NL2040277A

NL2040277A - A vacuum exhaust valve for casting

Info

Publication number: NL2040277A
Application number: NL2040277A
Authority: NL
Inventors: Wang Yuanhao; Xiong Jingui; Chen Yuanfang; Zhang Xiaoling; Shi Jun
Original assignee: Univ Chongqing Technology
Priority date: 2024-07-08
Filing date: 2025-04-30
Publication date: 2025-06-13
Also published as: CN118669572B; CN118669572A

Abstract

The invention discloses a vacuum exhaust valve for casting, comprising a movable valve shell, a static valve shell, a push rod, a trigger valve core, a sealing valve core, and a deﬂector plate. The upper end face of the movable valve shell is provided with a ﬂow channel. The interior of the movable valve shell is equipped with a ﬁrst mounting hole and a second mounting hole, both of which are connected to the ﬂow channel. The trigger valve core is installed in the ﬁrst mounting hole, and the sealing valve core is installed in the second mounting hole. The movable valve shell also has a third mounting hole, with the push rod installed in the third mounting hole. The third mounting hole is located between the ﬁrst and second mounting holes, with the ﬁrst mounting hole close to the inlet of the ﬂow channel. The lower end face of the static valve shell is provided with a groove corresponding to the ﬂow channel. The middle part of the deﬂector plate is hinged to the groove, with the trigger end of the deﬂector plate in contact with the upper end of the trigger valve core, and the force-bearing end of the deﬂector plate close to the inlet of the ﬂow channel. The invention optimizes the structure of the ﬂow channel, improves the power to push the trigger valve core, and helps increase the casting yield.

Description

A VACUUM EXHAUST VALVE FOR CASTING

TECHNICAL FIELD

The invention relates to the technical field of casting, specifically to a vacuum exhaust valve for casting.

BACKGROUND

Pressure die casting refers to a casting method in which molten or semi-molten metal is injected into a metal mold at high speed and crystallizes under pressure, referred to as die casting. The commonly used injection pressure is 30-70 MPa, and the filling speed is about 0.5-50 m/s. The die casting mold includes a fixed mold and a movable mold.

The movable mold covers the fixed mold and, when closed, forms a mold gate, mold cavity, and overflow groove between the fixed mold and the movable mold. The movable and fixed molds also have a pressurized chamber. During the process of filling the die casting mold cavity with molten metal, gases such as ordinary air and vaporized release agents are generated within the mold cavity. If these gases cannot be expelled from the cavity, they will affect the quality of the finished product. Therefore, it is necessary to have an exhaust valve connected to the overflow groove at the end of the mold.

Patent CN214888876U discloses a casting exhaust vacuum valve, which includes a movable valve shell, a static valve shell, a trigger valve core, and a sealing valve core; it also includes a connecting disk connected to the trigger valve core and sealing valve core. The trigger valve core is pushed by molten metal to drive the connecting disk and sealing valve core, thereby causing the sealing valve core to block the exhaust hole. The interior of the movable valve shell has two first sliding blocks that contact the conical end of the trigger valve core. Each of the first sliding blocks has a protrusion that contacts the connecting disk, and the connecting disk has two limiting holes, with each limiting hole located next to one protrusion. The middle part of the trigger valve core has a limiting disk, and the connecting disk has a limiting groove corresponding to the limiting disk. The movable valve shell is equipped with a tightening component to press the connecting disk tightly against the two protrusions.

The above-mentioned exhaust vacuum valve uses a tightening component and the trigger valve core to together drive the sealing valve core, reducing the kinetic energy of molten metal needed to push the valve core. This increases the acceleration when the vacuum valve core closes and reduces the possibility of jamming. However, it still has shortcomings: since the first sliding blocks and the connecting disk are both pressed below the push rod, the frictional resistance between the first sliding blocks and the connecting disk is large, requiring significant pressure for the trigger valve core to push the first sliding blocks. Due to the straight-through design of the flow path, without any obstructing structures, some molten metal flows first to the trigger valve core during the exhaust process. However, this small amount of molten metal cannot push the trigger valve core, which can result in the exhaust vacuum valve not closing properly and causes overflow of molten metal, affecting product quality.

