A liquid chromatograph one-way valve

Abstract

The utility model relates to one -way valve technical field especially relates to a liquid chromatograph one -way valve, solved the problem among the prior art. A liquid chromatograph one -way valve, including the tubulature, both ends of tubulature all have the threaded connection pipe of intercommunication, the inside one side of tubulature is connected with the water inlet pipe, the top elastic connection of water inlet pipe has the valve cover, the inside upper portion one side of water inlet pipe is fixedly connected with the connecting plate. The utility model makes the valve cover and the connecting plate between form by the initiative reset mechanism of extension spring drive, has improved the response speed and action reliability of valve cover closing significantly, even under the working condition that pump cavity pressure drops rapidly or exists transient negative pressure, can also ensure that the valve cover resets seal quickly, has prevented the reverse leakage of mobile phase, improved the stability of infusion flow and the repeatability of analysis data, avoided the baseline fluctuation and chromatographic peak distortion caused by backflow or bubble introduction.

Description

Technical Field

[0001] This utility model relates to the field of one-way valve technology, and in particular to a one-way valve for a liquid chromatograph. Background Technology

[0002] The one-way valve in a high-performance liquid chromatograph (HPLC) is a key control component in the flow path system. Its main function is to ensure that the mobile phase flows strictly in one direction along a preset path, preventing backflow and thus guaranteeing stable liquid supply from the pumping system and the accuracy of the chromatographic separation process. As one of the core components of the HPLC pump, the one-way valve's opening and closing sensitivity, sealing performance, and structural reliability have a decisive impact on the overall operational stability of the instrument, the repeatability of analytical results, and the system's pressure resistance. Especially in the core process of alternating suction and discharge cycles in the high-pressure pump, existing ball-type one-way valves have gradually revealed a series of significant limitations and technical problems when handling high-viscosity mobile phases, those containing small particles, or those with frequent start-stop cycles.

[0003] Existing ball-type check valves commonly suffer from delayed opening and closing responses and untimely closure during practical use. Traditional structures typically rely on the ball's own gravity for reverse sealing. When the pump chamber pressure drops rapidly or a momentary negative pressure occurs, the ball cannot quickly and accurately return to the valve seat sealing surface, leading to minute backflow of the mobile phase or bubble aspiration. This severely affects the accuracy and flow stability of the infusion, thereby reducing the resolution and quantitative accuracy of chromatographic peaks. Therefore, addressing the core issues of traditional ball-type check valves in liquid chromatography—namely, their difficulty in closing after opening, affecting their effectiveness, and insufficient fixation at the connection point—we urgently need an innovative check valve structure to solve these problems. Utility Model Content

[0004] The purpose of this invention is to provide a one-way valve for a liquid chromatograph, which solves the problem in the prior art that usually relies on the valve ball's own gravity to achieve reverse sealing. When the pump chamber pressure drops rapidly or a momentary negative pressure occurs, the valve ball cannot quickly and accurately fall back to the valve seat sealing surface, resulting in slight backflow of the mobile phase or the generation of air bubbles, which seriously affects the accuracy and flow stability of the infusion.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A one-way valve for a liquid chromatograph includes a tube body with threaded connecting pipes at both ends. An inlet pipe is connected to one side of the inner side of the tube body. A valve cover is elastically connected to the top of the inlet pipe. A connecting plate is fixedly connected to the upper inner side of the inlet pipe. Telescopic rods are fixedly connected to both sides of the top of the connecting plate. The tops of the two telescopic rods are fixedly connected to the top inner side of the valve cover. A tension spring is fitted on each of the two telescopic rods. The top inner side of the valve cover is fixedly connected to the top of the connecting plate through the tension springs.

[0007] Preferably, side frames are fixedly connected to both the top and bottom sides of the pipe body, arc-shaped clamps are provided on both sides of the two threaded connecting pipes, and threaded rods are provided on one side of each of the four side frames. One end of the threaded rod passes through one side of the side frame through a threaded groove, wherein the extension end of the threaded rod is rotatably connected to one side of the arc-shaped clamp.

