Vacuum pouring anti-breaking vacuum system and working method thereof

Abstract

The invention discloses a vacuum pouring anti-breaking vacuum system and a working method thereof. The system comprises a first-stage hopper, a floating plate, a first rubber tube valve assembly, a second-stage hopper, a vacuum breaking valve and a second rubber tube valve assembly. The first-stage hopper is located on the upper portion of the second-stage hopper, the first-stage hopper and the second-stage hopper are communicated through a first rubber tube valve assembly, the floating plate is arranged on the top of the first-stage hopper, the vacuum breaking valve is arranged on the second-stage hopper, and a second rubber tube valve assembly is arranged at the bottom of the second-stage hopper. The anti-breaking vacuum cone can increase the flowing resistance of the middle slurry of the secondary hopper, reduce the flowing speed and reduce the difference between the flowing speed of the middle slurry and the flowing speed of the side slurry. The safety of the product pouring process can be improved, the pouring quality of the product is guaranteed, the production efficiency is improved, the production cost is reduced, the production efficiency is improved, and the personal safety of workers is guaranteed.

Description

Technical Field

[0001] The present invention belongs to the technical field of vacuum casting, and particularly relates to a vacuum pouring anti-breaking vacuum system and its working method. Background Art

[0002] Currently, in the casting of composite solid propellants for small solid rocket motors, the "manual face-to-face" operation is still adopted: operators control the feed valve and observe at the casting station. During the multi-product and multi-station casting process, each station requires someone to be on duty for feeding, discharging, observing, and adjusting the valve. This "manual face-to-face" operation method with concentrated personnel has high labor intensity, high safety risks, and low production efficiency. At the same time, the volatile gases of the propellant are toxic and harmful to the human body. The production mode of the propellant is not matching the task requirements, and there are serious deficiencies in ensuring the safety of the production process and the reliability of product quality. In the existing "manual face-to-face" operation process, it mainly relies on the experience of workers, without actual parameters for support. At the same time, because the casting equipment is relatively backward and there is no effective data monitoring means, it is difficult to online test the detailed microscopic state information during the casting process.

[0003] Another major deficiency of the existing production mode is also manifested in the excessive "manual face-to-face" operations. The high safety risks in the production process of the propellant are related to the large number of "manual face-to-face" operations. For a long time in the past, due to the complex and strict requirements of solid rocket motors for the performance of the propellant, many production links can only ensure the quality through on-site "manual face-to-face" by personnel. Coupled with the large variety and small total amount of propellant production requirements in the past, the difficulty of developing a new fully automated production line is very high, and the problem of "manual face-to-face" operations has not been completely solved. The large number of "manual face-to-face" operations also leads to the production process being disassembled into many isolated processes. With the start of large-scale emergency production, problems such as long transfer times between isolated processes seriously limit the improvement of production efficiency. Front-line production personnel can only complete production tasks by extending working hours and "rotating multiple shifts, day and night without stopping". This greatly increases the fatigue degree of personnel and equipment, and is prone to errors during the production process of the propellant, further increasing safety and quality risks. Summary of the Invention

[0004] In view of the above technical problems, the present invention provides a vacuum pouring anti-breaking vacuum system and its working method, which solve the problems of low production efficiency, inconsistent product quality, high labor intensity, high safety risks, etc. faced by manual "face-to-face" pouring.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] A vacuum pouring anti-breaking vacuum system includes a primary hopper, a floating plate, a first rubber hose valve assembly, a secondary hopper, a vacuum-breaking valve, and a second rubber hose valve assembly;

[0007] The primary hopper is located above the secondary hopper, and the two are connected through a first rubber hose valve assembly. The floating plate is arranged at the top of the primary hopper. The vacuum-breaking valve is arranged on the secondary hopper, and the second rubber hose valve assembly is arranged at the bottom of the secondary hopper.

[0008] Further, it further includes an anti-vacuum-breaking cone. The anti-vacuum-breaking cone is arranged at the center inside the secondary hopper. The anti-vacuum-breaking cone can increase the flow resistance of the slurry in the middle of the secondary hopper, reduce the flow speed, and reduce the flow speed difference between the slurry in the middle and the slurry on the side.

