A lead-free brass water meter shell casting device and casting process

Abstract

This invention discloses a casting apparatus and casting process for lead-free brass water meter housings, relating to the field of brass casting technology. It includes a main body, a fixing unit, a pretreatment unit, a pneumatic unit, and a control unit. The fixing unit clamps the water meter housing; the control unit monitors the casting temperature in real time via a temperature sensor. When the water meter housing is in the hot brittle range above 300°C, the air supply unit only outputs airflow for gentle cooling to prevent deformation and cracking of the casting. When the temperature drops to 200°C from 300°C, the air supply unit outputs high-pressure airflow to drive a vibrating unit, using high-frequency self-excited oscillation to break down and peel off the internal molding sand. When the temperature drops below 200°C, the air supply unit outputs pulsed airflow to drive a striking unit, reciprocatingly striking the outer wall of the water meter housing to remove residual molding sand. Finally, the extraction unit uses negative pressure to extract and separate the molding sand. This invention solves the problem of easy damage or difficult sand removal of lead-free brass water meter housings at different cooling stages, achieving efficient and non-destructive sand removal.

Description

Technical Field

[0001] This invention relates to the field of brass casting, and more specifically, to a casting apparatus and casting process for a lead-free brass water meter casing. Background Technology

[0002] As a core metering instrument for trade settlement in water supply systems, water meters are in direct contact with residential water supply for extended periods. With increasingly stringent global environmental regulations, particularly the rising standards for drinking water safety in various countries, traditional leaded brass has been gradually phased out due to the potential for lead leaching during use, which could cause secondary water pollution. Lead-free brass, by replacing lead with elements such as bismuth and silicon, maintains good machinability and casting performance while fundamentally eliminating the health risks associated with lead leaching, making it the mainstream material for manufacturing water-related components such as water meter casings. However, water meter casings are typical thin-walled, complex-structured castings with curved internal channels and varied cavities. After casting, a large amount of molding sand tightly fills these complex internal cavities. Furthermore, lead-free brass is highly sensitive to hot working processes; the mechanical properties of the casting vary significantly across different temperature ranges during solidification and cooling, posing a significant challenge to subsequent cleaning and sand removal processes.

[0003] In existing technologies, cleaning the molding sand inside castings often involves manual hammering, mechanical drum vibration, or shot blasting. However, for lead-free brass water meter housings, the temperature of the casting immediately after being removed from the mold is typically above 500℃, placing it in the hot brittle zone of the material. At this temperature, the strength between the alloy grain boundaries is low. If mechanical hammering or strong vibration is used for sand cleaning, it can easily cause micro-cracks or even overall deformation and scrapping of the casting housing, resulting in irreversible damage. If the casting is allowed to cool completely to room temperature before cleaning, although the risk of hot brittleness is avoided, the binder in the molding sand undergoes a secondary solidification effect after being baked at high temperatures, greatly increasing its compactness. This results in the sand adhering stubbornly to the inner wall of the flow channel, making it difficult for conventional vibration or shot blasting methods to completely remove it, often leaving cleaning dead zones that affect the flow and metering accuracy of the water meter housing. Although some existing equipment has introduced pneumatic purging, it only relies on the scouring force of the airflow, which is insufficient for crushing the solidified and agglomerated molding sand. In summary, existing technologies lack a full-process, staged sand removal solution that can dynamically match the mechanical properties of lead-free brass materials at different temperature stages, making it difficult to achieve efficient and highly clean sand removal while protecting the integrity of the casting. Summary of the Invention

[0004] In order to overcome the above-mentioned defects of the prior art, the present invention provides a casting apparatus and casting process for lead-free brass water meter housings to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a casting device for a lead-free brass water meter casing, comprising a main body, and further comprising: Fixing unit: It includes a clamp, which includes an upper clamp and a lower clamp, and also includes a cylinder and a connecting part for driving the upper clamp to move; Pre-treatment unit: It includes a vibration section and a striking section, which can perform vibration treatment and striking treatment on the outer wall of the water meter shell respectively according to the temperature range of the casting. Pneumatic unit: It includes an air supply section and an extraction section; the air supply section is connected to an air blowing hood, the air blowing hood is connected to the inside of the clamp, and the extraction section is connected to the inner cavity of the clamp through a sand suction pipe; Control unit: It includes a temperature sensor, which is installed inside the lower clamp and can contact the outer wall of the water meter casing in real time; the control unit controls the air supply unit to output airflow for flexible heat dissipation and cooling when the water meter casing is in the first temperature range, based on the temperature detected by the temperature sensor; when the water meter casing drops to the second temperature range, the control unit controls the air supply unit to output airflow to drive the vibration unit to perform high-frequency vibration treatment; when the water meter casing drops to the third temperature range, the control unit controls the air supply unit to output pulse airflow to drive the striking unit to strike the outer wall of the water meter casing; during the sand removal stage, the control unit controls the extraction unit to perform negative pressure extraction through the sand suction pipe.

[0006] Preferably, the main body is provided with multiple sliding columns, the connector is slidably connected to the sliding columns, the lower end of the connector is fixedly connected to the upper clamp, the upper clamp and the lower clamp are closed to form a clamping cavity for accommodating the water meter shell, and the clamp is provided with a connection channel communicating with the outside atmosphere.

[0007] Preferably, the fixture has an independent air passage communicating with the air blowing hood, and a sliding groove communicating with the air passage is provided inside the fixture, and the sliding groove is communicating with the interior of the fixture.

