A urea core injection type molding device

Abstract

This invention provides a urea core injection molding device, belonging to the field of investment casting and wax pattern manufacturing. The technical solution includes a sealed melting cylinder, a pressure supply section, a nozzle section, and a mold. The sealed melting cylinder includes a melting cylinder body, a sealing cap, an exhaust valve, and a cylinder heating assembly. The pressure supply section includes an air inlet valve and a pressure regulating assembly. The nozzle section includes a ball valve, a nozzle shell, a nozzle tip, a nozzle tip spring, and a covered heating block. The nozzle shell has a cavity with a nozzle outlet at the front end, and a nozzle tip and nozzle tip spring are installed inside the nozzle shell. The covered heating block covers the outside of the nozzle shell. The mold includes a left template, a right template, a mold nozzle opening, and a mold cavity. The beneficial effects of this invention are: the invention has a simple structure, improves production efficiency, and enhances the molding quality of urea cores.

Description

Technical Field

[0001] This invention relates to the field of investment casting wax mold manufacturing and molding, and more particularly to a urea core injection molding device. Background Technology

[0002] In the field of investment casting, wax models with complex internal cavities are typically created using urea core molding, especially since urea is inexpensive and melts quickly, making it the preferred method for forming complex wax model cavities. Traditional urea core molding methods generally involve manual gravity casting, which is inefficient, produces numerous surface pores and defects, and has low strength, making it prone to breakage. This severely affects the smoothness of the wax model's internal cavity and the efficiency of wax model production. Summary of the Invention

[0003] The purpose of this invention is to provide a urea core injection molding device that solves the problem of low urea core molding efficiency and improves the surface quality and core strength of urea cores.

[0004] This invention is achieved through the following measures: A urea core injection molding device includes a sealed melting cylinder, a gas supply section, an injection nozzle section, and a mold. The sealed melting cylinder includes a melting cylinder body, a sealing cover, an exhaust valve, and a cylinder heating assembly. The sealing cover is sealed onto the melting cylinder body, and the cylinder heating assembly is used to melt and heat the urea inside the melting cylinder body. The air pressure supply section is connected to the melting cylinder. The air pressure supply section includes an air inlet valve and an air pressure regulating component, which are used to introduce and regulate the injection pressure gas into the melting cylinder. The nozzle section is connected between the discharge end of the melting cylinder and the mold. The nozzle section includes a ball valve, a nozzle housing, a nozzle tip, a nozzle tip spring, and a covered heating block. The ball valve is located between the discharge end of the melting cylinder and the inlet side of the nozzle housing, and is used to control the entry of liquid urea into the nozzle housing. The nozzle housing has a cavity with a nozzle outlet at its front end. The nozzle tip and nozzle tip spring are located within the nozzle housing. The nozzle tip spring is used to retract the nozzle tip. The nozzle outlet is closed. When the nozzle orifice is not pressing against the nozzle tip, the nozzle tip is in the closed position under the elastic force of the nozzle tip spring, preventing liquid urea from flowing out. When the nozzle orifice presses against the nozzle tip, the nozzle tip moves backward against the elastic force of the nozzle tip spring, forming an annular flow channel between the nozzle tip and the nozzle housing. Liquid urea flows out of the nozzle outlet through the annular flow channel and enters the nozzle orifice and the mold cavity. The encapsulated heating block covers the outside of the nozzle housing and is used to heat and keep the nozzle housing warm. The mold includes a left template, a right template, a mold nozzle, and a mold cavity. The left and right templates interlock to form a mold cavity between them that corresponds to the shape of the urea core to be formed. The mold cavity is used to accommodate liquid urea injected by the nozzle and to allow the liquid urea to cool and solidify to form a urea core. The mold nozzle is located on the left or right template and is a tapered inlet that mates with a corresponding component of the nozzle. The outer diameter of the mold nozzle is larger than the inner diameter to facilitate alignment between the mold and the nozzle tip and reduce material leakage between the mold nozzle and the nozzle tip during injection. The mold nozzle is used to press against the nozzle tip and connect the nozzle to the mold cavity. Specifically, the outer end of the mold nozzle is used to abut against the nozzle tip, and the inner end of the mold nozzle communicates with the mold cavity. In this process, the urea in the melting cylinder is melted and then enters the mold cavity sequentially through the ball valve, the nozzle, and the mold nozzle under the action of injection pressure gas to form a urea core.

[0005] The invention also has the following specific features: It also includes a mold clamping mechanism; The mold clamping mechanism includes a fixed frame, with rotating frames on both sides of the fixed frame. The two rotating frames are symmetrical and each has a clamping plate at its front end. Each rotating frame has a sector gear at its rear end, with the sector gears on both sides arranged symmetrically. A middle plate is provided on the fixed frame, with racks on both sides of the middle plate. The two racks mesh with the sector gears on their respective sides. A driving component is provided on the fixed frame to drive the racks to move back and forth. Under the action of the driving component, the middle plate moves back and forth, driving the rotating frames on both sides to rotate simultaneously through the racks. When they rotate inward simultaneously, the two clamping plates clamp the mold in the middle. When they rotate outward simultaneously, the two clamping plates move away from each other.

[0006] The fixing frame includes a U-shaped plate, and the rotating frame is respectively arranged on the two outer plates of the U-shaped plate. The rotating frame includes a pair of parallel guide rods. One end of each guide rod is hinged to the outer plate, and the other end of the two guide rods on the same side is hinged to a clamping rod parallel to the outer plate. Specifically, a pair of mounting grooves are provided on the outer plate and the clamping rod. A rotating shaft is provided in the mounting groove. The two ends of the guide rod are respectively arranged around the corresponding rotating shaft. The clamping plate is provided on the inner end of the clamping rod near the other rotating frame. The sector gear is provided on the inner guide rod. The sector gear is close to the outer plate, and the rotation axis of the sector gear coincides with the rotation axis of the inner guide rod on the outer plate. Specifically, the inner guide rod refers to the guide rod closer to the other rotating frame among the two guide rods.