SUMMARY

The present invention aims to optimize the flow channel structure, increase the driving force for pushing the trigger valve core, and reduce the number of defective products by addressing the deficiencies in the prior art. This invention provides a vacuum exhaust valve for casting, which includes a movable valve shell, a static valve shell, a push rod, a trigger valve core, a sealing valve core, and a turbulence plate. The upper end surface of the movable valve shell is equipped with a flow channel, and the interior of the movable valve shell 1s provided with a first installation hole and a second installation hole, both of which communicate with the flow channel. The trigger valve core is installed in the first installation hole, and the sealing valve core is installed in the second installation hole. The movable valve shell also has a third installation hole, in which the push rod is installed, and the third installation hole is located between the first and second installation holes, with the first installation hole being close to the liquid inlet of the flow channel. The lower end surface of the static valve shell has a groove corresponding to the flow channel. The middle part of the turbulence plate is hinged in the groove, and the triggering end of the turbulence plate contacts the upper end of the trigger valve core, with the force-bearing end of the turbulence plate being near the liquid inlet of the flow channel. The flow channel is equipped with a deflection plate that curves towards the liquid inlet of the flow channel, with the end of the deflection plate being adjacent to the force-bearing end of the turbulence plate. The molten metal flows through the space between the deflection plate and the turbulence plate, causing the triggering end of the turbulence plate to press the trigger valve core. The interior of the movable valve shell has a linkage plate adapted to the lower part of the trigger valve core, as well as two triggering plates adapted to the lower end of the trigger valve core. The linkage plate has two opposing positioning holes, and each triggering plate has a boss adapted to the positioning holes. The linkage plate is pressed between the push rod and one of the triggering plates, and the edge of the linkage plate is connected to the sealing valve core. By moving the trigger valve core downward, the bosses of the two triggering plates are moved into the corresponding positioning holes, thereby causing the push rod to push the linkage plate, which moves the sealing valve core downward to seal the flow channel.

The beneficial effects of this device are as follows: By reducing the cross-sectional area

IO of the flow channel near the liquid inlet through the turbulence plate and deflection plate, even a small amount of molten metal flowing through this structure will push the force- bearing end of the turbulence plate upward, causing the triggering plate to swing downward and press the trigger valve core downward. The bosses of the two triggering plates then move into the corresponding positioning holes, and the balance between the push rod, linkage plate, and triggering plates is disrupted. Under the downward pressure of the push rod, the linkage plate and sealing valve core are moved downward, sealing the flow channel. Compared to conventional vacuum exhaust valves, the previously insufficient molten metal that could not move the sealing valve core downward is now able to do so because the turbulence plate utilizes a lever mechanism, amplifying the kinetic energy of the flowing molten metal to push the sealing valve core downward.

This increases the driving force for the trigger valve core, improves the sensitivity of the vacuum exhaust valve, and helps increase the casting yield.

Preferably, the side of the movable valve shell has a drainage port, which communicates with the side of the second installation hole. The second installation hole is equipped with a sliding sleeve, and the sealing valve core is slidably connected to the sliding sleeve. The side of the sliding sleeve has a through hole corresponding to the drainage port. The sealing valve core moves downward to seal the sliding sleeve, thereby sealing the flow channel. The interior of the movable valve shell is equipped with a reset hole opposite the lower end of the sealing valve core, and the reset hole has a first spring that contacts the lower end of the sealing valve core. Before the trigger valve core is activated (i.e., before sealing), the first spring’s elasticity is used to push the sealing valve core upward, ensuring that the flow channel is unobstructed and gas can be discharged promptly.

Preferably, an elastically deformable diaphragm is installed between the force-bearing end and the groove to seal the gap between the turbulence plate and the groove. After the gap between the flow plate and the groove is sealed, the molten metal can only flow through the space between the turbulence plate and the deflection plate, thereby pushing the turbulence plate to rotate counterclockwise, ensuring the uniqueness of the linkage, and reducing the failure rate of the vacuum exhaust valve.

Preferably, the part of the turbulence plate near the liquid inlet is arc-shaped, and the remaining part of the turbulence plate is a straight bar. The straight bar part of the turbulence plate contacts the trigger valve core. The arc-shaped piece near the force- bearing end increases the contact area with the molten metal, allowing the flowing molten metal to fully impact the arc-shaped piece, improving the efficiency of converting kinetic energy into mechanical energy. On the other hand, the straight bar trigger end is designed to reduce the resistance between the trigger end and the molten metal, allowing the flowing molten metal to not affect the downward movement of the trigger end.

Preferably, the upper end of the static valve shell has an adjustment hole opposite the push rod, and the adjustment hole is equipped with a second spring that tightens the push rod. The adjustment hole has a sliding sealing cover and a threaded cap, and the second spring is located between the sliding sealing cover and the threaded cap, with the sliding sealing cover positioned between the second spring and the push rod. The upper half of the adjustment hole has a thread that is adapted to the threaded cap, allowing the adjustment of the threaded cap’s insertion length to regulate the push rod’s thrust, making the device adaptable to different casting requirements for metals.

