阅读说明：本技术 一种两片式车轮轮辋的低压铸造模具及铸造工艺 (Low-pressure casting die and casting process for two-piece wheel rim ) 是由 张细荣 甑国生 王传斌 于 2019-11-01 设计创作，主要内容包括：本发明提供一种两片式车轮轮辋的低压铸造模具,属于汽车车轮制造领域,该模具包括模具架、上模、下模和侧模；上模、下模和侧模合拢后的内腔组成轮辋型腔和内浇道,内浇道设于轮辋型腔中间部位,内浇道的出料端连通轮辋型腔,内浇道的进料端连通浇口,内浇道为下凹式结构,其下凹方向朝向浇口方向；还包括水冷设备和保温设备,水冷设备设于轮辋型腔外侧,保温设备设于内浇道外侧。由于内浇道采用下凹式,可以顺利实现铝液的回流,并配合分体式的模具设计,水冷和保温措施,由于本发明提供的轮辋胚体比常规胚体要省去了中间内浇道的部分,进一步保障了轮辋胚体的冷却速度,解决了现有的轮辋铸造的工序复杂,耗时长,原料利用率低,制造成本高问题。(The invention provides a low-pressure casting die for a two-piece wheel rim, belonging to the field of automobile wheel manufacturing, and the die comprises a die frame, an upper die, a lower die and a side die; the inner cavity formed by the closed upper die, the lower die and the side die forms a rim cavity and an ingate, the ingate is arranged in the middle of the rim cavity, the discharge end of the ingate is communicated with the rim cavity, the feed end of the ingate is communicated with a sprue, the ingate is of a concave structure, and the concave direction of the ingate faces the direction of the sprue; the wheel rim is characterized by further comprising water cooling equipment and heat preservation equipment, wherein the water cooling equipment is arranged on the outer side of the wheel rim cavity, and the heat preservation equipment is arranged on the outer side of the ingate. Because the inner pouring gate adopts a concave type, the back flow of the aluminum liquid can be smoothly realized, and the split type mould design, water cooling and heat preservation measures are matched, the wheel rim blank provided by the invention saves the part of the middle inner pouring gate compared with the conventional blank, the cooling speed of the wheel rim blank is further ensured, and the problems of complicated working procedures, long time consumption, low raw material utilization rate and high manufacturing cost of the conventional wheel rim casting are solved.)

1. A low-pressure casting die for a two-piece wheel rim comprises a die frame, an upper die, a lower die and a side die; the upper die, the lower die and the side dies are arranged on the inner side of the die frame, the inner cavities of the closed upper die, the closed lower die and the side dies form a rim cavity and an ingate, the ingate is arranged in the middle of the rim cavity, the discharge end of the ingate is communicated with the rim cavity, the feed end of the ingate is communicated with a sprue,

the inner pouring gate is of a concave structure, and the concave direction of the inner pouring gate faces to the direction of the pouring gate;

still include water-cooling equipment and heat preservation equipment, the rim die cavity outside is located to the water-cooling equipment, the heat preservation equipment is located the ingate outside.

2. The low pressure casting mold for a two-piece wheel rim according to claim 1, wherein the upper mold and the lower mold are of split design, the upper mold comprising an upper rim insert and a runner insert; the lower die comprises a lower rim insert and a lower runner insert;

the upper rim insert, the lower rim insert and the side die form the rim cavity;

the upper pouring gate insert and the lower pouring gate insert form the inner pouring gate;

the upper rim insert and the upper pouring gate insert are tightly attached to one side close to the ingate and the rim cavity, and are not contacted with each other on one side far away from the ingate and the rim cavity; the lower rim insert and the lower runner insert are tightly attached to one side close to the ingate and the rim cavity, and are not contacted with each other on one side far away from the ingate and the rim cavity.

3. The low pressure casting mold for a two-piece wheel rim according to claim 2, wherein the separation of the upper rim insert and the runner insert and/or the separation of the lower rim insert and the runner insert is a predetermined rim product water cut-off level.

4. The low-pressure casting mold for the two-piece wheel rim according to claim 1, wherein the side mold is of a split type design, and comprises a side mold insert and a side mold body, wherein the side mold insert is arranged on the inner side of the side mold body and is of a split type design with the side mold body; the side mold insert is directly contacted with the rim cavity; the side die insert is tightly attached to the side die body at one side close to the rim cavity, and is not in contact with one side far away from the rim cavity.

