CN114682765A

CN114682765A - Low-pressure casting die for aluminum gear chamber

Info

Publication number: CN114682765A
Application number: CN202011585855.7A
Authority: CN
Inventors: 刘海军
Original assignee: Xinxing Heavy Industry Hubei 3611 Mechanical Co Ltd
Current assignee: Xinxing Heavy Industry Hubei 3611 Mechanical Co Ltd
Priority date: 2020-12-29
Filing date: 2020-12-29
Publication date: 2022-07-01

Abstract

The utility model provides an aluminium gear room low pressure casting mould, including the metal type mould that mould and lower mould are constituteed, gear cavity psammitolite, go up the last die cavity of mould, metal type model cavity is constituteed to the lower die cavity of lower mould, gear cavity psammitolite upper portion is arranged in the lower die cavity of lower mould, form the foundry goods die cavity between gear cavity psammitolite upper portion surface and the last die cavity surface of last mould, two sets of gating systems are connected with the foundry goods die cavity, the gating system includes the sprue, the cross gate includes horizontal cross gate section, perpendicular cross gate section one end is connected with horizontal cross gate section inner, perpendicular cross gate section other end and gear feeding runner, gear feeding runner is connected with the die cavity department that is located the middle distal end of foundry goods die cavity and is used for forming gear cavity boss. The mold integrally meets the casting solidification temperature field gradient, the casting can be prevented from being retained on the lower mold, the deformation is reduced, the feeding coverage of the pouring system is wide, and the feeding effect is good.

Description

Low-pressure casting die for aluminum gear chamber

Technical Field

The invention relates to an aluminum gear chamber casting mold, and belongs to the field of casting equipment.

Background

The gear chamber is used as one of key parts of an automobile engine, is arranged between a cylinder body and a flywheel shell, is externally connected with a cylinder cover, a starter and an oil pan, is internally provided with a gear assembly, and plays a role in connecting a machine body and a carrier. The gear chamber is generally divided into gray iron or aluminum alloy, but the aluminum alloy is lighter in weight and more suitable for the development requirement of light weight, so the market demand is more and more increased. Along with the continuous improvement of the design and integration of the engine, the aluminum gear chamber has a complex shape, a large size and a concave structure, and belongs to a large aluminum alloy thin-wall part. At present, the concave aluminum gear chamber is generally manufactured by a gravity casting process, but the convex plate of the inner cavity of the gear has large thermal section, poor feeding effect, more product shrinkage porosity, low yield of aluminum liquid and serious generation of oxide slag.

Disclosure of Invention

The invention aims to provide an aluminum gear chamber low-pressure casting die which meets the requirements of higher strength and rigidity and complex shape.

In order to achieve the above purpose, the technical solution of the present invention is: the casting device comprises a metal mold formed by an upper mold and a lower mold, and a gear cavity sand core located in a metal mold cavity, wherein an upper cavity of the upper mold and a lower cavity of the lower mold form the metal mold cavity, the upper part of the gear cavity sand core is arranged in the lower cavity of the lower mold, a casting cavity is formed between the surface of the upper part of the gear cavity sand core and the surface of the upper cavity of the upper mold, two sets of casting systems are connected with the casting cavity, each casting system comprises a sprue and a cross runner, the cross runner comprises a horizontal cross runner section and a vertical cross runner section, the horizontal cross runner section and the vertical cross runner section are in lap joint with the end surface of the casting cavity, one end of the vertical cross runner section is connected with the inner end of the horizontal cross runner section, the other end of the vertical cross runner section is connected with a gear feeding runner, and the gear feeding runner is connected with the cavity, which is located at the middle far end of the casting cavity and is used for forming a boss of the gear cavity.

The sprue consists of a middle sprue positioned at the bottom of the sand core of the gear cavity and a lower sprue positioned on the lower die, a sprue pit is arranged on the upper die corresponding to the sprue outlet, and a sprue inlet is connected with the liquid lifting pipe.

