CN218080350U - Hollow sand core with inner runner for gold sand type low-pressure casting aluminum shell - Google Patents

Abstract

The utility model belongs to the technical field of sand cores, and relates to an in-band pouring gate hollow sand core for a gold sand type low pressure casting aluminum shell, which comprises a 3D printing sand core shell, wherein one side of the sand core shell is integrally connected with a flange, and a main pouring gate and a branch pouring gate are arranged in the sand core shell; the main pouring gate comprises a longitudinal main pouring gate arranged along the vertical direction and a transverse main pouring gate arranged along the horizontal direction, the bottom of the longitudinal main pouring gate is a liquid flow inlet, and the transverse main pouring gate is arranged perpendicular to the longitudinal main pouring gate; the branch pouring gate comprises a plurality of horizontal pouring gates arranged along the horizontal direction, an oblique branch pouring gate arranged on one side of the longitudinal main pouring gate and a longitudinal branch pouring gate arranged on one side of the transverse main pouring gate; the horizontal pouring gate is communicated with the longitudinal main pouring gate; the transverse main pouring gate is positioned on one side of the shell with the flange, and the longitudinal branch pouring gate is arranged in the flange; seal heads are arranged at the top end and the bottom end of the sand core shell, and exhaust channels are formed in the seal heads. Solves the problems of sand core collapsibility, poor air permeability and difficult cleaning of castings.

Description

Hollow sand core with inner runner for gold sand type low-pressure casting aluminum shell

Technical Field

The utility model belongs to the technical field of the psammitolite, concretely relates to gold sand type low pressure casting aluminium casing is with hollow psammitolite of in-band pouring gate.

Background

The high-voltage switch cast aluminum shell bears 0.5-0.8MPa of insulating gas pressure for a long time, and parts are required to have excellent tissue compactness and higher mechanical properties. In order to realize effective feeding of castings with complex structures, a pouring system is usually arranged in a sand core and bears the pressure maintaining crystallization and solidification pressure of 0.05-0.12MPa, and manual solid core sand cores and cold core shooting half-core combined sand cores of furan resin sand are usually adopted for casting sand cores.

The defects and shortcomings of the prior art:

(A) In order to form the integral solid sand core with the inner pouring gate, the manual solid sand core of furan resin sand needs to draw out a pouring gate pattern outwards to form the pouring gate with the size gradually increased from the center of the sand core to the surface of the sand core, and the feeding requirement of an ideal pouring system is just opposite to the feeding requirement of the casting system to form the defect of shrinkage porosity at the joint of the pouring gate and a casting; meanwhile, the casting temperature of the aluminum alloy is low, the sand core is solid, the sand core cannot be burnt through, the sand core has poor collapsibility, difficult sand falling and poor air permeability, and not only is the cleaning efficiency low, but also the surface damage of the casting and the waste generation of holes are easily caused.

(B) The half-core combined sand core for cold core sand shooting can only adopt the sand core to form a sand core ingate by two half combined structures during core making, and for an assembly surface, because the mold is filled under the pressure of low-pressure casting, molten metal often overflows from the combined surface, the instability of the pouring process is caused, the qualified rate of castings is lower, the labor intensity of casting cleaning and polishing is large, and the waste of materials is avoided.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a gold sand type low pressure casting aluminium casing is with hollow psammitolite of in-band pouring channel has solved the problem that psammitolite collapsibility, gas permeability are poor and the difficult clearance of foundry goods.