[0008] Preferably, the striking part includes a sensing block, which is slidably connected to the slide groove, and a striking block is provided on the side of the sensing block near the connecting channel; a guide groove communicating with the slide groove is provided in the fixture, and a guide post is slidably connected in the guide groove, one end of the guide post is fixedly connected to the sensing block, and the other end of the guide post is fixedly connected to the side wall of the guide groove via a first spring.

[0009] Preferably, the vibration unit includes a vibration chamber formed within the fixture, and an impact piston is slidably sealed within the vibration chamber. The impact piston is connected to the side wall of the chamber via a high-frequency spring. The sensing block is configured such that when it slides along the slide groove to a preset position under airflow drive, the slide groove can communicate with the air inlet of the vibration chamber. A pressure relief hole is formed on the side wall of the vibration chamber, and the pressure relief hole is located at the limit stroke of the impact piston compressing the high-frequency spring. The pressure relief hole penetrates the outer wall of the fixture and communicates with the external environment. The high-pressure airflow entering the vibration chamber can push the impact piston to overcome the high-frequency spring and expose the pressure relief hole, thereby causing the air pressure in the chamber to change periodically, driving the impact piston to perform high-frequency mechanical self-excited oscillation impact.

[0010] Preferably, the lower clamp has a receiving groove, the temperature sensor is located in the receiving groove, and a second spring is fitted on the temperature sensor between its stepped surface and the side wall of the receiving groove.

[0011] Preferably, the air supply unit includes an electromagnetic pulse valve that communicates with the air blowing hood, and the other end of the electromagnetic pulse valve can be communicated with the air storage unit.

[0012] Preferably, the extraction section further includes a cyclone separator and an extraction pump. The air inlet of the cyclone separator is connected to the sand suction pipe, and its air outlet is connected to the extraction pump, so that the extracted molding sand is retained in the cyclone separator.

[0013] Preferably, the control unit is configured as follows: When the temperature sensor detects that the water meter casing temperature is in the first temperature range, the air supply unit is controlled to output basic cooling airflow for flexible heat dissipation and cooling. At this time, the airflow pressure is insufficient to drive the sensing block to open the air inlet of the vibration chamber. When the temperature sensor detects that the water meter housing temperature has dropped to the second temperature range, the control air supply unit outputs a stable airflow with the first pressure, drives the sensing block to overcome the first spring and slide to a preset position away from the water meter housing and opens the air inlet of the vibration chamber. At this time, the striking block and the water meter housing are separated. The airflow enters the vibration chamber and pushes the impact piston to overcome the high-frequency spring and expose the pressure relief hole, generating a high-frequency mechanical self-excited oscillation impact, which drives the clamp and the water meter housing to vibrate, causing the internal molding sand to collapse and peel off. When the temperature sensor detects that the water meter casing temperature has dropped to the third temperature range, it controls the air supply unit to output a pulsed airflow with a second pressure. The second pressure is lower than the first pressure. The pulsed airflow drives the sensing block to move away from the water meter casing against the first spring. During the airflow pulse interval, the reset force of the first spring drives the striking block to strike the outer wall of the water meter casing, thereby achieving reciprocating striking to remove sand and eliminate residual molding sand. When the preset sand removal time is reached, the control unit shuts off the air supply and starts the extraction pump. It uses outside air to replenish the air supply through the connection channel to form a directional sweeping airflow, which draws the molding sand through the sand suction pipe to the cyclone separator for separation and collection.

[0014] A casting process for a lead-free brass water meter casing includes the following steps: S1: The water meter casing that has been cast and is in a high temperature state is placed into the lower clamp. The upper clamp is closed by the cylinder and the connecting parts to form a sealed clamping cavity. The temperature sensor in the cavity is in close contact with the outer wall of the water meter casing under the action of the second spring, and the water meter casing temperature is detected in real time and fed back to the control unit. S2: When the temperature sensor detects that the water meter housing temperature is in the first temperature range, the material of the water meter housing is very susceptible to deformation and cracking under external force. At this time, the air supply unit is activated, and the airflow is introduced into the inner cavity of the fixture through the air blowing hood. Only the airflow is used for flexible heat dissipation and cooling and thermal stress release to avoid mechanical stress damaging the casting structure. S3: When the temperature sensor detects that the water meter housing temperature has dropped to the second temperature range, the air supply unit is controlled to output a high-pressure stable airflow. The high-pressure airflow drives the sensing block to overcome the first spring and move to a preset position away from the water meter housing, so that the striking block is separated from the water meter housing and the slide is connected to the vibration chamber. The high-pressure airflow pushes the impact piston and periodically opens the pressure relief hole connected to the outside, generating a high-frequency mechanical self-excited oscillation impact, which drives the clamp and the water meter housing to vibrate. The high-frequency excitation force causes the molding sand inside the water meter housing to undergo mesh-like collapse and peeling. S4: When the temperature sensor detects that the water meter casing temperature has dropped to the third temperature range, the control unit controls the electromagnetic pulse valve to output a pulse airflow to the air blowing hood. This pulse airflow is guided into the slide to drive the sensing block to move away from the water meter casing against the first spring. During the airflow pulse interval, the first spring's reset force is used to drive the striking block to strike the outer wall of the water meter casing to remove sand. S5: When the sand removal conditions are met, the control unit shuts off the air supply and starts the extraction pump. At this time, outside air is drawn into the inner cavity of the clamp through the connecting channel, forming a directional sweeping airflow. The stripped internal molding sand is drawn through the sand suction pipe and preferentially intercepted and collected in the pre-installed cyclone separator. The filtered hot airflow is then discharged into the atmosphere through the extraction pump. After the sand removal is completed, the extraction section is kept under a slight negative pressure to remove residual heat until the water meter casing drops to a safe operating temperature. The clamp is then opened, and the sand removal is completed.