Preferably, the interior of the movable valve shell has an internal sliding cavity parallel to the second installation hole, and the internal sliding cavity is equipped with a balance sliding block connected to the other side of the linkage plate.

Preferably, the interior of the movable valve shell is equipped with a disc spring to tighten the two triggering plates. After each casting cycle, the movable and static valve shells separate as the moving and fixed molds separate, and the elastic force of the disc spring helps to remove the cooled metal from the flow channel, making cleaning more convenient.

BRIEF DESCRIPTION OF THE FIGURES

In order to more clearly illustrate the specific implementation of the present invention or the technical solution in the prior art, the following will briefly introduce the drawings required for the specific implementation or prior art description. In all drawings, similar 5 elements or parts are generally identified by similar figure marks. In the drawings, each element or part 1s not necessarily drawn according to the actual scale.

Figure 1 is a schematic diagram of the internal structure of the moving valve housing and the static valve housing in this embodiment;

Figure 2 is a schematic diagram of the flow channel after sealing in Figure 1;

Figure 3 is a schematic diagram of the structure of the spoiler in this embodiment;

Figure 4 is a bottom view of Figure 3.

In the attached drawings, the movable valve housing 1; the static valve housing 2; the push rod 3; the trigger valve core 4; the sealing valve core 5; the spoiler 6; the flow channel 7; the first mounting hole 8; the second mounting hole 9; the third mounting hole 10; the liquid discharge port 11; the linkage plate 12; the trigger plate 13; the positioning hole 14; the boss 15; the sliding sleeve 16; the liquid inlet 17; the through hole 18; the reset hole 19; the first spring 20; the inner sliding cavity 21; the balancing slider 22; the disc spring 23; the groove 24; the hinge shaft 25; the guide plate 26; the arc sheet 27; the straight rod 28; the diaphragm 29; the adjustment hole 30; the second spring 31; the sliding sealing cover 32; the threaded cap 33.

DETAILED DESCRIPTION OF THE INVENTION

The following is a detailed description of the embodiments of the technical solution of the present invention in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present vention, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present invention.

It should be noted that, unless otherwise specified, the technical terms or scientific terms used in this application should be the common meanings understood by technicians in the field to which the present invention belongs.

As shown in Figure 1, the present embodiment provides a vacuum exhaust valve for casting, including a moving valve shell 1, a static valve shell 2, a push rod 3, a trigger valve core 4, a sealing valve core 5, and a deflector plate 6. The upper end surface of the moving valve shell 1 is provided with a flow passage 7, and the interior of the moving valve shell 1 is provided with a first mounting hole 8 and a second mounting hole 9 communicating with the flow passage 7. The trigger valve core 4 is installed in the first mounting hole 8, and the sealing valve core 5 is installed in the second mounting hole 9.

The moving valve shell 1 is also provided with a third mounting hole 10, in which the push rod 3 is installed. The third mounting hole 10 is located between the first mounting hole 8 and the second mounting hole 9, with the first mounting hole 8 being close to the inlet 17 of the flow passage 7. The corresponding side of the moving valve shell 1 is provided with a drainage port 11, which communicates with the side of the second mounting hole 9. The third mounting hole 10 in this embodiment is not connected to the flow passage 7, and the flow passage 7 bypasses the third mounting hole 10 from its side.

Similar to existing exhaust valves, a linkage plate 12 adapted to the lower part of the trigger valve core 4 is arranged inside the moving valve shell 1, as well as two trigger plates 13 adapted to the lower end of the trigger valve core 4. The linkage plate 12 is provided with two opposite positioning holes 14, and each trigger plate 13 is provided with a boss 15 adapted to the positioning hole 14. The linkage plate 12 is pressed between the push rod 3 and one of the trigger plates 13, and the edge of the linkage plate 12 is connected to the sealing valve core 5. When the trigger valve core 4 moves downward, it pushes the bosses 15 of the two trigger plates 13 to move into the corresponding positioning holes 14, thus causing the push rod 3 to push the linkage plate 12, which drives the sealing valve core 5 downward to seal the flow passage 7. The sealing principle of the flow passage 7 is as follows: a sliding sleeve 16 is arranged in the second mounting hole 9, and the sealing valve core 5 is slidably connected to the sliding sleeve 16. The side of the sliding sleeve 16 is provided with a through hole 18 corresponding to the drainage port 11. By moving the sealing valve core 5 downward, the upper end of the sealing valve core 5 blocks the sliding sleeve 16, thus sealing the flow passage 7. The interior of the moving valve shell 1 is provided with a reset hole 19 opposite to the lower end of the sealing valve core 5, and the reset hole 19 is equipped with a first spring 20 that contacts the lower end of the sealing valve core 5. Before the trigger valve core 4 is activated, i.e, before sealing, the first spring 20 is used to push the sealing valve core 5 upward, ensuring that the flow passage 7 remains unobstructed,

allowing gas to be discharged in a timely manner.

