Experimental device and method for casting charge variable-speed water-entry solidification process

Abstract

The invention provides a variable-speed water-entry solidification process test system. The variable-speed water-entry solidification process test system specifically comprises four subsystems, namely a water circulation system, a hot air system, a water-entry solidification device and an online test system, the water circulation system provides cooling water for the casting charge sequential solidification process; the hot air system provides hot air for the box body environment to ensure that the molten composite explosive cannot be solidified in advance; the water entry solidification device realizes the charge variable-speed water entry solidification process; the on-line test system completes temperature field and stress field tests in the charge internal solidification process, and provides data and basis for development of fusion casting charge theoretical research, defect prediction and the like. By means of the water entry solidification device, variable-speed water entry of casting charge is achieved, the liquid level is changed to rise at a constant speed, the solid phase growth rule is controlled more finely, tiny defects are reduced, and the solidification efficiency is improved; meanwhile, the test system can carry out new mechanism research on the charging solidification process through real-time on-line temperature stress test, die water entering speed, water temperature and other process parameters precise control, charging defects are more effectively reduced, the charging density and the product quality are improved, and the casting charging process is made to develop towards more lean control.

Description

Technical Field

[0001] The present invention belongs to the technical field of the casting charge process, and relates to an experimental device and method for a variable-speed water-entry solidification process of casting charge. Background Art

[0002] During the casting charge process, defects such as shrinkage cavities, porosity, and cracks are extremely likely to form, which affect the power and service safety of the warhead. At present, the mature casting charge processes at home and abroad mainly include layered casting, hot mandrel, and sequential solidification. Among them, sequential solidification, due to the uniform upward movement of the cooling medium, controls the growth order of the solid-liquid interface of the slurry, ensures that the volume of the slurry in the projectile shrinks during solidification is replenished, and reduces defects such as shrinkage cavities and porosity. Therefore, it is still the main developed process. However, for large-caliber and large-length-diameter-ratio charges, the solidification rates of the liquid surfaces at different positions are different, and the solidification conditions of the feeding channels are also different. The currently adopted method of uniform upward movement of the liquid surface will still bring subtle defects and the solidification efficiency is not high.

[0003] Based on this, the present invention designs an experimental device for a variable-speed water-entry solidification process of casting charge to carry out research on the variable-speed water-entry process, so as to further improve the quality of casting charge. Summary of the Invention

[0004] In view of the above situation, in order to improve the quality of casting charge, the purpose of the present invention is to provide a variable-speed water-entry solidification process test system, which uses a water-entry solidification device to control the water-entry speed of the mold under the hoisting mechanism through a servo motor, thereby controlling the liquid surface descent speed, controlling the solidification sequence and speed, and at the same time using real-time online temperature measurement and realizing precise control of process parameters such as the water-entry speed and water temperature during the charging process.

[0005] To achieve the above object, the present invention provides the following technical solution: providing a variable-speed water-entry solidification process test system, which specifically includes four subsystems: a water circulation system, a hot air system, a water-entry solidification device, and an online test system; the water circulation system provides cooling water for the sequential solidification process of casting charge; the hot air system provides hot air for the box environment to ensure that the molten mixed explosive will not solidify in advance; the water-entry solidification device realizes the variable-speed water-entry solidification process of the charge; the online test system completes the measurement of the temperature field and stress field during the internal solidification process of the charge, providing data and basis for carrying out theoretical research on casting charge and predicting defects.

[0006] The water circulation system consists of a water inlet pipe, a water outlet pipe, and a mold temperature controller; the water outlet pipe of the mold temperature controller is connected to one side of the water-entry solidification device, and the water inlet pipe is connected back to the mold temperature controller from the other side of the water-entry solidification device.

[0007] The hot air system is composed of a hot air blower, a wind direction converter, a left air duct, a middle air duct, a right air duct, and a sling connecting air duct. The air duct is led out from the hot air blower and is respectively connected to the left air duct, the right air duct, and the middle air duct through the direction converter. The hot air system enters the left and right sides and the middle position of the back of the water inlet solidification device through the left air duct, the right air duct, and the middle air duct. The middle air duct is the sling connecting air duct inside the water inlet solidification device.