[0008] Preferably, one end of each of the four threaded rods is rotatably connected to one side of each of the four arc-shaped clamps via a rotating shaft.

[0009] Preferably, each of the four arc-shaped clamps has a slider fixedly connected to one side of its bottom, and the slider is slidably connected to the side wall of the side frame through a groove.

[0010] Preferably, a sealing ring is fixedly connected to the bottom of the valve cover, and a sealing groove is provided on the top of the water inlet pipe to cooperate with the sealing ring.

[0011] Preferably, the four sliders are all clearance fits with the four grooves.

[0012] This utility model has the following beneficial effects:

[0013] By installing a connecting plate on the upper inner side of the inlet pipe and mounting a telescopic rod and tension spring on its top, an active return mechanism driven by the tension spring is formed between the valve cover and the connecting plate. This significantly improves the response speed and reliability of the valve cover closing. Even under conditions of rapid pressure drop in the pump chamber or instantaneous negative pressure, it ensures that the valve cover quickly returns to its sealed position, preventing reverse leakage of the mobile phase, improving the stability of the infusion flow rate and the repeatability of analytical data, and avoiding baseline fluctuations and chromatographic peak distortion caused by reflux or air bubble introduction. The telescopic rod not only provides guidance and support for the up-and-down movement of the valve cover, preventing it from tilting or jamming during opening and closing, but also works in conjunction with the tension spring. The combined effect ensures the balance of forces on both sides and improves the consistency of the seal. At the same time, the threaded connecting pipes at both ends of the tube provide a standardized, high-strength fluid interface. Compared with traditional ferrule or simple threaded connection, it has higher connection strength and sealing reliability, which can effectively resist the continuous high-pressure pulsation and vibration in the liquid chromatography system, reduce the risk of leakage at the interface, and improve the system safety and maintenance cycle. The overall structure, by introducing an elastic pull-back mechanism and a reinforced connection method, significantly improves the dynamic response performance and structural durability of the one-way valve, better meeting the high precision, high stability and high reliability requirements of high-performance liquid chromatographs for flow path components. Attached Figure Description

[0014] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the overall main structure of this utility model;

[0016] Figure 2 This is a schematic diagram of the inner side structure of the tube body of this utility model;

[0017] Figure 3 This is a top view of the structure of this utility model;

[0018] Figure 4 This is a schematic diagram of the valve cover structure of this utility model;

[0019] Figure 5 This is a top view of the water inlet pipe structure of this utility model.

[0020] In the diagram: 1. Pipe body; 2. Threaded connecting pipe; 3. Side frame; 4. Arc-shaped clamp; 5. Slider; 6. Slide groove; 7. Threaded rod; 8. Inlet pipe; 9. Valve cover; 10. Telescopic rod; 11. Tension spring; 12. Sealing ring; 13. Sealing groove; 14. Connecting plate. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0022] Reference Figure 1-5 A one-way valve for a liquid chromatograph includes a tube body 1, with threaded connecting pipes 2 connected to both ends of the tube body 1. An inlet pipe 8 is connected to the inner side of the tube body 1, and a valve cover 9 is elastically connected to the top of the inlet pipe 8. A connecting plate 14 is fixedly connected to the upper inner side of the inlet pipe 8. Telescopic rods 10 are fixedly connected to both sides of the top of the connecting plate 14, and the tops of the two telescopic rods 10 are fixedly connected to the top inner side of the valve cover 9. A tension spring 11 is sleeved on each of the two telescopic rods 10, and the top inner side of the valve cover 9 is fixedly connected to the top of the connecting plate 14 through the tension spring 11.

