An automated air tightness test screening machine and method for three-way valves

Abstract

This invention discloses an automated airtightness testing and screening machine and method for three-way valves, belonging to the technical field of valve testing equipment. The equipment consists of a frame, a testing platform, a feeding mechanism, a discharging mechanism, a truss mechanism, and an airtightness tester. The testing platform features three sets of clamping fixtures arranged in a triangular layout, with a central clamping fixture equipped with a weighing device. The upper and middle clamping components utilize telescopic torsion components paired with detachable sealing connectors, adaptable to different valve port structures. The truss mechanism is equipped with double sets of three-jaw grippers for automatic valve transfer and positioning. This method relies on the equipment to complete the entire process of automatic feeding, valve port sealing, pressure holding airtightness testing, and automatic sorting of good / defective products. This invention is compatible with various specifications of Y-type three-way valves, allows for quick replacement of parts without requiring overall mold changes, and has strong versatility. It employs pneumatic pressure holding testing, ensuring high testing accuracy. The fully automated operation reduces labor costs and quality risks, ensures smooth process transitions, and is suitable for continuous batch testing and production of valves.

Description

Technical Field

[0001] This invention relates to the field of valve testing equipment technology, specifically to an automated airtightness testing and screening machine and method for three-way valves. Background Technology

[0002] As a core control component of urban gas transmission and distribution networks, residential stoves, and wall-hung boiler gas pipelines, gas valves directly determine the safety of gas use and the baseline for public disaster prevention through their airtightness. This is a mandatory inspection item for valves before they leave the factory. Statistics on safety accidents show that gas leaks caused by pinholes in the valve body, poor sealing surface fit, and incomplete valve closure are the leading causes of residential gas explosions and indoor poisoning accidents, accounting for over 60% of all gas safety incidents. With the iterative upgrades of gas terminal products, various types of gas valves, such as stove valves, wall-hung boiler control valves, pipeline self-closing valves, and multi-way diversion valves, are being mass-produced simultaneously. Different models of valve bodies exhibit significant differences in their length, width, and height dimensions, and there are no uniform specifications for the number of valve body ports and the arrangement of pipe openings. Since various types of valves are mostly produced in batches on the same automated production line, there is an objective requirement that the gas tightness testing fixtures be compatible with clamping and positioning all types of valve bodies. If the gas tightness testing fixtures are not sufficiently adaptable or the clamping and fixing are not in place, pipe opening seal failures and distorted test data can easily occur. Substandard valves entering the market not only cause terminal equipment malfunctions and repairs but also pose flammable and explosive safety hazards.

[0003] like Figure 1 , Figure 2 , Figure 3 , Figure 4 The four types of gas valves shown are similar in size and appearance, except that the upper and middle valve ports of the Y-shaped valves are different. There is no testing equipment that can be used for all three types of gas valves. Therefore, it is necessary to develop a universal chemical fixture that can adapt to multiple valve body sizes and has an adjustable clamping stroke, and to build an airtightness testing solution that can be adapted to all types of valves. This is an essential requirement for quality control in gas valve production.

[0004] Currently, gas valve airtightness testing is mainly divided into two types: underwater immersion leak detection and pressure holding test. Underwater testing relies on observing bubbles after immersion in water to determine leakage. While the equipment investment is low, the workpiece is prone to corrosion from water, requiring an additional drying process. The test results rely on human judgment, resulting in poor accuracy and difficulty in automation integration. Pressure holding test uses pressure sensors to monitor pressure drop. It is non-destructive, provides traceable data, and is more suitable for automated production lines. However, it has stringent requirements for the sealing performance of the tooling nozzles and the accuracy of valve body clamping and positioning. In actual production, multiple specifications of gas valves are produced on the same line. Most existing testing tooling uses a fixed limiting structure, and the clamping stroke cannot be adjusted independently. One set of tooling can only match a single three-dimensional valve body, making it impossible to clamp multiple valve models at the same station and difficult to switch product airtightness testing processes as needed.

[0005] Among existing publicly available patents, many valve airtightness testing devices have achieved partial automation, but they have significant shortcomings in terms of universal clamping for multi-size valve bodies and adaptive adjustment of the clamping mechanism's stroke. Firstly, referring to the comparative patent CN110823463B, the fixture mechanism of this patent is designed according to the specific valve model's shape, size, and hole layout. The clamping structure is a fixed limiting structure, and the extension length of the clamping hand is not adjustable. It can only adapt to a single specification of valve body and cannot be compatible with multiple gas valves with different three-dimensional length and width dimensions. This is fundamentally different from the technical approach of this invention, which achieves multi-model shared tooling through the extension and retraction adjustment of the clamping hand. At the same time, the entire machine of this patent is only equipped with a station positioning and airtightness testing structure, without an automatic workpiece loading and conveying component or an automatic sorting mechanism after testing. It relies on manual workpiece loading and unloading and product sorting, and cannot achieve full-chain automated closed-loop testing. Secondly, compared with patent CN113125145B (Gas Valve Testing Device and Testing Method), this patent establishes a high and low pressure dual-circuit gas supply testing gas path, which can automatically complete the high and low pressure opening and closing airtightness test of the gas self-closing valve. However, the matching fixture is a fixed groove positioning structure, and the groove limit size and the sealing plug installation position are all fixed values. The clamping parts have no telescopic adjustment function, which cannot be adapted to various gas valves with different length, width and height dimensions. When switching to different models of products, the entire fixture module must be replaced. The equipment has extremely poor versatility. Moreover, the whole machine only focuses on airtightness data acquisition and lacks automated feeding and automatic sorting units. After the test is completed, the workpieces still need to be sorted manually.