[0007] The horizontal plate of the U-shaped plate has a pair of vertical plates, and the two vertical plates are located inside the U-shaped plate. Specifically, the vertical plates are fixed to the horizontal plate inside the U-shaped plate. The inner surfaces of the two vertical plates are provided with grooves, and a matching slide plate is slidably arranged between the two grooves. The middle plate is provided on the front side of the slide plate facing the sector gear. Specifically, the middle plate is located in the middle of the front side of the slide plate. The rear side of the slide plate has a threaded hole that extends to the middle plate. Specifically, the threaded hole is located in the middle of the rear side of the slide plate. A matching lead screw is provided in the threaded hole. The driving component is a motor, which is located on the outer surface of the horizontal plate. The corresponding end of the lead screw moves through the horizontal plate and is located on the output shaft of the motor. When the motor rotates, it drives the lead screw to rotate, thereby driving the slide plate to slide, thereby driving the middle plate to move. This drives the sector gears on both sides to rotate through the rack, and finally, the clamping plates on both sides achieve clamping or loosening of the mold.

[0008] It also includes a base plate, on which the sealing melting cylinder is mounted. A T-shaped groove is provided on the base plate on one side of the nozzle. A matching slider is slidably mounted in the groove. A support column is rotatably mounted on the slider. The mold clamping mechanism is rotatably mounted on the upper end of the support column. The rotatably mounted mold clamping mechanism can easily clamp the mold. For example, the mold can be clamped on one side of the sealing melting cylinder, then rotated to align with the nozzle for liquid urea injection. After injection, the mold clamping mechanism is rotated to move the mold to the other side of the sealing melting cylinder for mold opening.

[0009] The Z-shaped plate is provided with a pair of extension rods at its rear end away from the rotating frame, and a reinforcing rod and a handle are provided between the two extension rods; An mounting plate is provided between the lower side of the horizontal plate and the reinforcing rod. The mounting plate is rotatably mounted on the upper end of the support column via a rotating shaft structure. By holding the handle, the mold clamping mechanism can be rotated, which facilitates clamping the mold from one side and then rotating it to the nozzle side for liquid urea injection. A plate is provided on the front side of the slider facing the nozzle, and a plate is provided at the front end of the groove. A spring is provided between the plate and the plate. One end of the spring is fixed on the plate and the other end is fixed on the plate. By pushing the mold clamping mechanism with a handle or by using an electric telescopic rod, the mold moves forward, so that the mold nozzle mouth presses against the nozzle top, thereby realizing the injection of liquid urea. After the injection is completed, the mold clamping mechanism and the mold are reset by the action of the spring.

[0010] The mold clamping mechanism also includes an auxiliary mold opening mechanism. The auxiliary mold opening mechanism includes a T-shaped strip plate disposed on the side of the intermediate plate. A matching ejector rod is slidably disposed around the periphery of the strip plate. Specifically, a T-shaped groove is disposed on the lower side of the ejector rod to match the T-shaped strip plate, and the T-shaped groove passes through the rear end of the ejector rod. The front end of the ejector rod is set as a pointed tip. Both the left and right mold plates are provided with inclined surfaces on the outer side away from the mold nozzle. The inclined surfaces on both sides form inclined slots to match the pointed tip. When the pointed tip is inserted into the inclined slot, it will separate the left and right mold plates when pressed forward.

[0011] A portal plate is provided on one side of the top rod, and a through hole one is provided on the horizontal plate of the portal plate. A through hole two is provided on the corresponding side of the top rod, which is coaxial with the through hole. The through hole two extends into the T-shaped slide groove, and a stop bar is slidably provided through the through hole one and the through hole two. A limiting groove is provided on the upper side of the long strip plate. A limiting block is provided on the rear end face of the ejector rod away from the mold, which cooperates with the limiting groove. The limiting block is used in conjunction with the stop rod. When the limiting block slides against the front end face in the limiting groove, the stop rod is slid so that it is in front of the front end face of the long strip plate and its outer side is against the front end face of the long strip plate. At this time, the stop rod has a limiting function, so that the stop rod cannot slide backward along the long strip plate. When the intermediate plate moves forward, the action of the front end face of the long strip plate and the stop rod will drive the ejector rod to move forward, thereby realizing the mold opening action.

[0012] An annular baffle is provided around the stop bar located within the portal plate. A second spring is provided around the stop bar between the annular baffle and the corresponding side of the top rod. Under the action of the second spring, the annular baffle abuts against the transverse plate of the portal plate. At this time, the front end of the stop bar disengages from the T-shaped slide groove and no longer interacts with the long strip plate. The top rod can slide backward along the long strip plate and no longer exert force on the mold, thus releasing the mold opening action. An auxiliary plate is provided on the U-shaped plate. A sliding plate is slidably provided on the auxiliary plate through a slide groove structure. The front end of the sliding plate slides out of the front end face of the auxiliary plate. A first fixing plate is provided on the auxiliary plate, and a second fixing plate is provided on the sliding plate, passing through the first fixing plate. A threaded rod is screwed onto a fixed plate 1. The front end of the threaded rod is rotatably mounted on a fixed plate 2, which is located near the rear end of the sliding plate. A handle is provided at the rear end of the threaded rod. Rotating the handle pushes the sliding plate forward via the threaded rod. A push plate is provided at the front end of the sliding plate to cooperate with the rear end of the stop rod. The rear end of the stop rod is arc-shaped. Manually rotating the handle causes the sliding plate to slide forward. The push plate presses against the rear end of the stop rod, causing the stop rod to move forward against the force of the spring 2 and onto the front end face of the long strip plate. Then, driven by a motor, the force of the long strip plate on the stop rod pushes the ejector rod forward, thus performing the mold opening action.