[0023] When the liquid chromatograph starts operating, and the external high-pressure mobile phase enters from the inlet end of the inlet pipe 8, the liquid pressure acts on the bottom of the valve cover 9, overcoming the tension of the tension spring 11 and the possible damping of the telescopic rod 10, pushing the valve cover 9 upward to disengage it from the sealed port of the inlet pipe 8, thereby opening the flow channel. The liquid enters the tube body 1 through the opened valve port and is delivered to the pump chamber or analysis system of the liquid chromatograph through the threaded connection pipe 2 connected to the other end of the tube body 1. When the infusion pump completes a discharge stroke or the system pressure decreases, the pressure at the inlet end of the inlet pipe 8 drops rapidly or even momentarily becomes negative. At this time, the pressure at the bottom of the valve cover 9... When the force disappears or decreases, the tension spring 11 connected between the connecting plate 14 and the inner top of the valve cover 9 contracts under the action of elastic restoring force. The telescopic rod 10 pulls the valve cover 9 to quickly return it downward, so that it fits tightly against the sealing end face of the water inlet pipe 8, achieving fast and reliable closure and effectively preventing the liquid in the pipe body 1 and subsequent pipelines from flowing back through the water inlet pipe 8. When the system is in long-term operation or the pipeline is replaced, it can be disassembled or installed by rotating the two threaded connecting pipes 2 to the external pipeline joints to ensure the stability of the connection. The whole working process is completed automatically without manual intervention, ensuring the unidirectional and continuous transport of the mobile phase.

[0024] Furthermore, side frames 3 are fixedly connected to both the top and bottom sides of the pipe body 1. Arc-shaped clamps 4 are provided on both sides of the two threaded connecting pipes 2, and threaded rods 7 are provided on one side of each of the four side frames 3. One end of the threaded rod 7 passes through one side of the side frame 3 through a threaded groove. The extension end of the threaded rod 7 is rotatably connected to one side of the arc-shaped clamp 4. When the one-way valve needs to be installed on the instrument bracket or fixed plate, the arc-shaped clamps 4 on both sides of the two threaded connecting pipes 2 are aligned with the installation position, and then the threaded rod 7 is rotated to make it screw into the threaded groove, pushing the arc-shaped clamp 4 to move inward along the slide groove 6, thereby clamping the external fixed structure. This achieves the effect of enhancing the overall installation stability and vibration resistance of the one-way valve, effectively preventing the valve body from loosening or connection fatigue caused by high-frequency pulsation during equipment operation, and ensuring the long-term reliable operation of the flow path system.

[0025] Furthermore, one end of each of the four threaded rods 7 is rotatably connected to one side of each of the four arc-shaped clamping plates 4 via a rotating shaft. When the threaded rods 7 are rotated for clamping, the rotating shaft connection allows the arc-shaped clamping plates 4 to swing freely in the radial direction and adjust their angles. This enables the arc-shaped clamping plates 4 to adapt to small angular deviations or unevenness on different mounting surfaces, ensuring uniform distribution of clamping force, avoiding local stress concentration, and improving the reliability of clamping and the adaptability of the structure.

[0026] Furthermore, each of the four arc-shaped clamping plates 4 has a slider 5 fixedly connected to one side of its bottom. The slider 5 is slidably connected to the side wall of the side frame 3 through the slide groove 6. When the threaded rod 7 pushes the arc-shaped clamping plate 4 to move, the slider 5 at the bottom of the arc-shaped clamping plate 4 slides synchronously in the slide groove 6 in the side frame 3. This achieves the effect of providing linear guidance and motion stability for the arc-shaped clamping plate 4, preventing it from deflecting or getting stuck during clamping, ensuring smooth clamping action and consistency of clamping force on both sides, and improving the accuracy of installation and adjustment and the convenience of operation.

