A method for cutting off the flow of liquid material for pellet casting propellant

Abstract

The present invention provides a method for cutting off the flow of a pellet casting propellant casting liquid material, comprising: step 1, fixing an assembled mold in a casting tank, keeping a Robert clamp in an open state, and fixing one end of a casting hose through a fixing hole of the Robert clamp from bottom to top on a tail pipe of a bottom cover of the mold; step 2, moving the Robert clamp below the tail pipe, and connecting a casting hose with a switch to a casting liquid material container; step 3, closing a casting pipeline switch, and performing vacuum treatment on the casting tank and the liquid material container for 4 hours respectively; step 4, reducing the vacuum degree in the liquid material container according to the requirements of the process regulations, opening the casting pipeline switch, and closing the casting pipeline switch after the casting liquid fills the medicine particle bed; step 5, restoring the pressure in the casting tank and the liquid material container to atmospheric pressure, closing the Robert clamp and cutting off the hose, and transferring the casting mold to the next process. The present invention effectively improves production efficiency, ensures production safety, and reduces labor intensity.

Description

Technical Field

[0001] The invention belongs to the technical field of propellant manufacturing, relates to a particle casting propellant, and in particular to a method for cutting off the flow of a casting liquid material of a particle casting propellant. Background Art

[0002] The pellet casting process has flexible charging forms, which can realize free-loading charging and shell-bonded charging. The size of the charge column is not limited, and special-shaped charge columns with complex structures can be cast. Therefore, it is widely used in the preparation and production of modified double-base propellant charges. The pellet casting process is a key process for propellant forming. Its process principle is to use the difference in vacuum degree to press the casting liquid from the storage tank through the pipeline into the mold of the casting tank, so that the liquid fills the gaps between the medicine particles in the mold, thereby obtaining a solid-liquid mixture with a higher uniformity.

[0003] The schematic diagram of the casting process is shown in Figure 1 ,from Figure 1 It can be seen that the casting pipeline is an important channel connecting the casting mold and the liquid tank. The casting liquid needs to flow through the casting pipeline into the mold to complete the casting operation. Figure 2 , the specific operations are as follows:

[0004] First, before the casting operation begins, the casting pipeline is connected and fixed to the bottom cover of the mold. Currently, personnel use copper wire and explosion-proof pliers to complete the operation. During this process, neither personnel nor tools come into contact with hazardous materials.

[0005] Second, under the condition of human-machine isolation, the liquid is pressed into the casting mold through the casting pipeline through the vacuum pressure difference between the liquid tank and the casting tank. In order to prevent incomplete plasticization of the medicine particles and affect the propellant molding quality, the liquid casting height usually exceeds the upper part of the medicine particles by about 1 cm.

[0006] Third, after the casting process is completed, in order to prevent the liquid from flowing back, the pipeline at the mold end needs to be closed first. Currently, personnel use copper wire and explosion-proof pliers to complete the operation. The liquid pipeline is bent 180° and then fastened with copper wire. Since there is casting liquid in the pipeline, there is a squeezing effect on the liquid during the tightening process, which is very dangerous.

[0007] During the pipeline closure process, personnel need to enter the site, open the casting tank operation window, and use tools to bend and tighten the pipeline filled with casting liquid. The process of tightening the copper wire with pliers may cause the material to explode. Therefore, this method has problems such as high safety risks, low efficiency, and high labor intensity.

[0008] In order to solve the above problems, a Chinese invention patent with application publication number CN 108438296A provides a device and method for automatically tightening and cutting a cable tie. The method uses a motor to automatically tighten the cable tie. However, the cable tie cannot be effectively installed and positioned, and it is difficult to achieve complete human-machine isolation in the pipeline closure link of the pellet casting propellant process. In addition, the tightening process still cannot avoid mechanical stimulation of the material, posing a safety risk. Summary of the invention

[0009] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a method for cutting off the flow of a casting liquid material for a granular casting propellant, so as to solve the technical problem that the methods in the prior art still have safety risks.

[0010] In order to solve the above technical problems, the present invention adopts the following technical solutions to achieve the above problems:

[0011] A method for cutting off the flow of a pellet casting propellant casting liquid, the method comprising the following steps:

[0012] Step 1: Fix the assembled mold in the casting tank, keep the Robert clamp in the open state, pass one end of the casting hose from bottom to top through the fixing hole of the Robert clamp, and then fix it on the tail pipe of the bottom cover of the mold.

[0013] Step 2: Move the Robert clamp to the bottom of the tail pipe and connect the casting hose with a switch to the casting liquid container.

