阅读说明：本技术 一种铝合金压铸件毛坯精密成型工艺 (Precision forming process for aluminum alloy die casting blank ) 是由 欧盟 韩涛 于 2020-07-20 设计创作，主要内容包括：本发明涉及压铸件技术领域,具体涉及一种铝合金压铸件毛坯精密成型工艺,包括腔体清理、增压填充、稳压保温和冷却成型,其中采用的吹扫机的包括端盖、气瓶、真空泵和控制器；由于型腔的排气过程难以对附着在腔体内壁的杂质进行针对的清理,在压铸过程中会影响其中液体铝合金成型的传热效果,且在压铸完成后会造成铝合金毛坯表面的瑕疵,降低了精密成形工艺的应用效果；故此,本发明通过设置的端盖将压铸模的型腔完全封闭起来,配合端盖的封板上设置的输气管与回气管,使腔体内部在高气压状态下通过流通的氮气将其中悬浮附着的杂质带离出来,从而提升了铝合金压铸件毛坯精密成型工艺的使用效果。(The invention relates to the technical field of die castings, in particular to a precision forming process of an aluminum alloy die casting blank, which comprises cavity cleaning, pressurizing filling, pressure and heat preservation and cooling forming, wherein a adopted purging machine comprises an end cover, a gas cylinder, a vacuum pump and a controller; because the impurities attached to the inner wall of the cavity are difficult to be cleaned in the exhaust process of the cavity, the heat transfer effect of liquid aluminum alloy forming in the cavity can be influenced in the die-casting process, the surface of an aluminum alloy blank can be flawed after the die-casting is finished, and the application effect of a precision forming process is reduced; therefore, the die cavity of the die-casting die is completely sealed through the end cover, and the gas transmission pipe and the gas return pipe which are arranged on the sealing plate of the end cover are matched, so that impurities suspended and attached in the cavity are taken out through circulating nitrogen in a high-pressure state, and the using effect of the precision forming process of the aluminum alloy die-casting blank is improved.)

1. A precision forming process of an aluminum alloy die casting blank is characterized by comprising the following steps:

s1, cleaning the cavity: injecting nitrogen from an end cover (1) of a die-casting cavity port through a gas cylinder (2) of a purging machine to enable the pressure inside the cavity to be within 0.7-0.9MPa, controlling the nitrogen to circulate in the cavity for 3-4min, then pumping out the nitrogen inside the die-casting cavity through a vacuum pump (3), keeping the pressure inside the cavity below 0.03MPa, and controlling the temperature of the cavity to be within 40-45 ℃ through a thermostat;

s2, pressurizing and filling: pouring molten metal of aluminum alloy into the cavity of S1, pressurizing and supplementing the molten metal after the inner space of the cavity is fully poured, and enabling the volume of the molten metal filled into the cavity to exceed 8-11% of the volume of the cavity;

s3, pressure stabilization and heat preservation: after the pouring process of the molten metal in S2 is completed, keeping the pressure in the cavity in a stable state for more than 2 hours, and simultaneously controlling the temperature of the cavity in a heating state to be within 660-750 ℃;

s4, cooling and forming: after the pressure stabilizing treatment of the molten metal in the cavity of S3 is completed, closing the heating of the cavity and opening the die orifice of the cavity to naturally cool the cavity to the normal temperature state, and maintaining the constant temperature treatment of the cavity for 40-70min when the aluminum alloy in the cavity is cooled to the range of 90-120 ℃, and finally obtaining a formed aluminum alloy die-casting blank;

the blowing machine in the S1 comprises an end cover (1), a gas cylinder (2), a vacuum pump (3) and a controller; the end cover (1) is arranged on the port of the cavity, and the end cover (1) enables the cavity to be in a closed state; the end cover (1) comprises a cover plate (4), a panel (5) and a closing plate (6); the inner wall of the cover plate (4) is slidably arranged on the outer wall of the panel (5); a through groove (7) is formed in the middle of the cover plate (4) and the panel (5), and the cover plate (4) and the panel (5) are divided into two parts by the through groove (7); the sealing plate (6) is slidably mounted on the outer walls of the tops of the cover plate (4) and the panel (5), the sliding direction of the sealing plate (6) is perpendicular to the sliding direction of the cover plate (4), and the cover plate (4) and the panel (5) which are divided into two parts are connected through the sealing plate (6); the seal plate (6) is provided with a gas pipe (8), and the tail end of the gas pipe (8) is communicated with the gas cylinder (2); an air return pipe (9) is arranged on the cover plate (4), and the tail end of the air return pipe (9) is communicated with a vacuum pump (3); the controller is used for controlling the operation of the blowing machine.