[0027] Furthermore, a sealing ring 12 is fixedly connected to the bottom of the valve cover 9, and a sealing groove 13 for use with the sealing ring 12 is opened at the top of the water inlet pipe 8. When the valve cover 9 is reset and closed under the action of the tension spring 11, the sealing ring 12 at the bottom of the valve cover 9 is embedded in the sealing groove 13 opened at the top of the water inlet pipe 8, forming a surface contact or line contact sealing pair, which significantly improves the sealing performance when the valve port is closed, effectively prevents leakage of trace liquids or gas intake, enhances the shut-off reliability of the one-way valve, and ensures the flow path sealing integrity of the liquid chromatography system under high pressure conditions.

[0028] Furthermore, the four sliders 5 are all clearance fit with the four slide grooves 6, allowing the sliders 5 to have a certain amount of small movement space within the slide grooves 6. This achieves the effect of avoiding jamming of the sliding parts due to thermal expansion and contraction caused by processing errors or temperature changes, ensuring that the arc-shaped clamping plate 4 can still move flexibly during long-term use, improving the fault tolerance and service life of the structure, while not affecting the normal clamping function.

[0029] In summary:

[0030] When the liquid chromatograph starts operating, and the external high-pressure mobile phase enters from the inlet end of the inlet pipe 8, the liquid pressure acts on the bottom of the valve cover 9, overcoming the tension of the tension spring 11 and the possible damping of the telescopic rod 10, pushing the valve cover 9 upward, causing it to disengage from the sealed port of the inlet pipe 8, thereby opening the flow channel. The liquid enters the interior of the tube body 1 through the opened valve port, and is delivered to the pump chamber or analysis system of the liquid chromatograph through the threaded connecting pipe 2 connected to both ends of the tube body 1. When the infusion pump completes a discharge stroke or the system pressure decreases, the pressure at the inlet end of the inlet pipe 8 drops rapidly or even momentarily becomes negative. At this time, the pressure at the bottom of the valve cover 9 disappears or decreases, while the pressure at the bottom of the valve cover 9 is reduced. The tension spring 11 between the tops contracts under the action of elastic restoring force, and pulls the valve cover 9 downwards quickly through the telescopic rod 10, so that it fits tightly against the sealing end face of the water inlet pipe 8, achieving fast and reliable closure, effectively preventing the liquid in the pipe body 1 and subsequent pipelines from flowing back through the water inlet pipe 8; when the system needs to install the one-way valve on the instrument bracket or fixing plate, align the arc-shaped clamps 4 set on both sides of the two threaded connecting pipes 2 with the installation position, rotate the threaded rod 7 on the side frame 3, the threaded rod 7 advances in the threaded groove that passes through the side frame 3, and its extension end is rotatably connected to one side of the arc-shaped clamp 4 through the rotating shaft, pushing the arc-shaped clamp 4 to move inward, while the slider 5 at the bottom of the arc-shaped clamp 4 moves inward on the side of the side frame 3. The sliding mechanism slides synchronously within the groove 6 of the wall, providing guiding support and ensuring smooth and linear clamping action. When the valve cover 9 is reset and closed, its bottom sealing ring 12 is embedded in the sealing groove 13 at the top of the water inlet pipe 8, forming a reliable sealing pair to prevent leakage. Throughout the installation and operation, the slider 5 and the groove 6 are in clearance fit, allowing for slight displacement and avoiding jamming due to machining errors or temperature changes, thus ensuring the long-term flexibility and stability of the clamping mechanism. By setting a connecting plate 14 on the upper inner side of the water inlet pipe 8 and installing a telescopic rod 10 and a tension spring 11 on its top, an active return mechanism driven by the tension spring 11 is formed between the valve cover 9 and the connecting plate 14, significantly improving the closing efficiency of the valve cover 9. The valve cover 9's rapid reset and reliable operation ensures a smooth seal even under conditions of rapid pressure drop in the pump chamber or instantaneous negative pressure, preventing reverse leakage of the mobile phase and improving the stability of the infusion flow rate and the repeatability of analytical data. The telescopic rod 10 not only provides guidance and support for the up-and-down movement of the valve cover 9, preventing it from skewing or jamming during opening and closing, but also works in conjunction with the tension spring 11 to ensure the balance of force on both sides and improve the consistency of the seal. The threaded connecting pipes 2 at both ends of the tube body 1 provide standardized, high-strength fluid interfaces with high connection strength and sealing reliability, effectively resisting continuous high-pressure pulsation in the liquid chromatography system.To further enhance installation stability, side frames 3 are fixedly connected to the top and bottom sides of the pipe body 1. Threaded rods 7 are installed on the side frames 3. These threaded rods 7 push the arc-shaped clamping plate 4 to clamp the external fixing structure, improving overall vibration resistance and preventing valve body loosening due to high-frequency pulsations during equipment operation. The threaded rods 7 are connected to the arc-shaped clamping plate 4 via a rotating shaft, allowing it to swing freely during clamping to adapt to angular deviations of the mounting surface and ensure uniform distribution of clamping force. The slider 5 at the bottom of the arc-shaped clamping plate 4 slides within a groove 6, providing linear guidance, preventing deflection, and improving clamping accuracy. The slider 5 and the groove 6 are fitted with a clearance fit. To prevent jamming due to thermal expansion and contraction or processing errors, the clamping mechanism is designed for long-term reliable operation. The sealing ring 12 at the bottom of the valve cover 9 cooperates with the sealing groove 13 at the top of the inlet pipe 8 to form an effective seal in the closed state, preventing leakage of trace amounts of liquid or gas intake, thus enhancing shut-off reliability. The overall structure, through the introduction of an elastic pull-back mechanism, enhanced sealing design, and the addition of an external clamping and fixing device, significantly improves the dynamic response performance, sealing integrity, and installation stability of the one-way valve, better meeting the stringent requirements of high-performance liquid chromatographs for high precision, high stability, and high reliability of flow path components.

