Die casting vacuum structure

Abstract

The invention discloses a die-casting vacuum pumping structure, which belongs to the field of high-pressure casting. The valve body is provided with a through hole and a connecting hole connected with the through hole, the exhaust pipe is installed in the connecting hole, the end surface of the valve body away from the oil cylinder is provided with a groove, the through hole is arranged in the groove, the valve body is also provided with a receiving groove, the receiving groove and the through hole are coaxially arranged, the diameter of the receiving groove is larger than the diameter of the through hole, the rod body part of the valve stem is located in the through hole, the end cover is located at the top of the valve body, and an exhaust passage is formed between the side wall, the transition surface and the groove, the chamfer and the convex edge of the valve body. The oil cylinder drives the valve stem to move downward in the axial direction relative to the valve body, and the cross-sectional area of ​​the exhaust passage is reduced. When the side wall of the valve stem contacts the convex edge, the exhaust passage is closed, and the oil cylinder is not completely retracted at this time; the valve stem continues to move downward until the end cover is completely located in the receiving groove, and the oil cylinder is completely retracted at this time. During the retraction of the oil cylinder, effective sealing is performed in advance, and the aluminum liquid located on the upper part of the end cover cannot enter the valve body, thereby avoiding damage to the die-casting vacuum pumping structure.

Description

Technical Field

[0001] The invention relates to the field of high pressure casting, in particular to a die casting vacuum extraction structure. Background Art

[0002] In recent years, new energy vehicles have developed rapidly. New energy vehicles have put forward new requirements for structure, requiring a lighter body, while ensuring the safety of the vehicle. Therefore, a large number of automotive structural parts use aluminum alloy high-pressure casting.

[0003] In aluminum alloy high-pressure casting, the mold cavity contains a large amount of gas, which will lead to a high gas content in the product, directly affecting the product's performance. In addition, automotive structural parts need to be heat treated to improve the mechanical properties of the product. During heat treatment, the gas in the product will precipitate, causing bubbling of the product, affecting the product's appearance and performance. Therefore, it is necessary to minimize the gas content of the product, which gave rise to advanced vacuum die-casting technology for die-casting molds. By removing the gas in the die-casting mold cavity during the die-casting process, the pores and dissolved gases in the die-casting are eliminated or significantly reduced, thereby improving the mechanical properties and surface quality of the die-casting.

[0004] In the current vacuum die-casting technology, there are three main ways to evacuate the vacuum: 1. Hydraulic active valve, 2. Mechanical valve, 3. Vacuum exhaust plate. For large or lightweight products with high vacuum requirements, hydraulic active valves are mainly used, but the existing hydraulic active valve sealing surfaces include cone seals and straight + cone seals. It often happens that the oil cylinder does not return to the right position or the valve closing delay time is improperly set, causing aluminum liquid to rush into the vacuum valve, resulting in production failures. Summary of the invention

[0005] In order to overcome the deficiencies of the prior art, one of the objects of the present invention is to provide a die-casting vacuum pumping structure that can prevent aluminum liquid from rushing into the vacuum valve due to the oil cylinder not returning to its position or the improper setting of the valve closing delay time.

[0006] One of the purposes of the present invention is achieved by the following technical solution:

[0007] The die-cast vacuum structure comprises a drive assembly, a valve stem, a vacuum valve and an exhaust pipe, wherein the drive assembly comprises an oil cylinder and an oil pipe connected to the oil cylinder, the valve stem is drivingly connected to the oil cylinder, the vacuum valve comprises a valve body, the valve body is provided with a through hole coaxially arranged with the valve stem and a connecting hole connected with the through hole, the exhaust pipe is installed in the connecting hole, the end surface of the valve body away from the oil cylinder is provided with a groove, the through hole is arranged in the groove, the convex edge of the top of the through hole is provided with a chamfer, and the convex edge is formed at the intersection of the chamfer and the through hole, the valve body is also provided with a receiving groove, the receiving groove is coaxially arranged with the through hole, the diameter of the receiving groove is larger than the diameter of the through hole, and in the axial direction, the receiving groove is located between the groove and Between the connecting holes, the valve stem includes a rod body and an end cover located at the end of the rod body, the end cover includes a side wall and a transition surface, the transition surface extends from the bottom of the side wall to the end of the valve stem, the rod body is partially located in the through hole, and the end cover is located at the top of the valve body, and an exhaust passage is formed between the side wall, the transition surface of the end cover and the groove, chamfer and convex edge of the valve body. During the exhaust process of the exhaust pipe, the oil cylinder drives the valve stem to move axially downward relative to the valve body, and the cross-sectional area of ​​the exhaust passage is reduced. When the side wall of the valve stem contacts the convex edge, the exhaust passage is closed, and the oil cylinder is not fully retracted at this time; the valve stem continues to move downward until the end cover is completely located in the receiving groove, and the oil cylinder is fully retracted at this time.