[0014] Step three, turn off the casting pipeline switch and perform vacuum treatment on the casting tank and liquid container for 4 hours respectively.

[0015] Step 4: Reduce the vacuum degree in the liquid container according to the process regulations, open the casting pipeline switch, and close the casting pipeline switch after the casting liquid fills the medicine particle bed.

[0016] Step 5: restore the pressure in the casting tank and the liquid container to atmospheric pressure, close the Robert clamp and cut off the hose, and transfer the casting mold to the next process.

[0017] The present invention also has the following technical features:

[0018] The forming process of the pelletized propellant is a gap-filling casting process, in which the casting liquid enters the mold from the bottom under pressure to fill the gaps between the pellet beds.

[0019] The inner diameter of the mold ranges from 40 mm to 500 mm.

[0020] The outer diameter of the hose is in the range of 10 mm to 40 mm.

[0021] The inner diameter of the Robert clamp ranges from 10 mm to 40 mm, matching the outer diameter of the hose.

[0022] Compared with the prior art, the present invention has the following technical effects:

[0023] (I) The present invention combines material properties to effectively improve production efficiency, ensure production safety, and reduce labor intensity, which is of great significance to the field.

[0024] (II) The present invention adopts Robert clamp components to achieve flow cutoff of casting liquid, which provides a constructive idea for the design of human-machine isolation process in the pipeline closure link of the pellet casting propellant casting process. It has the advantages of safety, high efficiency and convenience, and can be applied to the process and equipment design of human-machine isolation process prototypes, which is conducive to the realization of the automated process of pellet casting propellant forming.

[0025] (III) This method is applicable to the casting process of pelletized propellants of various common sizes; this method is applicable to the casting process of pelletized propellants of various casting flow rates; this method is applicable to various types of Robert clamp structures.

[0026] (IV) The present invention aims at the characteristics of liquid filling gap flow in the double propellant granulation casting process, and adopts the principle of portable Robert clamp to cut off flow, so as to realize convenient flow stopping of casting liquid. The method has the advantages of good cutting effect, high safety and high efficiency, and establishes a good theoretical foundation for the automation improvement of pipeline sealing operation in the granulation casting process of double propellant casting. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of the casting process.

[0028] Figure 2 Schematic diagram of the casting process.

[0029] The specific contents of the present invention are further explained in detail below in conjunction with embodiments. DETAILED DESCRIPTION

[0030] It should be noted that, unless otherwise specified, all raw materials and equipment in the present invention are raw materials and equipment known in the prior art.

[0031] The overall technical concept of the present invention is: the present invention provides a method for cutting off the flow of casting liquid based on Robert clamp. First, the working principle of Robert clamp to prevent the backflow of liquid is to press the inner wall of the hose tightly, and the locking structure has strong reliability, which highly matches the characteristics of the flow of liquid in the hose during the casting process; secondly, Robert clamp is made of plastic materials such as polyvinyl chloride, and the extrusion generated during the switching process is small, and there is almost no friction on the liquid, so the safety risk is relatively low; in addition, Robert clamp is small in size, low in cost, and easy to replace, which is convenient for installation on the casting pipeline. It only needs a single-direction action to complete the closure, and can be transported with the mold to the subsequent workstation. Based on the above characteristics, this method for cutting off the flow of casting liquid has good pipeline sealing effect and process matching.

[0032] Specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent changes made on the basis of the technical solution of this application fall within the protection scope of the present invention.

[0033] Embodiment 1:

[0034] This embodiment provides a method for cutting off the flow of a pellet casting propellant casting liquid material, the method comprising the following steps:

[0035] Step 1: Fix the assembled Φ40mm sample mold in the sample casting tank, keep the Robert clamp with an inner diameter of 12mm in the open state, pass one end of the casting hose with an outer diameter of 12mm from bottom to top through the fixing hole of the Robert clamp, and then fix it on the tail pipe of the bottom cover of the mold.

[0036] Step 2: Move the Robert clamp to the bottom of the tail pipe and insert the casting hose with a switch into the beaker containing the casting liquid.

[0037] Step three, turn off the casting pipeline switch and treat the casting tank and liquid container with a vacuum of -0.095MPa for 4 hours respectively.

[0038] Step 4: The ambient pressure of the liquid container is increased to -0.035MPa, and the casting pipeline switch is turned on to allow the casting liquid to fill the medicine particle bed and then the casting pipeline switch is closed.

[0039] Step 5: restore the pressure in the casting tank and the liquid container to atmospheric pressure, close the Robert clamp and cut off the hose below it, and transfer the casting mold to the next process.