5. The low-pressure casting die for the two-piece wheel rim according to claim 2, wherein the water cooling device comprises an upper rim water-cooling disc, the upper rim water-cooling disc is arranged in the upper rim insert, and the upper rim water-cooling disc is of an annular structure and is provided with a water inlet and a water outlet.

6. The low-pressure casting mold for the two-piece wheel rim according to claim 2, wherein the water cooling device further comprises a lower rim water-cooling disc, the lower rim water-cooling disc is arranged in the lower rim insert, and the lower rim water-cooling disc is of an annular structure and is provided with a water inlet and a water outlet.

7. The low-pressure casting mold for the two-piece wheel rim according to claim 4, wherein the water cooling equipment comprises side mold water cooling discs, the side mold water cooling discs are arranged in the side mold insert, the number of the side mold water cooling discs is the same as that of the side molds, and one side mold water cooling disc is arranged in each side mold.

8. The low pressure casting mold for a two-piece wheel rim according to claim 2, wherein the insulation apparatus comprises an upper mold insulation and a lower mold insulation, the upper mold insulation is disposed outside the upper runner insert, and the lower mold insulation is disposed outside the lower runner insert;

the upper die heat preservation and the lower die heat preservation are heat preservation cotton or heat preservation paste or a heating device and are used for realizing the heat preservation of the ingate.

9. The low-pressure casting die for the two-piece wheel rim according to claim 2, further comprising an upper die air duct, a lower die air duct and a side die air duct, wherein the upper die air duct comprises a plurality of upper die air ducts which are arranged at intervals outside the upper rim insert; the lower die air pipes are arranged on the outer sides of the lower rim inserts at intervals; the side die air pipes are multiple and are arranged on the outer sides of the side dies at intervals.

10. A method of rim casting using the low pressure casting mold for a two-piece wheel rim according to any one of claims 1 to 9, comprising the steps of:

the upper die, the lower die and the side die are combined, dry air is blown in, molten metal liquid is injected into an ingate from the position of the sprue to start to fill the die under the action of air pressure, after the wheel rim die cavity is completely filled with the metal through the ingate, water cooling equipment is started to carry out rapid water cooling, the air pressure is relieved after the water cooling is finished, the heat-preserved metal liquid in the ingate flows back and flows out from the sprue, the die is naturally cooled, and the die is opened to take out the workpiece from the wheel rim die cavity.

Technical Field

The invention relates to the field of automobile wheel manufacturing, in particular to a low-pressure casting die and a casting process of a two-piece wheel rim.

Background

The rim, commonly known as a rim, is a component for mounting and supporting a tire on the periphery of a wheel, and forms a wheel with spokes, and is a component playing a key role in the wheel. The two-piece type hub consists of a rim and a spoke, can combine rims with different widths and thicknesses on one hub, and can obtain more options by combining the width and the offset. Two formula spokes can exchange, when maintenance and change, need not change whole wheel hub, only need change the part can, finally fasten with high strength bolt. Accordingly, wheel hubs of two-piece construction are also becoming increasingly popular.

At present, the rim structure on the market mostly adopts the deformation aluminum alloy spin forming, realizes integration through the welded mode, and production efficiency is low, and the process is more, especially the welding position because the technological requirement is high, produces structural change in the welding process, so the mechanical properties of welding position can be weaker than other positions of body, has certain safety risk.

Although there are also processes for manufacturing rims by casting, the cast rims are all cast integrally by low-pressure or gravity casting, have thick wall, heavy weight, 15-20% heavier than spun rims, and have low material utilization rate.

Therefore, although the two-piece type wheel rim is convenient to use, the application and popularization of the two-piece type wheel rim are always limited due to the fact that the manufacturing process is complex, long in time consumption, low in raw material utilization rate and high in manufacturing cost.