[0015] The technical effects and advantages of this invention are as follows: 1. This invention, through the coordinated design of the control unit and the pneumatic unit, achieves intelligent switching between cooling modes and sand removal methods based on different temperature ranges during the cooling process of the water meter casing. When the casting is in the first temperature range of high temperature and brittleness, only a gentle airflow is output from the air supply unit for flexible heat dissipation and cooling, effectively avoiding deformation and cracking of the high-temperature fragile casting caused by mechanical stress, and ensuring the dimensional accuracy and structural integrity of the casting.

[0016] 2. This invention utilizes an airflow-driven vibration section and a striking section to remove sand from the casting at different temperature ranges. When the casting cools to the second temperature range and its strength increases, the high-pressure airflow drives the vibration section to generate high-frequency self-excited oscillations, causing the entire fixture and water meter housing to vibrate together. This causes the internal molding sand to collapse and peel off in a large area due to fatigue, resulting in high sand removal efficiency and no impact damage to the casting body.

[0017] 3. When the casting temperature drops to the third temperature range and the adhesion of residual molding sand weakens, this invention outputs pulsed airflow through the control unit to drive the striking block of the striking part to continuously and reciprocate striking the outer wall of the water meter casing. This localized striking vibration precisely removes stubborn residual molding sand. Finally, the extraction part is activated to form a directional airflow sweep, thoroughly sucking up the detached molding sand, ensuring thorough sand removal, resulting in a smooth inner and outer surface of the casting and improving the quality of the finished product. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0019] Figure 2 This is a schematic diagram of the structure of the fixing unit in this invention.

[0020] Figure 3 This is a schematic diagram of the air supply unit and clamp in this invention.

[0021] Figure 4 This is a schematic diagram of the structure of the vibration part and the striking part in this invention.

[0022] Figure 5 For the present invention Figure 4 A magnified view of A in the middle.

[0023] In the picture: 1. Main body; 2. Fixing unit; 21. Clamp; 211. Upper clamp; 212. Lower clamp; 22. Cylinder; 23. Connector; 24. Sliding column; 25. Connecting channel; 3. Pre-treatment unit; 31. Vibration section; 32. Impact section; 33. Air blowing hood; 34. Slide groove; 35. Sensing block; 36. Impact block; 37. Guide groove; 38. First spring; 39. Vibration chamber; 310. Guide column; 311. Impact piston; 312. High-frequency spring; 313. Pressure relief hole; 4. Pneumatic unit; 41. Air supply unit; 42. Extraction unit; 43. Sand suction pipeline; 44. Cyclone separator; 45. Extraction pump; 46. Air passage; 47. Electromagnetic pulse valve; 5. Control unit; 51. Temperature sensor; 52. Receiving groove; 53. Second spring. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0025] Example 1 In existing technologies, the sand removal process for lead-free brass water meter casing castings is often carried out using a single method throughout the entire process. However, due to the high sensitivity of lead-free brass materials to hot working processes, their strength is extremely low in the high-temperature brittle stage immediately after demolding. Mechanical impact or severe vibration can easily cause deformation and cracking of the casting. If cleaning is delayed until the casting has completely cooled, the molding sand will solidify again due to high-temperature baking, greatly increasing its adhesion and making it difficult to remove completely using conventional methods, easily creating sand removal dead zones. In addition, existing pneumatic sand removal devices mostly provide a constant airflow output, which cannot be dynamically adjusted according to the difficulty of stripping the molding sand and the casting's tolerance at different temperature ranges, making it difficult to simultaneously meet the dual requirements of protecting the casting and efficiently removing sand.

[0026] To resolve the above technical issues, please refer to Figures 1 to 5 As shown, the present invention provides a casting apparatus for a lead-free brass water meter casing, comprising a main body 1, and further comprising: Fixing unit 2: It includes a clamp 21, which includes an upper clamp 211 and a lower clamp 212, and also includes a cylinder 22 for driving the upper clamp 211 to move and a connecting member 23; Pretreatment unit 3: It includes a vibration section 31 and a striking section 32. The vibration section 31 and the striking section 32 can perform vibration treatment and striking treatment on the outer wall of the water meter shell respectively according to the temperature range of the casting. Pneumatic unit 4: It includes an air supply unit 41 and an extraction unit 42; the air supply unit 41 is connected to an air blowing hood 33, which is connected to the inside of the clamp 21; the extraction unit 42 is connected to the inner cavity of the clamp 21 through a sand suction pipe 43; when extracting from the inside of the clamp 21, the extraction direction of the sand suction pipe 43 is opposite to the direction of the slide 34; the molding sand in the clamp 21 and the water meter housing will move towards the sand suction pipe 43 and will not enter the slide 34. Control unit 5 includes a temperature sensor 51, which is installed inside the lower clamp 212 and can contact the outer wall of the water meter casing in real time. Based on the temperature detected by the temperature sensor 51, when the water meter casing is in the first temperature range, the control unit 5 controls the air supply unit 41 to output airflow for flexible heat dissipation and cooling. When the water meter casing drops to the second temperature range, the control unit 5 controls the air supply unit 41 to output airflow to drive the vibration unit 31 to perform high-frequency vibration. When the water meter casing drops to the third temperature range, the control unit 5 controls the air supply unit 41 to output pulse airflow to drive the striking unit 32 to strike the outer wall of the water meter casing. During the sand removal stage, the control unit 42 controls the extraction unit 42 to perform negative pressure extraction through the sand suction pipe 43. The first temperature range is greater than 300°C, the second temperature range is 300°C to 200°C, and the third temperature range is below 200°C.