[0013] An L-shaped limiting rod that cooperates with the stop rod is provided on one side of the sliding plate; The push rod is a telescopic rod, including a main rod that slides with the long strip and a secondary rod that slides around the main rod. The front end of the secondary rod is pointed, and a locking bolt is threaded through the upper side of the secondary rod. The secondary rod is slidable so that its pointed end is inserted into the inclined slot, and then the locking bolt is tightened to press it against the main rod, thereby fixing the secondary rod to the main rod. The length of the push plate matches the stop rod. Specifically, by manual force, the push plate presses the rear end of the stop rod so that it is positioned at the front end of the long strip. The rear end of the stop rod is driven by the motor. The lower part slides along the length of the push plate. When the stop bar slides out of the push plate, it resets under the action of the second spring and no longer interacts with the long plate. At this time, the tip no longer applies force to the mold in front, and the subsequent push rod will move backward along the long plate under the action of the L-shaped limit rod. The distance that the stop bar slides is the distance that the tip moves forward, which is the mold opening distance. The mold opening distance does not exceed the edge width of the mold. That is, the mold opening distance can achieve the mold opening effect but does not exceed the distance from the bottom of the inclined slot to the mold cavity. This can avoid the damage to the urea core caused by the continuous forward movement of the tip. The clamping plates are L-shaped, and both clamping plates have waist holes. A long bolt with external threads is movably installed near the front end through the waist holes. The left and right templates are both provided with threaded holes that mate with the long bolt. When clamping the mold, the mold is held by the two flat sides of the clamping plates, and the horizontal side of the clamping plates abuts against the side of the mold. Then, the long bolt is screwed into the threaded hole, and the long bolt is positioned at the front end of the waist hole. In this embodiment, the long bolt only has a small section of external threads near the front end, and the rear is a smooth round rod. This is because during the mold opening process, the clamping plates on both sides will move to the sides, and the smooth round rod facilitates the movement of the clamping plates.

[0014] The mold opening process is as follows: At this time, the mold is clamped by the mold clamping mechanism and the long bolt is installed on the mold near the front side of the waist hole. Therefore, the rack is located at the rear end near the motor. Then, the push rod is slid so that the limiting block slides against the front end face in the limiting groove. Then, the handle is manually turned so that the sliding plate slides forward. The push plate presses the rear end of the stop rod so that it is located on the front end face of the long plate. At this time, the push rod is limited by the limiting block and the stop rod. Then, the auxiliary rod is slid so that the tip is inserted into the inclined slot. Then, the locking bolt is tightened to fix it. Finally, the motor is started so that the middle plate and the rack move forward. At this time, the tip will push forward. With the cooperation of the long bolt, the left template and the right template are separated to both sides. After the stop rod passes the push plate, the push rod moves backward along the long plate under the action of the L-shaped limiting rod. Under the continuous action of the motor, the side clamps abut against the ends of the long bolt. Then, the left template and the right template are separated by the long bolt.

[0015] The beneficial effects of this invention are as follows: 1. The device has a simple structure and fast injection molding time, which is superior to manual casting and has high efficiency; 2. The urea core is formed under pressure, resulting in high density, high strength, and resistance to breakage; 3. The urea core is formed under pressure, resulting in full filling and a smooth appearance; 4. The urea core is formed under pressure, and the gas inside the liquid urea overflows along the mold parting surface or venting groove, which basically eliminates the problem of surface bubble defects in traditional urea core manufacturing. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a partial section in Embodiment 1 of the present invention.

[0017] Figure 2 for Figure 1 A magnified view of A in the middle.

[0018] Figure 3 This is a schematic diagram of the overall structure of Embodiment 2 of the present invention.

[0019] Figure 4 for Figure 3 A magnified view of B in the middle.

[0020] Figure 5 This is a schematic diagram of the mold clamping mechanism in Embodiment 2 of the present invention.

[0021] Figure 6 for Figure 5 A magnified view of C.

[0022] Figure 7 for Figure 6 A magnified view of D.

[0023] The attached diagram is labeled as follows: 1. Melting cylinder; 2. Exhaust valve; 3. Sealing cap; 4. Intake valve; 5. Nozzle section; 6. Base plate; 7. Mold; 8. Mold clamping mechanism; 9. Spring 1; 10. Support column; 11. Angled slot; 12. Mold cavity; 13. Encased heating block; 14. Ball valve; 15. Nozzle top; 16. Mold nozzle opening; 17. Nozzle housing; 18. Nozzle top spring; 19. Motor; 20. Z-shaped plate; 21. 21. Sector gear; 22. Guide rod; 23. Gripper rod; 24. Clamping plate; 25. Waist hole; 26. Long bolt; 27. Top rod; 28. Handle; 29. ​​Vertical plate; 30. Slide plate; 31. Middle plate; 32. Long strip plate; 33. Rack; 36. Portal plate; 37. Spring II; 38. Stop bar; 39. Push plate; 40. Sliding plate; 41. Auxiliary plate; 42. Fixed plate II; 43. Fixed plate I; 44. Threaded rod; 45. L-shaped limit rod. Detailed Implementation

[0024] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0025] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0026] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0027] To clearly illustrate the technical features of this solution, the following detailed implementation method will be used to explain the solution.

