the sand core has chamber with dual connecting posts fixed with upper and lower cores; the thickness of main body is 10-60mm. And the production comprises that producing upper and lower cores whose connecting surfaces relative to the connecting post are lower than side wall, and central has through hole; the upper and lower cores are opposite, to align their through holes; compressing upper and lower cores, to connect their through holes to form connecting posts. The invention can obtain hollow sand core main body, to confirm support strength, and avoid crack.

Description

A kind of cold core

Technical field

The present invention relates to the core that uses in a kind of casting and molding, be specifically related to the cold core sand core structure is improved and preparation method thereof.

Background technology

Employed core can be divided into two kinds of hot core and cold cores according to the difference of its manufacture craft in the foundary industry, hot core is by core box being heated the core sand hardened forming that makes in the core box, but in the manufacturing process, core box is easily deformable because of being heated, and can the shape and size of core be exerted an influence; Cold core then is to mix the back with resin glue by core sand to add curing agent and make it be lower than hardened forming under 80 ℃ the temperature, difference according to curing agent is divided into triethylamine set process, sulfur dioxide method, β method etc., with the triethylamine set process is example, and its basic technology method is: 1. put into the core sand of polyisocyanate fat and the mixed system of phenol resin and penetrate tube; 2. inject in the core box of clamping (generally finishing) with pressure air by core shooting mechanism; 3. be blown into triethylamine through gasification; 4. core sand curing molding; 5. the demoulding goes out core.Because cold core is finished at normal temperatures, be easy to realize, thereby be used widely.

Along with the development of foundry industry, no longer be satisfied with and make small-sized foundry goods, as be used for the bracing frame, bogie side frame etc. of railroad car, large-scale core (general length is greater than 2 meters) need be provided.Under large scale, the deformation that hot core produces can reach 5 millimeter, thereby can not use.When using cold core, that adopts usually in the prior art has two kinds, and a kind of intensity after curing is at 14kg/cm ²About, when casting with existing cold core sand core structure, the foundry goods cooling can be subjected to bigger resistance when shrinking, and causes casting stress to concentrate the cracking at position to scrap under large scale; The another kind of water-glass sand that adopts, the intensity after it solidifies is at 2-3kg/cm ²Can't make large-sized core, can only adopt the mode of segment processing, the core that is about to make a foundry goods is divided into several sections, splice each core when casting then again and constitute whole complete core, in order to overcome the buoyancy of core in metal liquid, each split core need add stud in the position that is fit to.Yet the casting quality problem so just occurred, existed seam and stud bad with combining of foundry goods body in splicing place of each core, thereby make foundry goods in use, fash and the stress concentration point that becomes foundry goods in conjunction with bad place cause part failure; On the other hand, bigger because core is solid to the consumption of raw materials amount, especially in the making of large-scale core, increased the manufacturing cost of each foundry goods.

Summary of the invention

The cold core that the purpose of this invention is to provide a kind of architecture advances, foundry goods cracking, fash and stud occur in conjunction with bad problem when making the large scale foundry goods in the solution prior art.

To achieve the above object of the invention, the technical solution used in the present invention is: a kind of cold core comprises the core body, described body mainly is made of last core and following core, be provided with cavity in the body, the wall thickness of body is between 10～60 millimeters, and last core and following core are by compound formation integral sand core.

In the technique scheme, described cold core is meant in the prior art being lower than under 80 ℃ the temperature and solidifies the core that forms, the utilization core is filled the cavity of made foundry goods, foundry goods is subjected to the resistance of core in the cooling contraction process, be the suitable space that foundry goods shrinks that offers, in the cold core body, cavity is set, reduces the resistance intensity of core.Realize cavity in the core for making, core is divided into core and two in following core, this compound by the compound integral body that is connected between two cores, can be that the company's of setting stem stem carries out penetrating sand twice, also can be colloid is bonding, can also be screw is fixedly connected; Simultaneously, the wall thickness of body need reach 10～60 millimeters, so that enough compressive strengths of body and suitable foundry goods shrink space to be provided.

