Precision casting wax injection device

Abstract

The utility model discloses a precision casting wax injection device, which relates to the technical field of precision casting and comprises a base, a support is fixedly mounted on the top surface of the base, a hydraulic cylinder is fixedly mounted on the top surface of the support, and a lower die is fixedly mounted on the top surface of the base and positioned below the support. An output shaft of the hydraulic cylinder penetrates through the top surface of the bracket, extends to the lower part of the bracket and is connected with an upper mold, and an integrated processing mechanism consisting of a vacuum pump, a tank body, a coarse filter screen, a centrifugal separator, a flash dehydration tank, a small homogenizing and blending tank and a draw-off pump is arranged, so that redundant wax liquid in the mold and the injection device after wax injection can be automatically sucked; the treatment links of physical filtration, centrifugal impurity removal, dehydration and devolatilization, homogenizing and blending, performance repair and the like are performed in sequence. Instant and online recovery and closed-loop recycling of the excess materials are achieved, the wax material utilization rate is remarkably increased, and the raw material cost is reduced.

Description

Technical Field

[0001] This utility model relates to the field of precision casting technology, specifically to a precision casting wax injection device. Background Technology

[0002] Precision casting, especially investment casting, is an important process for producing high-precision, complex-structured metal castings. One of its core steps is wax injection, which involves injecting molten wax into a mold cavity using a wax injection device, where it cools to form a wax pattern. The quality of the wax pattern directly determines the success or failure of subsequent shell making, dewaxing, and pouring processes, ultimately affecting the dimensional accuracy, surface quality, and yield of the casting.

[0003] A search revealed Chinese patent CN213671688U, which discloses a wax injection device for precision casting. It includes a base assembly, a fixing device mounted on the upper right side of the base assembly, and a heating device mounted on the left side of the fixing device. The base assembly includes a base itself, a control panel mounted on the right side of the base, a fixed base mounted on the upper end of the base with a groove on its upper surface, a fixing plate mounted on the upper surface of the fixed base, a slider mounted on the bottom of the fixing plate, the slider and the groove being slidably connected, and a screw hole on the surface of the fixing plate containing a bolt, the bolt being threadedly connected to the screw hole. This invention can fix the casting above the fixed base, making it easier to stably inject wax into the casting.

[0004] However, current technologies cannot efficiently and promptly recover and treat the semi-liquid excess wax remaining in the mold runner, gating system, and injection plunger cavity after injection, resulting in a significant waste of valuable wax and increased production costs. Meanwhile, offline processing is cumbersome and time-consuming, and the recovered wax may suffer performance degradation due to the thermal process (such as component volatilization, oxidation, impurities, and water content). Direct reuse can affect the dimensional stability, surface finish, and shrinkage consistency of new wax molds, indirectly leading to a decrease in casting yield and limited production efficiency.

[0005] Therefore, based on the above-mentioned search and combined with existing technologies, a precision casting wax injection device is proposed to solve the above problems. Utility Model Content

[0006] The purpose of this invention is to provide a precision casting wax injection device to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, this utility model provides the following technical solution:

[0008] A precision casting wax injection device includes: a base, a bracket fixedly mounted on the top surface of the base, a hydraulic cylinder fixedly mounted on the top surface of the bracket, a lower mold fixedly mounted on the top surface of the base below the bracket, and an output shaft of the hydraulic cylinder extending through the top surface of the bracket to the bottom of the bracket and connected to an upper mold; a wax melting tank fixedly mounted on the rear side wall of the base, an injection cylinder fixedly mounted on the rear side wall of the base and one side of the wax melting tank, and an injection device fixedly mounted on the top surface of the base on one side of the lower mold; and a processing mechanism disposed on the base.

[0009] Preferably, the processing mechanism includes: a tank body, the tank body being mounted on a base, a vacuum pump being fixedly installed on the top surface of the base on one side of the tank body, a three-way pipe being provided on one side of the vacuum pump, and a connecting pipe being provided on the other side.

[0010] Preferably, the processing mechanism further includes: a coarse filter screen disposed in the inner wall of the tank, a centrifugal separator fixedly installed on the inner wall of the tank below the coarse filter screen, a flash dehydration tank fixedly installed on the inner wall of the tank below the centrifugal separator, and a detection component.