[0027] The main body 1 has multiple sliding columns 24. The connector 23 is slidably connected to the sliding columns 24. The lower end of the connector 23 is fixedly connected to the upper clamp 211. The upper clamp 211 and the lower clamp 212 are closed to form a clamping cavity that accommodates the water meter shell. The clamp 21 has a connection channel 25 that communicates with the outside atmosphere.

[0028] The fixture 21 has an air passage 46 that communicates with the air blowing hood 33, and a slide groove 34 that communicates with the air passage 46. The slide groove 34 communicates with the interior of the fixture 21.

[0029] The striking part 32 includes a sensing block 35, which is slidably connected to the slide groove 34. A striking block 36 is provided on the side of the sensing block 35 near the connecting channel 25. A guide groove 37 communicating with the slide groove 34 is provided inside the clamp 21. A guide post 310 is slidably connected within the guide groove 37. One end of the guide post 310 is fixedly connected to the sensing block 35, and the other end is fixedly connected to the side wall of the guide groove 37 via a first spring 38. The width of the connection between the striking block 36 and the sensing block 35 is much smaller than the width of the slide groove 34, so the striking block 36 will not affect the airflow into the slide groove 34. The sensing block 35 is... The triangular sensor block 35 has its inclined surface facing the air passage 46. When the airflow impacts the inclined surface of the sensor block 35 from the air passage 46, the airflow can push the inclined surface of the sensor block 35, causing the sensor block 35 to drive the guide column 310 to move away from the casting. The striking block 36 is made of elastic material. When the striking block 36 is not moving, it can seal the slide groove 34 to prevent dust inside the clamp 21 from entering the slide groove 34. When the clamp 21 is being extracted, the air supply 41 is closed, the striking block 36 is stationary and located at the opening of the slide groove 34, thus blocking the slide groove 34.

[0030] The vibration unit 31 includes a vibration chamber 39 formed within the clamp 21. An impact piston 311 is slidably sealed within the vibration chamber 39. The impact piston 311 is connected to the side wall of the chamber via a high-frequency spring 312. The sensing block 35 is configured such that when it slides along the slide groove 34 to a preset position under the drive of airflow, the slide groove 34 can communicate with the air inlet end of the vibration chamber 39. A pressure relief hole 313 is provided on the side wall of the vibration chamber 39. The pressure relief hole 313 is located at the limit stroke of the impact piston 311 compressing the high-frequency spring 312, and the pressure relief hole 313 penetrates the outer wall of the clamp 21 and communicates with the external environment. The high-pressure airflow entering the vibration chamber 39 can push the impact piston 311 to overcome the high-frequency spring 312 and expose the pressure relief hole 313, thereby causing the air pressure in the chamber to change periodically. This drives the impact piston 311 to perform high-frequency mechanical self-excited oscillation impact. It should be further noted that when the water meter casing is reduced to the third temperature range for reciprocating tapping to clean sand, the output pulse airflow has dynamic characteristics of high transient peak value and extremely short holding time. The transient peak pressure of the pulsed airflow is sufficient to drive the sensing block 35 to produce a relatively long sliding stroke, thereby allowing the first spring 38 to accumulate sufficient elastic potential energy to ensure that the striking block 36 has a sufficiently strong striking force during reset. Simultaneously, even if the sensing block 35 momentarily connects the slide groove 34 and the air inlet of the vibration chamber 39 at the end of its long stroke, the extremely short single air inlet time of the pulsed airflow, followed by a precipitous drop in airflow gap, means that the minute gas flow and transient pressure that momentarily enter the vibration chamber 39 are far from sufficient to overcome the static preload of the high-frequency spring 312 inside the vibration chamber 39. Therefore, the impact piston 311 cannot be substantially pushed, nor can the pressure relief hole 313 be opened, making it impossible for the high-frequency self-excited oscillation condition of the vibration part 31 to be established.

[0031] The lower clamp 212 has a receiving groove 52, the temperature sensor 51 is located in the receiving groove 52, and a second spring 53 is mounted on the temperature sensor 51 between its stepped surface and the side wall of the receiving groove 52.

[0032] The air supply unit 41 includes an electromagnetic pulse valve 47 that is connected to the air blowing hood 33, and the other end of the electromagnetic pulse valve 47 can be connected to the air storage unit.

[0033] The extraction unit 42 also includes a cyclone separator 44 and an extraction pump 45. The air inlet of the cyclone separator 44 is connected to the sand suction pipe 43, and its air outlet is connected to the extraction pump 45, so that the extracted molding sand is trapped in the cyclone separator 44.