2. The precision forming process of the aluminum alloy die casting blank according to claim 1, characterized in that: the sealing plate (6) is provided with filling blocks (61), the filling blocks (61) are respectively installed at two ends of the bottom of the sealing plate (6), and the filling blocks (61) enable the sealing plate (6) and the inner walls of the ports of the cover plate (4) and the panel (5) to be positioned on the same plane; the sealing plate (6) is also provided with a fixed cushion block (62), and the cushion block (62) is positioned on the through groove (7) of the panel (5); the panel (5) is provided with an insert (51), the insert (51) is fixed on the side surface of the end part of the panel (5), and the insert (51) enables the panel (5) to be overlapped with the side wall of the cover plate (4).

3. The precision forming process of the aluminum alloy die casting blank as recited in claim 2, wherein: a cavity (63) is formed in the filling block (61), the top end of the filling block (61) is communicated with the gas conveying pipe (8), and a notch (64) is formed in the side surface, facing the cavity, of the filling block (61); the air flow filled in the air pipe (8) enters the cavity from the notch (64) along the cavity (63) of the filling block (61).

4. The precision forming process of the aluminum alloy die casting blank according to claim 3, characterized in that: a notch (65) is arranged on the side wall of the notch (64), and a sliding elastic rod (66) is arranged in the notch (65); the elastic rod (66) is provided with a fixed sealing cloth (67), and the tail end of the sealing cloth (67) is wound in the filling block (61) at the bottom of the notch (64); the elastic rod (66) protrudes out of the side face of the filling block (61), and the elastic rod (66) is clamped on the port of the cavity to pull out the wound sealing cloth (67).

5. The precision forming process of the aluminum alloy die casting blank as recited in claim 2, wherein: a return plate (52) is arranged on the insert block (51), and an air return opening (53) is formed in the top of the return plate (52); the air return opening (53) is communicated with the air return pipe (9) through an embedded block (51).

6. The precision forming process of the aluminum alloy die casting blank according to claim 5, characterized in that: an electrostatic ring (531) is arranged at the end part of the air return opening (53), an electrostatic net (532) is further arranged on the inner wall of the cover plate (4) corresponding to the electrostatic ring (531), and the charge polarities of the electrostatic ring (531) and the electrostatic net (532) are opposite.

Technical Field

The invention relates to the technical field of die castings, in particular to a precision forming process of an aluminum alloy die casting blank.

Background

The aluminum alloy has excellent castability and corrosion resistance and is widely applied to industrial production activities, the aluminum alloy takes aluminum as a base material and is added with a certain amount of other metallization elements, and the filling and shaping process of the aluminum alloy in a cavity is required to be controlled in the die-casting quality of aluminum alloy molding; for the introduction of the aluminum alloy die casting process, Lei et al, research on low-pressure casting process of aluminum alloy castings [ J ], scientific and technological innovation report 2018(No.12), 81-82 can be mentioned.

The shaping effect of aluminum alloy die casting except the size precision of its self design, the alloy liquid is at the inside form transformation in-process of die cavity, and the exhaust process of die cavity is difficult to carry out the clearance that aims at to the impurity of attaching to the cavity inner wall, can influence wherein fashioned heat transfer effect of liquid aluminum alloy among them at the die-casting in-process, and can cause the flaw on aluminum alloy blank surface after the die-casting is accomplished.

Disclosure of Invention

In order to make up for the defects of the prior art, the invention provides a precision forming process of an aluminum alloy die casting blank, wherein a cavity of a die casting die is completely sealed by an arranged end cover, and a gas transmission pipe and a gas return pipe are arranged on a sealing plate of the end cover, so that suspended and attached impurities in the cavity are taken out by circulating nitrogen in a high-pressure state, and the closed installation of the cavities with different specifications is met by sliding adjustment among a cover plate, a panel and the sealing plate in the end cover, the application range of a purging machine is expanded, and the use effect of the precision forming process of the aluminum alloy die casting blank is improved.