[0008] Furthermore, the side wall and the receiving groove are tightly matched.

[0009] Furthermore, the tolerance zone of the side wall and the receiving groove is matched to E7 / h7.

[0010] Furthermore, the groove is in a straight line shape, and the width of the groove is greater than the maximum diameter of the chamfer.

[0011] Furthermore, the diameter of the chamfer gradually decreases from the groove to the through hole.

[0012] Furthermore, an extending direction of the groove is perpendicular to an axial direction of the connecting hole.

[0013] Furthermore, the transition surface is an arc-shaped surface.

[0014] Furthermore, the vacuum valve also includes a guide sleeve and a first sealing ring, the guide sleeve is installed inside the valve body, and the first sealing ring is located between the guide sleeve and the valve body to seal the guide sleeve and the valve body.

[0015] Furthermore, the vacuum valve further comprises a second sealing ring, wherein the second sealing ring is located between the guide sleeve and the rod body, and the second sealing ring seals the guide sleeve and the rod body.

[0016] Furthermore, the die-casting vacuum structure also includes a fixing component and a cooling component, the oil cylinder is installed on the fixing component, the cooling component includes a cooling plate and a coolant pipe connected to the cooling plate, and the cooling plate is located on the fixing component to cool the oil cylinder.

[0017] Compared with the prior art, the valve body of the die-cast vacuum structure of the present invention is provided with a through hole coaxially arranged with the valve stem and a connecting hole connected with the through hole, the exhaust pipe is installed in the connecting hole, the end face of the valve body away from the oil cylinder is provided with a groove, the through hole is arranged in the groove, the convex edge at the top of the through hole is provided with a chamfer, and the intersection of the chamfer and the through hole forms a convex edge, the valve body is also provided with a receiving groove, the receiving groove is coaxially arranged with the through hole, the diameter of the receiving groove is larger than the diameter of the through hole, and in the axial direction, the receiving groove is located between the groove and the connecting hole, the valve stem includes a rod body and an end cover located at the end of the rod body, the end cover includes a side wall and a transition surface, the transition surface extends from the bottom of the side wall to the end of the valve stem, the rod body is located in the through hole, and the end cover is provided with a side wall. The cover is located on the top of the valve body, and an exhaust channel is formed between the side wall, transition surface of the end cover and the groove, chamfer and convex edge of the valve body. During the exhaust process of the exhaust pipe, the oil cylinder drives the valve stem to move axially downward relative to the valve body, and the cross-sectional area of ​​the exhaust channel is reduced. When the side wall of the valve stem contacts the convex edge, the exhaust channel is closed, and the oil cylinder has not completely retracted at this time; the valve stem continues to move downward until the end cover is completely located in the receiving groove, and the oil cylinder is completely retracted at this time. Through the above design, when the oil cylinder drives the valve stem to retract, it has not yet retracted into place, the valve stem and the valve body are sealed, the exhaust channel is closed, and effective sealing is performed in advance. The aluminum liquid located on the upper part of the end cover cannot enter the valve body, thereby avoiding damage to the die-casting vacuum structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A three-dimensional diagram of the die-casting vacuum pumping structure of the present invention;

[0019] Figure 2 for Figure 1 A three-dimensional diagram of a valve stem of a die-cast vacuum structure;

[0020] Figure 3 A three-dimensional diagram of a vacuum valve for a die-casting vacuum pumping structure;

[0021] Figure 4 for Figure 3 A three-dimensional cross-sectional view of a vacuum valve;

[0022] Figure 5 for Figure 1 A cross-sectional view of a valve stem of a die-cast vacuum structure without retraction;

[0023] Figure 6 for Figure 1 The valve stem of the die-cast vacuum structure is retracted to the cross-sectional view just sealed;

[0024] Figure 7 for Figure 6 A magnified view of point A;

[0025] Figure 8 for Figure 1 Cross-sectional view of the valve stem of the die-cast vacuum structure returning to its original position.

