CN115889699A

CN115889699A - Pouring system for large excavator counterweight casting

Info

Publication number: CN115889699A
Application number: CN202211682717.XA
Authority: CN
Inventors: 闫旭; 赵松松; 牛晓琦; 张�杰; 王渊
Original assignee: Shanxi Huaxiang Group Co ltd
Current assignee: Shanxi Huaxiang Group Co ltd
Priority date: 2022-12-27
Filing date: 2022-12-27
Publication date: 2023-04-04

Abstract

A large excavator leveling heavy casting gating system having a rectangular runner disposed around a periphery of a casting cavity, the rectangular runner comprising: the casting mold comprises a horizontal pouring gate, an inner pouring gate and auxiliary pouring gates, wherein the horizontal pouring gate is arranged at a clamping groove on one side of a casting cavity in an overhead manner; the sprue is arranged on the cross runner and communicated with the sprue cup; two leading-out risers are respectively arranged on two wings of each side of a casting cavity, an auxiliary exhaust riser is additionally arranged between the two leading-out risers, and the bottoms of the three risers are connected to form a connecting lacing wire. The invention can solve the problems that the conventional V method for casting the counterweight casting of the large excavator is not easy to fully cast and feeding, and can greatly reduce the problems of the defective products such as product external dimension deformation, surface box expansion, casting bending and the like.

Description

Pouring system for large excavator counterweight casting

Technical Field

The invention belongs to the technical field of casting, and particularly relates to a pouring system for a large excavator counterweight casting.

Background

When a large excavator counterweight casting with a complex structure is produced by using a V-method process, because the casting is generally U-shaped, a die process is designed according to a traditional die-splitting mode, the casting is often designed into a bottom pouring type pouring system, the static pressure height of the pouring system is 1145mm, and under the action of the static pressure of molten iron, dislocation is easily generated among sand grains to move a mould wall, so that the size of a product is deformed, and the weight deviation is large; and the existing pouring structure is not easy to be fully poured, not easy to be fed and low in yield. Meanwhile, the wall thickness of the excavator balance weight casting is uneven, the shape is complex, the structure with the four ends extending out of the body is easy to deform, the existing pouring system is lack of a deformation prevention measure, the produced casting is easy to have the defects of product outer dimension deformation, surface expansion box, casting bending and the like, so that a large number of castings need to be repaired or even scrapped in the later period, and the production efficiency is low.

Disclosure of Invention

In view of the above problems, the technical problem to be solved by the present invention is to provide a pouring system for a counterweight casting of a large excavator, which solves the problems that the pouring system for the counterweight casting of the large excavator by the conventional V method is not easy to be fully poured and not easy to be fed, and at the same time, greatly reduces the problem of defective products in the aspect of casting deformation, and improves the yield.

According to the technical scheme, the invention provides a leveling and recasting casting pouring system of a large excavator, which comprises a pouring unit: a rectangular runner disposed around a periphery of the casting cavity, the rectangular runner comprising: the device comprises a cross gate arranged at a clamping groove at one side of a casting cavity in an overhead manner, ingates communicated with two sides of the cross gate, and auxiliary gates arranged in the middle of two wings of the casting cavity and at the clamping groove at the other side of the casting cavity; a feeding unit: the sprue is arranged on the cross gate and communicated with the pouring cup; a feeding unit: two leading-out risers are respectively arranged on two wings of each side of a casting cavity, an auxiliary exhaust riser is additionally arranged between the two leading-out risers, and the bottoms of the three risers are connected to form a connecting lacing wire.

Further, the height of the sprue is 597mm.

Further, the cross-sectional area ratio of the sprue, the cross runner and the ingate is S-straight: s horizontal: s intra =1.0: 1.4-1.6: 1.08 to 1.10.

Furthermore, the ingate adopts a thick sheet shape, the thickness is 70mm, the width is 100mm, and the ingate is horizontally introduced in the same direction.

Further, a screen system is provided on the runner.