The gear feeding runner is arranged on the gear cavity sand core, a sand core positioning hole is further formed in the gear cavity sand core, the lower die is provided with a positioning pin which is matched and positioned with the sand core positioning hole, the upper die is provided with two runner nests, the outer end of the horizontal cross runner section is communicated with the side face of each middle straight runner, the upper portion of the middle straight runner is communicated with the runner nests, the lower portion of the middle straight runner is communicated with the lower portion straight runner, and the lower portion straight runner inlet is connected with the ceramic riser tube.

The casting is a gear chamber, and the lap joint length of the inner end of the horizontal cross pouring gate section and the end surface of the casting cavity exceeds the lower mounting surface hot junction of the gear chamber; the outer surface of the casting cavity after pouring forms a joint surface with the engine cylinder body, the end surface of the casting cavity after pouring forms a lower mounting surface of the gear chamber, and the lower mounting surface of the gear chamber is connected with the connecting surface of the flywheel shell.

The width L of the horizontal cross gate section is 2-3 times of the lap joint length of the inner end of the horizontal cross gate section and the end surface of the casting cavity, and the height difference H between the bottom surface of the horizontal cross gate section and the end surface of the casting cavity is at least 5 mm.

The upper die is matched with an upper die insert connected through a first screw, and a drawing block in clearance fit is arranged in the upper die insert; the drawing block is provided with a positioning flange matched with the side surface of the upper die, and the inner end of the drawing block is in a pit shape of the cylinder cover surface. The upper die insert block is convenient for die processing. If go up the mould insert and can process alone, if not design the mould insert, this mould need dig with take out the mating holes of piece, inconvenient processing of whole mould. The upper die insert is provided with a hole matched with the pulling block.

The positioning pin is arranged at the bottom of the lower cavity of the lower die.

And a filter screen is placed at the joint of the sprue and the cross gate and pressed between the sand core of the inner cavity of the gear and the lower die.

The mold integrally meets the casting solidification temperature field gradient, and can prevent the casting from being retained in the lower mold and reduce deformation. The casting system has the advantages of high yield, convenient removal of the casting system, wide feeding coverage, good feeding effect and good slag avoiding effect.

During low-pressure casting, the lower mounting surface of the gear chamber faces downwards, and two casting systems, namely double-sprue low-pressure casting, are arranged on the side edge of the cylinder cover surface and opposite to the side edge. The single gating system comprises a casting cavity, a round sprue and a square cross sprue. The square cross gate is lapped with the lower mounting surface of the gear chamber, the lapping length mainly covers the lower mounting surface hot junction, the width L of the horizontal cross gate section is 2-3 times of the end surface width of the casting cavity, and all lap hot junctions of the gear chamber can perform feeding on thick and large gear inner cavity bosses by adding feeding channels on sand cores, so that the good quality of the gear inner cavity bosses is ensured. The casting system has wide feeding coverage and good effect. The filter screen is pressed by the gear inner chamber psammitolite and can not move, and the sprue of round platform shape is big end up down, and sprue upper portion is equipped with the hemisphere shape and waters the nest, and this riser cavity can be better to aluminium liquid buffering, reduces the production of pressing from both sides the sediment. One side of the sand core of the inner cavity of the gear forms the shape of the inner cavity of the gear, and the other side of the sand core of the inner cavity of the gear is provided with a gear feeding runner communicated with the vertical cross runner section. A filter screen is arranged at the joint of the straight pouring channel and the cross pouring channel. The filter screen can be laid flat and cannot move when pressed below by the sand core, the filtering effect is 100%, and the slag avoiding effect is good. The pouring system can not generate the phenomenon of emptying the molten aluminum, can better ensure the product quality and improve the product percent of pass. The height difference H between the bottom surface of the horizontal cross pouring channel section and the lower mounting surface of the gear chamber is at least 5mm, and the pouring system is very convenient to remove. During casting production, the filter screen is firstly placed at the opening part of the circular straight pouring gate of the bottom die, then the sand core of the inner cavity of the gear is placed on the bottom die, then the metal mold is assembled, and then low-pressure casting is carried out.