[0009] Further, the upper surface of the anti-vacuum-breaking cone is a gradually expanding surface from top to bottom.

[0010] Further, the lower part of the anti-vacuum-breaking cone includes a three-pronged claw, and the three-pronged claw is inserted into the bottom outlet of the secondary hopper for guiding and positioning.

[0011] Further, it further includes a perforated plate. The perforated plate is arranged at the outlet of the first rubber hose valve assembly, and a plurality of small holes are formed on the perforated plate.

[0012] Further, it further includes an explosion-proof camera. The explosion-proof camera is installed on the observation sight glass of the secondary hopper.

[0013] Further, it further includes a primary hopper water bath joint and a secondary hopper water bath joint. The primary hopper water bath joint is connected to the primary hopper, and the secondary hopper water bath joint is connected to the secondary hopper.

[0014] Further, it further includes a hopper clamp. The hopper clamp is used to connect the primary hopper and the secondary hopper.

[0015] Further, it further includes a pressure sensor. The pressure sensor is connected to the secondary hopper.

[0016] A working method of the vacuum casting anti-vacuum-breaking system according to the above includes the following steps:

[0017] Place the mold into the vacuum cylinder, place the secondary hopper at the pouring station, move the vacuum cylinder to the pouring station and position it below the secondary hopper, place the primary hopper filled with slurry on the secondary hopper and connect the primary hopper and the secondary hopper. After evacuating the secondary hopper, open the first hose valve assembly to start pouring the slurry. After completing the slurry pouring, close the first hose valve assembly. Pass nitrogen into the secondary hopper through the vacuum break valve, and at the same time evacuate the vacuum cylinder. After evacuating the vacuum cylinder, open the second hose valve assembly, and the slurry is poured into the mold through the second hose valve assembly. During the pouring process, the anti-vacuum break cone increases the flow resistance of the slurry in the middle of the secondary hopper, reduces the flow rate, reduces the flow rate difference between the middle slurry and the slurry on the side, and prevents the secondary hopper from breaking vacuum during the pouring process. When the pouring amount of the slurry in the mold reaches the set value, close the second hose valve assembly to complete the pouring.

[0018] Compared with the prior art, the advantages of the present invention include:

[0019] (1) The vacuum pouring anti-vacuum break system of the present invention improves the safety of the product pouring process, ensures the pouring quality of the product, and improves production efficiency by adopting a quantitative pouring method of primary and secondary hoppers in a closed environment of the vacuum cylinder. It can not only reduce production costs, improve production efficiency, and ensure product quality, but also effectively eliminate safety risks, achieve the goal of safe production, and ensure the personal safety of employees;

[0020] (2) The present invention adds an anti-vacuum break cone in the middle of the secondary hopper, increases the flow resistance of the slurry in the middle, reduces the flow rate, makes the flow rate on the side basically equal to the flow rate in the middle, makes the flow rate of the slurry tend to be balanced, reduces the flow rate difference of the slurry, reduces the size of the "eddy current", and avoids the destruction of the vacuum degree.

[0021] In addition to the features and advantages described above, the principle and other features and advantages of the present invention will be further described in detail below with reference to the drawings and embodiments. Brief Description of the Drawings

[0022] Figure 1 It is a schematic diagram of the overall structure of the vacuum pouring anti-vacuum break system.

[0023] Figure 2 It is a first perspective cross-sectional view of the vacuum pouring anti-vacuum break system.

[0024] Figure 3 It is a second perspective cross-sectional view of the vacuum pouring anti-vacuum break system.

[0025] Figure 4 It is a schematic diagram of the flower plate structure.

[0026] Figure 5 It is a schematic diagram of the anti-vacuum break cone structure.

[0027] Figure 6 Schematic diagram of the flow state of the slurry during the pouring process of the secondary hopper

[0028] Figure 7 Schematic diagram of the flow state of the slurry during the pouring process of the secondary hopper

[0029] Figure 8 Schematic diagram of the flow state of the slurry during the pouring process of the secondary hopper

[0030] Figure 9 Schematic diagram of the flow state of the slurry during the pouring process of the secondary hopper Specific implementation mode

[0031] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. The implementation of the present invention will be described in detail below in conjunction with specific embodiments.