[0028] Example 1 See Figures 1-2 A urea core injection molding device includes a sealed melting cylinder, an air pressure supply section, an injection nozzle section 5, and a mold 7. The sealed melting cylinder includes a melting cylinder body 1, a sealing cover 3, an exhaust valve 2, and a cylinder heating assembly. The sealing cover 3 is sealed on the melting cylinder body 1, and the cylinder heating assembly is used to melt and heat the urea inside the melting cylinder body 1. The air pressure supply section is connected to the melting cylinder 1. The air pressure supply section includes an air inlet valve 4 and an air pressure regulating component, which are used to introduce and regulate the injection pressure gas into the melting cylinder 1. The nozzle section 5 is connected between the discharge end of the melting cylinder 1 and the mold 7. The nozzle section 5 includes a ball valve 14, a nozzle housing 17, a nozzle top 15, a nozzle top spring 18, and a covered heating block 13. The ball valve 14 is located between the discharge end of the melting cylinder 1 and the inlet side of the nozzle housing 17, and is used to control the entry of liquid urea into the nozzle housing 17. The nozzle housing 17 has a cavity inside and a nozzle outlet at the front end. The nozzle top 15 and the nozzle top spring 18 are located inside the nozzle housing 17. The nozzle top spring 18 is used to reset the nozzle top 15 and close the nozzle outlet. When the mold nozzle opening 16 is not pressing against the nozzle top 15, the nozzle top 15 is in the closed position under the elastic force of the nozzle top spring 18, preventing liquid urea from flowing out; when the mold nozzle opening 16 presses against the nozzle top 15, the nozzle top 15 moves backward against the elastic force of the nozzle top spring 18, and an annular flow channel is formed between the nozzle top 15 and the nozzle housing 17. Liquid urea flows out of the nozzle outlet through the annular flow channel and enters the mold nozzle opening 16 and the mold cavity 12; the encased heating block 13 is encased on the outside of the nozzle housing 17 for heating and heat preservation of the nozzle housing 17; The mold 7 includes a left template, a right template, a mold nozzle 16, and a mold cavity 12. After the left and right templates are interlocked, a mold cavity 12 corresponding to the shape of the urea core to be formed is formed between them. The mold cavity 12 is used to accommodate the liquid urea injected by the nozzle part 5 and to allow the liquid urea to cool and solidify to form a urea core. The mold nozzle 16 is set on the left or right template. The mold nozzle 16 is a tapered inlet that cooperates with the corresponding part of the nozzle part 5. The outer diameter of the mold nozzle 16 is larger than the inner diameter to facilitate the alignment and cooperation between the mold 7 and the nozzle top 15 and reduce material leakage between the mold nozzle 16 and the nozzle top 15 during the injection process. The mold nozzle 16 is used to press the nozzle top 15 and connect the nozzle part 5 with the mold cavity 12. Specifically, the outer end of the mold nozzle 16 is used to abut against the nozzle top 15, and the inner end of the mold nozzle 16 communicates with the mold cavity 12. In this process, the urea in the melting cylinder 1 is melted and then enters the mold cavity 12 through the ball valve 14, the nozzle part 5 and the mold nozzle opening 16 under the action of injection pressure gas to form the urea core.

[0029] In a specific embodiment, a compressed gas source, a filter, pressure reducing and stabilizing assembly, a pressure gauge or pressure sensor, a safety relief valve, a check valve, a cylinder heating assembly, a cylinder temperature sensor, a temperature controller, an insulation layer, a sealing ring, a sealing cap 3 locking mechanism, a liquid filter screen, a connecting pipe and a nozzle temperature sensor are also provided. The compressed gas source is connected to the intake valve 4 through a gas pipeline. The filter, pressure reducing and stabilizing assembly is located between the compressed gas source and the intake valve 4 and is used to filter, reduce and stabilize the compressed gas entering the melting cylinder 1. The filtration, pressure reduction, and pressure stabilization assembly includes a gas-liquid separator, a pressure reducing valve, a pressure gauge, and a pressure stabilizing valve. The inlet of the gas-liquid separator is connected to the compressed gas source, and the outlet of the gas-liquid separator is connected to the inlet of the pressure reducing valve. The outlet of the pressure reducing valve is connected to the inlet of the pressure stabilizing valve, and the outlet of the pressure stabilizing valve is connected to the inlet valve 4. The pressure gauge is located at the outlet of the pressure reducing valve or the pressure stabilizing valve to display the gas pressure before entering the melting cylinder 1. The gas-liquid separator is used to remove moisture, oil mist, and solid particulate impurities from the compressed gas, preventing impurities and water vapor from entering the melting cylinder 1 and affecting the molding quality of liquid urea. The pressure reducing valve is used to reduce the gas pressure output from the compressed gas source to the pressure required for urea core injection. The pressure stabilizing valve is used to reduce gas source pressure fluctuations and keep the gas pressure entering the melting cylinder 1 stable. The pressure gauge is used by the operator to observe and adjust the injection pressure. A one-way valve is installed between the inlet valve 4 and the melting cylinder 1 to prevent pressurized gas or liquid urea in the melting cylinder 1 from flowing back into the gas source pipeline. A pressure gauge or pressure sensor is installed on the top, side wall, or inlet pipeline of the melting cylinder 1 to display or detect the internal pressure of the melting cylinder 1 in real time. A safety relief valve is connected to the melting cylinder 1; when the internal pressure of the melting cylinder 1 exceeds the set safety pressure, the safety relief valve automatically opens to release pressure, thereby improving the safety of equipment operation. The outer wall of the melting cylinder 1 is equipped with a cylinder heating assembly, which can be an electric heating coil, an electric heating plate, an electric heating jacket, or a heat transfer oil heating jacket. A cylinder temperature sensor is located inside the melting cylinder 1 to detect the temperature of the urea melt. A temperature controller is electrically connected to the cylinder heating assembly, the cylinder temperature sensor, the covered heating block 13, and the nozzle temperature sensor, respectively, to maintain the urea in the melting cylinder 1 in a molten state and to maintain the nozzle section 5 at a temperature suitable for the liquid urea, preventing premature solidification of the liquid urea in the discharge channel and nozzle. The outer side of the melting cylinder 1 is covered with an insulation layer to reduce heat loss from the melting cylinder 1 and improve the stability of the urea melting and insulation process. A sealing ring is provided between the sealing cap 3 and the melting cylinder 1. The sealing ring is a heat-resistant rubber sealing ring. The sealing cap 3 is pressed onto the melting cylinder 1 by the sealing cap 3 locking mechanism. The sealing cap 3 locking mechanism can adopt a circumferential bolt pressing structure or a clamp locking structure. Through the cooperation of the sealing ring and the sealing cap 3 locking mechanism, the melting cylinder 1 can maintain a reliable seal during pressurized injection to prevent leakage of liquid urea or pressurized gas. The bottom of the melting tank 1 is equipped with a discharge port, which is connected to the ball valve 14 via a connecting pipe. The discharge port and the connecting pipe constitute the discharge end of the melting tank 1. An insulation layer or an electric heating structure is installed on the outside of the connecting pipe to ensure that the liquid urea does not solidify when flowing from the melting tank 1 to the ball valve 14 and the nozzle section 5. A liquid filter screen is installed at the discharge port of the melting tank 1, inside the connecting pipe, or at the front end of the ball valve 14 to prevent incompletely melted urea particles and impurities from entering the ball valve 14 and the nozzle section 5, thereby reducing clogging. A nozzle temperature sensor is used to detect the nozzle temperature, and the temperature controller controls the operation of the encased heating block 13 based on the detection signal from the nozzle temperature sensor to keep the nozzle section 5 at a constant temperature.