In addition, the interior of the moving valve shell 1 is provided with an internal sliding cavity 21 parallel to the second mounting hole 9, in which a balance sliding block 22 is arranged and connected to the other side of the linkage plate 12. The role of the balance sliding block 22 is to balance the force on the linkage plate 12. Specifically, during the downward movement of the linkage plate 12, the balance sliding block 22 and the sealing valve core 5 are simultaneously moved downward, effectively preventing the linkage plate 12 from deviating during movement.

In this embodiment, the moving valve shell 1 is connected to the moving mold, and the corresponding static valve shell 2 is connected to the fixed mold. Inside the moving valve shell 1, there is a disc spring 23 used to press two trigger plates 13. After each casting is completed, the moving valve shell 1 and the static valve shell 2 are separated as the moving mold and fixed mold separate, and the elastic force of the disc spring 23 helps remove the cooled metal from the flow passage 7. making cleaning more convenient.

Unlike existing exhaust valves, the lower end surface of the static valve shell 2 is provided with a groove 24 corresponding to the flow passage 7. The middle part of the deflector plate 6 is hinged to the groove 24 through a hinge shaft 25, and the triggering end of the deflector plate 6 is in contact with the upper end of the trigger valve core 4, while the force-bearing end of the deflector plate 6 is near the inlet 17 of the flow passage 7. The flow passage 7 is provided with a guide plate 26 that curves toward the inlet 17 of the flow passage 7, and the end of the guide plate 26 is adjacent to the force-bearing end of the deflector plate 6. The molten alloy flows through the space between the guide plate 26 and the deflector plate 6, which causes the triggering end of the deflector plate 6 to push and compress the trigger valve core 4. The specific structure of the deflector plate 6 is as follows:

As shown in Figures 3 and 4, the part of the deflector plate 6 near the inlet 17 is shaped like an arc-shaped piece 27, and the remaining part of the deflector plate 6 is shaped like a straight rod 28. The straight rod 28 of the deflector plate 6 is in contact with the trigger valve core 4. The arc-shaped piece 27 near the force-bearing end increases the contact area with the molten alloy, allowing the flowing molten alloy to fully impact the arc- shaped piece 27, greatly improving the efficiency of converting kinetic energy into mechanical energy. On the other hand, the straight rod 28's triggering end is designed to reduce resistance between the triggering end and the molten alloy, allowing the flowing molten alloy not to affect the downward swing of the triggering end.

To ensure the molten metal can smoothly push the triggering end, a flexible diaphragm 29 is arranged between the force-bearing end and the groove 24 in this embodiment. The diaphragm 29 is heat-resistant and not melted by the high-temperature molten metal. The diaphragm 29 seals the gap between the deflector plate 6 and the groove 24. Once the gap between the flow plate and the groove 24 is sealed, the molten alloy can only flow through the space between the deflector plate 6 and the guide plate 26, thus ensuring that the molten alloy will push the deflector plate 6 to rotate counterclockwise, guaranteeing the uniqueness of the linkage mechanism and reducing the failure rate of the vacuum exhaust valve.

As shown in Figures 1 and 2, this embodiment reduces the cross-sectional area of the flow passage 7 near the inlet 17 by using the deflector plate 6 and guide plate 26. Even when only a small amount of molten alloy flows through this structure, it will push the force-bearing end of the deflector plate 6 to swing upwards, while the trigger plate 13 swings downward and compresses the trigger valve core 4. As a result, the bosses 15 of the two trigger plates 13 move into the corresponding positioning holes 14, breaking the balance between the push rod 3, linkage plate 12, and trigger plate 13. Under the downward pressure of the push rod 3, the linkage plate 12 and sealing valve core 5 are pushed downward, and after the sealing valve core 5 moves downward, it blocks the flow passage 7, thereby sealing the flow passage 7. Compared to existing vacuum exhaust valves, the sealing valve core 5, which would normally be unable to move downward due to a small amount of molten alloy, is instead moved downward by the lever principle utilized by the deflector plate 6, amplifying the kinetic energy of the flowing molten alloy to push the sealing valve core 5 downward. This increases the force pushing the trigger valve core 4 and improves the sensitivity of the vacuum exhaust valve, which is beneficial for improving the casting yield.