The utility model discloses a realize through following technical scheme:

a hollow sand core with an inner pouring gate for a gold sand type low-pressure casting aluminum shell comprises a sand core shell which is manufactured by 3D printing, wherein one side of the sand core shell is integrally connected with a flange, and a main pouring gate and a branch pouring gate are arranged in the sand core shell;

the main pouring channels comprise a longitudinal main pouring channel distributed along the vertical direction and a transverse main pouring channel distributed along the horizontal direction, the bottom of the longitudinal main pouring channel is a liquid flow inlet, and the transverse main pouring channel is vertical to the longitudinal main pouring channel;

the branch pouring gate comprises a plurality of horizontal pouring gates arranged along the horizontal direction, an oblique branch pouring gate arranged on one side of the longitudinal main pouring gate and a longitudinal branch pouring gate arranged on one side of the transverse main pouring gate; the horizontal pouring gate is communicated with the longitudinal main pouring gate;

the transverse main pouring gate is positioned on one side of the shell with the flange, and the longitudinal branch pouring gate is arranged in the flange;

seal heads are arranged at the top end and the bottom end of the sand core shell, and exhaust channels are formed in the seal heads.

Furthermore, the inclined branch pouring channels are arranged in an upward inclined mode according to the structure position of the casting.

Furthermore, the outlet end of the branch pouring channel is prefabricated into a shrinkage cavity.

Furthermore, a weight-reducing cavity is formed in a solid area formed by the branch pouring channel and the main pouring channel.

Further, the horizontal pouring channels comprise a first horizontal branch pouring channel, a second horizontal branch pouring channel, a third horizontal branch pouring channel and a fourth horizontal branch pouring channel which are sequentially arranged in parallel from bottom to top;

the first horizontal branch pouring channel, the second horizontal branch pouring channel and the third horizontal branch pouring channel are positioned below the transverse main pouring channel, and the fourth horizontal branch pouring channel is positioned at the top end of the shell.

Furthermore, the first horizontal branch pouring channel, the second horizontal branch pouring channel and the fourth horizontal branch pouring channel are hole bodies penetrating through the thickness of the shell in the horizontal direction, and the inclined branch pouring channel and the third horizontal branch pouring channel are arranged in the shell far away from one side of the flange.

Furthermore, a weight reducing cavity is formed in a solid area formed by the second horizontal branch pouring gate, the transverse main pouring gate and the longitudinal main pouring gate, and a reinforcing column is arranged in the weight reducing cavity.

Furthermore, a weight reducing cavity is formed in a solid area formed by the fourth horizontal branch pouring gate, the transverse main pouring gate and the longitudinal main pouring gate, and a reinforcing column is arranged in the weight reducing cavity.

Further, the diameter of the main pouring channel is recorded as phi a3, the diameter of the branch pouring channel is recorded as phi a2, and the diameter of the outlet end of the branch pouring channel is recorded as phi a1;

wherein Φ a3=4-5 δ, Φ a2=2-3 δ, Φ a1=1.25-1.5 δ, and δ is the structural wall thickness of the connecting part of the aluminum shell casting and the pouring channel.

Furthermore, an annular sealing stop belt is arranged at the core head part of the sand core shell.

Compared with the prior art, the utility model discloses following profitable technological effect has:

the utility model discloses a gold sand type low pressure casting aluminium casing is with hollow psammitolite of in-band pouring channel, psammitolite casing adopt the whole psammitolite of taking hollow structure, have realized improving at low pressure casting psammitolite collapsibility, and shakeout efficiency improves more than 50%. When the sand core is cleaned, the sand core is easy to break into small blocks only by short-time vibration or impact, and the sand falling efficiency is improved. The horizontal pouring channels comprise a first horizontal branch pouring channel, a second horizontal branch pouring channel, a third horizontal branch pouring channel and a fourth horizontal branch pouring channel which are sequentially arranged in parallel from bottom to top; the first horizontal branch pouring gate, the second horizontal branch pouring gate and the third horizontal branch pouring gate are positioned below the transverse main pouring gate, and the fourth horizontal branch pouring gate is positioned at the top end of the shell, so that sequential mold filling pouring and remote solidification feeding of complex castings from bottom to top are realized. And the 3D sand core printing technology is adopted to realize the automatic production of the gold sand type low-pressure casting complex sand core with the pressure requirement.