Chinese patent document (CN108637220A A low-pressure casting mould of aluminum wheel rim with heat conduction system) discloses a low-pressure casting mould of aluminum wheel rim, which comprises four side moulds with the same structure, a top mould and a bottom mould, wherein the four side moulds, the top mould and the bottom mould form a thin-wall rim cavity after being closed; a heat conduction system and a temperature sensor for measuring the temperature of the side mold wall are arranged in the mold wall of each side mold, and the heat conduction system is used for quickly conducting heat precipitated in the alloy solidification process; the outer surface of each side die is provided with a heat conduction system, and the heat conduction system is used for rapidly increasing the temperature of the die at the rim part. Although the temperature of the rim part die can be controlled through temperature regulation, the rim part die also needs to be cast in an integral casting mode in the process of casting the rim, the rim part is not only cast, and the casting time and the raw material utilization rate are very low.

Therefore, how to improve the existing rim casting mold to provide a novel casting mold, improve casting efficiency and raw material utilization rate, become the technical problem to be solved in the field.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides a novel low-pressure casting die and a casting process for a two-piece wheel rim, wherein a low-pressure casting integrated forming mode is adopted, the production efficiency is improved by forced cooling with water, then the wheel rim is extruded and formed through a spinning process, the performance of materials after spinning can approach or reach the performance index of the existing forged wheel rim, and the utilization rate of raw materials in the production process is very high.

The specific technical scheme provided by the invention is as follows:

a low-pressure casting die for a two-piece wheel rim comprises a die frame, an upper die, a lower die and a side die; the upper die, the lower die and the side dies are arranged on the inner side of the die frame, the inner cavities of the closed upper die, the closed lower die and the side dies form a rim cavity and an ingate, the ingate is arranged in the middle of the rim cavity, the discharge end of the ingate is communicated with the rim cavity, the feed end of the ingate is communicated with a sprue,

the inner pouring gate is of a concave structure, and the concave direction of the inner pouring gate faces to the direction of the pouring gate;

still include water-cooling equipment and heat preservation equipment, the rim die cavity outside is located to the water-cooling equipment, the heat preservation equipment is located the ingate outside.

Preferably, the upper die and the lower die are in split design, and the upper die comprises an upper rim insert and an upper runner insert; the lower die comprises a lower rim insert and a lower runner insert;

the upper rim insert, the lower rim insert and the side die form the rim cavity;

the upper pouring gate insert and the lower pouring gate insert form the inner pouring gate;

the upper rim insert and the upper pouring gate insert are tightly attached to one side close to the ingate and the rim cavity, and are not contacted with each other on one side far away from the ingate and the rim cavity; the lower rim insert and the lower runner insert are tightly attached to one side close to the ingate and the rim cavity, and are not contacted with each other on one side far away from the ingate and the rim cavity.

Preferably, the position where the upper rim insert and the upper pouring gate insert are separated and/or the position where the lower rim insert and the lower pouring gate insert are separated are preset rim product water breaking surfaces.

Preferably, the side die is designed in a split mode, the side die comprises a side die insert and a side die body, and the side die insert is arranged on the inner side of the side die body and designed in a split mode with the side die body; the side mold insert is directly contacted with the rim cavity; the side die insert is tightly attached to the side die body at one side close to the rim cavity, and is not in contact with one side far away from the rim cavity.

Preferably, the water cooling equipment comprises an upper rim water cooling disc, the upper rim water cooling disc is arranged in the upper rim insert, and the upper rim water cooling disc is of an annular structure and is provided with a water inlet and a water outlet.

Preferably, the water cooling equipment further comprises a lower rim water-cooling disc, the lower rim water-cooling disc is arranged in the lower rim insert, and the lower rim water-cooling disc is of an annular structure and is provided with a water inlet and a water outlet.

Preferably, the water cooling equipment comprises side-form water cooling discs, the side-form water cooling discs are arranged in the side-form mold insert, the number of the side-form water cooling discs is the same as that of the side forms, and one side-form water cooling disc is arranged in each side mold.

Preferably, the heat preservation equipment comprises an upper die heat preservation and a lower die heat preservation, the upper die is arranged on the outer side of the upper pouring gate insert in a heat preservation mode, the lower die is arranged on the outer side of the lower pouring gate insert in a heat preservation mode, and the upper die heat preservation and the lower die heat preservation are heat preservation cotton or heat preservation paste or a heating device and are used for realizing heat preservation of the inner pouring gate.