To meet the exhaust requirements for different types of metal casting, the upper end of the static valve shell 2 in this embodiment is provided with an adjustment hole 30 opposite the push rod 3. A second spring 31 is installed inside the adjustment hole 30 to press the push rod 3. The adjustment hole 30 is equipped with a sliding seal cover 32 and a threaded cap 33, with the second spring 31 positioned between the sliding seal cover 32 and the threaded cap 33, and the sliding seal cover 32 positioned between the second spring 31 and the push rod 3. The upper part of the adjustment hole 30 is provided with threads that match the threaded cap 33. By adjusting the insertion length of the threaded cap 33, the thrust of the push rod 3 can be adjusted to adapt to different metal casting requirements,

Finally, it should be noted that the above embodiments are only intended to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that modifications can be made to the technical solutions described in the embodiments, or some or all of the technical features can be equivalently substituted. Such modifications or substitutions do not depart from the scope of the technical solutions of the present invention, and they should be included within the scope of the claims and description of the present mvention.

Claims

Conclusions

1. A vacuum exhaust valve for casting, characterized in that it comprises a movable valve housing, a static valve housing, a push rod, a trigger valve core, a sealing valve core and a deflector plate; the upper end of the movable valve housing is provided with a flow channel, and the interior of the movable valve housing is provided with a first mounting hole and a second mounting hole, both of which communicate with the flow channel, the trigger valve core being mounted in the first mounting hole and the sealing valve core being mounted in the second mounting hole; the movable valve housing further has a third mounting hole in which the push rod is installed, and the third mounting hole is located between the first and second mounting holes, the first mounting hole being located close to the inlet of the flow channel; the lower end of the static valve body is provided with a groove corresponding to the flow channel, and the middle portion of the deflector plate pivots in the groove, with the trigger end of the deflector plate in contact with the upper end of the trigger valve core and the force-bearing end of the deflector plate being close to the inlet of the flow channel; the flow channel is provided with a deflector plate that bends toward the inlet of the flow channel, and the end of the deflector plate is adjacent to the force-bearing end of the deflector plate, and passes through the molten alloy between the deflector plate and the deflector plate, whereby the trigger end of the deflector plate presses the trigger valve core; the interior of the movable valve body is provided with a connecting plate that is adapted to the lower portion of the trigger valve core, and two trigger plates that are adapted to the lower end of the trigger valve core; the connecting plate has two opposite positioning holes, and each trigger plate has a protrusion that is matched with the positioning hole; the connecting plate is pressed between the push rod and one trigger plate, and the edge of the connecting plate is connected to the core of the sealing valve, whereby, by moving the core of the trigger valve downward, the protrusions of the two trigger plates are moved to the corresponding positioning holes, thereby making the push rod push the connecting plate and move the core of the sealing valve downward to seal the flow channel.

2. The vacuum exhaust valve for casting according to claim 1, characterized in that the side of the movable valve shell is provided with a discharge port, which communicates with the side of the second mounting hole.

3. The vacuum exhaust valve for casting according to claim 2, characterized in that the second mounting hole is provided with a sliding sleeve in which the sealing valve core is slidably mounted, and the side of the sliding sleeve is provided with a through hole corresponding to the discharge port, so that the sealing valve core moves downward to block the sliding sleeve with its upper end and thus seal the flow channel.

4. The vacuum exhaust valve for casting according to claim 3, characterized in that the interior of the movable valve shell is provided with a reset hole opposite to the lower end of the sealing valve core, and the reset hole includes a first spring contacting the lower end of the sealing valve core.

5. A vacuum exhaust valve for casting according to claim 1, characterized in that a flexible diaphragm is provided between the pressure-bearing element and the groove, which seals the opening between the deflector plate and the groove.

6. A vacuum exhaust valve for casting according to claim 1, characterized in that the portion of the deflector plate near the inlet is arcuate and the remaining portion of the deflector plate is a straight rod, the straight deflector plate contacting the core of the trigger valve.

7. A vacuum exhaust valve for casting according to claim 1, characterized in that the upper end of the static valve housing 1s is provided with an adjustment hole opposite the push rod, in which a second spring is placed for pressing the push rod.

8. The vacuum exhaust valve for casting according to claim 7, characterized in that the adjustment hole is provided with a sliding cover and a screw cover, the second spring is located between the sliding cover and the screw cover, and the sliding cover is located between the second spring and the push rod.

9. The vacuum exhaust valve for casting according to claim 1, characterized in that the interior of the movable valve shell is provided with an internal slide cavity parallel to the second fixing hole, in which a balance slide is connected to the other side of the connecting plate.

10. The vacuum exhaust valve for casting according to claim 1, characterized in that the interior of the movable valve shell is provided with a disc spring for pressing the two actuating plates.