Further, the utility model discloses an inside most region of psammitolite has both satisfied low pressure casting pressure for subtracting heavy cavity structure, has realized lightening psammitolite weight again, and the saving is with sand volume 40% -70%, has the cast characteristics of green. An exhaust system inside the sand core is formed through the weight reduction cavity, so that the air permeability of the sand core is improved, the weight of the sand core is reduced, the probability of defects of air holes and shrinkage porosity is reduced, and the defect of shrinkage cavities and shrinkage porosity is reduced.

Furthermore, the outlets of the branch pouring channels are all necking, so that the feeding effect of the branch pouring channels on the castings is guaranteed, structural hot spots formed by the branch pouring channels and the castings are reduced, and the shrinkage porosity and shrinkage cavity tendency of the connecting parts of the branch pouring channels and the castings is reduced.

Furthermore, a seal head seat with an exhaust passage is arranged at the end head of the sand core head, when external molten metal is applied with pressure from the outside, the self-sealing of the sand core seal head along the pressure direction is realized, and meanwhile, the sand core seal head can be communicated with the weight reduction cavity to ensure the smoothness of the exhaust passage.

Furthermore, an annular sealing stop band is arranged at the head of the sand core, so that the phenomenon that the ventilation of the core head is not smooth due to the fact that molten metal is removed to seep out to wrap the core head is prevented.

Drawings

Fig. 1 is a solid view of the runner section structure of the in-band pouring gate hollow sand core for a gold sand type low pressure casting aluminum shell of the present invention;

FIG. 2 isbase:Sub>A cross-sectional view A-A of FIG. 1;

the casting mold comprises a core shell, a positioning surface, a longitudinal main pouring gate, a transverse main pouring gate, a first horizontal branch pouring gate, a second horizontal branch pouring gate, a third horizontal branch pouring gate, a slant branch pouring gate, a fourth horizontal branch pouring gate, a longitudinal branch pouring gate, a seal head, an exhaust passage and an annular sealing stop belt, wherein the core shell is 1, the core shell is 2, the shrinkage cavity is 3, the reinforcing column is 4, the positioning surface is 5, the longitudinal main pouring gate is 6, the transverse main pouring gate is 7, the first horizontal branch pouring gate is 8, the second horizontal branch pouring gate is 9, the third horizontal branch pouring gate is 10, the slant branch pouring gate is 11, the fourth horizontal branch pouring gate is 12, the longitudinal branch pouring gate is 13, the seal head is 14, the exhaust passage is 15, and the annular sealing stop belt is 16.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clear, the following detailed description is made with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention, i.e., the described embodiments are only some, but not all, of the embodiments of the present invention.

The components described and illustrated in the drawings and embodiments of the present invention may be arranged and designed in a wide variety of different configurations, and accordingly, the detailed description of the embodiments of the present invention provided in the drawings below is not intended to limit the scope of the claimed invention, but is merely representative of selected embodiments of the present invention. Based on the drawings and embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts belong to the protection scope of the present invention.

It should be noted that: the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, element, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, element, method, article, or apparatus. Furthermore, the terms "horizontal" and "vertical" are based on the orientation and positional relationship of the devices or components shown in the drawings and are only used for better describing the present invention, but do not require that the devices, components or equipment shown must have this particular orientation, and therefore should not be construed as limiting the present invention.

The features and properties of the present invention are further described in detail below with reference to examples.