Preferably, the wheel rim further comprises an upper mold air pipe, a lower mold air pipe and side mold air pipes, wherein the upper mold air pipes comprise a plurality of air pipes which are arranged on the outer side of the upper rim insert at intervals; the lower die air pipes are arranged on the outer sides of the lower rim inserts at intervals; the side die air pipes are multiple and are arranged on the outer sides of the side dies at intervals.

The invention also provides a method for casting a rim by using the low-pressure casting die of any two-piece wheel rim, which is characterized by comprising the following steps of:

the upper die, the lower die and the side die are combined, dry air is blown in, molten metal liquid is injected into an ingate from the position of the sprue to start to fill the die under the action of air pressure, after the wheel rim die cavity is completely filled with the metal through the ingate, water cooling equipment is started to carry out rapid water cooling, the air pressure is relieved after the water cooling is finished, the heat-preserved metal liquid in the ingate flows back and flows out from the sprue, the die is naturally cooled, and the die is opened to take out the workpiece from the wheel rim die cavity.

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

(1) the invention adopts low-pressure casting and integral molding, and realizes the improvement of production efficiency by forced cooling with water.

(2) The structure of the low-pressure casting die provided by the invention is of an innovative design, and the smooth backflow of the aluminum liquid can be realized due to the fact that the inner pouring gate is of a concave type. Meanwhile, in order to ensure the smooth backflow of the aluminum liquid, heat preservation equipment is arranged near the ingate, and in order to realize the rapid cooling of the aluminum liquid to obtain a casting blank, water cooling equipment on the outer side of the rim cavity is designed. Through the design, the aluminum liquid is ensured to be rapidly cooled, and the aluminum liquid can flow back to the holding furnace after the pressure maintaining is finished, so that the material utilization rate of the casting is improved. By adopting the structure provided by the invention, the rim can be rapidly molded, and the production efficiency can be improved by more than 50% compared with the traditional casting mode.

(3) The upper die and the lower die of the invention are used as the mould blocks for forming the rim casting, both adopt split type design and all adopt water cooling structures, through the arrangement, the quick cooling of the aluminum liquid in the rim cavity can be realized, not only can a plurality of water cooling devices ensure the quick cooling, but also the cooling speed is improved, and the improved split type design form can also ensure that the great temperature exchange can not occur among all the structures. For example, go up the mould in the rim mold insert and the runner mold insert for split type non-contact design each other, leave the space between the two, can ensure that the runner mold insert can not take place the conflict to the heat preservation effect of ingate and the cooling effect of going up the rim mold insert to the rim die cavity, go up two functions of mould and can both realize smoothly. According to the invention, the production efficiency of the rim workpiece is improved through the water cooling structure, the water/electricity/gas loss caused by overlong cooling time is reduced, and the effects of energy conservation and emission reduction are achieved. Compared with the traditional rim anchoring mode, the invention can improve the utilization rate of the aluminum liquid by about 30 percent.

(4) The heat preservation equipment comprises an upper die for heat preservation and a lower die for heat preservation, and the upper die and the lower die are respectively arranged on the upper side and the lower side of the ingate, so that the aluminum liquid in the ingate is further prevented from solidifying.

Drawings

FIG. 1 is a block diagram of one embodiment of a prior art casting with a rim low pressure casting mold.

Fig. 2 is a structural view of an embodiment of a low-pressure casting mold for a two-piece wheel rim provided by the present invention.

Fig. 3 is an exploded view of a part of the structure of a low-pressure casting mold of a two-piece wheel rim provided by the invention.

Fig. 4 is a schematic diagram of a related structure of an upper mold provided by the present invention.

Fig. 5 is a schematic diagram of a related structure of a lower die provided by the present invention.

Fig. 6 is a schematic diagram of a related structure of a side mold provided by the invention.

Figure 7 is a partial cross-sectional view of a prior art rim cavity during rim casting.

FIG. 8 is a partial cross-sectional view of a rim cavity structure provided by the present invention.

FIG. 9 is a schematic view of the ingate structure provided by the present invention.