[0006] In summary, most current testing fixtures follow a customization logic of "one valve, one fixture; size determines stroke." Gas valves with different three-dimensional dimensions require their own dedicated clamping and sealing fixtures. When enterprises engage in flexible production of multiple models, they need to purchase large quantities of non-standard fixtures and add multiple dedicated testing equipment, significantly increasing equipment procurement and fixture warehousing costs. Frequent replacement of complete sets of fixtures also incurs equipment downtime for debugging, reducing production line uptime. At the same time, existing equipment generally separates the feeding, testing, and sorting processes. Feeding is done manually, testing is conducted independently by a single machine, and good and defective products are manually picked after testing. The entire chain cannot achieve an automated closed loop, which increases labor costs and is prone to quality risks due to manual sorting errors leading to defective products being shipped out of the factory. Summary of the Invention

[0007] To address the aforementioned technical problems, the present invention aims to provide an automated airtightness testing and screening machine and method for three-way valves. This equipment is compatible with various specifications of Y-type gas three-way valves, allows for quick replacement of parts without requiring overall mold replacement, and has strong versatility. It adopts air pressure holding testing, resulting in high testing accuracy. The entire process is automated, reducing labor costs and quality risks, and ensuring smooth process connections, making it suitable for batch continuous testing and production of valves.

[0008] To achieve the above objectives, the technical solution of the present invention is as follows: An automated air tightness testing and screening machine for a three-way valve, wherein the three-way valve is a Y-shaped valve, the air tightness testing and screening machine includes a frame, a feeding mechanism and a discharging mechanism mounted on the frame and respectively installed on the left and right sides of the testing platform, a truss mechanism for clamping and transferring the valve, and an air tightness tester for testing air tightness. Three sets of low-tightness fixtures are installed on the testing platform in a triangular arrangement, and a clamping fixture is installed at the center of the three sets of low-tightness fixtures. The three sets of low-tightness fixtures are a lower left low-tightness component, a lower right low-tightness component, and a middle-upper low-tightness component. The lower left low-tightness component mainly consists of a low-tightness cylinder and a low-tightness plug. The low-tightness plug is detachably installed at the front end of the cylinder shaft of the low-tightness cylinder, which is fixed to the testing platform. The lower right low-tightness component mainly consists of an inflation cylinder and an inflation plug. The inflation plug is fixed to the cylinder head of the inflation cylinder, and its air pipe is connected to an airtightness tester. The middle-upper low-tightness component mainly consists of a telescopic torque assembly and a sealing joint. The telescopic torque assembly is telescopically installed towards the clamping fixture, and the sealing joint is detachably installed at the front end of the telescopic torque assembly. The low-tightness plug, inflation plug, and sealing joint move simultaneously towards the center and seal the three-way valve. The clamping fixture includes a weighing device and a valve clamping fixture fixed on the weighing device. A countersunk hole is provided on the testing platform for the weighing device to be inserted. The three-way valve is placed flat in the valve clamping fixture and clamped. The three valve ports of the three-way valve correspond to the lower left low clamping component, the lower right low clamping component, and the upper middle low clamping component, respectively. The truss mechanism includes a gantry frame built above the loading mechanism, unloading mechanism and detection platform, and a power component installed on the gantry frame. A valve gripper is installed at the drive end of the power component, and the valve gripper keeps the three-way valve in a horizontal state when holding it.

[0009] Furthermore, the telescopic tightening assembly includes two support seats fixed on the testing platform, a worm shaft rotatably connected to the two support seats, a turbine meshing with the worm shaft, and a motor driving the turbine to rotate. A radial sliding bearing is also rigidly connected to the worm shaft, and a radially extending S-shaped cam groove is provided on the outer surface of the radial sliding bearing. A guide seat is provided on the testing platform, and a guide post matching the cam groove is provided on the guide seat. The sealing joint is detachably connected to the front end of the worm shaft.

[0010] Furthermore, the sealing connector consists of an integrated quick-release tail end and a sealing front end. The quick-release tail end has a quick-release structure and connects to the worm shaft. The sealing front end is a triangular pyramid, with a sealing ring at the point where the diameter of the triangular pyramid is the largest. The inside of the triangular pyramid has an axial deformation gap, which divides the front end of the triangular pyramid into three segments. Alternatively, the sealing front end is a threaded post with threads on its outer surface. The side of the threaded post near the quick-release tail end has a sealing ring, and the threaded post matches the internal thread of the three-way valve.