[0030] Additionally, venting grooves for the mold 7 are provided at the end, high point, or parting surface of the mold cavity 12. These venting grooves communicate with the outside of the mold 7 and are used to expel air from the cavity when liquid urea enters it, ensuring the liquid urea fills the mold cavity 12 and reducing defects such as bubbles, shrinkage cavities, and incomplete filling. The dimensions of the venting grooves for the mold 7 are designed to allow gas to escape while preventing excessive overflow of liquid urea. In a specific embodiment, the mold 7 can be cooled by air cooling to accelerate the cooling and solidification of the urea core within the mold cavity 12; specifically, a corresponding fan can be installed on one side of the mold 7.

[0031] Example 2 See Figures 3 to 7 The difference from Example 1 is that the urea core injection molding device also includes a mold clamping mechanism 8; The mold clamping mechanism 8 includes a fixed frame, with rotating frames on both sides of the fixed frame. The two rotating frames are symmetrical and each has a clamping plate 24 at its front end. Each of the two rotating frames has a sector gear 21 at its rear end. The sector gears 21 on both sides are symmetrically arranged. A middle plate 31 is provided on the fixed frame. A rack 33 is provided on both sides of the middle plate 31. The two racks 33 mesh with the sector gears 21 on the corresponding sides. A driving component is provided on the fixed frame to drive the racks 33 to move back and forth. Under the action of the driving component, the middle plate 31 moves back and forth, driving the rotating frames on both sides to rotate simultaneously through the racks 33. When they rotate inward simultaneously, the two clamping plates 24 clamp the mold 7 in the middle. When they rotate outward simultaneously, the two clamping plates 24 move away from each other.

[0032] The fixed frame includes a U-shaped plate 20, and rotating frames are respectively provided on the two outer side plates of the U-shaped plate 20. The rotating frames include a pair of parallel guide rods 22. One end of each guide rod 22 is hinged to the outer side plate, and the other end of the two guide rods 22 on the same side is hinged to a clamping link 23 parallel to the outer side plate. Specifically, a pair of mounting grooves are provided on the outer side plate and the clamping link 23. A rotating shaft is provided in the mounting groove. The two ends of the guide rod 22 are respectively located around the corresponding rotating shaft. A clamping plate 24 is provided on the inner end of the clamping link 23 near the other rotating frame. A sector gear 21 is provided on the inner guide rod 22. The sector gear 21 is close to the outer side plate, and the rotation axis of the sector gear 21 coincides with the rotation axis of the inner guide rod 22 on the outer side plate. Specifically, the inner guide rod 22 refers to the guide rod 22 closer to the other rotating frame among the two guide rods 22.

[0033] A pair of vertical plates 29 are provided on the horizontal plate of the Z-shaped plate 20, and the two vertical plates 29 are located on the inner side of the Z-shaped plate 20. Specifically, the vertical plates 29 are fixed to the horizontal plate on the inner side of the Z-shaped plate 20. Each of the two vertical plates 29 has a sliding groove on its opposite inner surface. A matching slide plate 30 is slidably arranged between the two sliding grooves. A middle plate 31 is provided on the front side of the slide plate 30 facing the sector gear 21. Specifically, the middle plate 31 is located in the middle of the front side of the slide plate 30. A threaded hole is provided on the rear side of the slide plate 30, and the threaded hole extends to... Specifically, the intermediate plate 31 has a threaded hole located in the middle of the rear side of the slide plate 30. A matching lead screw is installed in the threaded hole. The driving component is a motor 19, which is located on the outer side of the horizontal plate. The corresponding end of the lead screw moves through the horizontal plate and is located on the output shaft of the motor 19. When the motor 19 rotates, it drives the lead screw to rotate, thereby causing the slide plate 30 to slide, which in turn drives the intermediate plate 31 to move. This, in turn, drives the sector gears 21 on both sides to rotate through the rack 33. Finally, the clamping plates 24 on both sides achieve the clamping or loosening of the mold 7.

[0034] It also includes a base plate 6, with the sealing melting cylinder part set on the base plate 6. A T-shaped groove is provided on the base plate 6 on one side of the nozzle part 5. A matching slider is slidably set in the groove. A support column 10 is rotatably set on the slider. A mold clamping mechanism 8 is rotatably set on the upper end of the support column 10. The rotatably set mold clamping mechanism 8 can easily clamp the mold 7. For example, the mold 7 can be clamped on one side of the sealing melting cylinder part, and then rotated to align with the nozzle part 5 for injection of liquid urea. After the injection is completed, the mold clamping mechanism 8 is rotated to rotate the mold 7 to the other side of the sealing melting cylinder part for mold opening operation.