[0011] Preferably, the detection component includes: a small homogenizing tank, which is fixedly installed on the top surface of the base, and the top surface of the small homogenizing tank is connected to the bottom surface of the tank body. A solenoid valve is provided at the bottom of the flash dehydration tank. When the solenoid valve is opened, the wax liquid in the flash dehydration tank flows into the small homogenizing tank. The detection component also includes an extraction component.

[0012] Preferably, the extraction component includes: an extraction pump, which is fixedly installed on the top surface of the base, a suction pipe is provided between the extraction pump and the small homogenizing tank, and a discharge pipe is provided between the extraction pump and the wax melting tank.

[0013] Preferably, a power distribution box is fixedly installed on the left side wall of the base, and a controller is fixedly installed on the front side wall of the base.

[0014] Preferably, the two sides of the three-way pipe are respectively connected to the plunger on the injection device and the side wall of the lower mold, and the other side is connected to the right side of the vacuum pump. The connecting pipe connects the left side of the vacuum pump and the top surface of the tank. The vacuum pump, the three-way pipe and the connecting pipe are used to extract excess wax liquid from the plunger on the injection device and the lower mold into the tank for processing.

[0015] Compared with the prior art, the beneficial effects of this utility model are:

[0016] 1. This utility model incorporates an integrated processing mechanism consisting of a vacuum pump, a tank, a coarse filter, a centrifugal separator, a flash dehydration tank, a small homogenizing and blending tank, and an extraction pump. This mechanism automatically extracts excess wax from the mold and injection device after wax injection, and sequentially processes it through physical filtration, centrifugal impurity removal, dehydration and devolatilization, homogenization and blending, and performance restoration. This achieves real-time, online recycling and closed-loop reuse of residual materials, significantly improving wax utilization and reducing raw material costs. Furthermore, performance restoration ensures that the mixing of recycled wax with new materials does not affect the final wax mold quality, thus enhancing the environmental friendliness and economy of the production process.

[0017] 2. In this utility model, by setting up a precise controller and complete sensor monitoring logic, the mold closing and opening of the hydraulic cylinder, the pressure and stroke of the injection device, and the sequential start-stop and linkage of each unit of the processing mechanism can be precisely coordinated. This achieves automated and intelligent control of the entire process of wax injection, pressure holding, residual material recovery, and purification and regeneration. This not only reduces manual intervention and ensures the consistency and repeatability of the process, but also effectively avoids production interruptions or quality problems that may be caused by incorrect operating timing or incomplete processing, thus improving the reliability and production efficiency of the device. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the left side structure of this utility model;

[0019] Figure 2 This is a schematic diagram of the right side of the present invention;

[0020] Figure 3 This is a schematic diagram of the rear structure of this utility model;

[0021] Figure 4 This is a schematic diagram of the front structure of this utility model;

[0022] Figure 5 This is a partial structural diagram of the processing mechanism of this utility model;

[0023] Figure 6 This is a schematic diagram of a partial explosion of the processing mechanism of this utility model.

[0024] In the diagram: 1. Base; 2. Support; 3. Hydraulic cylinder; 4. Lower mold; 5. Upper mold; 6. Wax melting tank; 7. Injection cylinder; 8. Injection device; 9. Tank body; 10. Vacuum pump; 11. T-connector; 12. Connecting pipe; 13. Coarse filter screen; 14. Centrifuge; 15. Flash dehydration tank; 16. Small homogenizing and blending tank; 17. Extraction pump; 18. Suction pipe; 19. Discharge pipe; 20. Electrical control box; 21. Controller. Detailed Implementation

[0025] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0026] In the description of this utility model, it should be noted that the terms "upper", "lower", "inner", "outer", "top", "bottom", "side", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model 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. Therefore, they should not be construed as limitations on this utility model.