[0034] Control unit 5 is configured as follows: When the temperature sensor 51 detects that the water meter casing temperature is within the first temperature range, it controls the air supply unit 41 to output basic cooling airflow for flexible heat dissipation and cooling. At this time, the airflow pressure is insufficient to drive the sensing block 35 to open the air inlet of the vibration chamber 39. The water meter casing has three openings: a dial opening, a water inlet, and a water outlet, corresponding to the three openings of the clamp 21, with the water outlet corresponding to... Figure 1 The connecting channel 25 of the clamp 21 corresponds to the dial opening. Figure 4 The opening of clamp 21 on the right side corresponds to the position of the water inlet. Figure 4 The opening in the middle of the clamp 21 is connected to the sand suction pipe 43. When the air supply unit 41 supplies air to the clamp 21 through the air blowing hood 33, a small portion of the gas enters the air passage 46, and most of the gas enters the dial opening. Figure 4 The airflow enters the water meter housing through the dial opening on the right side, and enters the gap between the clamp 21 and the water meter housing. Finally, the airflow is discharged to the outside through the connecting channel 25 and the water outlet. Only a small part enters the air passage 46. Therefore, the airflow pressure is insufficient to drive the sensing block 35 to open the air inlet of the vibration chamber 39.

[0035] When the temperature sensor 51 detects that the water meter housing temperature has dropped to the second temperature range, it controls the air supply unit 41 to output a stable airflow with the first pressure, drives the sensing block 35 to overcome the first spring 38 and slide to a preset position away from the water meter housing and open the air inlet of the vibration chamber 39. At this time, the striking block 36 is separated from the water meter housing. The airflow enters the vibration chamber 39 and pushes the impact piston 311 to overcome the high-frequency spring 312 and expose the pressure relief hole 313, generating a high-frequency mechanical self-excited oscillation impact, which drives the clamp 21 and the water meter housing to vibrate, causing the internal molding sand to collapse and peel off. When the temperature sensor 51 detects that the water meter casing temperature has dropped to the third temperature range, the control air supply unit 41 outputs a pulsed airflow with a second pressure. The second pressure is lower than the first pressure. This pulsed airflow drives the sensing block 35 to move away from the water meter casing against the first spring 38. During the airflow pulse interval, the return force of the first spring 38 drives the striking block 36 to strike the outer wall of the water meter casing, realizing reciprocating striking to remove sand and remove residual molding sand. When the preset sand removal time is reached, the control unit 5 shuts off the air supply unit 41 and starts the extraction pump 45. The outside air is replenished from the connecting channel 25 to form a directional sweeping airflow, which draws the molding sand through the sand suction pipe 43 to the cyclone separator 44 for separation and collection.

[0036] The first spring 38, the second spring 53, and the high-frequency spring 312 are all made of high-temperature resistant materials. During use, the water meter casing, which has been cast and is still at a high temperature, is placed into the cavity of the lower clamp 212. The cylinder 22 is activated, and the piston rod of the cylinder 22 pushes the connecting piece 23. The connecting piece 23 slides smoothly downward along the multiple sliding columns 24 on the main body 1, causing the upper clamp 211 to move downward and close with the lower clamp 212, forming a sealed clamping cavity that encloses the high-temperature water meter casing.

[0037] As the upper clamp 211 and the lower clamp 212 close, the temperature sensor 51 installed in the receiving groove 52 of the lower clamp 212, under the elastic thrust of the second spring 53, has its probe end pressed tightly against the outer wall of the water meter casing, and begins to collect the surface temperature of the water meter casing in real time, and continuously feeds the temperature signal back to the control unit 5.

[0038] When the temperature sensor 51 detects that the water meter casing temperature is above 300°C in the first temperature range, the control unit 5 activates the air supply unit 41, and the electromagnetic pulse valve 47 opens. Compressed air in the air storage unit, at a lower pressure than the basic cooling airflow, is introduced into the clamp 21 through the air blowing hood 33. This gentle cooling airflow flows around the water meter casing in the clamping cavity, providing uniform and flexible heat dissipation and cooling, and releasing the thermal stress generated by the high temperature in the casting. At this time, the airflow pressure is low. Although some of it enters the air passage 46 and reaches the slide groove 34, generating a certain thrust on the inclined surface of the sensing block 35, this thrust is insufficient to overcome the elastic force of the first spring 38. Most of the gas enters the dial opening. Figure 4 The airflow from the opening on the right side enters the water meter housing through the dial opening and enters the gap between the clamp 21 and the water meter housing. Finally, the airflow is discharged to the outside through the connecting channel 25 and the water outlet of the water meter housing to dissipate heat from the water meter housing. During this process, the sensing block 35 remains in place in the slide groove 34, so the striking block 36 also remains stationary. The entire device only performs the air cooling function to avoid mechanical impact on the fragile high-temperature casting.

[0039] As cooling continues, when the temperature sensor 51 detects that the water meter casing temperature has dropped to the second temperature range of 200°C to 300°C, the strength of the casting has been improved. At this time, the control unit 5 controls the electromagnetic pulse valve 47 of the air supply unit 41 to switch to outputting a high-pressure stable airflow with the first pressure. This high-pressure airflow enters the fixture 21 through the air blowing hood 33. Part of the airflow continues to cool the casting, while the other part enters the air passage 46. The high-pressure airflow impacts the inclined surface of the sensing block 35 in the slide groove 34, generating sufficient thrust to overcome the tension of the first spring 38, pushing the sensing block 35 to slide along the slide groove 34 away from the water meter casing. During this process, the striking block 36, which is fixedly connected to the sensing block 35, moves along with it, completely separating from the outer wall of the water meter casing to avoid interference. At the same time, the guide post 310, which is fixedly connected to the sensing block 35, slides synchronously in the guide groove 37, compressing the first spring 38 to store energy.