[0008] The on-line testing system is composed of a fiber Bragg grating sensor, a debugging and demodulation instrument, a fiber Bragg grating sensor wire duct, and a fiber Bragg grating sensor bracket. First, the optical fiber with gratings is arranged according to the test point positions. The gratings are welded on the optical fiber, and the positions of the gratings are the positions of the measurement points. Then, each optical fiber is welded to the bracket, and the bracket is placed in the mold. Finally, the wiring of the fiber Bragg grating sensor is led out through the wire duct and connected to the fiber Bragg grating sensor debugging and demodulation instrument.

[0009] The water inlet solidification device is composed of a servo electric cylinder, a heat preservation box, a sling mechanism, a riser heat preservation mechanism, heat preservation glass, a water tank, a mold mechanism, and a heat preservation baffle. The heat preservation box is placed on the ground, the servo electric cylinder is placed on the top plate of the box body of the heat preservation box, the water tank is placed on the bottom plate of the box body of the heat preservation box, and the box body frame of the heat preservation box is installed with heat preservation glass and a box door.

[0010] The sling mechanism is composed of a servo electric cylinder ejector rod connecting flange, a stainless steel pipe connecting flange, a sling, a locknut, and a double-threaded stainless steel pipe. One end of the double-threaded stainless steel pipe is connected to the lead screw of the servo electric cylinder with two circular flanges, and the other end of the double-threaded stainless steel pipe is connected to the top end of the sling through a locknut.

[0011] The box body frame of the heat preservation box is composed of a cross beam connecting the servo electric cylinder flange, a cross beam for installing the riser heat preservation mechanism, a steel plate for installing glass on the side, and a support beam. The box body frame is welded by stainless steel square pipes. T-shaped through grooves are processed on the side of the cross beam of the box body frame, and grooves with a width smaller than the side length of the slider are processed on the bottom as the sliding track of the hot air diversion cover.

[0012] The riser heat preservation mechanism is composed of a hot air diversion cover, a long rod, and a slider. The riser heat preservation mechanism is connected to the hot air system through an air duct and is installed on the cross beam of the heat preservation box body frame. Moving the hot air diversion cover can make it close to or away from the mold to insulate the riser.

[0013] The mold mechanism is composed of a mold and a riser. The types of projectile molds include head-loading projectiles, tail-loading projectiles, and ordinary cylindrical molds. The riser can be connected to the mold through bolts.

[0014] A variable-speed water inlet solidification process method for casting charge includes the following steps: Step 1: Preparation of the hot air system; Manually assist in installing the riser insulation mechanism on the top crossbeam of the insulation box. One end of the wind direction converter is connected to the hot air blower, and the other end is connected to three air ducts. The three air ducts are respectively connected to two hot air diversion covers and the sling. The air ducts and the riser insulation mechanism are fixed with clamps; Step 2: Preparation of the water circulation system; The inlet and outlet water pipes of the water tank are respectively connected to the mold temperature controller. The mold temperature controller is started and the water temperature in the water tank is controlled at 20 - 70 °C; Step 3: Installation of sensors; First, lay the optical fiber with gratings according to the positions of the test points. The gratings are welded on the optical fiber, and the positions of the gratings are the positions of the measurement points. Then, weld each optical fiber to the bracket and place the bracket into the mold. Finally, the wiring of the fiber Bragg grating sensor is led out through the wire duct and connected to the fiber Bragg grating sensor debugging and demodulation instrument; Step 4: Injection of medicine and installation of the mold mechanism; The projectile mold and the riser are fixed with bolts. Manually assist in injecting the molten mixed explosive into the mold, and hang the mold mechanism on the sling. Manually assist in moving the heat insulation baffle to cover the riser to ensure a reasonable temperature inside the riser and prevent the slurry in the riser from solidifying prematurely; Step 5: Start the hot air system. Turn on the hot air blower, set the temperature to 80 - 95 °C, and close the door of the insulation box; Step 6: Control of the solidification of the cast charge when it enters the water. Start the servo electric cylinder. Through PLC control, the push rod of the electric cylinder extends, so that the sling mechanism and the mold mechanism move downward at a certain speed, and the speed range can be controlled within 0.05 - 0.6 mm·s-1; The motor control system real-time feedbacks motion data such as displacement and speed, and the on-line test system real-time collects the internal temperature and strain parameters of the slurry. The PLC can conduct quality prediction based on this, and carry out research on the influence of process parameters on quality by controlling the descending displacement speed.

