CN102513507A - Core bar of sand core of steel pipe and manufacturing method of sand core - Google Patents

Abstract

The invention discloses a core bar of a sand core of a steel pipe, wherein the steel pipe is higher than the sand core so that the sand core is exposed from a hanging hole of the upper part of the steel pipe; the diameter of the steel pipe is less than that of the sand core; and a plurality of evenly distributed strip-shaped vent holes are arranged on the steel pipe. The invention further discloses a manufacturing method of the sand core. The structure of the sand core of the invention is simple, the production cost is reduced, the operation is simplified, the quality of the sand core is ensured, and the production efficiency is improved.

Description

Steel pipe mud core arbor and mud core preparation method thereof

Technical field

The present invention relates to the manufacturing technology field of foundry goods mud core, particularly relate to a kind of steel pipe mud core arbor and mud core preparation method thereof.

Background technology

At present domestic a lot of massive casting factory make large tube-like mud core (diameter >=500mm, the round steel that general use is uneven in length in a large number in the time of highly >=3000mm) is as mud core arbor, unpacking process is lost easily; In order to guarantee the gas permeability of mud core, prevent to produce casting flaw such as pore and use fuse cord or hollow nylon rope to form the outside bleed of passage; The mud core diameter is bigger, and the molding sand use amount is big, and molten metal after filling up die cavity surrounds the mud core; Mud core radiating effect is poor, and it is thick to be easy to generate the metallographic structure of foundry goods endoporus, influences the serviceability of foundry goods; For strengthening cooling; At endoporus chill is set, improves the endoporus metallographic structure, but this has increased the complexity of operation; It is high to make large tube-like mud core production cost, complicated operation, and production efficiency is low.

Summary of the invention

The objective of the invention is to overcome the deficiency that above-mentioned existing production method exists, the method that provides a kind of steel pipe mud core arbor and mud core thereof to make adopts steel pipe as mud core arbor; Steel pipe is placed on the center of core box, puts sand molding, will be after the sand mold sclerosis through the lifting eye of steel pipe reservation; The mud core is hung out from core box, reduce production costs, simplify the operation; Guarantee mud core quality, enhance productivity.

Technical solution of the present invention is following:

A kind of steel pipe mud core arbor, its characteristics are the height of the height of this steel pipe greater than the mud core, make the lifting eye that is positioned at steel pipe top expose the mud core, the diameter of steel pipe is provided with a plurality of equally distributed bar shaped passages less than the diameter of mud core on described steel pipe.

Every row is provided with four described bar shaped passages on described steel pipe, and two in the ranks are staggered.

Said two row's spacings are 300～350mm.

The wall thickness of steel pipe is 20 ~ 30mm.

A kind of mud core preparation method is characterized in that this method comprises the steps:

1. steel pipe mud core arbor according to claim 1 is prepared steel pipe;

2. core box is placed on the bumper;

3. described steel pipe is put into core box;

4. toward the interior filling self-hardening resin sand of core box, the vibrations of sand limit, fully consolidation are put in the limit;

5. resin sand sclerosis, the mud core is shaped;

6. open core box, hang out the mud core, the mud core completes.

Compared with prior art, the present invention uses steel pipe to make the mud core as large tube-like mud core arbor, has the following advantages:

1) recycling rate of waterused is high;

2) mud core good permeability;

3) select for use the steel pipe of different-diameter to control mud core mold thickness, reduce the molding sand use amount;

4) improve mud core heat dispersion, improve the endoporus metallographic structure;

5) do not use vent material, chill, easy and simple to handle, production efficiency is high.

Description of drawings

Fig. 1 is the structural representation of steel pipe mud core arbor of the present invention.

Fig. 2 is the structural representation of mud core.

The specific embodiment

Below in conjunction with accompanying drawing and embodiment the present invention is described further, but should limit protection scope of the present invention with this.

Please consult Fig. 1 earlier, Fig. 1 is the structural representation of steel pipe mud core arbor of the present invention, and is as shown in the figure; A kind of steel pipe mud core arbor, the selection standard steel pipe is processed into; The height of steel pipe is greater than the height of mud core; Make the lifting eye 1 that is positioned at steel pipe top expose the mud core, the diameter of steel pipe is provided with a plurality of equally distributed bar shaped passages 2 less than the diameter of mud core on described steel pipe.

In the present embodiment:

1) steel pipe height H=mud core height+(200～250) mm;

2) diameter of steel tube=mud core diameter-(200～300) mm;

3) lifting eye diameter=(50～70) mm;

4) wall thickness d=(20～30) mm;

5) bar shaped passage size: (130～150) * (15～25) mm, 4 of every rows, two row's spacings are 300～350mm, are staggered, row's number is (H/500-1) round numbers.

When the big marine diesel engine cylinder jacket was produced, according to technological requirement, every cylinder sleeve need be made a bobbin mud core, mud core diameter (450～900) mm, highly (3000～5000) mm.Manufacturing process may further comprise the steps (the mud cored structure is referring to Fig. 2):

1) prepare steel pipe, steel pipe length guarantees that greater than mud core height lifting eye exposes the mud core.

2) core box is placed on the bumper.

3) steel pipe is put into core box.

4) filling self-hardening resin sand in the core box, limit are put the vibrations of sand limit, fully consolidation.

5) resin sand sclerosis, the mud core is shaped.

6) open core box, hang out the mud core, the mud core completes.

7) change next procedure (coating, join case etc.) over to.

Experiment shows that the large-scale bobbin mud core that adopts the inventive method to make can be controlled mud core mold thickness according to demand, reduces the sand consumption, and production process is simple, and is easy to operate, and production efficiency is high, and is with short production cycle, reduces chill simultaneously and uses, and has reduced production cost.

Claims (5)

1. a steel pipe mud core arbor is characterized in that, the height of this steel pipe makes the lifting eye that is positioned at steel pipe top expose the mud core greater than the height of mud core, and the diameter of steel pipe is provided with a plurality of equally distributed bar shaped passages less than the diameter of mud core on described steel pipe.

2. steel pipe mud core arbor according to claim 1 is characterized in that every row is provided with four described bar shaped passages on described steel pipe, and two in the ranks are staggered.

3. steel pipe mud core arbor according to claim 2 is characterized in that, said two row's spacings are 300～350mm.

4. steel pipe mud core arbor according to claim 1 and 2 is characterized in that the wall thickness of described steel pipe is 20 ~ 30mm.

5. a mud core preparation method is characterized in that this method comprises the steps:

1. steel pipe mud core arbor according to claim 1 is prepared steel pipe;

2. core box is placed on the bumper;

3. described steel pipe is put into core box;

4. toward the interior filling self-hardening resin sand of core box, the vibrations of sand limit, fully consolidation are put in the limit;

5. resin sand sclerosis, the mud core is shaped;

6. open core box, hang out the mud core, the mud core completes.

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