[0011] Furthermore, the valve clamping clamp is a three-jaw clamping clamp, which is fixed vertically upwards, and the three claws of the three-jaw clamping clamp are respectively clamped at the inside corner of the Y-shaped valve.

[0012] Furthermore, the valve gripper is a three-jaw gripper, which is installed vertically downwards. A clamping column is also provided in the middle of the three gripping fingers of the three-jaw gripper. When gripping the three-way valve, the three gripping fingers of the three-jaw gripper are gripped at the inside corner of the Y-shaped valve. At this time, the clamping column is tightly clamped at the intersection of the three-way valve.

[0013] Furthermore, the valve gripper is provided in two sets, which are installed side by side on the suspension frame. The distance between the two sets is greater than the area occupied by a three-way valve. The suspension frame is fixed to the drive end of the power component.

[0014] Furthermore, the feeding mechanism includes a feeding conveyor belt and valve holders. The valve holders are arranged sequentially on the feeding conveyor belt via holder brackets. The valve holders are disc-shaped with a Y-shaped channel in the middle to accommodate a three-way valve. The three valve ports of the three-way valve extend beyond the Y-shaped channel. In addition, a feeding robot is installed on the side of the feeding conveyor belt. The drive end of the feeding robot is equipped with a rotating gripper for gripping the three-way valve and placing it onto the valve holder according to its orientation.

[0015] Furthermore, the feeding mechanism is divided into a qualified product area and a defective product area side by side, and the valve gripper passes through the qualified product area and the defective product area to complete the sorting of the three-way valve.

[0016] An automated airtightness testing and screening method for three-way valves, applied to the aforementioned automated airtightness testing and screening machine for three-way valves, includes the following steps: S1. The loading robot places the three-way valve on the loading conveyor belt according to the preset position, completing the valve pre-loading arrangement. S2. The truss mechanism drives the valve gripper to move to the feeding conveyor belt to grab a single three-way valve and transfer it to the clamping fixture on the detection platform. After the weighing device detects that the three-way valve is in place, it sends a sensing signal to the control system. After receiving the sensing signal, the control system first sends a preliminary alignment and placement signal to release the three gripping fingers of the three-jaw clamp, and then sends a secondary clamping signal to clamp the three-way valve. S3. Allow the lower left abutment, lower right abutment, and upper middle abutment to receive the linkage signal from the valve clamping fixture, and simultaneously extend and block the three valve ports of the three-way valve; S4. The control system receives the blocking linkage signal and sends a lifting signal again. The valve clamp is lifted and reset, and the clamping column is released from the pressure of the three-way valve. S5. The air tightness tester inflates the three-way valve with air, completes the inflation operation according to the system's preset inflation time, and detects and collects the internal air pressure data of the three-way valve during the inflation period. S6. The control system determines whether the three-way valve is a qualified product or a defective product based on the air pressure detection data and outputs the corresponding sorting signal. The truss mechanism moves the corresponding stroke distance according to the sorting signal, and the valve gripper is released at the preset position, so that the qualified product and the defective product fall into the qualified product area and the defective product area respectively. S7. The equipment continuously performs the above steps in a loop to complete the automated airtightness test and screening of the three-way valve.

[0017] Furthermore, in step S5, the airtightness tester adopts a pressure-holding test mode. After inflation, it first maintains the preset pressure holding time, and then monitors the pressure drop value in the valve body in real time. When the pressure drop value is lower than the preset threshold of the system, it is judged as a qualified product; otherwise, it is judged as a leaking defective product.

[0018] The advantages of this invention compared to the prior art are: I. High versatility, cost reduction and efficiency improvement This technology solves the technical problems of frequent mold changes, high tooling and maintenance costs, and long production line downtime associated with producing multiple models on the same line. All tooling components are detachable and replaceable. The sealing connector is compatible with different structures such as standard valve ports and internal thread valve ports. The telescopic tightening component can also adaptively adjust its stroke. Combined with a three-jaw clamp, it is compatible with various Y-shaped three-way valves of different ports and shapes, eliminating the need for complete module replacement. This significantly reduces tooling procurement costs, minimizes mold change and debugging time, and improves production line operating efficiency.

[0019] II. Full-process automation reduces human error and potential quality risks. This technology solves the technical problems of traditional equipment's fragmented processes and reliance on manual loading, unloading, and sorting. It also overcomes the shortcomings of existing technologies, such as underwater leak detection which easily causes valve body corrosion and requires an additional drying step. This technology integrates automatic feeding, airtightness testing, and automatic sorting functions, requiring no manual intervention throughout the entire process. It employs pressure-holding air pressure testing, which is non-destructive and prevents valve body rusting, eliminating the need for a drying step. This reduces labor costs and completely avoids errors caused by manual judgment and sorting, ensuring product quality from the outset.