[0015] Compared with the prior art, the beneficial effects of the present invention are: The use of the water-entry solidification device realizes the variable-speed water entry of the cast charge, changes the method of the liquid surface rising at a constant speed, more precisely controls the solid-phase growth law, reduces subtle defects, and improves the solidification efficiency; At the same time, the test system can conduct precise control through real-time on-line temperature stress testing, the water entry speed of the mold, water temperature and other process parameters, carry out research on the new mechanism of the charge solidification process, more effectively reduce the charge defects, thereby improving the charge density and product quality, and making the cast charge process develop towards more refined control. Description of the Drawings

[0016] Figure 1 It is the overall schematic diagram of the test system of the present invention; Figure 2 It is the overall structural schematic diagram of the water-entry solidification device of the present invention; Figure 3 It is the schematic diagram of the frame of the insulation box body of the present invention; Figure 4 It is a schematic diagram of the sling mechanism of the present invention; Figure 5 It is a schematic diagram of the use of the riser heat preservation mechanism of the present invention; Figure 6 is Figure 5 A-A direction sectional view of the schematic diagram of the use of the riser heat preservation mechanism; Figure 7 It is a schematic diagram of the riser heat preservation mechanism of the present invention; Figure 8 It is a schematic diagram of the mold mechanism of the present invention; Figure 9 It is the front view of the hot air system of the present invention; Figure 10 It is the top view of the hot air system of the present invention; Figure 11 It is a schematic diagram of the water circulation system of the present invention; Figure 12 It is a schematic diagram of the on-line testing system of the present invention; Figure 13 It is a schematic diagram of the structure of the fiber Bragg grating sensor of the present invention; Figure 14 It is a schematic diagram of the fiber Bragg grating layout of the on-line testing system of the present invention.

[0017] In the figure: 1. Water inlet solidification device; 11. Servo electric cylinder; 12. Heat preservation box; 121. Servo electric cylinder flange connection cross beam; 122. Riser heat preservation mechanism installation cross beam; 123. Steel plate; 124. Support beam; 13. Sling mechanism; 131. Servo electric cylinder ejector rod connection flange; 132. Stainless steel pipe connection flange; 133. Sling; 134. Locknut A; 135. Locknut B; 136. Double-threaded stainless steel pipe; 14. Riser heat preservation mechanism; 141. Slide block; 142. Long rod; 143. Hot air diversion cover; 15. Heat preservation glass; 16. Water tank; 17. Mold mechanism; 171. Cylindrical mold; 1711. Riser; 1712. Projectile mold; 172. Head-loading type projectile; 173. Tail-loading type projectile; 18. Heat preservation baffle; 2. Hot air system; 21. Hot air blower; 22. Wind direction converter; 23. Left air duct; 24. Middle air duct; 25. Right air duct; 26. Sling connection air duct; 3. Water circulation system; 31. Mold temperature controller; 32. Outlet pipe; 33. Inlet pipe; 4. On-line testing system; 41. Fiber Bragg grating sensor debugging and demodulation instrument; 42. Fiber Bragg grating sensor wire duct; 43. Fiber Bragg grating sensor bracket; 44. Grating; 45. Optical fiber. Specific embodiments

[0018] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention.

[0019] AsFigure 1 As shown in the figure, the present invention relates to a test system for the variable-speed water-entry solidification process of cast charges, which is applicable to the charging process of the water bath sequential solidification process; it includes 4 subsystems: a water-entry solidification device 1, a hot air system 2, a water circulation system 3, and an on-line testing system 4; among them, the on-line testing system is arranged on the top of the water-entry solidification device, and the hot air system and the water circulation system are externally connected to the water-entry solidification device.

