Liquid chromatograph ultra-high pressure injection valve assembly

Abstract

The utility model discloses a kind of liquid chromatograph ultrahigh pressure sampling switching valve groups, it is related to valve body appliance technical field, including protective shell, protective shell is equipped with sealing assembly, and protective shell is equipped with valve assembly in installation, sealing assembly includes the installation groove of transverse opening in the upper front and rear end of protective shell inner cavity, limit platform is installed below installation groove, and first sealing rubber ring is installed in installation groove;The first protective plate of cooperation installation groove and limit platform is slidably connected on the upper end of protective shell, and the rear end of protective shell and first protective plate is equipped with locating groove;In the utility model, by the combination structure of protective shell, first protective plate and second protective plate, cooperation first sealing rubber ring in installation groove, second sealing rubber ring in airtight groove and third sealing rubber ring in protective groove, form all-round sealed defense line, can resist the pressure impact when ultrahigh pressure sampling.

Description

Technical Field

[0001] This utility model relates to the field of valve body and fixture technology, and in particular to an ultra-high pressure injection switching valve assembly for a liquid chromatograph. Background Technology

[0002] In the field of liquid chromatography analysis technology, ultra-high pressure injection switching valve assemblies are the core components for achieving precise sample injection and channel switching. Their sealing performance and ease of assembly directly determine the accuracy of detection results and the efficiency of equipment operation and maintenance. However, existing ultra-high pressure injection switching valve assemblies have many problems to be solved in practical applications: The sealing performance of ultra-high pressure systems is insufficient. Existing valve assemblies often have relatively simple sealing structures, relying on only a single protective shell or a single seal to achieve sealing, failing to form a multi-dimensional sealing defense. For example, the connection between the protective shell and the protective plate, and the junction between the valve assembly and the protective structure, lack targeted sealing designs. Furthermore, the placement of the sealing rings is unreasonable, making it difficult to withstand the pressure impact generated during ultra-high pressure injection, which easily leads to sample leakage. This not only causes sample loss but also interferes with the accuracy of the detection data. At the same time, impurities in the outside air can easily enter the valve assembly through the sealing gaps, contaminating the core components and further affecting the analytical accuracy. There are also weak points in the sealing at the wiring connection. Ultra-high pressure injection switching valve assemblies require circuit control via external wiring. The inlet positions of existing valve assemblies are mostly simple perforated structures, lacking effective flexible sealing and anti-leakage designs. Therefore, the above problems need to be solved. Utility Model Content

[0003] The purpose of this invention is to address the shortcomings of existing technologies by proposing an ultra-high pressure injection switching valve group for a liquid chromatography analyzer.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: a high-pressure injection switching valve assembly for a liquid chromatograph, comprising a protective shell, a sealing assembly installed on the protective shell, and a valve assembly installed inside the protective shell. The sealing assembly includes a mounting groove laterally opened at the front and rear ends above the inner cavity of the protective shell, a limiting stage installed below the mounting groove, and a first sealing ring installed inside the mounting groove; a first protective plate slidably connected to the upper end of the protective shell to match the mounting groove and the limiting stage, and a positioning groove is opened at the rear end of the protective shell and the first protective plate.

[0005] Preferably, the protective shell and the first protective plate are engaged with a second protective plate having a matching positioning groove. A cylindrical cable entry platform is connected and installed above the rear end of one side of the second protective plate. A flexible airbag is installed inside the cable entry platform, and a one-way tube is installed in the middle of the front end of the cable entry platform connected to the airbag. The one-way tube has a built-in spring structure and the one-way end faces forward. A sealing groove is opened on the inner wall of the other side of the second protective plate, and a second sealing ring is installed in the sealing groove.

[0006] Preferably, the valve assembly includes a stepper motor mounted on the bottom surface of the protective housing, a positioning plate mounted on one side of the top surface of the stepper motor, a circuit board mounted on the top surface of the positioning plate, a laser sensor with the detection port facing downwards mounted on the front end of the positioning plate, and a planetary gear set fixedly connected to the output shaft of the stepper motor.

[0007] Preferably, the output gear in the middle of the planetary gear set is fixedly connected to a rotating platform, an encoding plate is sleeved on the outside of the rotating platform, the encoding plate is placed at the detection end of the laser sensor, and a sealed bearing is sleeved on one side of the rotating platform.