As shown in fig. 1-2, the utility model provides an in-band pouring gate hollow sand core for a gold sand type low pressure casting aluminum shell, which comprises a shell sand core which is made by 3D printing and contains a lightening cavity 1, wherein one side of the shell sand core is integrally connected with a flange, and a main pouring gate and a branch pouring gate are arranged in the shell sand core; the main pouring channels comprise longitudinal main pouring channels 6 distributed along the vertical direction and transverse main pouring channels 7 distributed along the horizontal direction, the bottoms of the longitudinal main pouring channels 6 are liquid flow inlets, and the transverse main pouring channels 7 are perpendicular to the longitudinal main pouring channels 6; the branch pouring channels comprise a plurality of horizontal pouring channels distributed along the horizontal direction, an oblique branch pouring channel 11 arranged at one side of the longitudinal main pouring channel 6 and a longitudinal branch pouring channel 13 arranged at one side of the transverse main pouring channel 7; the horizontal pouring gate is communicated with the longitudinal main pouring gate 6; the transverse main pouring gate 7 is positioned on one side of the sand core of the shell with the flange, and the longitudinal branch pouring gate 13 is arranged in the flange; the top end and the bottom end of the shell sand core are both provided with end sockets 14, and the end sockets 14 are provided with exhaust channels 15.

The sand core is matched with a metal mold low-pressure casting mold for use, and the lower core head positioning surface 5 of the sand core and a gold sand mold low-pressure casting lower mold are positioned and arranged on the lower mold, so that aluminum liquid is sequentially filled in a casting system in the sand core and is cast under pressure. The method avoids the problems of large gas evolution, sand core cracking and sand shakeout difficulty of the traditional solid sand core, and improves the surface quality and the sand shakeout collapsibility of the inner cavity of the aluminum casting.

The method comprises the steps of designing and arranging a pouring system of a sand core according to the wall thickness delta (mm) of a cast aluminum shell structure and a low-pressure casting riser tube, wherein the pouring system in the low-pressure casting sand core of the golden sand type comprises a main pouring gate and a branch pouring gate with a neck, and the riser tube of the low-pressure casting machine is communicated with a metal mold cavity to form a liquid flow direction and a feeding channel from bottom to top, so that the effective pressure transmission required by feeding of a hot spot part is met.

The outlet end of the branch pouring channel is prefabricated into a shrinkage cavity 3, the diameter of the shrinkage cavity 3 is recorded as phi a1, phi a1=1.25-1.5 delta (mm), the diameter of the branch pouring channel is recorded as phi a2, phi a2=2-3 delta (mm), and the diameter of the main pouring channel is recorded as phi a3=3.5-4.5 delta (mm).

The wall thickness of the hollow sand core shell 2 is positively correlated with the low-pressure casting pressure maintaining pressure P (MPa), and the wall thickness B =300 XP (mm) of the sand core shell 2 contacted with the molten metal.

An annular sealing stop belt 16 is arranged at the head of the sand core, so that the phenomenon that the ventilation of the core head is not smooth due to the fact that molten metal seeps out of the wrapped core head is prevented.

The method is characterized in that an exhaust passage 15 in a sand core passage is formed by a hollow part of a sand core, a head socket 14 is arranged at the end head of the sand core, the exhaust passage 15 is arranged on the head socket 14, the diameter phi e of the exhaust passage 15 is =5mm, when the head socket 14 with holes is arranged on the main sand core and external metal liquid is applied from the outside, the self-sealing of the sand core head 14 along the pressure direction is realized, and meanwhile, the exhaust passage 15 is ensured to be smooth.

The inclined branch pouring gate 11 is arranged in an upward inclined mode, and feeding of the thick and large structure position of the aluminum shell casting is guaranteed.

And a weight-reducing cavity 1 is formed in a solid area formed by the branch pouring channel and the main pouring channel.

As shown in fig. 1, the horizontal runners comprise a first horizontal branch runner 8, a second horizontal branch runner 9, a third horizontal branch runner 10 and a fourth horizontal branch runner 12 which are arranged in parallel from bottom to top; a first horizontal branch runner 8, a second horizontal branch runner 9, a third horizontal branch runner 10 are located below the transverse main runner 7, and a fourth horizontal branch runner 12 is located at the top end of the shell. Realizing sequential mold filling and pouring of the complex casting from bottom to top and remote solidification and feeding.