[0040] When the sensing block 35 slides to the preset position, the slide groove 34 connects with the air inlet of the vibration chamber 39. High-pressure airflow then rushes into the vibration chamber 39, pushing the impact piston 311 inside the vibration chamber 39 to move outward against the elastic force of the high-frequency spring 312. When the impact piston 311 is pushed to its limit stroke, the pressure relief hole 313, which was originally sealed by its sidewall, is fully opened, and the high-pressure gas inside the vibration chamber 39 is instantly released from the pressure relief hole 313 to the external environment, causing a sudden drop in pressure inside the vibration chamber 39. The high-frequency spring 312 then pushes the impact piston 311 back to its original position, resealing the pressure relief hole 313. Thus, with the continuous entry of airflow and periodic pressure relief, the impact piston 311 forms a high-frequency reciprocating motion and violently impacts the sidewall of the vibration chamber 39, generating high-frequency mechanical self-excited oscillation. This intense vibration is transmitted directly to the water meter casing through the fixture 21, causing the entire casting to move at high frequency. This causes the molding sand filling the complex flow channels inside the casting to break into a network due to alternating stress, and then collapses in pieces, peeling off from the inner wall of the flow channels.

[0041] When the water meter casing temperature further drops to the third temperature range below 200℃, the remaining small amount of molding sand is mostly localized stubborn deposits. At this time, control unit 5 controls electromagnetic pulse valve 47 to output a pulsed airflow at a second pressure, lower than the first pressure used in the second range. The pulsating high-pressure airflow intermittently impacts the inclined surface of sensing block 35. When an airflow pulse arrives, the airflow pressure drives sensing block 35 to move striking block 36 away from the water meter casing, and the first spring 38 is compressed and stores energy. When the airflow pulse interval briefly disappears, the air pressure thrust disappears, and the elastic force stored in the first spring 38 is released instantaneously, pushing guide post 310 and causing sensing block 35 and striking block 36 to quickly return to the water meter casing. Thus, under the intermittent drive of the pulsed airflow and the continuous reset action of the first spring 38, striking block 36 forms a reciprocating motion, continuously impacting and striking the outer wall of the water meter casing. This causes the stubborn residual molding sand adhering to the inner wall of the flow channel to loosen and fall off due to direct impact, achieving the removal of residual molding sand.

[0042] When the sand removal conditions are met, i.e., the control unit 5 has a preset tapping time, the control unit 5 shuts off the air supply unit 41 after the preset tapping time is reached. Then, the extraction pump 45 of the extraction unit 42 is activated. The extraction pump 45 generates negative pressure, drawing in ambient air through the sand suction pipe 43 and the inner cavity of the clamp 21 via the connecting channel 25. The ambient air forms a directional sweeping airflow, flowing within the clamping cavity, entraining the broken and scattered molding sand particles within the cavity, and drawing them away together through the sand suction pipe 43. The airflow mixed with molding sand first enters the cyclone separator 44. Under centrifugal force, the molding sand particles are separated and collected at the bottom of the cyclone separator 44, while the clean airflow is discharged into the atmosphere from the outlet via the extraction pump 45. After the molding sand is extracted, the device maintains the extraction section 42 under a slight negative pressure to remove the residual heat of the casting until the water meter casing temperature drops to a safe operating range. Then, the cylinder 22 drives the upper clamp 211 to reset and open, allowing the clean and intact water meter casing casting to be removed. This completes the entire sand removal process.

[0043] Example 2 Please see Figures 1 to 5 As shown, this embodiment provides a casting process for a lead-free brass water meter casing, which is carried out using the casting apparatus of Embodiment 1 above, and includes the following steps: S1: The water meter casing that has been cast and is in a high temperature state is placed into the lower clamp 212. The upper clamp 211 is closed by the cylinder 22 and the connecting piece 23 to form a sealed clamping cavity. The temperature sensor 51 in the receiving groove 52 is in close contact with the outer wall of the water meter casing under the action of the second spring 53, and the water meter casing temperature is detected in real time and fed back to the control unit 5. S2: When the temperature sensor 51 detects that the water meter housing temperature is in the first temperature range, the material of the water meter housing is very easy to deform and crack under external force. At this time, the air supply unit 41 is activated, and the airflow is introduced into the inner cavity of the clamp 21 through the air blowing cover 33. Only the airflow is used for flexible heat dissipation and cooling and thermal stress release to avoid mechanical stress damaging the casting structure. S3: When the temperature sensor 51 detects that the water meter housing temperature has dropped to the second temperature range, the control air supply unit 41 outputs a high-pressure stable airflow. The high-pressure airflow drives the sensing block 35 to overcome the first spring 38 and move to a preset position away from the water meter housing, so that the striking block 36 is separated from the water meter housing and the slide 34 is connected to the vibration chamber 39. The high-pressure airflow pushes the impact piston 311 and periodically opens the pressure relief hole 313 connected to the outside, generating a high-frequency mechanical self-excited oscillation impact, which drives the clamp 21 and the water meter housing to vibrate. The high-frequency excitation force causes the molding sand inside the water meter housing to undergo mesh-like collapse and peeling. S4: When the temperature sensor 51 detects that the water meter housing temperature drops to the third temperature range, the control unit 5 controls the electromagnetic pulse valve 47 to output a pulse airflow to the air blowing cover 33. The pulse airflow is introduced into the slide groove 34 to drive the sensing block 35 to move away from the water meter housing against the first spring 38. During the airflow pulse interval, the reset force of the first spring 38 drives the striking block 36 to strike the outer wall of the water meter housing to remove sand. S5: When the desanding conditions are met, the control unit 5 shuts off the air supply unit 41 and starts the extraction pump 45. At this time, outside air is drawn into the inner cavity of the clamp 21 through the connecting channel 25, forming a directional sweeping airflow. The stripped internal molding sand is drawn through the sand suction pipe 43 and preferentially intercepted and collected in the pre-positioned cyclone separator 44. The filtered hot airflow is then discharged into the atmosphere through the extraction pump 45. After the desanding is completed, the extraction unit 42 is kept under a slight negative pressure to remove residual heat until the water meter casing drops to a safe operating temperature. The clamp 21 is then opened, and the desanding is completed.