[0027] In one typical embodiment of this application, please refer to Figures 1-4 A precision casting wax injection device includes: a base 1, serving as the support platform and frame for the entire device. A bracket 2 is bolted to the top surface of the base 1, and a hydraulic cylinder 3 is also bolted to the top surface of the bracket 2. A lower mold 4 is bolted to the top surface of the base 1 below the bracket 2. The output shaft (piston rod) of the hydraulic cylinder 3 extends downward through the top surface of the bracket 2 and is threaded or flanged to an upper mold 5. The extension and retraction of the hydraulic cylinder 3 drives the upper mold 5 to move up and down, achieving mold closing and opening with the lower mold 4.

[0028] A wax melting tank 6 is used to store and heat molten wax. It is fixed to the rear wall of the base 1 by welding or bolting. The inner bottom of the wax melting tank 6 is typically equipped with an electric heating coil (not shown in the figure) and a stirrer (not shown in the figure) to ensure that the wax is heated evenly and remains liquid. The bottom outlet of the wax melting tank 6 is connected to the inlet of a transfer pump (not shown in the figure, usually a gear pump or screw pump) through a first insulated pipe (not shown in detail in the figure). This transfer pump is fixedly mounted on the base 1, and its outlet is connected to the inlet of the injection cylinder 7 through a second insulated pipe. Through the operation of the transfer pump, the liquid wax in the wax melting tank 6 can be continuously and stably pumped into the injection cylinder 7 for storage and pressure maintenance. The injection cylinder 7 is fixedly connected to the rear wall of the base 1 by a support frame and is arranged adjacent to the wax melting tank 6.

[0029] The core function of the injection device 8 is to inject wax from the injection cylinder 7 into the closed mold cavity at a certain pressure and speed. The injection device 8 is bolted to the top surface of the base 1 and located on one side of the lower mold 4. The injection device 8 typically includes an injection plunger (not shown in detail in the figure) driven by a servo motor or hydraulic motor. This injection plunger is connected to the outlet of the injection cylinder 7 via a third pipe. When the injection device 8 is activated, the injection plunger moves forward, applying pressure to the wax in the injection cylinder 7, forcing the wax to be injected through a fourth pipe into the gating system of the lower mold 4, ultimately filling the cavity formed by the closing of the lower mold 4 and the upper mold 5.

[0030] The processing mechanism is used for online recovery and preliminary treatment of excess wax (i.e., residual material) in the mold runner after wax injection. The entire processing mechanism is mounted on the base 1.

[0031] Specifically, the processing mechanism includes a tank 9, which is connected to the top surface of the base 1 via a support frame or directly fixed, serving as a centralized processing container for the recovered wax liquid. A vacuum pump 10 is bolted to one side of the tank 9, located on the top surface of the base 1. The exhaust port of the vacuum pump 10 is connected to the top of the tank 9 via a connecting pipe 12. The suction port of the vacuum pump 10 is connected to two target pipelines via a three-way pipe 11: one port is connected to the injection plunger chamber of the injection device 8 (used to recover residual wax liquid in the chamber when the plunger retracts); the other port is connected to the end of the flow channel of the lower mold 4 or the cold slug well (used to recover excess wax liquid in the mold casting system). When the vacuum pump 10 is started, negative pressure is generated in the aforementioned pipelines and mold flow channels, thereby drawing the remaining semi-liquid material into the tank 9.

[0032] The tank 9 integrates multiple processing units. First, a removable coarse filter 13 is installed below the top inlet of the tank 9. It is fixed to the inner wall of the tank 9 by clips or flanges to intercept large impurities drawn into the tank 9. Below the coarse filter 13, a centrifugal separator 14 is fixedly connected by a support frame. The inlet of the centrifugal separator 14 is connected to the flow channel of the coarsely filtered wax liquid. Its high-speed rotating drum, under the action of centrifugal force, can separate out the denser small solid impurities (such as sand particles and metal shavings) in the wax liquid. Below the centrifugal separator 14, a flash dehydration tank 15 is also fixedly connected by a support frame. The flash dehydration tank 15 maintains a certain vacuum degree (provided by an independent small vacuum device) and is equipped with a heating device. In this tank, the wax liquid is subjected to a low temperature and reduced pressure environment, and the water and low-boiling-point volatiles contained therein are rapidly vaporized and drawn away, thereby achieving dehydration and devolatization.