[0008] Preferably, a positioning platform is installed on one side of the sealed bearing, the positioning platform is sleeved on the outside of the rotating platform, and a plurality of equally spaced threaded holes are opened on one side of the positioning platform. A first protective groove that matches the positioning platform is opened on one side of the inner cavity of the protective shell, and a second protective groove is opened on the other side of the first protective groove. A third sealing ring is installed in the first protective groove and the second protective groove.

[0009] Preferably, a base with a U-shaped cross-section is fixedly connected to one side of the rotating platform, a gasket is installed inside the base, and a snap-fit ​​groove is opened on one side of the base, in which a fixed platform is snapped, and a top cover with a mating threaded hole is fixedly connected to one side of the fixed platform.

[0010] Compared with the prior art, the beneficial effects of this utility model are as follows: In this utility model, the combination structure of the protective shell, the first protective plate and the second protective plate, together with the first sealing ring in the mounting groove, the second sealing ring in the sealing groove and the third sealing ring in the protective groove, form an all-round sealing defense line, which can resist the pressure impact during ultra-high pressure sample injection; the flexible airbag in the inlet station is inflated through the one-way tube and then tightly attached to the external line, ensuring the line connection while sealing the gaps. The spring structure of the one-way tube can also prevent air leakage from causing sealing failure. In addition, the sliding connection of the first protective plate and the snap-fit ​​design of the second protective plate can be quickly assembled without precise alignment, shortening the installation time, effectively avoiding sample leakage or intrusion of external impurities under ultra-high pressure, and improving the accuracy of sample injection detection. Attached Figure Description

[0011] The accompanying drawings, which are included to provide a further understanding of the present invention and form part of this application, illustrate exemplary embodiments of the present invention and, together with the description thereof, serve to explain the present invention and do not constitute an undue limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the overall structure proposed in this utility model; Figure 2 This is a schematic diagram of the circuit board and stepper motor structure proposed in this utility model; Figure 3This is a schematic diagram of the feed station and airbag structure proposed in this utility model; Figure 4 This is a half-sectional schematic diagram of the overall structure proposed in this utility model; Figure 5 The present utility model proposes Figure 2 Enlarged diagram of part A in the middle; Figure 6 The present utility model proposes Figure 3 Enlarged diagram of section B; Figure 7 The present utility model proposes Figure 4 Enlarged diagram of section C.

[0012] The components in the diagram are numbered as follows: 1. Protective shell; 2. First protective plate; 3. Second protective plate; 4. Inlet platform; 5. Airbag; 6. One-way tube; 7. Third sealing ring; 8. Mounting groove; 9. First sealing ring; 10. Limiting platform; 11. Positioning groove; 12. Sealing groove; 13. Second sealing ring; 14. Stepper motor; 15. Positioning plate; 16. Circuit board; 17. Laser sensor; 18. Planetary gear set; 19. Rotating platform; 20. Encoding plate; 21. Base; 22. Gasket; 23. Fixing platform; 24. Top cover; 25. Positioning platform. Detailed Implementation

[0013] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0014] Example: See Figures 1 to 7This utility model discloses an ultra-high pressure injection switching valve assembly for a liquid chromatograph, comprising a protective shell 1, which provides a mounting base for subsequent sealing and valve assemblies; a sealing assembly is mounted on the protective shell 1, and a valve assembly is installed inside the protective shell 1; the sealing assembly includes a mounting groove 8 horizontally formed at the front and rear ends above the inner cavity of the protective shell 1, which facilitates the installation of a first sealing ring 9; a limiting stage 10 is installed below the mounting groove 8, and the first sealing ring 9 is installed inside the mounting groove 8; the first sealing ring 9 provides a seal at the connection between the protective shell 1 and the first protective plate 2; the upper end of the protective shell 1 is slidably connected to the first protective plate 2, which mates with the mounting groove 8 and the limiting stage 10, allowing the first protective plate 2 to slide with the protective shell 1; a positioning groove 11 is formed at the rear ends of the protective shell 1 and the first protective plate 2, which provides a limiting position for the installation of a second protective plate 3 on the protective shell 1 and the first protective plate 2; the second protective plate, which mates with the positioning groove 11, is engaged with the protective shell 1 and the first protective plate 2. 3. The second protective plate 3 facilitates the protective sealing of the valve assembly in conjunction with the protective shell 1 and the first protective plate 2. A cylindrical inlet platform 4 is connected to the upper rear end of one side of the second protective plate 3, allowing external wiring to enter the sealing assembly composed of the protective shell 1, the first protective plate 2, and the second protective plate 3. A flexible airbag 5 is installed inside the inlet platform 4, allowing external circuitry to enter the sealing assembly and ensuring its airtightness. The airbag 5 is also connected to the middle of the front end of the inlet platform 4. A one-way tube 6 is installed to ensure that air can be supplied to the airbag 5 without external tools and to prevent the airbag 5 from deflating and causing the seal to fail. The one-way tube 6 has a built-in spring structure and the one-way end faces forward. A sealing groove 12 is opened on the inner wall of the other side of the second protective plate 3. The sealing groove 12 facilitates the installation of the second sealing ring 13. The second sealing ring 13 is installed in the sealing groove 12 and provides a seal at the connection between the second protective plate 3 and the protective shell 1 and the first protective plate 2.