Drawings

The invention will be further described in detail with reference to the embodiments provided in the drawings;

FIG. 1 is a front view of a schematic of the structure of the present invention;

FIG. 2 is a cross-sectional view of a schematic of the structure of the present invention;

FIG. 3 is a schematic view of the gating system of the present invention;

in the figure, 1, an upper die, 2, a gear cavity sand core, 3, a filter screen, 4, a ceramic riser tube, 5, a holding furnace, 6, a lower die, 7, a pouring gate nest, 8, a sprue, 9, a gear chamber casting, 10, a cross gate, 11, a gear feeding pouring gate, 12, a screw I, 13, an upper die insert, 14, a drawing block, 15, a sand core positioning hole, 16, a screw II, 17, a lower die cylindrical pin, 18, a positioning flange, 19 and a gear cavity boss.

Detailed Description

In the figures 1, 2 and 3, the invention comprises a metal mold consisting of an upper mold 1 and a lower mold 6, and a gear cavity sand core 2 positioned in a cavity of the metal mold. The lower die 6 is provided with two lower part sprues and a lower die cylindrical pin (namely a positioning pin) 17 which is matched and positioned with the sand core positioning hole 15, the lower part of the lower die cylindrical pin 17 is fixed on the lower die 6 through a second screw 16, and the inlet of the lower part sprues is connected with the ceramic riser tube 4. The lower part of the sand core of the gear cavity is provided with a middle sprue, a cross sprue 10 and a gear feeding sprue 11. The horizontal runner 10 includes a horizontal runner section and a vertical runner section, and the cross sections of the horizontal runner section and the vertical runner section are square. One surface of the gear cavity sand core 2 forms the shape of a gear cavity of a flywheel shell joint surface, and the other surface of the gear cavity sand core 2 is provided with a gear feeding runner 11 connected with a gear cavity boss 19 and a positioning hole matched with a lower die cylindrical pin 17. The upper die 1 forms the shape of an inner cavity of a cylinder body joint surface, an upper die insert 13 connected through a first screw 12 is matched with the upper die, and a drawing block 14 in clearance fit is arranged in the upper die insert 13. The drawing block 14 is provided with a positioning flange 18 matched with the side surface of the upper die 1, forms a pit shape of a cylinder cover surface and avoids gear installation. The middle part sprue at the bottom of the gear cavity sand core 2 and the lower part sprue on the lower die 6 form two sprues 8, and the sprues 8 are in a circular truncated cone shape and are large in small upper part. The upper die 1 is provided with a runner nest 7 corresponding to a lower sprue on the lower die. The area of the filter screen 3 is larger than that of the sprue 8. During operation, firstly, the filter screen 3 is laid flat and covered above two sprues 8 (pouring gates) of the lower die, then the sand core is placed on the filter screen 3 through the lower die 6 in a positioning fit mode, then the upper die 1 is closed, and the upper die 1 presses the sand core 2 of the inner cavity of the gear to prevent the sand core from running in the pouring process. Finally, the block positioning flange 18 of the block 14 is pushed to be flush with the side of the upper mold. When the casting device works, aluminum liquid in the heat preservation furnace 5 enters the sprue 8 from the ceramic liquid lifting pipe 4, the aluminum liquid enters the sprue pit 7 from the sprue 8 through the filter screen 3, then enters the cross gate 10 of the sand core 2 of the inner cavity of the gear, and enters the casting cavity from the cross gate 10 to form a casting 9 of the gear chamber. When the piece is taken out, the upper die 1 is firstly opened, the pulling block 14 is pulled out, and the pulling block is separated from the gear chamber casting 9 after being pulled out, so that the gear chamber casting 9 can be taken out.

In fig. 1, the cross runner 10 can cover the lug thermal node on the flywheel housing junction surface of the aluminum gear chamber, and the gear feeding runner 11 is arranged on the boss 19 of the inner cavity of the intermediate far-end gear and connected with the cross runner 10.

In fig. 2, the sand core 2 is directly pressed on the surface of the filter screen 3, the filter screen 3 can be laid horizontally and pressed by the sand core, the sand core cannot move, the filtering effect is 100%, and the slag avoiding effect is good.