[0032] Combined with Figures 1-3 , an automatic vacuum pouring system of the present invention mainly adopts two-stage hopper pouring, including a primary hopper 1, a floating plate 2, a first hose valve assembly 3, an explosion-proof camera 4, a perforated plate 5, a secondary hopper 6, a vacuum-breaking cone 7, a vacuum-breaking valve 8, a water bath joint 9 for the primary hopper, a water bath joint 10 for the secondary hopper, a hopper clamp 11, a pressure sensor 12, and a second hose valve assembly 13.

[0033] The primary hopper 1 is equipped with a water circulation interface. After connecting the circulating water, the slurry in the primary hopper 1 can be heated to a specified temperature. After a certain amount of slurry is loaded in the primary hopper, the floating plate 2 presses on the slurry to prevent the slurry from generating a suction vortex phenomenon resulting in vacuum breakage. The secondary hopper 6 is equipped with a water circulation interface. After connecting the circulating water, the slurry in the secondary hopper 6 can be heated to a specified temperature. The secondary hopper 6 is equipped with a vacuum interface and can be evacuated to achieve a vacuum environment in the secondary hopper 6.

[0034] The on-off between the primary hopper 1 and the secondary hopper 6 is controlled by the first hose valve assembly 3. The on-off between the secondary hopper 6 and the curing mold is controlled by the hose valve assembly 13. The mold mainly plays the role of slurry pouring, forming, curing and transporting, and can be composed of different types of propellant mold shells, mold covers, mold transport trays, etc. Temperature sensors are arranged above both the primary hopper and the secondary hopper to monitor the temperature and liquid level of the slurry in real time.

[0035] The inlet of the secondary hopper 6 is equipped with a perforated plate 5 (such as Figure 4As shown in the figure, the ceiling 5 adopts a structure similar to a flower sprinkler. This structure is provided with many small holes to increase the contact area between the slurry and the vacuum environment. Under the action of vacuum pumping, the air bubbles in the slurry can be effectively eliminated. The driving force for the slurry to enter the secondary hopper 6 from the primary hopper 1 is the pressure difference between vacuum and atmospheric pressure. The secondary hopper 6 is equipped with a vacuum-breaking valve 8, which is connected to the nitrogen gas source. Opening the vacuum-breaking valve 8 can change the secondary hopper from a vacuum environment to normal pressure or slightly positive pressure. The secondary hopper 6 is equipped with an observation sight glass, and an explosion-proof camera 4 is also installed on the sight glass to achieve remote real-time monitoring of the slurry situation in the secondary hopper 6. The secondary hopper 6 is equipped with a pressure sensor 12 to monitor the vacuum pressure in the secondary hopper 6 in real time.