[0035] A pair of extension rods are provided at the rear end of the zigzag plate 20 away from the rotating frame, and a reinforcing rod and a handle 28 are provided between the two extension rods; An mounting plate is provided between the lower side of the horizontal plate and the reinforcing rod. The mounting plate is rotatably mounted on the upper end of the support column 10 via a rotating shaft structure. By holding the handle 28, the mold clamping mechanism 8 can be rotated, making it convenient to clamp the mold 7 from one side and then rotate it to the side of the nozzle part 5 for liquid urea injection. A plate 1 is provided on the front side of the slider facing the nozzle part 5, and a plate 2 is provided at the front end of the groove. A spring 9 is provided between the plate 1 and the plate 2. One end of the spring 9 is fixed on the plate 1, and the other end of the spring 9 is fixed on the plate 2. By holding the handle 28 to push the mold clamping mechanism 8 or by using the electric telescopic rod to push the mold clamping mechanism 8, the mold 7 moves forward, so that the mold nozzle opening 16 presses against the nozzle top 15, thereby realizing the injection of liquid urea. After the injection is completed, the mold clamping mechanism 8 and the mold 7 are reset by the action of the spring 9.

[0036] The mold clamping mechanism 8 also includes an auxiliary mold opening mechanism. The auxiliary mold opening mechanism includes a long strip plate 32 with a T-shaped structure, which is set on the upper side of the intermediate plate 31. A matching ejector rod 27 is slidably arranged around the long strip plate 32. Specifically, a T-shaped groove is provided on the lower side of the ejector rod 27 to match the long strip plate 32 with the T-shaped structure, and the T-shaped groove passes through the rear end of the ejector rod 27. The front end of the ejector rod 27 is set as a pointed tip. The left and right mold plates are both provided with inclined surfaces on the outer side away from the mold nozzle 16. The inclined surfaces on both sides form inclined slots 11 to match the pointed tip. When the pointed tip is inserted into the inclined slot 11, it will separate the left and right mold plates when it is pressed forward.

[0037] A portal plate 36 is provided on one side of the top rod 27. A through hole 1 is provided on the horizontal plate of the portal plate 36. A through hole 2, which is coaxial with the through hole, is provided on the corresponding side of the top rod 27. The through hole 2 extends into the T-shaped slide groove. A stop rod 38 is slidably provided through the through hole 1 and the through hole 2. A limiting groove is provided on the upper side of the long strip 32. A limiting block that cooperates with the limiting groove is provided on the rear end face of the ejector rod 27 away from the mold 7. The limiting block is used in conjunction with the stop rod 38. When the limiting block slides against the front end face in the limiting groove, the stop rod 38 slides so that it is in front of the front end face of the long strip 32 and its outer side abuts against the front end face of the long strip 32. At this time, the stop rod 38 has a limiting function, so that the stop rod 38 cannot slide backward along the long strip 32. When the intermediate plate 31 moves forward, the action of the front end face of the long strip 32 and the stop rod 38 will drive the ejector rod 27 to move forward, thereby realizing the mold opening action.

[0038] An annular baffle is provided around the stop bar 38 located inside the portal plate 36. A second spring 37 is provided around the stop bar 38 between the annular baffle and the corresponding side of the push rod 27. Under the action of the second spring 37, the annular baffle abuts against the transverse plate of the portal plate 36. At this time, the front end of the stop bar 38 disengages from the T-shaped slide groove and no longer interacts with the long strip plate 32. The push rod 27 can slide backward along the long strip plate 32 and no longer exert force on the mold 7, thus releasing the mold opening action. An auxiliary plate 41 is provided on the Z-shaped plate 20. A sliding plate 40 is slidably provided on the auxiliary plate 41 through a slide groove structure. The front end of the sliding plate 40 slides out of the front end face of the auxiliary plate 41. A first fixing plate 43 is provided on the auxiliary plate 41, and a second fixing plate 42 is provided on the sliding plate 40, passing through the first fixing plate 43. A threaded rod 44 is screwed on, and the front end of the threaded rod 44 is rotatably mounted on a fixed plate 42. The fixed plate 42 is close to the rear end of the sliding plate 40. A handle is provided at the rear end of the threaded rod 44. By rotating the handle, the sliding plate 40 is pushed forward by the threaded rod 44. A push plate 39 is provided at the front end of the sliding plate 40 to cooperate with the rear end of the stop rod 38. The rear end of the stop rod 38 is arc-shaped. By manually rotating the handle, the sliding plate 40 slides forward, and the push plate 39 presses against the rear end of the stop rod 38, thereby causing the stop rod 38 to move forward against the force of the spring 37 and be positioned on the front end face of the long plate 32. Then, driven by the motor 19, the force of the long plate 32 on the stop rod 38 pushes the ejector rod 27 forward to perform the mold opening action.

[0039] An L-shaped limiting rod 45 that cooperates with the stop rod 38 is provided on one side of the sliding plate 40; The push rod 27 is a telescopic rod, including a main rod that slides with the long strip plate 32 and a secondary rod that slides around the main rod. The front end of the secondary rod is pointed, and a locking bolt is threaded through the upper side of the secondary rod. The secondary rod is slidable so that its pointed end is inserted into the inclined slot 11, and then the locking bolt is tightened to press it against the main rod, thereby fixing the secondary rod to the main rod. The length of the push plate 39 matches the stop rod 38. Specifically, by manually pressing the push plate 39 against the rear end of the stop rod 38 so that it is at the front end of the long strip plate 32, the rear end of the stop rod 38 moves along the length of the push plate 39 under the drive of the motor 19. When the stop rod 38 slides out of the push plate 39, it returns to its original position under the action of the spring 37 and no longer interacts with the long plate 32. At this time, the tip no longer exerts force on the mold 7 in front, and the ejector rod 27 will move backward along the long plate 32 under the action of the L-shaped limit rod 45. The distance that the stop rod 38 slides is the distance that the tip moves forward, which is the mold opening distance. The mold opening distance does not exceed the edge width of the mold 7. That is, the mold opening distance can achieve the mold opening effect but does not exceed the distance from the bottom of the inclined slot 11 to the mold cavity 12. This can avoid the damage to the urea core caused by the continuous forward movement of the tip. The clamping plates 24 have an L-shaped structure and both clamping plates 24 are provided with waist holes 25. A long bolt 26 with external threads is movably installed near the front end through the waist holes 25. The left and right templates are provided with threaded holes that mate with the long bolt 26. When clamping the mold 7, the mold 7 is clamped by the two flat sides of the clamping plates 24, and the horizontal side of the clamping plates 24 abuts against the side of the mold 7. Then the long bolt 26 is screwed into the threaded hole and the long bolt 26 is located at the front end of the waist hole 25. In this embodiment, the long bolt 26 only has a small section of external threads near the front end and is a smooth round rod at the rear. This is because the clamping plates 24 on both sides will move to the sides during the mold opening process, and the smooth round rod will facilitate the movement of the clamping plates 24.