[0033] The processing mechanism also includes a detection component. This component primarily includes a small homogenizing tank 16, which is fixedly connected to the top surface of the base 1 via a support frame, located below the tank body 9. The small homogenizing tank 16 is equipped with an online viscometer and a shrinkage meter for rapid detection. Furthermore, the small homogenizing tank 16 can be equipped with an additive compensation liquid and an automatic injection system to address specific performance issues. Based on performance defects (such as low viscosity or high shrinkage), the controller 21 calculates and precisely injects corresponding additives (such as polymeric thickeners, low-shrinkage modifiers, and antioxidants) to repair chain breakage and oxidation damage caused by repeated melting and use of the wax at the molecular level, restoring its performance to a controllable and usable range. The top inlet of the small homogenizing tank 16 is connected to the bottom outlet of the flash dehydration tank 15 via a pipe. A first solenoid valve (not shown in the figure) controlled by the controller 21 is installed on this pipe. When the first solenoid valve opens, the dehydrated wax flows into the small homogenizing tank 16 by gravity or a slight pressure difference. The small homogenizing tank 16 is equipped with a stirrer (not shown) for homogenizing the wax liquid.

[0034] The testing assembly also includes an extraction component. The extraction component includes an extraction pump 17, which is bolted to the top surface of the base 1. The inlet of the extraction pump 17 is connected to the bottom outlet of the small homogenizing tank 16 via a suction pipe 18. The outlet of the extraction pump 17 is connected to the top or side return port of the wax melting tank 6 via a discharge pipe 19. When the extraction pump 17 is activated, the processed recycled wax liquid in the small homogenizing tank 16 can be pumped back to the wax melting tank 6 for a new round of recycling.

[0035] The left side wall of the base 1 is fixedly connected to the distribution box 20 by bolts. The box integrates electrical components such as circuit breakers, contactors, and transformers to provide power distribution and control circuits for hydraulic cylinders 3, pumps, heating devices, controllers 21, etc.

[0036] The front side wall of the base 1 is fixedly connected to the controller 21 by bolts or a panel. The controller 21 is a programmable logic controller (PLC), which is the brain of the entire device and is responsible for coordinating the actions of each actuator.

[0037] The detection and control logic of controller 21 is explained in detail below:

[0038] Detection of wax injection completion: The controller 21 mainly determines the end of the wax injection process in two ways.

[0039] Position and displacement feedback: The drive motor (servo motor) of the injection device 8 or the hydraulic cylinder 3 is equipped with an encoder or displacement sensor. The controller 21 reads the displacement signal of the injection plunger in real time. When the displacement reaches the "injection endpoint" position preset according to the mold cavity volume, the controller 21 determines that the wax has been injected completely.

[0040] Pressure feedback: A pressure sensor (not shown in the figure) is installed at the end of the cavity of the lower mold 4 or in the gating system. The controller 21 monitors the pressure value in real time. When the pressure value reaches a preset stable value during the holding phase and is maintained for a period of time, the controller 21 determines that the filling is complete and the injection process ends.

[0041] Start-stop control of the processing unit:

[0042] Once the controller 21 determines that the wax injection and pressure holding stages are complete using the aforementioned method, it first controls the hydraulic cylinder 3 to open the mold. After the mold has opened to a certain position, the controller 21 will issue commands according to a preset timing sequence.

[0043] Controller 21 starts the vacuum pump 10 and simultaneously controls the corresponding pneumatic or solenoid valve (not shown in the figure) on the three-way pipe 11 to switch to the path connecting the mold flow channel and the plunger cavity. The negative pressure draws the remaining material in the flow channel and the plunger cavity into the tank 9.

[0044] The controller 21 controls the motor of the centrifuge 14 to start according to the program to perform solid-liquid separation.

[0045] The controller 21 controls the heater and vacuum pipeline valves of the flash dehydration tank 15 to carry out the dehydration operation.

[0046] When the flash dehydration tank 15 has finished processing, the controller 21 controls the first solenoid valve to open, allowing the wax liquid to flow into the small homogenizing tank 16.

[0047] The controller 21 controls the stirrer of the small homogenizing tank 16 to work for a certain period of time to homogenize the wax liquid.