[0044] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A casting device for a lead-free brass water meter casing, comprising a main body (1), characterized in that, Also includes: Fixing unit (2): It includes a clamp (21), which includes an upper clamp (211) and a lower clamp (212); Pretreatment unit (3): It includes a vibration part (31) and a striking part (32), wherein the vibration part (31) and the striking part (32) can respectively perform vibration treatment and striking treatment on the outer wall of the water meter shell according to the change of the casting temperature range; Pneumatic unit (4): It includes an air supply unit (41) and an air extraction unit (42); Control unit (5): It includes a temperature sensor (51) installed in the clamp (21) and capable of contacting the outer wall of the water meter casing in real time; the control unit (5) controls the air supply unit (41) to output airflow for flexible heat dissipation and cooling when the water meter casing is in the first temperature range, based on the temperature detected by the temperature sensor (51); when the water meter casing drops to the second temperature range, the control unit (5) controls the air supply unit (41) to output airflow to drive the vibration unit (31) to perform high-frequency vibration treatment; when the water meter casing drops to the third temperature range, the control unit (41) controls the air supply unit (41) to output pulse airflow to drive the striking unit (32) to strike the outer wall of the water meter casing; during the sand removal stage, the control unit (42) controls the extraction unit (42) to perform negative pressure extraction.

2. The casting apparatus for the lead-free brass water meter housing according to claim 1, characterized in that, The main body (1) is provided with multiple sliding columns (24). The fixing unit (2) includes a cylinder (22) for driving the upper clamp (211) to move and a connecting piece (23). The connecting piece (23) is slidably connected to the sliding column (24). The lower end of the connecting piece (23) is fixedly connected to the upper clamp (211). The upper clamp (211) and the lower clamp (212) are closed to form a clamping cavity for accommodating the water meter shell. The clamp (21) is provided with a connection channel (25) that communicates with the outside atmosphere.

3. The casting apparatus for the lead-free brass water meter housing according to claim 1, characterized in that, The air supply unit (41) is connected to an air blowing hood (33), which is connected to the inside of the clamp (21). The extraction unit (42) is connected to the inner cavity of the clamp (21) through a sand suction pipe (43). An air passage (46) connected to the air blowing hood (33) is independently opened inside the clamp (21). A sliding groove (34) connected to the air passage (46) is opened inside the clamp (21). The sliding groove (34) is connected to the inside of the clamp (21). The extraction unit (42) also includes a cyclone separator (44) and an extraction pump (45).

4. The casting apparatus for the lead-free brass water meter housing according to claim 1, characterized in that, The striking part (32) includes a sensing block (35), which is slidably connected to the slide groove (34). A striking block (36) is provided on the side of the sensing block (35) near the connecting channel (25). A guide groove (37) communicating with the slide groove (34) is provided in the clamp (21). A guide post (310) is slidably connected in the guide groove (37). One end of the guide post (310) is fixedly connected to the sensing block (35), and the other end of the guide post (310) is fixedly connected to the side wall of the guide groove (37) via a first spring (38).

5. The casting apparatus for the lead-free brass water meter housing according to claim 1, characterized in that, The vibration unit (31) includes a vibration chamber (39) formed within the clamp (21). An impact piston (311) is slidably sealed within the vibration chamber (39). The impact piston (311) is connected to the side wall of the chamber via a high-frequency spring (312). The sensing block (35) is configured such that when it slides along the slide groove (34) to a preset position under airflow drive, the slide groove (34) communicates with the air inlet of the vibration chamber (39). A pressure relief hole is provided on the side wall of the vibration chamber (39). 313), the pressure relief hole (313) is located at the limit stroke of the high-frequency spring (312) compressed by the impact piston (311), and the pressure relief hole (313) penetrates the outer wall of the clamp (21) and communicates with the external environment; the high-pressure airflow entering the vibration chamber (39) can push the impact piston (311) to overcome the high-frequency spring (312) and expose the pressure relief hole (313), thereby causing the air pressure in the chamber to change periodically, driving the impact piston (311) to perform high-frequency mechanical self-excited oscillation impact.