[0020] III. Reliable positioning and sealing, resulting in higher detection accuracy. This technology employs a triangular layout clamping fixture combined with a central clamping structure. The three-jaw clamp precisely holds the valve's internal corner position, and a pressure column assists in limiting movement during transport, ensuring stable valve body positioning. Various sealing accessories come with integrated sealing rings and deformation structures, allowing for a tight fit to different valve ports. Combined with a pressure-holding and pressure drop testing method, it effectively prevents false or missed detections caused by sealing failures and positioning deviations, resulting in accurate and reliable test results.

[0021] IV. Smooth inter-mechanical coordination, suitable for batch continuous production. This technology relies on a control system to achieve intelligent linkage between various mechanisms. After the valve body is in place, actions such as clamping, sealing, and resetting are triggered sequentially, with orderly process connections. The equipment is equipped with dual sets of grippers to improve transfer efficiency. The overall mechanical movements are stable and coordinated, allowing for long-term, uninterrupted operation, effectively increasing production cycle time, and is fully adaptable to the large-scale, continuous batch testing scenarios of gas valves. Attached Figure Description

[0022] Figure 1 This is a plan view of the three-way valve in Example 2; Figure 2 This is a plan view of the three-way valve in Example 2; Figure 3 This is a plan view of the T-junction invention in Embodiment 1; Figure 4 This is a plan view of the T-junction invention in Embodiment 1; Figure 5 This is a schematic diagram of the main structure of an automated airtightness testing and screening machine. Figure 6 A three-dimensional structural diagram of the valve gripper; Figure 7 This is a top-view schematic diagram of the mating and installation structure of the clamping fixture and the low-tightness fixture on the testing platform of Example 1. Figure 8 This is a top-view planar schematic diagram of the clamping fixture and the low-tightening fixture in Embodiment 2. Figure 9 A schematic diagram of the main structure of a three-way valve placed on a disc-shaped valve holder; Figure 10 A top view of a three-way valve placed on a disc-shaped valve holder; Figure 11 A flowchart illustrating the workflow for automated airtightness testing and screening methods.

[0023] Reference numerals: 1. Frame; 2. Testing platform; 20. Weighing device; 21. Valve clamping fixture; 3. Feeding mechanism; 30. Feeding conveyor belt; 31. Clamping bracket; 32. Valve clamping seat; 33. Feeding robot; 4. Unloading mechanism; 5. Truss mechanism; 50. Power component; 51. Valve gripper; 52. Pressing column; 6. Lower left low-tightening component; 60. Low-tightening cylinder; 61. Low-tightening plug; 7. Lower right low-tightening component; 70. Inflation cylinder; 71. Inflation plug; 72. External air pipe; 8. Upper middle low-tightening component; 80. Support seat; 81. Worm shaft; 82. Turbine; 83. Drive motor; 84. Radial sliding bearing; 840. Cam groove; 85. Guide seat; 86. Sealing joint; 86-1. Threaded column; 86-2. Triangular pyramid structure; 9. Air tightness tester. Detailed Implementation

[0024] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below with reference to specific embodiments.

[0025] Example 1: Figure 2 , Figure 3 The automated airtightness testing and screening machine for the three-way valve shown. like Figures 5 to 10 As shown, the entire equipment relies on the frame as the supporting foundation. The testing platform 2 is erected on the frame 1. The feeding mechanism 3 and the unloading mechanism 4 are respectively arranged on the left and right sides of the testing platform 2. The gantry truss mechanism 5 is erected on top of all the mechanisms. The air tightness tester 9 is independently arranged inside the frame 1 and is connected to the testing end through pipelines.

[0026] On the left side of the testing platform 2 is the feeding mechanism 3, which consists of a feeding conveyor belt 30, a bracket 31, and a disc-shaped valve bracket 32. The valve brackets 32 are arranged equidistantly along the conveyor belt, and a Y-shaped channel is opened in the center of the valve bracket 32 ​​to accommodate a Y-shaped three-way valve with the three valve ports exposed outward. A feeding robot 33 (three-axis or five-axis robot) is installed on the side of the feeding conveyor belt 30. The feeding robot 33 is equipped with a rotating gripper at the end, which can grab and place the valve at the required angle for testing to ensure the valve body is in a uniform position. The feeding robot 33 can grab the three-way valve at the production line exit and then place it on the valve bracket according to the preset position. The feeding conveyor belt circulates and transports the valve.

[0027] To the right of the testing platform 2 is the unloading mechanism 4, which is divided into a qualified product area and a defective product area that are adjacent to each other on the left and right. The two areas are independently separated and are used to receive valves after testing to achieve automatic sorting.

[0028] The truss mechanism 5 is based on a gantry frame, on which a power component 50 is mounted. The power component 50 is either a pneumatic cylinder or an electric cylinder. The output end of the power component is connected to a suspension frame. Two sets of three-jaw valve grippers 51 are installed side by side on the suspension frame. The distance between the two sets of valve grippers is greater than the space occupied by a single valve. The valve grippers are set vertically downwards. The three gripping fingers of the valve grippers are correspondingly locked at the inside corner of the Y-shaped valve. A clamping column 52 is set at the center of the gripping fingers. When clamping the valve body, the clamping column 52 can press against the valve intersection position to maintain the valve body in a horizontal position throughout the process.