[0048] Finally, controller 21 starts extraction pump 17 and pumps the processed wax back to wax melting tank 6. Throughout the process, controller 21 can control the duration and sequence of each step using signals from the devices themselves or simple timers.

[0049] Working principle:

[0050] In use, the wax block is first added to the wax melting tank 6 for melting. Controller 21 controls the hydraulic cylinder 3 to close the upper mold 5 and lower mold 4. Then, controller 21 controls the drive mechanism of the injection device 8 to inject the heat-insulated wax from the injection cylinder 7 into the mold cavity at a set pressure and speed. After injection, the pressure holding stage begins. After pressure holding, controller 21 first controls the hydraulic cylinder 3 to slightly retract and open the mold, and then immediately starts the processing mechanism: opening the vacuum pump 10 and corresponding pipeline valves to draw the semi-liquid residue in the mold flow channel and injection plunger cavity into the tank 9. The residue undergoes coarse filtration, centrifugal separation, and flash dehydration in the tank 9. The processed wax liquid is temporarily stored in a small homogenizing tank 16 and finally sent back to the wax melting tank 6 by the extraction pump 17 for mixing and reuse. This achieves online real-time recovery and preliminary purification of wax injection residue, improving wax utilization and reducing waste.

[0051] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A precision investment wax injection device characterized by: The utility model relates to a wax injection molding machine, including: The top surface of base (1) is fixedly installed with support (2), the top surface of support (2) is fixedly installed with hydraulic cylinder (3), the top surface of base (1) is fixedly installed with lower mould (4) below support (2), the output shaft of hydraulic cylinder (3) extends to the below of support (2) and is connected with upper mould (5) through the top surface of support (2); Wax melting tank (6) is fixedly installed on the rear side wall of base (1), the rear side wall of base (1) and one side of wax melting tank (6) are fixedly installed with injection cylinder body (7), the top surface of base (1) is fixedly installed with injection device (8) on one side of lower mould (4); Processing mechanism is arranged on base (1).

2. A precision investment wax injection device according to claim 1 wherein: Processing mechanism includes: Tank body (9) is arranged on base (1), vacuum pump (10) is fixedly installed on the top surface of base (1) on one side of tank body (9), three-way pipe (11) is arranged on one side of vacuum pump (10), and connecting pipe (12) is arranged on the other side of vacuum pump (10).

3. A precision investment wax injection device according to claim 2, wherein: Processing mechanism further includes: Coarse filter screen (13) is arranged in the inner wall of tank body (9), centrifugal separator (14) is fixedly installed on the inner wall of tank body (9) below coarse filter screen (13), flash dewatering tank (15) is fixedly installed on the inner wall of tank body (9) below centrifugal separator (14), and processing mechanism further includes detection assembly.

4. A precision investment wax injection device according to claim 3, wherein: Detection assembly includes: Small homogenization blending tank (16) is fixedly installed on the top surface of base (1), the top surface of small homogenization blending tank (16) is connected with the bottom of tank body (9), the bottom of flash dewatering tank (15) is provided with electromagnetic valve, when the electromagnetic valve is opened, the wax liquid in flash dewatering tank (15) flows into small homogenization blending tank (16), and detection assembly further includes extraction part.

5. A precision investment wax injection device according to claim 4, wherein: Extraction part includes: Extraction pump (17) is fixedly installed on the top surface of base (1), suction pipe (18) is arranged between extraction pump (17) and small homogenization blending tank (16), and discharge pipe (19) is arranged between extraction pump (17) and wax melting tank (6).

6. A precision investment wax injection device according to claim 1 wherein: The left side wall of base (1) is fixedly installed with distribution box (20), and the front side wall of base (1) is fixedly installed with controller (21).

7. A precision investment wax injection device according to claim 2 wherein: The two sides of three-way pipe (11) are connected with the plunger on injection device (8) and the side wall of lower mould (4) respectively, the other side is connected with the right side of vacuum pump (10), the left side of vacuum pump (10) is connected with the top surface of tank body (9) through connecting pipe (12), and the vacuum pump (10), three-way pipe (11) and connecting pipe (12) are used to extract the excess wax liquid in the plunger on injection device (8) and lower mould (4) into tank body (9) for processing.

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