[0031] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A one-way valve for a liquid chromatograph, comprising a tubular body (1), characterized in that, Both ends of the pipe body (1) are connected to threaded connecting pipes (2). One side of the inner side of the pipe body (1) is connected to a water inlet pipe (8). The top of the water inlet pipe (8) is elastically connected to a valve cover (9). One side of the upper inner side of the water inlet pipe (8) is fixedly connected to a connecting plate (14). Both sides of the top of the connecting plate (14) are fixedly connected to telescopic rods (10). The tops of the two telescopic rods (10) are fixedly connected to the top inner side of the valve cover (9). Both telescopic rods (10) are fitted with tension springs (11). Both sides of the top inner side of the valve cover (9) are fixedly connected to the top of the connecting plate (14) through the tension springs (11).

2. The one-way valve for a liquid chromatograph according to claim 1, characterized in that, The top two sides and bottom two sides of the tube body (1) are fixedly connected with side frames (3), the two threaded connecting pipes (2) are provided with arc-shaped clamps (4) on both sides, and the four side frames (3) are provided with threaded rods (7) on one side. One end of the threaded rod (7) passes through the threaded groove through one side of the side frame (3), and the extension end of the threaded rod (7) is rotatably connected to one side of the arc-shaped clamp (4).

3. A one-way valve for a liquid chromatograph according to claim 2, characterized in that, One end of each of the four threaded rods (7) is rotatably connected to one side of each of the four arc-shaped clamps (4) via a pivot.

4. A one-way valve for a liquid chromatograph according to claim 2, characterized in that, Each of the four arc-shaped clamps (4) has a slider (5) fixedly connected to one side of its bottom, and the slider (5) is slidably connected to the side wall of the side frame (3) through the slide groove (6).

5. A one-way valve for a liquid chromatograph according to claim 1, characterized in that, The bottom of the valve cover (9) is fixedly connected to a sealing ring (12), and the top of the water inlet pipe (8) is provided with a sealing groove (13) that is used in conjunction with the sealing ring (12).

6. A one-way valve for a liquid chromatograph according to claim 4, characterized in that, The four sliders (5) are all clearance fits with the four grooves (6).

Images