The invention relates to a precision forming process of an aluminum alloy die casting blank, which comprises the following steps:

s1, cleaning the cavity: injecting nitrogen from an end cover of a die-casting cavity port through a gas cylinder of a purging machine to enable the air pressure inside the cavity to be within 0.7-0.9MPa, controlling the nitrogen to circulate in the cavity for 3-4min, then pumping out the nitrogen inside the die-casting cavity by a vacuum pump, keeping the pressure in the cavity below 0.03MPa, and controlling the temperature of the cavity to be within 40-45 ℃ through a thermostat; circulating nitrogen pressurization circulation is carried out on the die-casting cavity, impurities attached to the air in the cavity are cleaned, and finally the cavity is maintained in a negative pressure state, so that the metal liquid poured subsequently can be filled into the space in the cavity fully, and the defect caused by the bubble phenomenon in the metal liquid is reduced;

s2, pressurizing and filling: pouring molten metal of aluminum alloy into the cavity of S1, pressurizing and supplementing the molten metal after the inner space of the cavity is fully poured, and enabling the volume of the molten metal filled into the cavity to exceed 8-11% of the volume of the cavity; the pressurizing condition in the aluminum alloy die-casting is achieved by pouring excessive molten metal into the cavity, and the pressurizing pouring parameters are controlled according to the preset molten metal content;

s3, pressure stabilization and heat preservation: after the pouring process of the molten metal in S2 is completed, keeping the pressure in the cavity in a stable state for more than 2 hours, and simultaneously controlling the temperature of the cavity in a heating state to be within 660-750 ℃; the pressure stabilization and heat preservation of the molten metal in the cavity eliminate the residual stress effect generated by the impact between the molten metal and the inner wall of the cavity in the pouring process, and the state of the molten metal tends to be stable under the continuous heating action of the cavity, so that the molten metal has a balanced phase state in the subsequently formed aluminum alloy;

s4, cooling and forming: after the pressure stabilizing treatment of the molten metal in the cavity of S3 is completed, closing the heating of the cavity and opening the die orifice of the cavity to naturally cool the cavity to the normal temperature state, and maintaining the constant temperature treatment of the cavity for 40-70min when the aluminum alloy in the cavity is cooled to the range of 90-120 ℃, and finally obtaining a formed aluminum alloy die-casting blank; internal stress in the formed solid aluminum alloy is consumed through waste heat of constant temperature treatment of the cavity, and stability of physical properties of the aluminum alloy die-cast blank is ensured;

the blowing machine in the S1 comprises an end cover, a gas cylinder, a vacuum pump and a controller; the end cover is arranged on the port of the cavity, and the end cover enables the cavity to be in a closed state; the end cover comprises a cover plate, a panel and a closing plate; the inner wall of the cover plate is slidably mounted on the outer wall of the panel; the middle parts of the cover plate and the panel are provided with through grooves which divide the cover plate and the panel into two parts; the sealing plate is slidably arranged on the outer walls of the tops of the cover plate and the panel, the sliding direction of the sealing plate is perpendicular to that of the cover plate, and the cover plate divided into two parts is connected with the panel through the sealing plate; the seal plate is provided with a gas pipe, and the tail end of the gas pipe is communicated with the gas cylinder; an air return pipe is arranged on the cover plate, and the tail end of the air return pipe is communicated with a vacuum pump; the controller is used for controlling the operation of the purging machine; when the die-casting die is used, the die cavity can contact air impurities and remain in the cavity during storage, the impurities are mixed into poured molten metal and are attached to the surface of aluminum alloy in the die-casting process, the surface quality of a die-casting blank is reduced, the impurities attached to the inner wall of the cavity are difficult to be cleaned in the exhaust process of the die cavity, the heat transfer effect of liquid aluminum alloy forming in the die-casting process can be influenced, the surface defects of the aluminum alloy blank can be caused after the die-casting is finished, and the application effect of a precision forming process is reduced; therefore, the invention uses the end cover arranged on the cavity, before the die casting process, the sliding adjustment among the cover plate, the panel and the closing plate in the end cover is adapted to be arranged on the ports of the cavities with different specifications, the cavity is sealed, the controller is started, the gas cylinder in the blowing machine is filled with circulating nitrogen into the cavity, and impurities attached to the inner wall of the cavity are cleaned out by the negative pressure effect generated by the adsorption effect of the vacuum pump at the tail end of the gas return pipe and are collected by the gas return pipe; the die cavity of the die-casting die is completely sealed by the aid of the end cover, and the gas transmission pipe and the gas return pipe which are arranged on the sealing plate of the end cover are matched, so that suspended and attached impurities in the cavity are taken out by flowing nitrogen in a high-pressure state, and the closed installation of the die cavities with different specifications is met by sliding adjustment among the cover plate, the embedded plate and the sealing plate in the end cover, the application range of the purging machine is expanded, and accordingly the using effect of the precision forming process of the aluminum alloy die-casting blank is improved.