The first horizontal branch pouring gate 8, the second horizontal branch pouring gate 9 and the fourth horizontal branch pouring gate 12 are hole bodies penetrating through the thickness of the shell in the horizontal direction, and the inclined branch pouring gate 11 and the third horizontal branch pouring gate 10 are arranged in the shell on the side far away from the flange.

When the size of the sand core cavity is larger than 400mm, a sand core reinforcing column 4 is additionally arranged in the direction vertical to the size, the diameter phi B of the sand core reinforcing column 4 is =0.6-0.8B (mm), and the local structure of the sand core is reinforced.

Specifically, a weight-reducing cavity 1 is formed in a solid area formed by the second horizontal branch pouring gate 9, the transverse main pouring gate 7 and the longitudinal main pouring gate 6, and a reinforcing column 4 is arranged between the weight-reducing cavities 1;

and a weight reducing cavity 1 is formed in a solid area formed by the fourth horizontal branch pouring gate 12, the transverse main pouring gate 7 and the longitudinal main pouring gate 6, and a reinforcing column 4 is arranged between the weight reducing cavities 1.

By three-dimensional modeling and slicing technology, the automatic resin sand spreading of the main sand core and the sand core end socket 14 is completed by adopting 3DP printing technology, and the hardening agent is printed by ink jet on the solid part to form a sand core with the internal molding sand hardened and the local unhardened partThe sand core structure of (1). The unhardened part of the molding sand inside the sand core is provided with a sand discharge port close to the end part of the core head, the molding sand of the unhardened part is removed from the sand discharge port to form a cavity structure of the main sand core, a pouring system and a sand core seal head 14 with holes, a conical seal head 14 is arranged at the air passage part of the end part of the cavity structure core head of the sand core, and the seal head 14 is formed

And when external molten metal is applied from the outside, the air outlet realizes self-sealing of the sand core seal head 14 along the pressure direction, and meanwhile, the smoothness of the scheduling channel can be ensured.

The sand core uses quartz sand with the granularity of 40-70 meshes, furan resin binder accounts for 2 percent of the sand amount, hardener accounts for 30 percent of the resin amount, and the printing layer has the thickness of 0.3-0.5mm, and the bonding and hardening of the sand core material are carried out by adopting an ink-jet printing hardener way, so as to reach the gas forming amount of the sand core less than or equal to 14ml/g, the compressive strength of 1.5-2.0MPa and the high temperature resistance of 750 ℃. The low-pressure casting pressure of 0.12MPa can be borne. The problems of complex casting process and poor quality stability of the conventional sand mould and sand core are solved, and the automatic production of the shell metal mould low-pressure casting sand core is realized.

During pouring, molten metal enters a main pouring gate in the sand core from a heat preservation furnace through a feed inlet of a metal mold die through a riser pipe under the action of pressure, then sequentially enters a casting cavity formed by the sand core and a metal mold outer die through a lower pouring gate, an upper pouring gate and other branch pouring gates with necking necks, and through the stages of filling, pressurizing and pressure maintaining, the molten metal realizes the functions of sequential filling and multidirectional feeding of the molten aluminum in a stepped mode by virtue of a stepped pouring system arranged in the sand core, so that a shell type casting with compact structure is formed. In the casting process, gas generated by high temperature in the sand core is exhausted through a cavity penetrating through the sand core and an exhaust passage 15 on a seal head 14 arranged at the core head.

Finally, it should be noted that: the above embodiments are only used for illustrating the technical solutions of the present invention and not for limiting the same, and although the present invention is described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: modifications and equivalents of the embodiments of the invention may be made without departing from the spirit and scope of the invention, which should be construed as falling within the scope of the claims of the invention.