[0040] The mold opening process is as follows: At this time, mold 7 is clamped by mold clamping mechanism 8 and long bolt 26 is installed on mold 7 near the front side of waist hole 25. Therefore, rack 33 is located at the rear end near motor 19. Then, slide push rod 27 to make limit block slide against the front end face in limit groove. Then, manually turn handle to make sliding plate 40 slide forward. Push plate 39 presses the rear end of stop rod 38 so that it is on the front end face of long plate 32. At this time, push rod 27 is limited by limit block and stop rod 38. Then slide auxiliary rod to make pointed insert Insert it into the inclined slot 11, then tighten the locking bolt to fix it, and finally start the motor 19 to make the middle plate 31 and rack 33 move forward. At this time, the tip will push forward, and with the cooperation of the long bolt 26, the left template and the right template will separate to the sides. When the stop bar 38 passes the push plate 39, the push rod 27 moves backward along the long strip plate 32 under the action of the L-shaped limit rod 45. Under the continuous action of the motor 19, the two side clamps 24 abut against the ends of the long bolt 26, and then the left template and the right template will be separated by the long bolt 26.

[0041] Working process: In use, first open the sealing cap 3, add solid urea into the melting cylinder 1, then tighten the sealing cap 3 using the locking mechanism, and seal it using the sealing ring. Start the cylinder heating assembly; the cylinder temperature sensor detects the temperature inside the melting cylinder 1, and the temperature controller controls the cylinder heating assembly to melt the urea into a liquid state within the melting cylinder 1. Simultaneously, the encapsulated heating block 13 is activated to heat the nozzle housing 17, and the nozzle temperature sensor detects the nozzle temperature, maintaining the nozzle portion 5 at a preset insulation temperature.

[0042] Once the urea has completely melted and reached the injection temperature, close the exhaust valve 2 and open the intake valve 4. Compressed gas from the compressed gas source enters the melting cylinder 1 after being processed by the filter, pressure reducing, and pressure regulating assembly. A pressure gauge or pressure sensor displays or detects the internal pressure of the melting cylinder 1. The filter, pressure reducing, and pressure regulating assembly adjusts the internal pressure of the melting cylinder 1 to the preset injection pressure. A one-way valve prevents backflow of gas or liquid urea within the melting cylinder 1, and a safety relief valve prevents overpressure in the melting cylinder 1.

[0043] The mold 7 is clamped by the mold clamping mechanism 8 and the long bolt 26 is screwed in, and then the mold nozzle 16 is aligned with the nozzle top 15. The mold clamping mechanism 8 is then pushed, causing the mold nozzle 16 to press against the nozzle top 15. The nozzle top 15 moves backward against the spring force of the nozzle top spring 18, forming a liquid urea flow channel between the nozzle top 15 and the nozzle housing 17. After the ball valve 14 is opened, the liquid urea in the melting cylinder 1, under gas pressure, sequentially flows through the bottom outlet of the melting cylinder 1, the liquid filter screen, the connecting pipe, the ball valve 14, the flow channel between the nozzle housing 17 and the nozzle top 15, and the mold nozzle 16 into the mold cavity 12.

[0044] During the process of liquid urea entering the mold cavity 12, the air inside the mold cavity 12 is discharged through the venting groove of the mold 7, allowing the liquid urea to fill the entire mold cavity 12. After filling, the preset pressure is maintained for a period of time, allowing the liquid urea to shrink under pressure and increase the density of the urea core. Then the ball valve 14 is closed, and after cooling, the liquid urea in the mold cavity 12 solidifies into a urea core. After the urea core solidifies, the venting valve 2 is opened to release the residual pressure in the melting cylinder 1, and the mold clamping mechanism 8 is moved backward to allow the mold 7 to disengage from the nozzle part 5. The nozzle top head 15 is reset under the action of the nozzle top head spring 18 and closes the nozzle outlet. Finally, the mold 7 is opened through the auxiliary mold opening mechanism to remove the urea core.

[0045] The technical features of this invention not described can be implemented by or using existing technology, and will not be repeated here. Of course, the above description is not a limitation of this invention, and this invention is not limited to the examples above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of this invention should also be within the protection scope of this invention.

Claims

1. A urea core injection-molding apparatus characterized by comprising: It includes a sealed melting cylinder, a gas supply section, a nozzle section (5), and a mold (7); The sealed melting cylinder includes a melting cylinder body (1), a sealing cover (3), an exhaust valve (2), and a cylinder heating assembly. The sealing cover (3) is sealed on the melting cylinder body (1). The air pressure supply section is connected to the melting cylinder (1), and the air pressure supply section includes an air inlet valve (4) and an air pressure regulating component; The nozzle part (5) is connected between the discharge end of the melting cylinder (1) and the mold (7). The nozzle part (5) includes a ball valve (14), a nozzle shell (17), a nozzle top (15), a nozzle top spring (18), and a covered heating block (13). The ball valve (14) is located between the discharge end of the melting cylinder (1) and the feed side of the nozzle shell (17). The nozzle housing (17) has a cavity inside and a nozzle outlet at the front end. The nozzle housing (17) is provided with the nozzle top (15) and the nozzle top spring (18). The enclosed heating block (13) is enclosed on the outside of the nozzle housing (17). The mold (7) includes a left template, a right template, a mold nozzle (16) and a mold cavity (12). The mold nozzle (16) is located on the left template or the right template and is a tapered inlet that cooperates with the corresponding component of the nozzle part (5).