Preferably, the sealing plate is provided with filling blocks, the filling blocks are respectively arranged at two ends of the bottom of the sealing plate, and the filling blocks enable the sealing plate, the cover plate and the inner wall of the port of the embedded plate to be positioned on the same plane; the sealing plate is also provided with a fixed cushion block, and the cushion block is positioned on the through groove of the panel; the panel is provided with an insert block which is fixed on the side surface of the end part of the panel, and the insert block enables the panel to be overlapped with the side wall of the cover plate; the end covers are mounted on cavities with different specifications by adjusting the position relation among the cover plate, the panel and the closing plate, and the sealing effect of the end covers is weakened by staggered inner walls of the end parts during sliding adjustment; through setting up packing block and the cushion on the shrouding, and cooperate with the abaculus of panel tip, at the in-process of the regulation end cover size that slides, the packing block compensaties the lateral wall breach between apron and the panel, the through groove breach to panel top is supplyed to the cushion, the abaculus increases the lateral part inner wall of apron and coincides on the lateral part inner wall of panel, the internal surface that makes the end cover lateral wall laminates with the port of die cavity completely, satisfy the airtight effect between its cover and die cavity of ensureing when to different die cavity mounting effects, thereby the application scope of aluminum alloy die casting blank precision molding technology has been promoted.

Preferably, a cavity is arranged in the filling block, the top end of the filling block is communicated with the gas pipe, and a notch is formed in the side surface, facing the cavity, of the filling block; the air flow filled in the air conveying pipe enters the cavity from the notch along the cavity of the filling block; when the size of the filling block is adjusted to be matched with the port of the installed cavity, the filling block in the through groove is required to be completely attached to the cavity due to the sealing requirement of the end cover, and the sealing performance of the filling block in the deformation process is not interfered; through the cavity that sets up in the filling block, cooperate with the gas-supply pipe on its top, in the in-process of filling nitrogen gas to the die cavity, the air current supplements to the die cavity through the filling block for the filling block laminating of deformation after the adjustment is on the terminal surface of die cavity, ensures the airtight effect of filling block in leading to the groove, thereby has reached the leakproofness requirement of aluminum alloy die casting blank precision molding technology.

Preferably, a notch is arranged on the side wall of the notch, and a sliding elastic rod is arranged in the notch; the elastic rod is provided with fixed sealing cloth, and the tail end of the sealing cloth is wound in the filling block at the bottom of the notch; the elastic rod protrudes out of the side face of the filling block, and is clamped on the port of the cavity to pull out the wound sealing cloth; after the end cover is installed on the cavity ports with different specifications, the degree that the inner wall of the end cover extends into the cavity ports is different, so that the bottom of the notch in the filling block is directly contacted with the cavity, the injected nitrogen acts on the cavity exposed at the notch, and the air flow pushes away the filling block by taking the cavity as a reference, so that the sealing effect of the end cover is damaged; through setting up the notch in the notch, make wherein slidable mounting's bullet pole will convolute the sealed cloth in the filling block and pull out, and utilize bullet pole protrusion in the surface of filling block, make the end cover lift up the bullet pole on the die cavity port of installation, the die cavity position that corresponds the notch is by sealed cloth separation, the air current of filling simultaneously is used in the sealed cloth and has increased its and die cavity laminating effect within a definite time, the condition of having avoided pushing away the filling block, thereby the application effect of aluminum alloy die casting blank precision molding technology has been promoted.

Preferably, the embedded block is provided with a backflow plate, and the top of the backflow plate is provided with an air return opening; the air return inlet is communicated with the air return pipe through an embedded block; in the nitrogen circulation process in the cavity, impurities in the cavity are taken away, and the air return pipe driven by the vacuum pump is used as a backflow source of air in the cavity, so that air flow conveyed in the air conveying pipe can be directly sucked away, and the cleaning effect of the filling air flow on the cavity is reduced; through setting up the backward flow board on the abaculus, make the return air inlet of backward flow board towards the inner wall of apron, weakened the direct adsorption to the end cover position when the vacuum pump moves for fill to the inside air current of cavity with adnexed impurity suspension, float to the position of end cover under the air current effect of circulation, absorbed through the backward flow board, thereby promoted the application effect of the accurate forming technology of aluminum alloy die casting blank.