[0029] The reason for designing two sets of three-jaw valve grippers 51 is to achieve high efficiency. Since the feeding mechanism 3 and unloading mechanism 4 are on both sides and the detection platform 2 is in the middle, the power unit needs to grab the valve from the feeding mechanism, place it on the detection platform in the middle, wait for the detection to be completed, and then place it on the unloading mechanism. With two sets, the three-jaw valve grippers 51 can grab two three-way valves at the starting position at once. When pausing in the middle position, they can first grab the product that has already been detected, then place an undetected three-way valve, and then move to the end position to put down the three-way valve. After that, they return to the starting position and grab two more three-way valves. This saves time. The detection platform is always working when grabbing three-way valves, which can improve efficiency.

[0030] The detection platform 2 has a countersunk hole in the center, and a weighing device 20 is embedded in the countersunk hole. A valve clamping fixture 21 is fixed above the weighing device 20. The valve clamping fixture is a three-jaw clamping jaw installed facing upwards. The jaw fingers are corresponding to the inside corner of the valve. The weighing device senses the valve body positioning signal and transmits it to the control system.

[0031] Three sets of low-tightness fixtures are arranged in a triangular pattern around the valve clamping fixture 21: the lower left low-tightness component 6, the lower right low-tightness component 7, and the upper middle low-tightness component 8. The lower left low-tightness component 6 consists of a low-tightness cylinder 60 and a detachable low-tightness plug 61. The low-tightness cylinder 60 is fixed to the testing platform 2, and the low-tightness plug 61 is installed at the front end of the cylinder shaft. The lower right low-tightness component 7 includes an inflation cylinder 70 and an inflation plug 71. The inflation plug is fixed to the cylinder head, and an external air pipe 72 connects to the airtightness tester. Both the low-tightness plug and the inflation plug have rubber sealing plugs at their front ends, which are conical in shape. A sealing ring is fitted at the maximum outer diameter of the cone. Under the action of the cylinder, the lower left and lower right valve ports of the three-way valve can be quickly sealed. The inflation plug is a hollow structure. The external air pipe 72 inflates the valve through the hollow inflation plug. The air tightness tester 9 detects whether the air pressure inside the valve is stable. After inflation, the valve is blocked again to detect whether the air source inside is stable and whether there is any leakage, thereby judging the air tightness of the three-way valve.

[0032] The upper-middle-low tension component 8 is a telescopic torque assembly with a detachable sealing joint. The telescopic torque assembly includes two sets of support seats 80, a worm shaft 81, a worm gear 82, and a drive motor 83. The worm shaft is rotatably mounted between the support seats, and the worm gear meshes with the worm shaft, driven by the motor. A radial sliding bearing 84 is fixed on the outer side of the worm shaft. The outer surface of the radial sliding bearing 84 is machined with a radial S-shaped cam groove 840. A guide seat 85 is fixed on the detection platform. A guide post matching the cam groove is provided on the guide seat. The guide post is embedded in the cam groove 840. During operation, the worm shaft rotation and linear telescopic movement are synchronized by the cooperation of the cam groove and the guide post.

[0033] like Figure 2 , Figure 3 The three-way valve shown has an internally threaded valve port in the upper middle position. Using a standard internal plug rubber stopper would result in delayed sealing due to the threaded nature of the thread. Therefore, the above structure is adopted to synchronize the rotation and linear extension of the worm shaft. The detachable plug connector 86 is designed as an integrated structure, with a quick-release rear end for rapid connection with the worm shaft. The plug's front end is a threaded post 86-1, with threads on its outer surface. A sealing ring is located on the side of the threaded post 86-1 near the quick-release end. The threaded post matches the internal thread of the three-way valve (e.g., ...). Figure 7 As shown), the worm gear shaft completes the synchronous action of rotation and linear extension under the action of the guide post, so that the threaded post 86-1 can be screwed into the valve port to achieve a leak-free seal when the tension is low.

[0034] During equipment operation, the truss mechanism 5 drives the gripper to grasp the valve and move it to the clamping fixture. After the weighing device senses the position, the three-jaw clamping jaws fix the valve body. Three sets of low-tightness fixtures extend towards the center simultaneously. The low-tightness plug 61, the inflation plug 71, and the sealing connector 86 respectively seal the three valve ports. After sealing and positioning are completed, the three-jaw valve gripper 51 on the truss is lifted upward and detached from the valve body. All mechanical structures of the machine cooperate with each other to stably complete the valve clamping, sealing, and airtightness testing pre-operation. The unloading mechanism divides adjacent qualified product areas and defective product areas. The truss mechanism moves to the corresponding area according to the test results to complete the valve sorting and unloading. Example 2: For example Figure 1 , Figure 4 The three-way valve shown

[0035] like Figure 1 , Figure 4 The three-way valve shown is Figure 1The valve port in the upper middle position has external threads, but the inner hole is smooth. Based on the first embodiment, the detachable sealing connector 86 can be disassembled and replaced. The rear end is a quick-release structure that can quickly connect with the worm shaft 81. The front end adopts a triangular pyramid structure 86-2. A sealing ring is fitted at the maximum outer diameter of the cone. The cone has an axial deformation gap and is divided into three parts. After being squeezed, it can adaptively fit the inner wall of the valve port to achieve a reliable seal.