In fig. 3, the lower mounting surface of the gear chamber of the runner 10, which exceeds the aluminum gear chamber casting 9, is higher than the lower mounting surface of the gear chamber, so that when the lower mounting surface of the gear chamber, namely the flywheel housing connecting surface, is cut, the cutting area of the exceeding part surface is reduced, the whole gating system can be removed, and the method is very convenient.

Claims

1. The utility model provides an aluminium gear room low pressure casting mould which characterized in that: comprises a metal mold formed by an upper mold (1) and a lower mold (6), and a gear cavity sand core (2) positioned in a metal mold cavity, wherein the upper mold cavity of the upper mold (1) and the lower mold cavity of the lower mold (6) form the metal mold cavity, the upper part of the gear cavity sand core (2) is arranged in the lower mold cavity of the lower mold (6), gear inner chamber psammitolite (2) upper portion surface and last die cavity surface of last mould (1) between form the foundry goods die cavity, two sets of gating systems are connected with the foundry goods die cavity, the gating system includes sprue (8), cross gate (10) include with the terminal surface lapped horizontal cross gate section of foundry goods die cavity, perpendicular cross gate section one end is connected with horizontal cross gate section inner, perpendicular cross gate section other end and gear feeding runner (11), gear feeding runner (11) are connected with the die cavity department that is located the middle distal end of foundry goods die cavity and is used for forming gear inner chamber boss (19).

2. The aluminum gear chamber low pressure casting mold of claim 1, wherein: the sprue (8) is composed of a middle sprue positioned at the bottom of the gear cavity sand core (2) and a lower sprue positioned on the lower die (6), a sprue pit (7) is arranged on the upper die (1) corresponding to the sprue outlet, and the sprue inlet is connected with the riser pipe (4).

3. The aluminum gear chamber low pressure casting mold of claim 2, wherein: gear feeding runner (11) sets up on gear inner chamber psammitolite (2), still is equipped with psammitolite locating hole (15) on gear inner chamber psammitolite (2), and lower mould (6) are equipped with the locating pin with psammitolite locating hole cooperation location, and it is equipped with two runners nest (7) to go up mould (1), and horizontal cross gate section outer end is linked together with each middle part sprue side, middle part sprue upper portion and runner nest (7) intercommunication, middle part sprue lower part and lower part sprue intercommunication, lower part sprue entry linkage ceramic stalk (4).

4. The aluminum gear chamber low pressure casting mold of claim 1, wherein: the casting is a gear chamber, and the lap joint length of the inner end of the horizontal cross pouring gate section and the end surface of the casting cavity exceeds the lower mounting surface hot junction of the gear chamber; the outer surface of the casting cavity after pouring forms a joint surface with the engine cylinder body, the end surface of the casting cavity after pouring forms a lower mounting surface of the gear chamber, and the lower mounting surface of the gear chamber is connected with the connecting surface of the flywheel shell.

5. The aluminum gear chamber low pressure casting mold of claim 4, wherein: the width L of the horizontal cross gate section is 2-3 times of the lap joint length of the inner end of the horizontal cross gate section and the end surface of the casting cavity, and the height difference H between the bottom surface of the horizontal cross gate section and the end surface of the casting cavity is at least 5 mm.

6. The aluminum gear chamber low pressure casting mold of claim 1, wherein: the upper die (1) is matched with an upper die insert (13) connected through a first screw (12), and a drawing block (14) in clearance fit is arranged in the upper die insert (13); the drawing block (14) is provided with a positioning flange (18) matched with the side face of the upper die, and the inner end of the drawing block (14) forms a pit shape of the cylinder cover face.

7. The aluminum gear chamber low pressure casting die of claim 1, wherein: the positioning pin is arranged at the bottom of the lower cavity of the lower die (6).

8. The aluminum gear chamber low pressure casting die of claim 1, wherein: and a filter screen (3) is arranged at the joint of the sprue and the cross gate and pressed between the gear cavity sand core (2) and the lower die (6).