Preferably, an electrostatic ring is arranged at the end part of the air return opening, an electrostatic network is further arranged on the inner wall of the cover plate corresponding to the electrostatic ring, and the electrostatic ring and the electrostatic network have opposite charge polarities; impurities floating to the end cover area are drawn by the circulating airflow, the flow velocity is reduced due to the airflow turning in the end cover area, the impurities tend to be balanced under the self gravity action and are difficult to move to the air return inlet, and the cleaning effect on the impurities in the cavity is weakened; through setting up the electrostatic network on the apron inner wall, exert electrostatic adsorption's effect to impurity, adsorb it to the apron inner wall of return air inlet top on, absorbed by the negative pressure environment in the return air inlet, the electric charge opposite with electrostatic network is applyed to the electrostatic ring on the return air inlet simultaneously, resumes the neutralization state of electrical property in the impurity, avoids producing mutual electrical adsorption and jam in the transmission course in the impurity return air pipe to the application effect of aluminum alloy die casting blank precision forming technology has been promoted.

The invention has the following beneficial effects:

1. the die-casting die has the advantages that the die cavity of the die-casting die is completely sealed through the arranged end cover, so that suspended and attached impurities in the die cavity are taken out through circulating nitrogen in a high-pressure state; the filling blocks, the cushion blocks and the embedded blocks are arranged on the sealing plate, so that the sealing effect on different cavity cavities during installation is met; the cavity in the filling block is arranged, so that air flow is supplemented into the cavity through the filling block, the filling block is attached to the end face of the cavity, and the sealing effect of the filling block in the through groove is ensured.

2. According to the invention, the sealing cloth wound in the filling block is pulled out by the spring rod which is arranged in the notch in a sliding manner, so that the situation that the filling block is pushed away by filling air flow is avoided; the air return opening of the backflow plate arranged on the embedded block faces the inner wall of the cover plate, and impurities float to the end cover under the action of circulating air flow and are absorbed by the backflow plate; the electrostatic net of setting on the apron inner wall adsorbs impurity and is absorbed on the apron inner wall of return air inlet top to through the neutralization state of electrostatic ring recovery electric property in the impurity, avoid the impurity in the return air pipe to produce electric property adsorption and jam.

Drawings

The invention is further described with reference to the following figures and embodiments.

FIG. 1 is a flow chart of a precision forming process of an aluminum alloy die casting blank in the invention;

FIG. 2 is a perspective view of the purge machine of the present invention;

FIG. 3 is a perspective view of the end cap assembly of the present invention;

FIG. 4 is an enlarged view of a portion of FIG. 3 at A;

FIG. 5 is a cross-sectional view of a filler body component of the present invention;

FIG. 6 is a perspective view of a return plate assembly of the present invention;

in the figure: the device comprises an end cover 1, a gas cylinder 2, a vacuum pump 3, a cover plate 4, a panel 5, an insert block 51, a backflow plate 52, an air return opening 53, an electrostatic ring 531, an electrostatic net 532, a sealing plate 6, a filling block 61, a cushion block 62, a cavity 63, a notch 64, a notch 65, a spring rod 66, a sealing cloth 67, a through groove 7, a gas pipe 8 and a gas return pipe 9.

Detailed Description

In order to make the technical means, the creation characteristics, the achievement purposes and the effects of the invention easy to understand, the invention is further described with the specific embodiments.

As shown in fig. 1 to 6, the precision forming process of the aluminum alloy die casting blank according to the invention comprises the following steps:

s1, cleaning the cavity: injecting nitrogen from an end cover 1 of a die-casting cavity port through a gas cylinder 2 of a purging machine to enable the air pressure inside the cavity to be within 0.7-0.9MPa, controlling the nitrogen to circulate in the cavity for 3-4min, then pumping out the nitrogen inside the die-casting cavity through a vacuum pump 3, keeping the pressure inside the cavity below 0.03MPa, and controlling the temperature of the cavity to be within 40-45 ℃ through a thermostat; circulating nitrogen pressurization circulation is carried out on the die-casting cavity, impurities attached to the air in the cavity are cleaned, and finally the cavity is maintained in a negative pressure state, so that the metal liquid poured subsequently can be filled into the space in the cavity fully, and the defect caused by the bubble phenomenon in the metal liquid is reduced;

s2, pressurizing and filling: pouring molten metal of aluminum alloy into the cavity of S1, pressurizing and supplementing the molten metal after the inner space of the cavity is fully poured, and enabling the volume of the molten metal filled into the cavity to exceed 8-11% of the volume of the cavity; the pressurizing condition in the aluminum alloy die-casting is achieved by pouring excessive molten metal into the cavity, and the pressurizing pouring parameters are controlled according to the preset molten metal content;