[0036] refer to Figure 4 The three-way valve, with the valve port in the upper middle position and Figure 1 The only difference is the outer surface; the inside of the valve port is smooth, only the diameters are different. Therefore, it is only necessary to design triangular pyramid structures with different diameters. In order to further ensure the sealing performance, the synchronous action of the worm shaft rotation and linear extension can also be used to achieve the effect of tight sealing.

[0037] During operation, the telescopic tightening assembly drives the sealing joint to extend forward and rotate at the same time. The triangular pyramid structure 86-2 is screwed into the valve port, and the sealing ring fits against the end face of the valve port, which not only achieves tightening and positioning but also completes the sealing of the valve port. The remaining mechanism structure, installation method, action logic and testing process are the same as in Example 1. Example 3: Targeting Figure 3 The three-way valve shown

[0038] like Figure 3 The three-way valve shown has its upper and middle valve ports connected to... Figure 2 Same, but the valve ports in the lower left and lower right positions are the same. Figure 1 The valve port structures in the upper and middle positions are the same. At this time, the front ends of the low-tight plug and the air plug are designed as triangular pyramid structures, with their structural diameters as distinguished as in Example 1. A sealing ring is fitted at the maximum outer diameter of the cone, and the cone is opened with an axial deformation gap and divided into three lobes. As for the air plug, it is still a hollow structure with an external air tube, which is connected to the air tightness tester.

[0039] During operation, the lower left and lower right low-tightening components seal the internal thread valve port under the action of cylinder push and thread rotation, while the upper middle low-tightening component seals the smooth valve port by relying on the deformation triangular pyramid. The three sealing structures operate synchronously, and the overall positioning, transportation, airtightness detection, and sorting process is consistent with that of Example 1, which can realize the collinear detection of valves with multiple structure ports. Example 4: An automated airtightness testing and screening method for three-way valves

[0040] like Figure 11 As shown, before the equipment is put into formal operation, the whole machine is debugged, parameters are set and the threshold of the air tightness tester is calibrated to determine the inflation time, pressure holding time and air pressure drop qualified threshold. Then the whole set of equipment enters the continuous operation state.

[0041] S1. First, the loading robot 33 moves to grab the Y-shaped three-way valve to be tested using the end-effector. It is then placed precisely in the valve seat 32 of the loading conveyor belt 30 at a preset angle. The valve body is positioned by the Y-shaped channel of the valve seat 32, completing the orderly arrangement of valves in the front of the entire line. The conveyor belt continues to operate and transport the workpiece.

[0042] S2. Under the drive of the power unit 50, the truss mechanism 5 moves above the loading mechanism 3. The valve gripper holds the valve in the valve seat 32 and keeps it in a horizontal position, smoothly transferring the valve body to the clamping fixture on the detection platform 2. When the weighing device 20 detects that the valve body is fully in place, it immediately sends a sensing signal to the control system. The control system first controls the gripping fingers of the valve gripper 51 to release, completing the initial alignment of the valve body, and then sends a command to the three-jaw clamping jaws (valve clamping fixture 21). The jaws then firmly clamp the valve.

[0043] S3. After the valve body is fixed, the control system sends a linkage command to the three sets of low-tightness fixtures. The lower left, lower right and upper middle low-tightness components extend forward simultaneously, and the sealing structure at each end precisely seals the three valve ports. After the valve ports are completely sealed, a sealing completion signal is generated and sent back to the control system.

[0044] S4. After receiving the signal, the control system raises the control truss mechanism 5 and the valve gripper 51 together, the clamping column 52 in the center of the gripper is removed from the valve surface, and the gripping mechanism is reset to the standby position.

[0045] S5. Next, the air tightness detector 9 starts working and fills the three-way valve with gas through the lower right inflation plug. The inflation operation is completed according to the preset time. After the inflation is completed, the pressure holding stage is entered. During the set pressure holding time, the air pressure data in the valve body is continuously collected to monitor the change of air pressure drop in real time.

[0046] S6. The control system compares the real-time pressure drop value with the preset qualified threshold to determine the product type. If the pressure drop is lower than the threshold, it is determined to be a qualified product; otherwise, it is determined to be a leaking defective product.

[0047] S7. The control system outputs a sorting signal based on the judgment result. The truss mechanism moves to the area above the qualified or defective product area according to the signal instruction, the valve gripper releases, and the corresponding valve falls into the designated area. After the inspection and sorting of a single set of workpieces is completed, the equipment automatically resets all mechanisms and repeats all the above processes in a cycle to continuously complete the automated airtightness inspection and screening of large batches of three-way valves.