6. The casting apparatus for the lead-free brass water meter housing according to claim 1, characterized in that, The lower clamp (212) has a receiving groove (52) inside, the temperature sensor (51) is located in the receiving groove (52), and a second spring (53) is fitted on the temperature sensor (51) between its stepped surface and the side wall of the receiving groove (52).

7. The casting apparatus for the lead-free brass water meter housing according to claim 1, characterized in that, The gas supply unit (41) includes an electromagnetic pulse valve (47) that is connected to the air blowing hood (33), and the other end of the electromagnetic pulse valve (47) can be connected to the gas storage unit.

8. The casting apparatus for the lead-free brass water meter housing according to claim 3, characterized in that, The air inlet of the cyclone separator (44) is connected to the sand suction pipe (43), and its air outlet is connected to the extraction pump (45) so that the extracted molding sand is trapped in the cyclone separator (44).

9. The casting apparatus for the lead-free brass water meter housing according to claim 1, characterized in that, The control unit (5) is configured as follows: When the temperature sensor (51) detects that the water meter casing temperature is in the first temperature range, the control air supply unit (41) outputs basic cooling airflow for flexible heat dissipation and cooling. At this time, the airflow pressure is insufficient to drive the sensing block (35) to open the air inlet of the vibration chamber (39). When the temperature sensor (51) detects that the water meter housing temperature has dropped to the second temperature range, the control air supply unit (41) outputs a stable airflow with the first pressure, drives the sensing block (35) to overcome the first spring (38) and slide to a preset position away from the water meter housing and open the air inlet of the vibration chamber (39). At this time, the striking block (36) is separated from the water meter housing. The airflow enters the vibration chamber (39) and pushes the impact piston (311) to overcome the high-frequency spring (312) and expose the pressure relief hole (313), generating a high-frequency mechanical self-excited oscillation impact, which drives the clamp (21) and the water meter housing to vibrate, causing the internal molding sand to collapse and peel off. When the temperature sensor (51) detects that the water meter casing temperature drops to the third temperature range, the control air supply unit (41) outputs a pulsed airflow with a second pressure. The second pressure is lower than the first pressure. The pulsed airflow drives the sensing block (35) to move away from the water meter casing against the first spring (38). During the airflow pulse interval, the reset force of the first spring (38) drives the striking block (36) to strike the outer wall of the water meter casing, thereby achieving reciprocating striking to remove sand and eliminate residual molding sand. When the preset sand removal time is reached, the control unit (5) shuts off the air supply unit (41), starts the extraction pump (45), and uses outside air to supplement the air from the connecting channel (25) to form a directional sweeping airflow, which draws the molding sand through the sand suction pipe (43) to the cyclone separator (44) for separation and collection.

10. A casting process for a lead-free brass water meter casing, characterized in that, The casting process, using the casting apparatus for lead-free brass water meter housings as described in any one of claims 1-9, includes the following steps: S1: The water meter casing that has been cast and is in a high temperature state is placed into the lower clamp (212). The upper clamp (211) is closed by the cylinder (22) and the connector (23) to form a closed clamping cavity. The temperature sensor (51) in the receiving groove (52) is in close contact with the outer wall of the water meter casing under the action of the second spring (53) to detect the temperature of the water meter casing in real time and feed it back to the control unit (5). S2: When the temperature sensor (51) detects that the water meter shell temperature is in the first temperature range, the material of the water meter shell is easily deformed and cracked by external force. At this time, the air supply unit (41) is activated, and the airflow is introduced into the inner cavity of the fixture (21) through the air blowing cover (33). Only the airflow is used for flexible heat dissipation and cooling and thermal stress release to avoid mechanical stress damaging the casting structure. S3: When the temperature sensor (51) detects that the water meter shell temperature drops to the second temperature range, the control air supply unit (41) outputs a high-pressure stable airflow. The high-pressure airflow drives the sensing block (35) to overcome the first spring (38) and move to a preset position away from the water meter shell, so that the striking block (36) is separated from the water meter shell and the slide (34) is connected to the vibration chamber (39). The high-pressure airflow pushes the impact piston (311) and periodically opens the pressure relief hole (313) connected to the outside, generating a high-frequency mechanical self-excited oscillation impact, which drives the clamp (21) and the water meter shell to vibrate. The high-frequency excitation force causes the molding sand inside the water meter shell to undergo mesh collapse and peeling. S4: When the temperature sensor (51) detects that the water meter casing temperature drops to the third temperature range, the control unit (5) controls the electromagnetic pulse valve (47) to output a pulse airflow to the air blower (33). The pulse airflow is introduced into the slide groove (34) to drive the sensing block (35) to move away from the water meter casing against the first spring (38). During the airflow pulse interval, the reset force of the first spring (38) drives the striking block (36) to hit the outer wall of the water meter casing to clean the sand. S5: When the desanding conditions are ripe, the control unit (5) shuts off the air supply section (41) and starts the extraction pump (45). At this time, outside air is drawn into the inner cavity of the clamp (21) through the connecting channel (25), forming a directional sweeping airflow. The stripped internal molding sand is drawn through the sand suction pipe (43) and preferentially intercepted and collected in the front-mounted cyclone separator (44). The filtered hot airflow is then discharged into the atmosphere through the extraction pump (45). After the desanding is completed, the extraction section (42) is kept under a slight negative pressure to remove residual heat until the water meter casing drops to a safe operating temperature. The clamp (21) is then opened to complete the desanding.

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