[0036] During the pouring process of the secondary hopper, the vacuum will also be broken without any treatment. Therefore, an anti-vacuum-breaking cone 7 is installed at the bottom of the secondary hopper. The slurry in the secondary hopper is affected by its own gravity and the air pressure formed by introducing nitrogen, and a pressure difference is formed with the vacuum in the bottom mold cavity. The slurry flows from the secondary hopper into the corresponding mold in the vacuum cylinder through the hose valve. During this process, the slurry at the outlet of the secondary hopper is affected by gravity and pressure difference and will flow into the mold at the shortest distance. However, the slurry within the inclined plane range of the secondary hopper is affected by the friction of the inner wall surface of the hopper and the flow distance, and the closer the slurry is to the wall surface, the slower its flow speed will be. This causes the liquid level of the slurry in the middle part of the secondary hopper to drop faster than that of the slurry near the inner wall, resulting in the vacuum-breaking phenomenon of the slurry in the secondary hopper. To avoid this situation, an anti-vacuum-breaking cone 7 is set at the outlet of the secondary hopper, which can increase the flow resistance of the slurry in the middle of the secondary hopper 6, reduce the flow speed, reduce the flow speed difference between the middle slurry and the slurry on the side, make the flow speed of the slurry on the side basically equal to that in the middle, reduce the speed of the "eddy current", and avoid the destruction of the vacuum degree. In a specific embodiment, as Figure 5 shown, this anti-vacuum-breaking cone 7 is inserted upside down at the outlet of the secondary hopper. The upper surface of the anti-vacuum-breaking cone 7 is a gradually expanding surface from top to bottom. The lower three-pronged claws are used for guiding and positioning at the outlet of the secondary hopper to prevent tipping and facilitate installation. By changing the flow state of the slurry in the secondary hopper through the structural characteristics of this anti-vacuum-breaking cone, it is ensured that the slurry in the secondary hopper will not have a vacuum-breaking phenomenon during the entire automatic pouring process; combined with Figures 6-9, through simulation means for theoretical verification, an anti - vacuum - breaking cone 7 is set at the bottom of the secondary hopper 6, nitrogen (shown in blue medium) is pressurized at the upper part of the secondary hopper, and a slurry (red medium) placed in the secondary hopper is a non - Newtonian fluid. Observe the flow state of the entire casting slurry and the change of the slurry liquid level in the secondary hopper, so as to explain the effect of this anti - vacuum - breaking cone on preventing vacuum - breaking during the entire casting process at the theoretical level; during the process of increasing nitrogen - pressurized casting, in the presence of the anti - vacuum - breaking cone 7, the slurry liquid level drops in a relatively stable state. Therefore, it can be concluded that this anti - vacuum - breaking cone has a relatively significant improvement in the risk of vacuum - breaking in the secondary hopper, and can effectively prevent the slurry in the secondary hopper from experiencing a vortex - sucking phenomenon and vacuum - breaking, avoiding the occurrence of casting process failure phenomena.

[0037] The operation process of the automatic vacuum casting system of the present invention is as follows:

[0038] 1. Mold preparation: Manually place the mold on the mold transport vehicle and transport it to the mold loading position;

[0039] 2. Secondary hopper 6 preparation: Manually place the secondary hopper 6 on the hopper storage rack;

[0040] 3. The truss manipulator places the mold on the mold buffer position into the mold access position of the casting cylinder (put into the vacuum cylinder);

[0041] 4. The truss manipulator places the secondary hopper 6 at the casting station, and at the same time, the vacuum cylinder moves to the casting station and rises to the position below the secondary hopper 6;

[0042] 5. Manually operate to distribute the material to the first - stage hopper 1;

[0043] 6. Manually place the first - stage hopper 1 on the hopper storage rack;

[0044] 7. The truss manipulator places the first - stage hopper 1 on the secondary hopper 6;

[0045] 8. Manually use connecting parts such as pipe clamp valves and hose clamps to physically connect the first - stage hopper 1 and the secondary hopper 6;

[0046] 9. After the connection is completed, the personnel leave the site;

[0047] 10. The secondary hopper 6 is evacuated to reach the preset vacuum degree, and the first hose valve assembly 3 of the first - stage hopper 1 is opened for pre - degassing of the slurry (the pre - degassing method is mainly realized by the secondary casting method. When casting for the first stage, the slurry is pre - degassed through the flower plate 5 and the vacuum degree of the secondary hopper. After pre - degassing, the gas in the slurry has been removed, and there will be no gas - breaking phenomenon when the secondary hopper 6 pours the slurry into the mold. At this time, the boiling layer can be eliminated, and thus the sputtering phenomenon when the slurry bubbles break can be eliminated);

[0048] 11. After the pouring of the secondary hopper 6 is completed, the first rubber hose valve assembly 3 of the primary hopper 1 is closed;

[0049] 12. Nitrogen is passed into the secondary hopper 6, and at the same time, the vacuum cylinder is evacuated;

[0050] 13. When the vacuum cylinder is evacuated to the preset vacuum degree, the second rubber hose valve assembly 13 of the secondary hopper 6 is opened for the pouring operation of the slurry (the anti - vacuum - breaking cone 7 plays the role of preventing the secondary hopper 6 from breaking vacuum during the pouring process);

[0051] 14. When the detection mechanism feedbacks that the pouring volume reaches the set value, the second rubber hose valve assembly 13 of the secondary hopper 6 for pouring is closed, and the vacuum cylinder is broken vacuum;

[0052] 15. The vacuum cylinder returns to the mold access position, and the truss manipulator takes the mold to the mold blanking station; the process ends.