Further technical scheme describedly goes up core and the closely pressing of play core periphery, is provided with company's stem stem that a plurality of and last core, following core are fixedlyed connected, and described even stem stem is distributed in body sidewall or the cavity.The distribution that connects stem stem is decided according to the size of cold core, can be distributed between the body sidewall, also can be distributed in the cavity, perhaps the company's of being equipped with stem stem in body sidewall and cavity.

In the technique scheme, adjacent described spacing≤400 millimeter that connect between the stem stem.Usually, connecting stem stem can evenly distribute, and guaranteeing the globality of cold core preferably, and makes between the upper and lower core and presses, and reduces the slit between the upper and lower core as far as possible.

Further technical scheme is, is provided with reinforcement in the described body cavity, and the thickness of reinforcement is between 10～60 millimeters, and the quantity of reinforcement and position can be according to size, the cavity volume decisions of made core, to improve the hot strength of core.

Optimized technical scheme is that the wall thickness of described body is between 16～25 millimeters.

The preparation method of above-mentioned cold core is an example with the company's of employing stem stem structure, may further comprise the steps:

(1) adopt core shooter to make respectively and go up core and following core, the corresponding position joint face that connects stem stem is lower than the surface of sidewall on described upward core and the following core, and central authorities are provided with through hole;

(2) it is staggered relatively to go up core and following core, and core is aimed at mutually with each corresponding lead to the hole site of following core;

(3) will go up core and play core pressing, through hole corresponding on last core and the following core be carried out Lian Xin, acquisition hollow core by core shooter;

(4) keep pressurization, treat the cold core curing and demolding, obtain the inner cold core that is provided with cavity.

Above, described core shooter is the machinery equipment that is used to make core used in the prior art, generally by frame, penetrate sand mechanism, sand penetrates tube, air blowing curing mechanism, core box clamping positioning mechanism and gas generator and control section is formed, earlier core sand is injected blasting unit, by penetrating sand mechanism core sand is injected in the core box, compressed air is blown into the gas that core sand is solidified, the demoulding behind the core sand curing molding, knockout.By last core in the above-mentioned coremaking process difference completing steps (1) and following core moulding, completing steps (2), (3) successively then will compress with following core mutually by respectively connecting the last core that stem stem connects in step (3), and both are integrated, reach sealing simultaneously, avoid the formation of fash.

Because the technique scheme utilization, the present invention compared with prior art has following advantage:

1. because core body of the present invention is synthetic by last core and following core, and cavity is set in body, the company's of utilization stem stem will be gone up core and connect into integral sand core with following core, compare with solid sand core in the past, when castings production, especially during heavy castings, intrinsic cavity provides enough yielding spaces for foundry goods shrinks, thereby the surface crack phenomenon occurs at stress concentration point can avoid the foundry goods cooling time;

2. pass through connecting company's core of core point, constituting makes upper and lower core close company's stem stem of core, simultaneously by two cores are pressurizeed, make core each sidewall seal closure corresponding with following core, constitute integral sand core, thereby can avoid the generation of fash, improve the smoothness of foundry goods inner surface afterwards, improve casting quality;

3. owing to be provided with cavity in the core body, be the hollow core, thereby can reduce the use of core sand raw material, reduce casting cost, also alleviate the core clean-up intensity simultaneously; On the other hand, all need use chemical products, reduce the use that the core sand raw material just can reduce chemicals, reduce pollution, also reduce production costs environment by the raw material of core sand and the hardened forming of core;

4. because the sidewall of core body is provided with exhaust duct, and this exhaust duct communicates with intrinsic cavity, under hot foundry goods situation, the gas in the closed cavity is derived, reduce interior pressure, improve the deformability of core body;

5. be integral sand core by core, cancelled stud, avoided stud to combine bad defective with foundry goods itself.

Description of drawings

The structural representation of accompanying drawing 1 embodiment of the invention one;

Accompanying drawing 2 is the structural representation of following core among Fig. 1;

Accompanying drawing 3 is the A-A cut-away enlarged view of Fig. 1.