[0020] As Figure 2 shown, the water-entry solidification device 1 includes: a servo electric cylinder 11, a heat preservation box 12, a lifting mechanism 13, a riser heat preservation mechanism 14, a heat preservation glass 15, a water tank 16, a mold mechanism 17, and a heat preservation baffle 18; the heat preservation box is of a cube structure, the lead screw of the servo electric cylinder is fixedly connected to the top plate of the heat preservation box by bolts, and the rest of the structures are placed inside the heat preservation box; the frame of the heat preservation box body is as Figure 3 shown, the box body frame is welded by stainless steel square tubes, fixed with cross beams at the top and bottom, and supported by steel plates on the sides; among them, the servo electric cylinder flange is connected to the cross beam 121, the riser heat preservation mechanism installation cross beam 122, the steel plate 123, and the support beam 124; as Figures 4 - 6 shown, in the lifting mechanism 13, manually assist to connect the internal thread of the ejector rod connection flange 131 with the external thread on the front flange of the servo electric cylinder 11, and the ejector rod connection flange 131 is fixedly connected to the stainless steel pipe connection flange 132 with bolts and nuts. The internal thread of the stainless steel pipe connection flange 132 is connected to one end of the double-threaded stainless steel pipe 136, and a locknut B135 is installed at the other end of the double-threaded stainless steel pipe 136. The lifting tool 133 is closely attached to the locknut B135 through the upper circular hole, and a locknut A134 is installed; the air inlet of the lifting tool is connected to the hot air blower through a hot air pipe; the mold and the riser are connected by bolts, as Figure 7 shown, the riser heat preservation mechanism includes: a slider 141, a long rod 142, and a hot air diversion cover 143. A protrusion is provided at the middle position on the outside of the hot air diversion cover 143, so that the hot air diversion cover is connected to the long rod 142. A slider 141 is provided at the top of the long rod, and the slider is matched with the T-shaped barrel groove on the cross beam of the box body frame; the riser welding flange is fixed by manually placing it into the supporting edge of the lifting tool; the hot air diversion cover is connected to the back of the heat preservation box frame, and the air inlet is connected to the hot air blower through a hot air pipe; as Figure 8 shown, the mold mechanism 17 includes: a cylindrical mold 171, a projectile with a head loading method 172, a projectile with a tail loading method 173, and a riser 1711 is connected to the projectile mold 1712.

[0021] As Figure 9 、 10As shown in the figure, in the hot air system 2, the pipeline extends from the hot air blower 21 and is respectively connected to the left air duct 23, the right air duct 25 and the middle air duct 24 through the diversion converter. The left air duct 23 and the right air duct 25 of the hot air system are respectively connected to the hot air diversion hood 143 with clamps. The middle air duct 24 and the sling connecting air duct 26 are connected with clamps, and the other end of the sling connecting air duct 26 is connected to the sling.

[0022] As Figure 11 shown in the figure, the structure of the water circulation system 3 includes: a mold temperature controller 31, a water outlet pipe 32, and a water inlet pipe 33; the water outlet pipe 32 of the mold temperature controller is connected to one side of the water inlet solidification device 1, and the water inlet pipe 33 is connected back to the mold temperature controller 31 from the other side of the water inlet solidification device 1.

[0023] As Figures 12 - 14 shown in the figure, the on-line testing system 4 includes: a fiber Bragg grating sensor debugging and demodulation instrument 41, a fiber Bragg grating sensor wire duct 42, a fiber Bragg grating sensor bracket 43, a grating 44 and an optical fiber 45; First, the optical fiber 45 with the grating 44 is arranged according to the test point position. As shown in the figure, the grating is welded on the optical fiber, and the position of the grating is the position of the measurement point. Then, each optical fiber is welded to the bracket 43, and the bracket 43 is placed into the mold 1712. Finally, the wiring of the fiber Bragg grating sensor is led out through the wire duct 42 and connected to the fiber Bragg grating sensor debugging and demodulation instrument 41.