Further, the filter screen system adopts a 120mm 20mm foamed ceramic filter screen.

Furthermore, the feeding unit further comprises a direct air-out type riser arranged at the middle convex position of the casting cavity.

Furthermore, the rectangular pouring gate is arranged close to the sand tire around the casting cavity.

Compared with the prior art, the invention has the following beneficial technical effects:

1. the sprue in the conventional bottom pouring type pouring system is changed into a detachable type, a top pouring type pouring system is formed, and the pouring gate unit plays a role of reinforcing ribs after being solidified, so that the deformation of a product is effectively reduced; the static pressure of the product for pouring can be reduced, so that the pouring temperature gradient is more reasonable, feeding is easy, and the process yield is further increased.

2. The riser parts in the conventional pouring system are changed to the two wings of the casting, so that the subsequent cleaning process is facilitated, and meanwhile, the bottoms of the risers are connected in series to form outer side tie bars, so that the tension on the two sides of the casting is restrained, and the deformation tendency is reduced; and the inner pouring channels are arranged at the two sides of the casting, so that the functions of the pouring channels and the lacing wires can be realized, and the inward bending deformation of the two wings is reduced.

3. The pouring system is suitable for casting of excavator castings with thin walls, complex shapes and large sizes, can overcome the defects of box expansion, deformation, overweight and the like of the castings, can improve the product percent of pass to more than 95 percent, can save the finishing, repairing and polishing operation time, and improves the production efficiency.

Drawings

FIG. 1: the invention discloses a structural schematic diagram of an embodiment of a pouring system for a counterweight casting of a large excavator.

FIG. 2: the partial structure of the embodiment shown in fig. 1 is disassembled schematically.

Detailed Description

As shown in fig. 1, which is an embodiment of the pouring system for the counterweight casting of the large excavator, the pouring system mainly comprises a feeding unit, a pouring unit and a feeding unit, wherein the pouring unit comprises a rectangular pouring gate which is arranged around the periphery of a casting cavity in a circle, the rectangular pouring gate comprises a cross gate 1 arranged at a clamping groove at one side of the casting cavity 10, ingates 2 communicated with two sides of the cross gate 1, and auxiliary pouring gates 3 arranged between two wings of the casting cavity 10 and at a clamping groove at the other side of the casting cavity 10; the feeding unit comprises a sprue 4 and a pouring cup, the sprue 4 is arranged on the runner 1, and the sprue 4 is communicated with the pouring cup (not shown in the figure). According to the invention, the pouring gate is arranged at the top, so that a top pouring type pouring system is formed, the gap between the pouring gate and the casting cavity is increased, the risk of sand mold deformation caused by the reduction of sand mold hardness during pouring is reduced, and the capability of the pouring system for resisting iron liquid scouring is improved.

On the other hand, compared with the conventional pouring system in which the sprue and the runner are fixed in the sand mold, the gate runner and the runner cannot play a role of a tie bar due to distribution conditions and connection characteristics. The sprue and the runner are arranged at the clamping groove of the casting cavity and are arranged in an overhead manner, so that after the sand mold is finished, the sprue and the runner can be directly taken out along with the sand mold and directly taken out from the side, and as shown in figure 2, the sprue and the runner in a detachable manner are formed. Meanwhile, the sprue 4, the cross runner 1 and the ingate 2 which are arranged around the periphery of the casting cavity are combined to form an integral lacing bar, so that the stress on two sides of a casting product can be reduced, and particularly the ingates arranged at two wings of the casting can reduce the probability of inward bending deformation of the two wings.

In addition, the height of the sprue 4 is set to be 597mm in the embodiment, namely the height of the upper sand mold is obviously shortened, compared with a traditional pouring system, the static pressure of molten iron is obviously reduced, the condition that the pouring is firstly carried out and the cooling is carried out is ensured, and the deformation of the sand mold caused by the reduction of the hardness of the sand mold during the pouring is eliminated.