[0026] In the figure: 10, drive assembly; 11, oil cylinder; 12, oil pipe; 20, fixing assembly; 30, cooling assembly; 31, cooling plate; 32, coolant pipe; 40, valve stem; 41, rod body; 42, end cover; 420, side wall; 421, transition surface; 50, vacuum valve; 51, valve body; 510, connecting hole; 511, through hole; 512, fixing groove; 513, groove; 514, chamfer; 515, convex edge; 516, receiving groove; 52, guide sleeve; 53, first sealing ring; 54, second sealing ring; 55, screw plug; 56, adjustment plate; 60, exhaust pipe; 70, pressure plate. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] It should be noted that when a component is referred to as being "fixed to" another component, it may be directly on the other component or there may be another intermediate component through which it is fixed. When a component is considered to be "connected to" another component, it may be directly connected to the other component or there may be another intermediate component at the same time. When a component is considered to be "set on" another component, it may be directly set on the other component or there may be another intermediate component at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0030] See also Figures 1 to 8The die-casting vacuum pumping structure includes a driving component 10, a fixing component 20, a cooling component 30, a valve stem 40, a vacuum valve 50, an exhaust pipe 60 and a pressing plate 70.

[0031] The driving assembly 10 includes an oil cylinder 11 and an oil pipe 12 . The oil pipe 12 is connected to the oil cylinder 11 . The oil pipe 12 supplies oil to the oil cylinder 11 to hydraulically drive the valve stem 40 to move axially.

[0032] The fixing assembly 20 is used to fix and install the driving assembly 10 .

[0033] The cooling assembly 30 includes a cooling plate 31 and a coolant pipe 32 . A cooling channel is provided in the cooling plate 31 . The coolant pipe 32 is connected to the cooling channel inside the cooling plate 31 . The cooling assembly 30 cools down the oil cylinder 11 .

[0034] The valve stem 40 is in transmission connection with the oil cylinder 11. During die casting, the oil cylinder 11 drives the valve stem 40 to extend, and the end cover 42 of the valve stem 40 presses against the aluminum liquid to perform die casting. After the die casting is completed, the valve stem 40 is retracted, and the air in the cavity is extracted by the exhaust pipe 60 during the retraction process. The valve stem 40 includes a rod body 41 and an end cover 42, and the end cover 42 is fixed to the end of the rod body 41. The diameter of the end cover 42 is larger than the diameter of the rod body 41. The end cover 42 is provided with a side wall 420 and a transition surface 421, the side wall 420 is cylindrical, and the transition surface 421 extends from the bottom of the side wall 420 to the top of the rod body 41. The transition surface 421 is a curved surface, and the transition surface 421 is an arc surface.

[0035] The vacuum valve 50 includes a valve body 51 , a guide sleeve 52 , a first sealing ring 53 , a second sealing ring 54 , a screw plug 55 and an adjustment plate 56 .

[0036] The valve body 51 is provided with a through hole 511, which passes through the valve body 51. The rod body 41 of the valve stem 40 is penetrated through the through hole 511 and can move along the through hole 511. A groove 513 is provided at the top of the valve body 51. The groove 513 is in a straight line shape. The through hole 511 is located in the groove 513. The diameter of the through hole 511 is smaller than the width of the groove 513. A chamfer 514 is provided at the top of the through hole 511. The top of the chamfer 514 extends to the groove 513, and the bottom of the chamfer 514 extends to the through hole 511. From the groove 513 to the through hole 511, the diameter of the chamfer 514 gradually decreases. A convex edge 515 is formed at the intersection of the chamfer 514 and the through hole 511.

[0037] The valve body 51 is further provided with a receiving groove 516, which is coaxially arranged with the through hole 511, and the diameter of the receiving groove 516 is larger than the diameter of the through hole 511. The receiving groove 516 is located at the top of the through hole 511, and is used to receive the retracted end cover 42.

[0038] The valve body 51 is also provided with a connecting hole 510, which is used to install the exhaust pipe 60. The connecting hole 510 is arranged along the radial direction of the valve body 51, and the connecting hole 510 is connected with the through hole 511. The exhaust pipe 60 exhausts air through the connecting hole 510, the through hole 511 and the air inlet channel. The valve body 51 is also provided with a fixing groove 512, which is located at the outer edge of the valve body 51, and is used to fix the pressure plate 70.

[0039] The guide sleeve 52 is installed inside the through hole 511, and the guide sleeve 52 is coaxially arranged with the through hole 511. The first sealing ring 53 is installed on the outer wall of the guide sleeve 52, and the first sealing ring 53 is located between the guide sleeve 52 and the valve body 51, and the first sealing ring 53 seals the guide sleeve 52 and the valve body 51.

[0040] The second sealing ring 54 is installed on the inner wall of the guide sleeve 52, and the second sealing ring 54 is located between the guide sleeve 52 and the rod body 41. The screw plug 55 is installed inside the valve body 51 and is threadedly matched with the valve body 51 to fix the guide sleeve 52 to the valve body 51. The adjustment plate 56 is installed at the bottom of the valve body 51.