[0024] The specific technological process is as follows: Step 1: Preparation of the hot air system; Manually assist in installing the riser insulation mechanism on the top cross beam of the insulation box. One end of the wind direction converter is connected to the hot air blower, and the other end is connected to three air ducts. The three air ducts are respectively connected to two hot air diversion hoods and the sling. Among them, the air duct and the riser insulation mechanism are fixed with clamps; Step 2: Preparation of the water circulation system; Place the insulation box 2 on the ground, open the box door, place the water tank 5 on the bottom plate of the box body. One end of the water inlet pipe 33 is connected to the water inlet of the water tank, and the other end is connected to the mold temperature controller 31. One end of the water outlet pipe 32 is connected to the water outlet of the water tank, and the other end is connected to the mold temperature controller 31. The mold temperature controller is started and the water temperature in the water tank is controlled at 20 - 70 °C; Step 3: Preparation of the sensor; Fix the optical fiber with the grating on the bracket, place the bracket into the mold, and lead out the wiring of the sensor through the wire duct and connect it to the debugging and demodulation instrument; Step 4: Installation of the die mechanism and the lifting tool mechanism and injection of medicine; Manually assist to connect the internal thread of the ejector rod connecting flange 131 with the external thread on the front flange of the servo electric cylinder 11. Fix the ejector rod connecting flange 131 and the stainless steel pipe connecting flange 132 by bolts and nuts. Connect the internal thread of the stainless steel pipe connecting flange 132 with one end of the double-threaded stainless steel pipe 136. Install the locknut B135 at the other end of the double-threaded stainless steel pipe 136. Make the lifting tool 133 close to the locknut B135 through the upper round hole and install the locknut A134. Fix the projectile die 1712 and the riser 1711 with bolts. Manually assist to inject the molten mixed explosive into the die 1712 and hang the die mechanism 17 on the lifting tool 133. Move the heat insulation baffle 18 to cover the riser 1711 to ensure that the slurry in the riser 1711 will not solidify in advance. Ordinary cylindrical dies 171, projectiles 172 with head loading method and projectiles 173 with tail loading method can be carried on the hanger; Step 5: Start the hot air system; Move the long rod 142 in the riser heat insulation mechanism 14 to make the slider 141 move on the back side of the cross beam 122 for installing the riser heat insulation mechanism, adjust the position to align the hot air diversion cover 143 with the die mechanism 13, turn on the hot air blower, and pass hot air at 85 - 95 °C through the box body to keep the slurry inside the projectile die 1712 in a liquid or molten state; Step 6: Control the solidification of the cast charge when it enters the water. Start the servo electric cylinder 11. Through PLC control, the electric cylinder push rod extends to make the lifting tool mechanism 13 and the die mechanism 17 move downward at a certain speed, and the speed range is 0.05 - 0.6 mm·s -1 , and the motor control system real-time feedbacks motion data such as displacement and speed. The on-line test system real-time collects the internal temperature and strain parameters of the slurry, and the PLC can make quality predictions based on this.

Claims

1. A variable-speed water-entry solidification process test system, which specifically includes 4 subsystems: a water circulation system, a hot air system, a water-entry solidification device, and an on-line testing system; the on-line testing system is arranged on the top of the water-entry solidification device, and the hot air system and the water circulation system are externally connected to the water-entry solidification device; Among them, the water circulation system provides cooling water for the sequential solidification process of the cast charge; the hot air system provides hot air for the box environment; the water-entry solidification device realizes the variable-speed water-entry solidification process of the charge; the on-line testing system completes the temperature field and stress field tests during the internal solidification process of the charge; the water circulation system consists of a water inlet pipe, a water outlet pipe, and a mold temperature controller; the water outlet pipe of the mold temperature controller is connected to one side of the water-entry solidification device, and the water inlet pipe is connected back to the mold temperature controller from the other side of the water-entry solidification device; the hot air system consists of a hot air blower, a wind direction converter, a left air duct, a middle air duct, a right air duct, and a sling connection air duct; the pipeline is led out from the hot air blower and is respectively connected to the left air duct, the right air duct, and the middle air duct through the sub-direction converter. The hot air system enters the left and right sides and the middle position of the back of the water-entry solidification device through the left air duct, the right air duct, and the middle air duct; the middle air duct is connected to the sling connection air duct inside the water-entry solidification device; the on-line testing system consists of fiber Bragg grating sensors, a debugging and demodulation instrument, a fiber Bragg grating sensor wire duct, and a fiber Bragg grating sensor support; optical fibers with gratings are arranged according to the test point positions, the gratings are welded on the optical fibers, and the positions of the gratings are the positions of the measurement points; each optical fiber is welded to the support, and the support is placed in the mold; the wiring of the fiber Bragg grating sensors is led out through the wire duct and connected to the fiber Bragg grating sensor debugging and demodulation instrument; the water-entry solidification device consists of a servo electric cylinder, a heat preservation box, a sling mechanism, a riser heat preservation mechanism, heat preservation glass, a water tank, a mold mechanism, and a heat preservation baffle; the heat preservation box is placed on the ground, the servo electric cylinder is placed on the top plate of the box body of the heat preservation box, the water tank is placed on the bottom plate of the box body of the heat preservation box, and the box body frame of the heat preservation box is installed with heat preservation glass and a box door; the sling mechanism consists of a servo electric cylinder ejector rod connection flange, a stainless steel pipe connection flange, a sling, a locknut, and a double-threaded stainless steel pipe; one end of the double-threaded stainless steel pipe is connected to the lead screw of the servo electric cylinder with two circular flanges, and the other end of the double-threaded stainless steel pipe is connected to the top end of the sling through a locknut.