The specific meanings of the symbols in the drawings are as follows:

1: an inner pouring channel; 2: a gate; 3: a rim cavity; 4: a rim insert is arranged; 5: a runner insert; 6: a lower rim insert; 7: a lower pouring gate insert; 8: a side mold insert; 9: a side form body; 10: a water-cooling disc of the upper rim; 11: a lower rim water-cooling disc; 12: a side-form water-cooling disc; 13: keeping the temperature of the upper die; 14: keeping the temperature of the lower die; 15: a ceramic throat; 16: an upper mold air duct; 17: a lower die air pipe; 18: a side mold air duct; 19: a mold frame; 20: a prior art mold; 21: a heat preservation furnace hearth; 22: an aluminum water holding furnace; 23: a low pressure casting frame; 24: a pressurized air inlet/outlet pipe; 25: a riser tube.

Detailed Description

The invention provides a two-piece wheel rim low-pressure casting die and a casting process.

Referring to fig. 2 to 9, the low-pressure casting mold for a two-piece wheel rim provided in this embodiment includes a mold frame 19, an upper mold, a lower mold, and side molds; the upper die, the lower die and the side dies are arranged on the inner side of the die frame 19, inner cavities formed by the closed upper die, the closed lower die and the side dies form a rim cavity and an ingate, the ingate is arranged in the middle of the rim cavity, the discharge end of the ingate is communicated with the rim cavity, the feed end of the ingate is communicated with a sprue, the ingate is of a concave structure, and the concave direction of the ingate faces the sprue direction; still include water-cooling equipment and heat preservation equipment, the rim die cavity outside is located to the water-cooling equipment, the heat preservation equipment is located the ingate outside.

The low-pressure die structure is designed in an innovative way in the embodiment: the inner pouring gate 1 adopts a concave type (shown in figure 9, which is also an important improvement of the invention), and can smoothly realize the backflow of the aluminum liquid. In addition, because the heat preservation equipment and the water cooling equipment are respectively arranged at the ingate and the rim cavity, heat preservation and cooling can be simultaneously carried out, the cooling time is also reduced, the aluminum liquid backflow is realized, and the material utilization rate of the casting is improved. The rim casting mold in the prior art adopts an integral casting form (figure 7), has no design of an ingate 1, can be taken out after the whole casting blank is cooled, and has low casting efficiency and low aluminum liquid utilization rate. Fig. 7 a shows the extra aluminum material from the prior art rim casting mold than the mold of the present invention, and when the prior art mold is used, the aluminum material at a needs to be cooled, which is more energy-consuming and time-consuming than the present invention.

In another embodiment of the invention, the upper die and the lower die are both in a split design, and the upper die comprises an upper rim insert 4 and an upper pouring gate insert 5; the lower die comprises a lower rim insert 6 and a lower runner insert 7; the upper rim insert 4, the lower rim insert 6 and the side die form a rim cavity 3; the up-runner insert 5 and the down-runner insert 7 form an ingate 1. Through the design, the convenient disassembly of the die can be realized. In addition, in the embodiment, the upper rim insert 4 and the runner insert 5 are tightly attached (about 4mm long) at one side close to the ingate and the rim cavity 3, and are not contacted with each other at one side far away from the ingate 1 and the rim cavity 3 (namely, gaps are formed at other parts except the tightly attached 4mm long part, and the gaps are about 2 mm); the lower rim insert 6 and the lower runner insert 7 are closely attached (about 4mm long) at one side close to the ingate and the rim cavity, and are not contacted with each other at one side far away from the ingate 1 and the rim cavity 3 (namely, the gap is about 2mm except the closely attached 4mm long part). The design of mutual non-contact can ensure that the rapid cooling of the rim cavity 3 and the heat preservation of the ingate 1 do not interfere with each other, the cooling speed of the casting blank is ensured together, and the aluminum liquid can flow back. But the side participating in the building of the rim cavity and ingate must be sealed, so there is a close fitting position of around 4mm for sealing.