[0053] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above - mentioned embodiments. What is described in the above - mentioned embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of the present invention claimed is defined by the appended claims and their equivalents.

Claims

1. A vacuum casting anti-break vacuum system, characterized in that, It includes a primary hopper (1), a floating plate (2), a first rubber hose valve assembly (3), a secondary hopper (6), a vacuum-breaking valve (8), and a second rubber hose valve assembly (13). The primary hopper (1) is located above the secondary hopper (6), and the two are connected through the first rubber hose valve assembly (3). The floating plate (2) is arranged at the top of the primary hopper (1). The vacuum-breaking valve (8) is arranged on the secondary hopper (6), and the second rubber hose valve assembly (13) is arranged at the bottom of the secondary hopper (6).

2. The vacuum casting anti-break vacuum system according to claim 1, characterized in that, It further includes an anti-vacuum-breaking cone (7). The anti-vacuum-breaking cone (7) is arranged at the center inside the secondary hopper (6). The anti-vacuum-breaking cone (7) can increase the flow resistance of the slurry in the middle of the secondary hopper (6), reduce the flow speed, and reduce the flow speed difference between the slurry in the middle and the slurry on the side.

3. The vacuum casting anti-break vacuum system according to claim 2, characterized in that, The upper surface of the anti-vacuum-breaking cone (7) is a gradually expanding surface from top to bottom.

4. The vacuum casting anti-break vacuum system according to claim 3, wherein, The lower part of the anti-vacuum-breaking cone (7) includes a three-pronged claw, and the three-pronged claw is inserted into the bottom outlet of the secondary hopper (6) for guiding and positioning.

5. The vacuum casting anti-break vacuum system according to any one of claims 2-4, characterized in that It further includes a perforated plate (5). The perforated plate (5) is arranged at the outlet of the first rubber hose valve assembly (3), and a plurality of small holes are provided on the perforated plate (5).

6. The vacuum casting anti-break vacuum system according to claim 5, wherein, It further includes an explosion-proof camera (4). The explosion-proof camera (4) is installed on the observation sight glass of the secondary hopper (6).

7. The vacuum casting anti-break vacuum system according to claim 5, characterized in that, It further includes a primary hopper water bath joint (9) and a secondary hopper water bath joint (10). The primary hopper water bath joint (9) is connected to the primary hopper (1), and the secondary hopper water bath joint (10) is connected to the secondary hopper (6).

8. The vacuum casting anti-breaking vacuum system according to claim 5, characterized in that, It further includes a hopper clamp (11). The hopper clamp (11) is used to connect the primary hopper (1) and the secondary hopper (6).

9. The vacuum casting anti-break vacuum system according to claim 5, characterized in that, It further includes a pressure sensor (12). The pressure sensor (12) is connected to the secondary hopper (6).

10. A working method of the vacuum casting anti-breaking vacuum system according to any one of claims 5-9, characterized in that, It includes the following steps: Place the mold in the vacuum cylinder, place the secondary hopper (6) at the pouring station, move the vacuum cylinder to the pouring station and position it below the secondary hopper (6), place the primary hopper (1) filled with slurry on the secondary hopper (6) and connect the primary hopper (1) and the secondary hopper (6). After the secondary hopper (6) is evacuated, open the first rubber hose valve assembly (3) to start pouring the slurry. After the slurry pouring is completed, close the first rubber hose valve assembly (3). Pass nitrogen into the secondary hopper (6) through the vacuum-breaking valve (8), and at the same time, evacuate the vacuum cylinder. After the vacuum cylinder is evacuated, open the second rubber hose valve assembly (13), and the slurry is poured into the mold through the second rubber hose valve assembly (13). During the pouring process, the anti-vacuum-breaking cone (7) increases the flow resistance of the slurry in the middle of the secondary hopper (6), reduces the flow speed, and reduces the flow speed difference between the slurry in the middle and the slurry on the side, preventing the secondary hopper (6) from breaking vacuum during the pouring process. When the pouring amount of the slurry in the mold reaches the set value, close the second rubber hose valve assembly (13) to complete the pouring.

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