A filter screen system can be arranged on the transverse pouring gate 1, and a 120mm 20mm foamed ceramic filter screen is selected in the embodiment, so that impurities in the molten metal can be effectively removed or reduced, the purity of the molten metal is improved, the surface of a cast product obtained by melting is smooth, the structure is uniform, the strength is improved, and slag pores of the cast product are reduced.

Molten iron is through filter screen system back, along 1 reentrant ingate 2 of horizontal runner, and ingate 2 hugs closely the sand child (not shown in the figure) and arranges, and ingate 2 can adopt the thick slice form, if: the thickness is 70mm, the width is 100mm, the horizontal introduction mode in the same direction is convenient for molten iron to enter the casting cavity 10 more quickly, and meanwhile, the auxiliary pouring gate 3 arranged between two wings of the casting cavity 10 can also increase the mold filling speed.

As shown in the figure, the feeding unit in this embodiment includes: two leading-out type risers 51 are respectively arranged on two wings of each side of the casting cavity 10, and the bottoms of the two risers are connected so as to discharge gas separated out from the cavity and molten metal and scum which are filled in the cavity firstly. An auxiliary exhaust riser 52 is additionally arranged between the two leading-out risers 51 to exhaust gas generated after molten iron convection, so that the blasting phenomenon caused by incapability of discharging the molten iron out of the cavity is avoided. Meanwhile, the bottoms of the three risers are connected to form a connecting tie bar, so that the effects of restraining the tension of two sides of a casting and reducing the deformation tendency can be achieved.

In this embodiment, 2 direct degassing risers 53 are further provided at the middle convex position of the casting cavity 10 to degas the gas generated inside the cavity.

Compared with the original pouring system, the invention also sets the cross section area ratio of the sprue, the cross sprue and the ingate as S is straight: s horizontal: s intra =1.0:1.4 to 1.6:1.08 to 1.10, so that molten metal can enter in a full flow manner in the whole filling and parting process and enters a sequential solidification state, and the molten iron is ensured to be solidified firstly at a part far away from a riser and then at a part close to the riser when filling and shunting, and the riser is solidified finally.

Claims

1. The utility model provides a large-scale machine of digging levels heavy casting gating system which characterized in that includes:

a pouring unit: a rectangular runner disposed around a periphery of the casting cavity, the rectangular runner comprising: the device comprises a cross gate arranged at a clamping groove at one side of a casting cavity in an overhead manner, ingates communicated with two sides of the cross gate, and auxiliary gates arranged in the middle of two wings of the casting cavity and at the clamping groove at the other side of the casting cavity;

a feeding unit: the sprue is arranged on the cross gate and communicated with the pouring cup;

a feeding unit: two leading-out risers are respectively arranged on two wings of each side of a casting cavity, an auxiliary exhaust riser is additionally arranged between the two leading-out risers, and the bottoms of the three risers are connected to form a connecting lacing wire.

2. The large excavator flat and heavy casting gating system of claim 1, wherein the sprue is 597mm in height.

3. The large excavator flat recast gating system of claim 1, wherein the cross sectional area ratio of the sprue, runner and ingate is S-straight: s horizontal: s intra =1.0: 1.4-1.6: 1.08 to 1.10.

4. The large excavator flat recast gating system of claim 3, wherein the ingate is in the form of a thick plate with a thickness of 70mm and a width of 100mm and is introduced horizontally in the same direction.

5. A large excavator flat and heavy casting gating system as claimed in claim 1, wherein a screen system is provided on the runner.

6. The large excavator flat and heavy casting gating system of claim 5, wherein the strainer system employs a 120mm by 20mm ceramic foam strainer.

7. The large excavator leveling recast gating system of claim 1, wherein the feeding unit further comprises: and a direct air outlet type riser is arranged at the middle convex position of the casting cavity.

8. The large excavator flat and heavy casting gating system of claim 1, wherein the rectangular runners are positioned adjacent to sand tires around the casting cavity.