Claims (10)

1. The hollow sand core with the inner pouring gate for the gold sand type low-pressure casting aluminum shell is characterized by comprising a sand core shell (2) manufactured by 3D printing, wherein one side of the sand core shell (2) is integrally connected with a flange, and a main pouring gate and a branch pouring gate are arranged in the sand core shell (2);

the main pouring gate comprises a longitudinal main pouring gate (6) distributed along the vertical direction and a transverse main pouring gate (7) distributed along the horizontal direction, the bottom of the longitudinal main pouring gate (6) is a liquid flow inlet, and the transverse main pouring gate (7) is vertical to the longitudinal main pouring gate (6);

the branch pouring channels comprise a plurality of horizontal pouring channels distributed along the horizontal direction, an oblique branch pouring channel (11) arranged at one side of the longitudinal main pouring channel (6), and a longitudinal branch pouring channel (13) arranged at one side of the transverse main pouring channel (7); the horizontal pouring gate is communicated with the longitudinal main pouring gate (6);

the transverse main pouring gate (7) is positioned on one side of the shell with the flange, and the longitudinal branch pouring gate (13) is arranged in the flange;

seal heads (14) are arranged at the top end and the bottom end of the sand core shell (2), and exhaust channels (15) are formed in the seal heads (14).

2. The core for an ingate hollow core for a low pressure casting aluminum housing of a foundry type according to claim 1, wherein the slant branch runners (11) are provided to be inclined upward depending on the casting structure position.

3. An in-sprue hollow core for gold-type low-pressure cast aluminium housings according to claim 1 characterised in that the outlet ends of the branch runners are pre-formed as shrinkage cavities (3).

4. The hollow core with the inner runner for the gold-sand type low-pressure casting aluminum shell as claimed in claim 1, wherein the solid area formed by the branch runner and the main runner is provided with a lightening cavity (1).

5. The hollow core with the pouring channel for the gold sand type low-pressure casting aluminum shell as claimed in claim 1, wherein the horizontal pouring channel comprises a first horizontal branch pouring channel (8), a second horizontal branch pouring channel (9), a third horizontal branch pouring channel (10) and a fourth horizontal branch pouring channel (12) which are arranged in parallel from bottom to top;

the first horizontal branch pouring channel (8), the second horizontal branch pouring channel (9) and the third horizontal branch pouring channel (10) are positioned below the transverse main pouring channel (7), and the fourth horizontal branch pouring channel (12) is positioned at the top end of the shell.

6. The hollow core with the pouring gate for the low-pressure casting aluminum shell of the foundry type according to claim 1, characterized in that the first horizontal branch pouring gate (8), the second horizontal branch pouring gate (9) and the fourth horizontal branch pouring gate (12) are holes penetrating the thickness of the shell in the horizontal direction, and the oblique branch pouring gate (11) and the third horizontal branch pouring gate (10) are arranged in the shell at the side far away from the flange.

7. The hollow core with the inner runner for the gold sand type low-pressure casting aluminum shell as claimed in claim 1, wherein a weight-reducing cavity (1) is formed in a solid area formed by the second horizontal branch runner (9), the transverse main runner (7) and the longitudinal main runner (6), and the reinforcing column (4) is arranged inside the weight-reducing cavity (1).

8. The hollow core with the inner pouring channel for the gold-sand type low-pressure casting aluminum shell is characterized in that a weight-reducing cavity (1) is formed in a solid area formed by the fourth horizontal branch pouring channel (12), the transverse main pouring channel (7) and the longitudinal main pouring channel (6), and a reinforcing column (4) is arranged inside the weight-reducing cavity (1).

9. The hollow core with the inner runner for the gold sand type low-pressure casting aluminum shell as claimed in claim 1, wherein the diameter of the main runner is recorded as Φ a3, the diameter of the branch runner is recorded as Φ a2, and the diameter of the outlet end of the branch runner is recorded as Φ a1;

wherein Φ a3=4-5 δ, Φ a2=2-3 δ, Φ a1=1.25-1.5 δ, and δ is the structural wall thickness of the connecting part of the aluminum shell casting and the pouring channel.

10. An in-band-sprue hollow core for gold-sand type low-pressure cast aluminium casings, according to claim 1, characterised in that an annular sealing spigot band (16) is provided at the core head portion of the core casing (2).

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