[0048] The air tightness tester adopts a pressure-holding test mode. After inflation, it first maintains the preset pressure holding time, and then monitors the air pressure drop value in the valve body in real time. When the air pressure drop value is lower than the preset threshold of the system, it is judged as a qualified product; otherwise, it is judged as a leaking defective product.

[0049] Two sets of valve grippers on the suspension frame are independently controlled, coordinating with the equipment's cycle time to alternately pick up and release materials: one set of grippers grabs the valves to be inspected from the feeding mechanism, while the other set simultaneously picks up valves that have already been inspected on the testing platform; the truss mechanism can complete both the "unloading of finished products + loading of products to be inspected" processes in a single movement, significantly reducing the mechanism's travel distance and waiting time. In addition to sensing the valve body's positioning signal, the weighing device can assist in verifying whether the valve body is missing or mis-installed. If an abnormal weight is detected, the system directly determines it as a defective product and transports it to the defective product area, eliminating the need for an airtightness test. The airtightness tester uses a pressure-holding testing mode, with preset inflation time, pressure holding time, and pressure drop thresholds. Test data is stored in real time for easy product quality traceability.

[0050] This system employs an overall electrical linkage control system, where all cylinders, motors, robotic arms, and gantry mechanisms are centrally controlled and coordinated, ensuring seamless integration of each process. The equipment boasts strong versatility; all sealing plugs and connectors are detachable and quick-change structures. For Y-shaped three-way valves with different shapes and valve port structures, only the corresponding sealing components need to be replaced to switch models, eliminating the need to disassemble the entire tooling module and reducing downtime for debugging. Simultaneously, the system integrates automatic feeding, automatic sealing, airtightness testing, and automatic sorting functions, requiring no manual intervention throughout the entire process. It offers high testing accuracy and strong operational stability, making it perfectly suited for large-scale, continuous production and testing scenarios for gas three-way valves.

[0051] The above provides a detailed description of the automated airtightness testing and screening machine and method for three-way valves provided by the present invention. The specific embodiments described are merely for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make various improvements and modifications to the present invention without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. An automated air tightness testing and screening machine for a three-way valve, wherein the three-way valve is a Y-shaped valve, the air tightness testing and screening machine includes a frame (1), a testing platform (2) built on the frame (1), a feeding mechanism (3) and a discharging mechanism (4) respectively installed on the left and right sides of the testing platform (2), a truss mechanism (5) for clamping and transferring the valve, and an air tightness tester (9) for testing air tightness. Its features are, Three sets of low-tightness fixtures are installed on the testing platform (2) in a triangular arrangement. A clamping fixture is installed at the center of the three sets of low-tightness fixtures. The three sets of low-tightness fixtures are the lower left low-tightness component (6), the lower right low-tightness component (7), and the upper middle low-tightness component (8). The lower left low-tightness component (6) mainly consists of a low-tightness cylinder (60) and a low-tightness plug (61). The low-tightness plug (61) is detachably installed at the front end of the cylinder shaft of the low-tightness cylinder (60), which is fixed on the testing platform (2). The lower right low-tightness component (7) mainly consists of an inflation cylinder (70) and an inflation plug (71). The inflation plug (71) is fixed to the cylinder head of the inflation cylinder. The air pipe of the inflation plug (71) is connected to an air tightness tester (9). The middle and upper low-tightness component (8) is mainly composed of a telescopic tightening assembly and a sealing connector (86). The telescopic tightening assembly is telescopically installed towards the clamping fixture. The sealing connector (86) is detachably installed at the front end of the telescopic tightening assembly. The low-tightness plug (61), the inflation plug (71), and the sealing connector (86) move towards the middle at the same time and seal the three-way valve. The clamping fixture includes a weighing device (20) and a valve clamping fixture fixed on the weighing device (20). A countersunk hole for the weighing device (20) to be inserted is provided on the testing platform. The three-way valve is placed flat in the valve clamping fixture and clamped. The three valve ports of the three-way valve correspond to the lower left low clamping component (6), the lower right low clamping component (7), and the upper middle low clamping component (8), respectively. The truss mechanism (5) includes a gantry frame built above the loading mechanism (3), unloading mechanism (4) and detection platform (2) and a power component (50) installed on the gantry frame. A valve gripper (51) is installed at the drive end of the power component (50). When the valve gripper (51) clamps the three-way valve, it keeps it in a horizontal state.

2. The automated airtightness testing and screening machine for a three-way valve according to claim 1, characterized in that, The telescopic tightening assembly includes two support seats (80) fixed on the testing platform (2), a worm shaft (81) rotatably connected to the two support seats (80), a turbine (82) meshing with the worm shaft, and a drive motor (83) driving the turbine to rotate. A radial sliding bearing (84) is also rigidly connected to the worm shaft (81). A radially extending S-shaped cam groove (840) is provided on the outer surface of the radial sliding bearing (84). A guide seat (85) is provided on the testing platform. A guide post matching the cam groove is provided on the guide seat (85). The sealing joint (86) is detachably connected to the front end of the worm shaft (81).