In another embodiment of the present invention, the separation of the upper rim insert 4 from the up-runner insert 5 and/or the separation of the lower rim insert 6 from the down-runner insert 7 is a predetermined rim product water break level. The rim product water break is generally at the two separations, as the two separations may be designed to be slightly different. The product water-break surface refers to a section of separation between a rim casting blank and a reflowable aluminum liquid in the ingate 1 (fig. 8 is a side structural sectional view of a rim cavity 3). The design of the invention and the split type design in the previous embodiment act together, so that the casting blank formed after the aluminum liquid is cooled can be ensured to meet the requirement, namely the casting blank cooling and the heat preservation operation of the inner pouring channel 1 are not interfered with each other, and the casting blank molding can be further ensured to meet the requirement by adjusting the cooling time and the like in the actual operation.

Further, for further guarantee cooling and heat retaining isolation degree, can all install thermal-insulated gasket additional between last rim mold insert 4 and the last mold insert 5 of watering, between lower rim mold insert 6 and the lower mold insert 7 of watering, between side form mold insert 8 and the side form body 9, this design can further guarantee thermal-insulated effect, guarantees cooling and heat preservation process mutually noninterfere.

In another embodiment of the invention, the side die is in a split type design, the side die comprises a side die insert 8 and a side die body 9, the side die insert 8 is arranged on the inner side of the side die body 9, and the side die insert and the side die body 9 are in a split type design; the side mould inserts 8 are in direct contact with the rim cavity 3. The side die insert and the side die body are tightly attached to one side close to the rim cavity (about 4mm in length), and are not in contact with each other on one side far away from the rim cavity (namely, gaps are formed in other parts except the tightly attached side die insert and the side die body which are 4mm in length, and the gaps are about 2 mm). The design can also ensure the quick cooling of the aluminum liquid.

Because the upper die, the lower die and the side die are designed in a split mode, the usable parts of the product can be subjected to rapid cooling, and the unnecessary parts of the product are subjected to heat preservation, so that the production efficiency can be improved, and the material utilization rate can be improved. In addition, the design also considers the sharing of the die, namely the die corresponding to the part (ingate part) which is not needed by the product can be commonly used on the products with similar sizes, and the manufacturing cost of the die can be effectively reduced.

In another embodiment of the present invention, the water cooling apparatus includes an upper rim water cooling disc 10, the upper rim water cooling disc 10 is disposed in the upper rim insert 4, the upper rim water cooling disc 10 is an annular structure and has a water inlet and a water outlet. The water cooling equipment further comprises a lower rim water cooling disc 11, the lower rim water cooling disc 11 is arranged in the lower rim insert 6, and the lower rim water cooling disc 11 is of an annular structure and is provided with a water inlet and a water outlet. The water cooling equipment comprises side-form water cooling discs 12, the side-form water cooling discs 12 are arranged in the side-form mold insert 8, the number of the side-form water cooling discs 12 is the same as that of the side forms, and one side-form water cooling disc 12 is arranged in each side mold. Because the upper die and the lower die are used as the blocks for forming the rim casting, and the water cooling structure is adopted, the cooling speed of the casting can be increased, and the mechanical property of the material is improved. In addition, the die is cooled by water, so that the solidification speed is high, the crystal grains are fine, and the material performance of the casting blank can be greatly improved.

In another embodiment of the invention, the heat preservation device comprises an upper die heat preservation 13 and a lower die heat preservation 14, wherein the upper die heat preservation 13 is arranged on the outer side of the upper pouring gate insert 5, and the lower die heat preservation 14 is arranged on the outer side of the lower pouring gate insert 7. The materials of the upper die heat preservation 13 and the lower die heat preservation 14 can be selected according to actual needs, and heat preservation cotton is adopted in the embodiment. According to the actual requirement, the heat preservation paste made of refractory fiber can also be used as heat preservation equipment (or called as substitute heat preservation equipment), and the coating thickness is preferably 5 cm. Practical verification proves that the high temperature of the part can be maintained above 500 ℃ when the heat preservation paste is coated. In order to further improve the heat preservation effect, the ceramic throat pipe 15 is adopted at the pouring gate position, and the heat preservation of the aluminum liquid can be further realized through the design. Because the heat preservation cotton or the heat preservation paste only has the heat preservation effect, in practical application, if the temperature needs to be adjusted or maintained for a long time (for example, in an extremely cold environment, the liquid form of the aluminum liquid is maintained by heating), the temperature control setting and/or the heating setting can be set so as to further adjust the temperature of the heat preservation equipment, further ensure the temperature of the aluminum liquid in the ingate 1 to ensure that the aluminum liquid is in the liquid form, and ensure that the aluminum liquid can realize backflow.