2. A variable-speed water-entry solidification process test system according to claim 1, characterized in that: the box body frame of the heat preservation box consists of a cross beam connecting the servo electric cylinder flange, a cross beam for installing the riser heat preservation mechanism, a steel plate for installing glass on the side, and a support beam; the box body frame is welded by stainless steel square pipes, and T-shaped through grooves are processed on the side of the cross beam of the box body frame, and grooves with a width smaller than the side length of the slider are processed on the bottom surface as the sliding track of the hot air diversion cover.

3. A variable-speed water-entry solidification process test system according to claim 1, characterized in that: the riser heat preservation mechanism consists of a hot air diversion cover, a long rod, and a slider; the riser heat preservation mechanism is connected to the hot air system through an air duct and is installed on the cross beam of the heat preservation box body frame. Moving the hot air diversion cover can make it close to or away from the mold to insulate the riser.

4. A variable-speed water-entry solidification process test system according to claim 1, characterized in that: the mold mechanism consists of a projectile mold and a riser; the types of projectile molds include head-loading projectiles, tail-loading projectiles, and ordinary cylindrical molds, and the riser can be connected to the mold by bolts.

5. A method for variable-speed water-entry solidification process of cast-charged explosives, characterized in that: a variable-speed water-entry solidification process test system is adopted, which specifically includes the following steps: Step 1: Preparation of the hot air system; manually assist in installing the riser insulation mechanism on the top crossbeam of the insulation box. One end of the wind direction converter is connected to the hot air blower, and the other end is connected to three air ducts. The three air ducts are respectively connected to two hot air diversion covers and a sling. The air duct and the riser insulation mechanism are fixed with clamps; Step 2: Preparation of the water circulation system; the inlet and outlet water pipes of the water tank are respectively connected to the mold temperature controller. The mold temperature controller is started and controls the water temperature in the water tank at 20-70 °C; Step 3: Installation of sensors; first, fiber optic cables with gratings are arranged according to the positions of the test points. The gratings are welded on the fiber optic cables, and the positions of the gratings are the positions of the measurement points. Then, each fiber optic cable is welded to a bracket, and the bracket is placed in the mold. Finally, the wiring of the fiber optic grating sensor is led out through a wire duct and connected to the fiber optic grating sensor debugging and demodulation instrument; Step 4: Injection of explosive and installation of the mold mechanism; the projectile mold and the riser are fixed with bolts. Manually assist in injecting molten mixed explosives into the mold, and suspend the mold mechanism on the sling. Manually assist in moving the heat insulation baffle to cover the riser to ensure a reasonable temperature inside the riser and prevent the slurry in the riser from solidifying prematurely; Step 5: Start the hot air system; turn on the hot air blower, set the temperature to 80-95 °C, and close the door of the insulation box; Step 6: Control of cast-charged explosive water-entry solidification; start the servo cylinder. Through PLC control, the cylinder push rod extends, so that the sling mechanism and the mold mechanism move downward at a certain speed, and the speed range can be controlled within 0.05-0.6 mm·s-1. The motor control system real-time feedbacks motion data such as displacement and speed, and the on-line test system real-time collects the internal temperature and strain parameters of the slurry. The PLC can conduct quality prediction based on this and study the influence of process parameters on quality by controlling the descending displacement speed.

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