[0040] The process operation of this embodiment shows that the flow cutoff method of the pellet casting propellant casting liquid material based on Robert clamp can effectively replace the original copper wire tying operation for sample casting. The process is simple and convenient, and there is no leakage after the Robert clamp is closed.

[0041] Embodiment 2:

[0042] This embodiment provides a method for cutting off the flow of a pellet casting propellant casting liquid material, the method comprising the following steps:

[0043] Step 1: Fix the assembled Φ158mm product mold in the product casting tank, keep the Robert clamp with an inner diameter of 20mm in the open state, pass one end of the casting hose with an outer diameter of 20mm from bottom to top through the fixing hole of the Robert clamp, and then fix it on the tail pipe of the bottom cover of the mold.

[0044] Step 2: Move the Robert clamp to the bottom of the tail pipe and connect it to the tank containing the casting liquid through a hose with a valve.

[0045] Step three, turn off the casting pipeline switch and treat the casting tank and liquid container with a vacuum of -0.095MPa for 4 hours respectively.

[0046] Step 4: Increase the pressure in the liquid storage tank to -0.035MPa, open the casting pipeline switch, allow the casting liquid to fill the medicine particle bed, and then close the casting pipeline switch.

[0047] Step 5: restore the pressure in the casting tank and the liquid storage tank to atmospheric pressure, close the Robert clamp and cut off the hose below it, and transfer the casting mold to the next process.

[0048] The process operation of this embodiment shows that the flow cutoff method of the pellet casting propellant casting liquid material based on Robert clamp can effectively replace the original copper wire tying operation for casting medium-sized products. The process is simple and convenient, and there is no leakage after the Robert clamp is closed.

[0049] Embodiment 3:

[0050] This embodiment provides a method for cutting off the flow of a pellet casting propellant casting liquid material, the method comprising the following steps:

[0051] Step 1: Fix the assembled Φ360mm cored product mold in the product casting pit, keep the 20mm inner diameter Robert clamp in the open state, pass one end of the 20mm outer diameter casting hose from bottom to top through the fixing hole of the Robert clamp, and then fix it on the oil inlet port at the top of the mold core.

[0052] Step 2: Move the Robert clamp to the top of the oil inlet pipe and connect it to the tank containing the casting liquid through a hose with a valve.

[0053] Step three, turn off the casting pipeline switch, and treat the casting pit and liquid storage tank with a vacuum of -0.095MPa for 4 hours respectively.

[0054] Step 4: Increase the pressure in the liquid storage tank to -0.035MPa, open the casting pipeline switch, allow the casting liquid to fill the medicine particle bed, and then close the casting pipeline switch.

[0055] Step 5: restore the pressure in the casting pit and the liquid material storage tank to atmospheric pressure, close the Robert clamp and cut off the hose above it, and transfer the casting mold to the next process.

[0056] The process operation of this embodiment shows that the flow cutoff method of the pellet casting propellant casting liquid material based on Robert clamp can effectively replace the original copper wire tying operation for casting large core products. The process is simple and convenient, and there is no leakage after the Robert clamp is closed.

Claims

1. A method for cutting off the flow of a pellet casting propellant casting liquid, characterized in that: The method comprises the following steps, Step 1: fix the assembled mold in the casting tank, keep the Robert clamp in the open state, pass one end of the casting hose from bottom to top through the fixing hole of the Robert clamp, and then fix it on the tail pipe of the bottom cover of the mold; Step 2: Move the Robert clamp to the bottom of the tail pipe and connect the casting hose with a switch to the casting liquid container; Step 3: Turn off the casting pipeline switch and perform vacuum treatment on the casting tank and liquid container for 4 hours respectively; Step 4: according to the process requirements, reduce the vacuum degree in the liquid container, open the casting pipeline switch, and close the casting pipeline switch after the casting liquid fills the medicine particle bed; Step 5: restore the pressure in the casting tank and the liquid container to atmospheric pressure, close the Robert clamp and cut off the hose, and transfer the casting mold to the next process; The inner diameter of the mold ranges from 40mm to 500mm; The outer diameter of the hose ranges from 10 mm to 40 mm; The inner diameter of the Robert clamp ranges from 10 mm to 40 mm, matching the outer diameter of the hose.

2. The method for stopping the flow of a pellet casting propellant casting liquid as claimed in claim 1, characterized in that: The forming process of the pellet casting propellant is a gap-filling casting process, in which the casting liquid enters the mold from the bottom under pressure to fill the gaps between the pellet beds.

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