s3, pressure stabilization and heat preservation: after the pouring process of the molten metal in S2 is completed, keeping the pressure in the cavity in a stable state for more than 2 hours, and simultaneously controlling the temperature of the cavity in a heating state to be within 660-750 ℃; the pressure stabilization and heat preservation of the molten metal in the cavity eliminate the residual stress effect generated by the impact between the molten metal and the inner wall of the cavity in the pouring process, and the state of the molten metal tends to be stable under the continuous heating action of the cavity, so that the molten metal has a balanced phase state in the subsequently formed aluminum alloy;

s4, cooling and forming: after the pressure stabilizing treatment of the molten metal in the cavity of S3 is completed, closing the heating of the cavity and opening the die orifice of the cavity to naturally cool the cavity to the normal temperature state, and maintaining the constant temperature treatment of the cavity for 40-70min when the aluminum alloy in the cavity is cooled to the range of 90-120 ℃, and finally obtaining a formed aluminum alloy die-casting blank; internal stress in the formed solid aluminum alloy is consumed through waste heat of constant temperature treatment of the cavity, and stability of physical properties of the aluminum alloy die-cast blank is ensured;

the blowing machine in the S1 comprises an end cover 1, a gas cylinder 2, a vacuum pump 3 and a controller; the end cover 1 is arranged on the port of the cavity, and the end cover 1 enables the cavity to be in a closed state; the end cover 1 comprises a cover plate 4, a panel 5 and a closing plate 6; the inner wall of the cover plate 4 is slidably mounted on the outer wall of the panel 5; the middle parts of the cover plate 4 and the panel 5 are provided with through grooves 7, and the cover plate 4 and the panel 5 are divided into two parts by the through grooves 7; the sealing plate 6 is slidably arranged on the outer walls of the tops of the cover plate 4 and the panel 5, the sliding direction of the sealing plate 6 is perpendicular to the sliding direction of the cover plate 4, and the cover plate 4 and the panel 5 which are divided into two parts are connected through the sealing plate 6; the seal plate 6 is provided with a gas pipe 8, and the tail end of the gas pipe 8 is communicated with the gas cylinder 2; an air return pipe 9 is arranged on the cover plate 4, and the tail end of the air return pipe 9 is communicated with a vacuum pump 3; the controller is used for controlling the operation of the purging machine; when the die-casting die is used, the die cavity can contact air impurities and remain in the cavity during storage, the impurities are mixed into poured molten metal and are attached to the surface of aluminum alloy in the die-casting process, the surface quality of a die-casting blank is reduced, the impurities attached to the inner wall of the cavity are difficult to be cleaned in the exhaust process of the die cavity, the heat transfer effect of liquid aluminum alloy forming in the die-casting process can be influenced, the surface defects of the aluminum alloy blank can be caused after the die-casting is finished, and the application effect of a precision forming process is reduced; therefore, according to the invention, through the end cover 1 arranged on the cavity, before the die-casting process is carried out, the end cover 1 is adapted to be mounted on the ports of the cavities with different specifications through the sliding adjustment among the cover plate 4, the panel 5 and the closing plate 6 in the end cover 1, the cavities are sealed, the controller is started, the gas cylinder 2 in the purging machine is filled with circulating nitrogen into the cavities, and impurities attached to the inner wall of the cavity are cleaned out through the negative pressure effect generated by the adsorption action of the vacuum pump 3 at the tail end of the gas return pipe 9 and are collected by the gas return pipe 9; the invention utilizes the arranged end cover 1 to completely seal the die cavity of the die casting die, and the gas transmission pipe 8 and the gas return pipe 9 which are arranged on the sealing plate 6 of the end cover 1 are matched to lead the suspended and attached impurities in the cavity to be taken out through the circulated nitrogen under the high-pressure state, and the closed installation of the die cavities with different specifications is met through the sliding adjustment among the cover plate 4, the panel 5 and the sealing plate 6 in the end cover 1, the application range of the purging machine is enlarged, thereby improving the use effect of the precision forming process of the aluminum alloy die casting blank.