In another embodiment of the invention, the wheel rim further comprises an upper mold air pipe 16, a lower mold air pipe 17 and a side mold air pipe 18, wherein the upper mold air pipe 16 comprises a plurality of air pipes which are arranged at the outer side of the upper wheel rim insert 4 at intervals; a plurality of lower die air pipes 17 are arranged at the outer side of the lower rim insert 6 at intervals; the side mold air ducts 18 are provided in plural, and are spaced apart from each other on the outside of the side mold (side mold body). The air pipes are holes formed in the die, and are preferably arranged at intervals of 15mm and used for air cooling of products.

The invention also provides a method for casting the rim, which comprises the following steps: the upper die, the lower die and the side die are combined well, dry air is blown from the position of a pouring gate 2 to apply pressure, molten metal liquid is injected into an ingate 1 from the position of the pouring gate 2 to start to fill under the action of air pressure, after metal is completely filled into a rim cavity 3 through the ingate 1, water cooling equipment is started to carry out quick water cooling, the air pressure is released after the water cooling is finished, the heat-preserving metal liquid in the ingate flows back and flows out from the pouring gate, the die is naturally cooled, the die is opened, a workpiece casting blank is taken out from the inside of the rim cavity, and the next step can be carried out.

One embodiment of the present invention is as follows: the specific working process of the invention comprises the following steps:

1 mold closing → 2 pressurization and mold filling → 3 mold cooling → 4 pressure relief aluminum liquid reflux insulation furnace → mold opening and workpiece taking out

The method specifically comprises the following steps (shown in figure 1):

the method comprises the following steps: when the mold is closed, the injection of dry compressed air is started through the pressurized air inlet/outlet pipe 24.

Step two: pressurizing and filling, filling aluminum liquid from a pouring gate 2 through a liquid lifting pipe 25 after injecting dry compressed air, completing filling of a product blank within about 30-35 seconds, starting a water cooling device (comprising an upper water cooling device and a lower water cooling device), opening all upper die air pipes, lower die air pipes and side die air pipes, rapidly cooling the product under the dual actions of air cooling and water cooling, solidifying and forming the product through injecting cooling water for about 30-40 seconds, and then releasing the pressure in the furnace, wherein the aluminum liquid in the upper pouring gate insert and the lower pouring gate insert of the pouring gate shown in figure 1 is still in a liquid state, and flows back into the heat preservation furnace after pressure relief. (conventional product dwell times are about 240 seconds, new process product dwell times are between about 60 and 80 seconds). And opening the die after the die is naturally cooled for about 35-45 seconds after pressure relief, taking out the workpiece, and repeating the production steps. The process provided by the invention starts from mold closing, and the whole operation process is about 120-180 seconds, which is far less than that of the traditional process.

Controlling a water cut-off position/an aluminum water solid/liquid separation line of a workpiece: the water cut-off level of the product is controlled according to the duration of the pressurized air (the term is called as the pressurization time). The production method provided by the embodiment controls the time from aluminum liquid filling to pressure relief to be 60-80 seconds, the condition is that the pressure holding time is long, and the finally obtained water break level is close to the central point (namely the water break level is short from the central gate position). If the pressure holding time is short, the water cut-off level is closer to the product.

It should be noted that the equipment provided by the invention can realize rapid cooling (by the design of the concave-down ingate 1, the volume of a blank is reduced, only a rim part needs to be cast, and due to the reduction of the volume, the time and energy required by cooling are greatly reduced, the production efficiency can be improved, the production cost can be reduced) and the aluminum liquid backflow (the consumption of the aluminum liquid is reduced, and the operation is convenient).

When the mould provided by the invention is used for rim casting, molten aluminum is stably filled in the production process, an effective blank (figure 9) is obtained by forced water cooling of each part after the filling is finished, the water cooling is quickly started to form the effective blank, and then the pressure is released to enable the molten aluminum at the middle pouring gate part to flow back to a holding furnace (the time process of cooling and forming a workpiece can be greatly reduced, so that the production period is shortened, and the production efficiency can be improved by 50% -60%).

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention shall fall within the protection scope of the present invention.