2. The urea core injection molded device of claim 1, wherein, It also includes a mold clamping mechanism (8); The mold clamping mechanism (8) includes a fixed frame, and rotating frames are provided on both sides of the fixed frame. The two rotating frames are symmetrical in structure and each has a clamping plate (24) at its front end. Each of the two rotating frames has a sector gear (21) at its rear end. The sector gears (21) on both sides are symmetrically arranged. An intermediate plate (31) is provided on the fixed frame. A rack (33) is provided on both sides of the intermediate plate (31). The two racks (33) mesh with the sector gears (21) on the corresponding sides respectively. A driving component for driving the racks (33) to move back and forth is provided on the fixed frame.

3. The urea core injection molded device of claim 2, wherein, The fixed frame includes a U-shaped plate (20), and the rotating frame is respectively provided on the two outer side plates of the U-shaped plate (20). The rotating frame includes a pair of parallel guide rods (22). One end of the two guide rods (22) on the same side is hinged to the outer side plate. The other end of the two guide rods (22) on the same side is hinged to a clamping rod (23) parallel to the outer side plate. The clamping rod (23) is provided with a clamping plate (24) near the inner end of the rotating frame on the other side. The sector gear (21) is provided on the inner guide rod (22). The sector gear (21) is close to the outer side plate and the rotation axis of the sector gear (21) coincides with the rotation axis of the inner guide rod (22) on the outer side plate.

4. The urea core injection molded device of claim 3, wherein, The horizontal plate of the Z-shaped plate (20) is provided with a pair of vertical plates (29), and the two vertical plates (29) are located on the inner side of the Z-shaped plate (20). The inner sides of the two vertical plates (29) are provided with grooves, and a matching slide plate (30) is slidably arranged between the two grooves. The front side of the slide plate (30) facing the sector gear (21) is provided with the middle plate (31). The rear side of the slide plate (30) is provided with a threaded hole, which extends through the middle plate (31). A matching lead screw is provided in the threaded hole. The driving component is a motor (19), and the motor (19) is located on the outer side of the horizontal plate. The corresponding end of the lead screw moves through the horizontal plate and is located on the output shaft of the motor (19).

5. The urea core injection molded device of claim 4, wherein, It also includes a base plate (6), the sealing melting cylinder is set on the base plate (6), and a groove with a T-shaped cross section is provided on the base plate (6) on one side of the nozzle part (5). A matching slider is slidably arranged in the groove, and a support column (10) is rotatably arranged on the slider. The mold clamping mechanism (8) is rotatably arranged on the upper end of the support column (10).

6. The urea core injection molded device of claim 5, wherein, The Z-shaped plate (20) is provided with a pair of extension rods at the rear end away from the rotating frame, and a reinforcing rod and a handle (28) are provided between the two extension rods; An mounting plate is provided between the lower side of the horizontal plate and the reinforcing rod, and the mounting plate is rotatably mounted on the upper end of the support column (10) via a rotating shaft structure; A plate is provided on the front side of the slider facing the nozzle part (5), a plate is provided at the front end of the groove, a spring (9) is provided between the plate and the plate, one end of the spring (9) is fixed on the plate and the other end of the spring (9) is fixed on the plate.

7. The urea core injection molded device of claim 1, wherein, The mold clamping mechanism (8) also includes an auxiliary mold opening mechanism. The auxiliary mold opening mechanism includes a long strip plate (32) with a T-shaped structure disposed on the upper side of the intermediate plate (31). A matching push rod (27) is slidably disposed on the periphery of the long strip plate (32). The front end of the push rod (27) is set as a pointed tip. The left and right templates are both provided with inclined surfaces on the outer side away from the mold nozzle (16). The inclined surfaces on both sides form inclined slots (11) that match the pointed tip.

8. The urea core injection molded device of claim 7, wherein, A gate-shaped plate (36) is provided on one side of the top rod (27), and a through hole one is provided on the horizontal plate of the gate-shaped plate (36). A through hole two coaxial with the through hole is provided on the corresponding side of the top rod (27). A stop rod (38) is slidably provided through the through hole one and the through hole two. The upper side of the long strip (32) is provided with a limiting groove, and the rear end face of the push rod (27) away from the mold (7) is provided with a limiting block that cooperates with the limiting groove.

9. The urea core injection molding apparatus according to claim 8, characterized in that, An annular baffle is provided around the stop bar (38) located inside the door-shaped plate (36), and a spring (37) is provided around the stop bar (38) between the annular baffle and the corresponding side of the top rod (27); An auxiliary plate (41) is provided on the zigzag plate (20). A sliding plate (40) is slidably provided on the auxiliary plate (41) through a sliding groove structure. The front end of the sliding plate (40) slides out of the front end face of the auxiliary plate (41). A first fixing plate (43) is provided on the auxiliary plate (41). A second fixing plate (42) is provided on the sliding plate (40). A threaded rod (44) is screwed through the first fixing plate (43). The front end of the threaded rod (44) is rotatably provided on the second fixing plate (42). A handle is provided at the rear end of the threaded rod (44). A push plate (39) is provided at the front end of the sliding plate (40) to cooperate with the rear end of the stop bar (38).

10. The urea core injection molding apparatus according to claim 9, characterized in that, An L-shaped limiting rod (45) that cooperates with the stop rod (38) is provided on one side of the sliding plate (40); The top rod (27) is a telescopic rod, including a main rod that slides with the long strip plate (32) and a secondary rod that slides around the main rod. The front end of the secondary rod is set as a pointed tip. A locking bolt is provided through the upper side of the secondary rod by a threaded structure. The length of the push plate (39) matches the length of the stop rod (38). The clamping plate (24) has an L-shaped structure and both clamping plates (24) are provided with waist holes (25). A long bolt (26) with external threads is movably disposed near the front end through the waist hole (25). The left template and the right template are provided with threaded holes that cooperate with the long bolt (26).

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