In one embodiment of the present invention, the sealing plate 6 is provided with filling blocks 61, the filling blocks 61 are respectively installed on two ends of the bottom of the sealing plate 6, and the filling blocks 61 make the sealing plate 6 and the inner walls of the ports of the cover plate 4 and the panel 5 on the same plane; the closing plate 6 is also provided with a fixed cushion block 62, and the cushion block 62 is positioned on the through groove 7 of the panel 5; the panel 5 is provided with an insert 51, the insert 51 is fixed on the side surface of the end part of the panel 5, and the insert 51 enables the panel 5 to be overlapped with the side wall of the cover plate 4; the end cover 1 is mounted on cavities with different specifications by adjusting the position relation among the cover plate 4, the panel 5 and the closing plate 6, and the staggered end inner walls weaken the sealing effect of the end cover 1 during sliding adjustment; through setting up packing 61 and cushion 62 on shrouding 6 to cooperate with the abaculus 51 of panel 5 tip, in the in-process of adjusting the size of end cover 1 that slides, packing 61 compensaties the lateral wall breach between apron 4 and panel 5, cushion 62 supplyes the logical groove 7 breach to panel 5 top, abaculus 51 increases the lateral part inner wall of apron 4 and coincides on the lateral part inner wall of panel 5, make the internal surface of end cover 1 lateral wall laminate completely with the port of die cavity, satisfy the airtight effect between its cover and die cavity of guaranteeing to different die cavity mounting effects, thereby the application scope of aluminum alloy die casting blank precision forming technology has been promoted.

As an embodiment of the invention, a cavity 63 is arranged in the filling block 61, the top end of the filling block 61 is communicated with the gas pipe 8, and a notch 64 is arranged on the side surface of the filling block 61 facing the cavity; the air flow filled in the air pipe 8 enters the cavity from the notch 64 along the cavity 63 of the filling block 61; when the size of the filling block 61 is adjusted to be matched with the port of the installed cavity, the filling block 61 in the through groove 7 needs to be completely attached to the cavity due to the requirement of the sealing performance of the end cover 1, and the sealing performance of the filling block 61 in the deformation process is not interfered; through the cavity 63 that sets up in the filling block 61, cooperate with the gas-supply pipe 8 on its top, in the in-process of filling nitrogen gas to the die cavity, the air current supplements to the die cavity through filling block 61 for the filling block 61 laminating of deformation after the adjustment is on the terminal surface of die cavity, ensures the airtight effect of filling block 61 in logical groove 7, thereby has reached the leakproofness requirement of aluminum alloy die casting blank precision molding technology.

As an embodiment of the present invention, a notch 65 is provided on a side wall of the notch 64, and a sliding elastic rod 66 is provided in the notch 65; the elastic rod 66 is provided with a fixed sealing cloth 67, and the tail end of the sealing cloth 67 is wound in the filling block 61 at the bottom of the notch 64; the elastic rod 66 protrudes out of the side face of the filling block 61, and the elastic rod 66 is clamped on the port of the cavity to pull out the wound sealing cloth 67; after the end cover 1 is installed on the cavity ports with different specifications, the degree that the inner wall of the end cover 1 extends into the cavity ports is different, so that the bottom of the notch 64 in the filling block 61 is directly contacted with the cavity, the injected nitrogen acts on the cavity exposed at the notch 64, the air flow pushes away the filling block 61 by taking the cavity as a reference, and the sealing effect of the end cover 1 is further damaged; through the notch arranged in the notch 64, the elastic rod 66 which is installed in the notch in a sliding mode is used for pulling out the sealing cloth 67 wound in the filling block 61, the elastic rod 66 protrudes out of the outer surface of the filling block 61, the end cover 1 is used for lifting the elastic rod 66 on the installed cavity port, the cavity position corresponding to the notch 64 is blocked by the sealing cloth 67, meanwhile, the attaching effect between the sealing cloth and the cavity is increased due to the action of filled air flow on the sealing cloth 67, the situation that the filling block 61 is pushed away is avoided, and therefore the application effect of the precision forming process of the aluminum alloy die casting blank is improved.

As an embodiment of the present invention, a return plate 52 is disposed on the insert 51, and an air return opening 53 is disposed on the top of the return plate 52; the air return opening 53 is communicated with the air return pipe 9 through an embedded block 51; in the nitrogen circulation process in the cavity, impurities in the cavity are taken away, and the air return pipe 9 driven by the vacuum pump 3 is used as a backflow source of air in the cavity, so that air flow conveyed in the air conveying pipe 8 can be directly sucked away, and the cleaning effect of the filling air flow on the cavity is reduced; through setting up the backward flow board 52 on the abaculus 51, make the return air inlet 53 of backward flow board 52 towards the inner wall of apron 4, weakened the direct adsorption to end cover 1 position when vacuum pump 3 moves for the air current of filling to the cavity inside suspends adnexed impurity, floats to the position of end cover 1 under circulation's air current effect, is absorbed through backward flow board 52, thereby has promoted the application effect of aluminum alloy die casting blank precision forming technology.