[0041] The air extraction pipe 60 is installed in the connection hole 510 .

[0042] When using the die-casting vacuum structure, after die-casting is completed, the exhaust pipe 60 is evacuated, and at this time, the side wall 420 of the end cover 42, the transition surface 421 and the groove 513, chamfer 514 and convex edge 515 of the valve body 51 form an exhaust channel for exhaust. The oil cylinder 11 drives the valve stem 40 to move downward axially relative to the valve body 51, and the cross-sectional area of ​​the exhaust channel is reduced. When the side wall 420 of the valve stem 40 contacts the convex edge 515, the exhaust channel is closed, and the oil cylinder 11 is not completely retracted at this time; the valve stem 40 continues to move downward until the end cover 42 is completely located in the receiving groove 516, and the oil cylinder 11 is completely retracted at this time. Through the above design, when the oil cylinder 11 drives the valve stem 40 to retract, it has not yet retracted into place, and the valve stem 40 and the valve body 51 are sealed, and the exhaust channel is closed, and effective sealing is performed in advance, and the aluminum liquid located on the upper part of the end cover 42 cannot enter the valve body 51, avoiding damage to the die-casting vacuum structure.

[0043] The above embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which are equivalent modifications and improvements made to the above embodiments based on the essential technology of the present invention, and all of them belong to the protection scope of the present invention.

Claims

1. A die-casting vacuum pumping structure, comprising a drive assembly, a valve stem, a vacuum valve and an air extraction pipe, wherein the drive assembly comprises an oil cylinder and an oil pipe connected to the oil cylinder, and the valve stem is drivingly connected to the oil cylinder, characterized in that: The vacuum valve comprises a valve body, the valve body is provided with a through hole coaxially arranged with the valve stem and a connecting hole connected with the through hole, the exhaust pipe is installed in the connecting hole, the end surface of the valve body away from the oil cylinder is provided with a groove, the through hole is arranged in the groove, the convex edge of the top of the through hole is provided with a chamfer, and the intersection of the chamfer and the through hole forms a convex edge, the valve body is also provided with a receiving groove, the receiving groove is coaxially arranged with the through hole, the diameter of the receiving groove is larger than the diameter of the through hole, and in the axial direction, the receiving groove is located between the groove and the connecting hole, the valve stem comprises a rod body and an end cover located at the end of the rod body, the The end cover includes a side wall and a transition surface, the transition surface extends from the bottom of the side wall to the end of the valve stem, the rod body is partially located in the through hole, and the end cover is located at the top of the valve body. An exhaust passage is formed between the side wall and the transition surface of the end cover and the groove, chamfer and convex edge of the valve body. During the exhaust process of the exhaust pipe, the oil cylinder drives the valve stem to move axially downward relative to the valve body, and the cross-sectional area of ​​the exhaust passage is reduced. When the side wall of the valve stem contacts the convex edge, the exhaust passage is closed, and the oil cylinder is not fully retracted at this time; the valve stem continues to move downward until the end cover is completely located in the receiving groove, and the oil cylinder is fully retracted at this time.

2. The die-casting vacuum structure according to claim 1, characterized in that: The side wall is tightly matched with the receiving groove.

3. The die-casting vacuum structure according to claim 2, characterized in that: The tolerance zone of the side wall and the receiving groove is matched to E7 / h7.

4. The die-casting vacuum structure according to claim 1, characterized in that: The groove is in a straight line shape, and the width of the groove is greater than the maximum diameter of the chamfer.

5. The die-casting vacuum structure according to claim 4, characterized in that: The diameter of the chamfer gradually decreases from the groove to the through hole.

6. The die-casting vacuum structure according to claim 1, characterized in that: The extending direction of the groove is perpendicular to the axial direction of the connecting hole.

7. The die-casting vacuum structure according to claim 1, characterized in that: The transition surface is an arc-shaped surface.

8. The die-casting vacuum structure according to claim 1, characterized in that: The vacuum valve further comprises a guide sleeve and a first sealing ring. The guide sleeve is installed inside the valve body. The first sealing ring is located between the guide sleeve and the valve body to seal the guide sleeve and the valve body.

9. The die-casting vacuum structure according to claim 8, characterized in that: The vacuum valve further comprises a second sealing ring, which is located between the guide sleeve and the rod body, and seals the guide sleeve and the rod body.

10. The die-casting vacuum structure according to claim 1, characterized in that: The die-casting vacuum structure also includes a fixing component and a cooling component. The oil cylinder is installed on the fixing component. The cooling component includes a cooling plate and a coolant pipe connected to the cooling plate. The cooling plate is located on the fixing component to cool the oil cylinder.

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