Wherein: 1, go up core; 2, following core; 3, cavity; 4, connect stem stem; 5, reinforcement; 6, body.

The specific embodiment

Below in conjunction with drawings and Examples the present invention is further described:

Embodiment one: referring to accompanying drawing 1 to shown in the accompanying drawing 3, a kind of cold core, comprise core body 6, described body comprises core 1 and following core 2, be provided with cavity 3 in the body, be provided with reinforcement 5 in the cavity, be used to connect 9 company's stem stems 4 of core and play core, it is arranged as: two row on the left and right sidewall of the body that is placed in, two companies of every row stem stem 4, be furnished with 3 even stem stems on the middle reinforcement 5, respectively be provided with 1 even stem stem 4 in the cavity of left and right both wings, laterally the company's stem stem spacing between row is 300 millimeters, and the spacing between vertically adjacent company's stem stem is 200 millimeters; Wall thickness between body cavity madial wall and the lateral wall is 20 millimeters.

The preparation method of present embodiment cold core may further comprise the steps:

(1) makes core and following core respectively by first, second 3C core shooter respectively;

(2) will go up core or down the core of one of core place the 3rd 3C core shooter, another core 180 degree that overturn place the 3rd 3C core shooter, make core corresponding with following each correspondence position of core;

(3) by the 3rd 3C core shooter company's core point corresponding on last core and the following core is carried out secondary and penetrate sand, company's core point butt joint until upper and lower core constitutes even stem stem, the setting of the 3rd 3C core shooter makes it can compress core and following core, gives uniform pressure, guarantees driving fit between the two;

(4) keep pressurization, treat the cold core curing and demolding, obtain the inner cold core that is provided with cavity.。

Between above-mentioned steps (1) and (2), close the core degree for improving to go up between core and the following core, can increase the operation of artificial core finishing, generally the last core of making in (1), following core are delivered to artificial core finishing station place respectively by manipulator, behind the core finishing, deliver to the 3rd 3C core shooter place by manipulator again, finish following (2), (3), (4) step, make a complete hollow core.

By penetrate the core body that has cavity that sand is finished by secondary, break through traditional solid cold core structure, thereby can be used for the manufacturing of heavy castings, have good deformability, can avoid foundry goods to be subjected to the excessive and hot tearing that occurs of deflation resistance; On the other hand, by connecting the setting of stem stem, two chips are connected to an integral body up and down, and the operation by pressurizeing, the fash that has been prone to when having avoided the chip splicing obtains a complete core body, the stress point that causes by fash when preventing foundry goods, the quality of raising foundry goods; The 3rd, because the existence of cavity can reduce the use to the core sand raw material, reduce production costs, reduce of the pollution of the required chemicals of core moulding simultaneously to environment; Thereby core of the present invention is applicable to the use of all kinds of foundry goods, especially the use in the heavy castings.

Embodiment two: a kind of cold core, comprise the core body, and described body mainly is made of last core and following core, is provided with cavity in the body, and the wall thickness of body is between 10～60 millimeters, and last core and following core are by compound formation integral sand core.In the present embodiment, pass through the bonding formation overall structure of colloid between last core and the following core.

Claims

1. cold core, comprise core body [6], described body mainly is made of last core [1] and following core [2], be provided with cavity [3] in the body, the wall thickness of body is between 10～60 millimeters, and last core and following core is characterized in that by compound formation integral sand core: described upward core [1] and the closely pressing of following core [2] periphery, the company's stem stem [4] that be provided with a plurality of and last core, plays core to fixedly connected, the described stem stem that connects is distributed in body sidewall or the cavity.

2. cold core according to claim 1 is characterized in that: adjacent described spacing≤400 millimeter that connect between the stem stem [4].

3. cold core according to claim 1 is characterized in that: be provided with reinforcement [5] in the described body cavity, the thickness of reinforcement is between 10～60 millimeters.

4. cold core according to claim 1 is characterized in that: the wall thickness of described body [6] is between 16～25 millimeters.