3. The automated airtightness testing and screening machine for a three-way valve according to claim 2, characterized in that, The sealing connector (86) consists of an integrated quick-release tail end and a sealing front end. The quick-release tail end has a quick-release structure and connects to the worm shaft. The sealing front end is a triangular pyramid, with a sealing ring at the point where the diameter of the triangular pyramid is the largest. The inside of the triangular pyramid has an axial deformation gap, which divides the front end of the triangular pyramid into three segments. Alternatively, the sealing front end is a threaded post (86-1), the outer surface of the threaded post (86-1) is threaded, and the side of the threaded post (86-1) near the quick-release tail end is equipped with a sealing ring. The threaded post matches the internal thread of the three-way valve.

4. The automated airtightness testing and screening machine for a three-way valve according to claim 1, characterized in that, The valve clamping clamp (21) is a three-jaw clamping clamp, which is fixed vertically upwards. The three claws of the three-jaw clamping clamp are respectively clamped at the inside corner of the Y-shaped valve.

5. An automated airtightness testing and screening machine for a three-way valve according to claim 1, characterized in that, The valve gripper (51) is a three-jaw gripper, which is installed vertically downwards. A clamping column is also provided in the middle of the three gripping fingers of the three-jaw gripper. When gripping the three-way valve, the three gripping fingers of the three-jaw gripper are gripped at the inside corner of the Y-shaped valve. At this time, the clamping column is tightly clamped at the intersection of the three-way valve.

6. An automated airtightness testing and screening machine for a three-way valve according to claim 5, characterized in that, The valve gripper (51) is provided in two sets. The two sets of valve grippers are installed side by side on the suspension frame. The distance between the two sets is greater than the area occupied by a three-way valve. The suspension frame is fixed to the drive end of the power component.

7. An automated airtightness testing and screening machine for a three-way valve according to claim 1, characterized in that, The feeding mechanism (3) includes a feeding conveyor belt (30) and a valve seat (32). The valve seat (32) is arranged in sequence on the feeding conveyor belt (30) through a seat bracket (31). The valve seat is disc-shaped and has a Y-shaped channel in the middle to accommodate a three-way valve. The three valve ports of the three-way valve extend beyond the Y-shaped channel. In addition, a loading robot (33) is installed on the side of the loading conveyor belt (30). The drive end of the loading robot (33) is equipped with a rotating gripper for gripping the three-way valve and placing it on the valve seat according to its orientation.

8. An automated airtightness testing and screening machine for a three-way valve according to claim 1, characterized in that, The feeding mechanism (4) is divided into a qualified product area and a defective product area side by side. The valve gripper passes through the qualified product area and the defective product area to complete the sorting of the three-way valve.

9. An automated airtightness testing and screening method for three-way valves, applied to the automated airtightness testing and screening machine for three-way valves as described in any one of claims 1-8, characterized in that, Includes the following steps: S1. The loading robot (33) places the three-way valve on the loading conveyor belt according to the preset position to complete the valve pre-loading arrangement; S2. The truss mechanism drives the valve gripper to move to the feeding conveyor belt to grab a single three-way valve and transfer it to the clamping fixture on the detection platform. After the weighing device detects that the three-way valve is in place, it sends a sensing signal to the control system. After receiving the sensing signal, the control system first sends a preliminary alignment and placement signal to release the three gripping fingers of the three-jaw clamp, and then sends a secondary clamping signal to clamp the three-way valve. S3. Allow the lower left abutment, lower right abutment, and upper middle abutment to receive the linkage signal from the valve clamping fixture, and simultaneously extend and block the three valve ports of the three-way valve; S4. The control system receives the blocking linkage signal and sends a lifting signal again. The valve clamp is lifted and reset, and the clamping column is released from the pressure of the three-way valve. S5. The air tightness tester inflates the three-way valve with air, completes the inflation operation according to the system's preset inflation time, and detects and collects the internal air pressure data of the three-way valve during the inflation period. S6. The control system determines whether the three-way valve is a qualified product or a defective product based on the air pressure detection data and outputs the corresponding sorting signal. The truss mechanism moves the corresponding stroke distance according to the sorting signal, and the valve gripper is released at the preset position, so that the qualified product and the defective product fall into the qualified product area and the defective product area respectively. S7. The equipment continuously performs the above steps in a loop to complete the automated airtightness test and screening of the three-way valve.

10. The automated airtightness testing and screening method for a three-way valve according to claim 9, characterized in that, In step S5, the air tightness tester adopts a pressure holding test mode. After inflation, it first maintains the preset pressure holding time, and then monitors the pressure drop value in the valve body in real time. When the pressure drop value is lower than the preset threshold of the system, it is judged as a qualified product; otherwise, it is judged as a leaking defective product.

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