As an embodiment of the present invention, an electrostatic ring 531 is disposed at an end of the air return opening 53, an electrostatic net 532 is further disposed on an inner wall of the cover plate 4 corresponding to the electrostatic ring 531, and charge polarities of the electrostatic ring 531 and the electrostatic net 532 are opposite; impurities floating to the end cover 1 area are drawn by the circulating airflow, the flow velocity is reduced due to the airflow steering in the end cover 1 area, the impurities tend to be balanced under the self gravity action and are difficult to move to the air return opening 53, and the cleaning effect on the impurities in the cavity is weakened; through the electrostatic net 532 arranged on the inner wall of the cover plate 4, the impurities are applied with electrostatic adsorption, and are adsorbed on the inner wall of the cover plate 4 above the air return opening 53 and absorbed by the negative pressure environment in the air return opening 53, and meanwhile, the electrostatic ring 531 on the air return opening 53 applies charges opposite to the electrostatic net 532, so that the electrical neutralization state in the impurities is recovered, the blockage caused by mutual electrical adsorption in the transmission process of the impurities in the air return pipe 9 is avoided, and the application effect of the precision forming process of the aluminum alloy die casting blank is improved.

When the die casting mold is used, the cavity can contact air impurities and remain in the cavity during storage, the impurities are mixed into the poured molten metal and attached to the surface of the aluminum alloy during die casting, and the surface quality of a die casting blank is reduced; through the end cover 1 arranged on the cavity, before the die-casting process is carried out, the end cover 1 is adapted to be installed on the ports of the cavities with different specifications through the sliding adjustment among the cover plate 4, the panel 5 and the closing plate 6, the cavities are sealed, the controller is started, the gas cylinder 2 in the blowing machine is filled with circulating nitrogen into the cavities, and impurities attached to the inner wall of the cavity are cleaned out through the negative pressure effect generated by the adsorption effect of the vacuum pump 3 at the tail end of the gas return pipe 9 and are collected by the gas return pipe 9; the filling block 61 and the cushion block 62 are arranged on the sealing plate 6 and matched with the insert block 51 at the end part of the panel 5, in the process of adjusting the size of the end cover 1 in a sliding way, the filling block 61 makes up a gap on the side wall between the cover plate 4 and the panel 5, the cushion block 62 supplements a gap on the through groove 7 above the panel 5, the insert block 51 heightens and coincides the inner wall of the side part of the cover plate 4 on the inner wall of the side part of the panel 5, so that the inner surface of the side wall of the end cover 1 is completely attached to the port of the cavity, and the sealing effect between a cover and the cavity is ensured while the installation effect on; the cavity 63 arranged in the filling block 61 is matched with the gas transmission pipe 8 at the top end of the cavity, and in the process of filling nitrogen into the cavity, airflow is supplemented into the cavity through the filling block 61, so that the adjusted deformed filling block 61 is attached to the end surface of the cavity, and the sealing effect of the filling block 61 in the through groove 7 is ensured; the sealing cloth 67 wound in the filling block 61 is pulled out by the elastic rod 66 arranged in the notch 64 in a sliding mode, the elastic rod 66 protrudes out of the outer surface of the filling block 61, the end cover 1 lifts the elastic rod 66 on the port of the installed cavity, the position of the cavity corresponding to the notch 64 is blocked by the sealing cloth 67, and meanwhile the filling air flow acts on the sealing cloth 67 to increase the attaching effect between the sealing cloth 67 and the cavity, so that the situation that the filling block 61 is pushed away is avoided; the return board 52 arranged on the insert 51 makes the return opening 53 of the return board 52 face the inner wall of the cover board 4, so that the direct adsorption effect on the position of the end cover 1 when the vacuum pump 3 operates is weakened, the air flow filled into the cavity suspends the attached impurities, floats to the position of the end cover 1 under the action of the circulating air flow, and is absorbed by the return board 52; the electrostatic net 532 arranged on the inner wall of the cover plate 4 exerts electrostatic adsorption effect on the impurities, and the impurities are adsorbed on the inner wall of the cover plate 4 above the air return opening 53 and absorbed by the negative pressure environment in the air return opening 53, and meanwhile, the electrostatic ring 531 on the air return opening 53 exerts electric charges opposite to the electrostatic net 532, so that the electric neutralization state in the impurities is recovered, and the blockage caused by mutual electric adsorption in the transmission process of the impurities in the air return pipe 9 is avoided.

The foregoing illustrates and describes the principles, general features, and advantages of the present invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.