[0015] In this invention, the valve assembly includes a stepper motor 14 mounted on the bottom surface of the inner casing 1. The stepper motor 14 facilitates the mounting of a positioning plate 15 via an external snap-fit ​​assembly. A positioning plate 15 is mounted on one side of the top surface of the stepper motor 14. A circuit board 16 and a laser sensor 17 are mounted on the positioning plate 15 via external bolts. The circuit board 16 is mounted on the top surface of the positioning plate 15, facilitating connection of the stepper motor 14 to external wiring and other incoming lines, and connection to an external control system. A detection sensor is mounted at the front end of the positioning plate 15. A laser sensor 17 with its measuring port facing downwards is used to easily detect the rotation data of the encoder plate 20. The laser sensor 17 is model M18. A planetary gear set 18 is fixedly connected to the output shaft of the stepper motor 14, which facilitates the reduction of the output speed of the stepper motor 14. A rotating platform 19 is fixedly connected to the output gear in the middle of the planetary gear set 18, which facilitates the mounting of the base 21 via a snap-fit ​​assembly. The encoder plate 20 is sleeved on the outside of the rotating platform 19 and is positioned at the detection end of the laser sensor 17. A sealed bearing is fitted onto one side of the rotating platform 19, and the encoder plate 20 facilitates the provision of a reference for the laser sensor 17. A positioning platform 25 is installed on one side of the sealed bearing, which facilitates the subsequent fixing of the upper cover 24 with threaded holes and limits the positioning base 21. The positioning platform 25 is fitted onto the outside of the rotating platform 19, and multiple equidistant threaded holes are opened on one side of the positioning platform 25. A first protective groove that mates with the positioning platform 25 is opened on one side of the inner cavity of the protective shell 1, and a second protective groove is opened on the other side of the first protective groove. A laser sensor 17 is installed in the first and second protective grooves. The third sealing ring 7 is used to ensure the seal at the connection between the valve assembly and the sealing assembly; a U-shaped base 21 is fixedly connected to one side of the rotating table 19, which facilitates the placement of the gasket 22; the gasket 22 is installed inside the base 21, which provides protection for the fixed table 23; and a snap-fit ​​groove is opened on one side of the base 21, in which the fixed table 23 is snapped, which facilitates the installation of the upper cover 24 with the positioning table 25; the upper cover 24 with a mating threaded hole is fixedly connected to one side of the fixed table 23.

[0016] Working principle: When using this utility model, firstly, the valve assembly is inserted into the protective shell 1, so that the third sealing ring 7 tightly abuts against the outside of the positioning platform 25, while the upper cover 24 of the valve assembly protrudes from the protective shell 1; next, the operator passes the external line through the inlet platform 4 through the second protective plate 3 and fixes it with the corresponding slot on the circuit board 16; then, the first protective plate 2 is slid along the limiting platform 10 at the upper end of the protective shell 1, so that it fits tightly against the first sealing ring 9 in the mounting groove 8; then, the second protective plate 3 is inserted into the positioning groove 11 at the rear end of the protective shell 1 and the first protective plate 2, and the second sealing ring 13 in the sealing groove 12 of the second protective plate 3 enhances the connection sealing; finally, the airbag 5 in the inlet platform 4 is inflated through the one-way tube 6 (the one-way tube has a built-in spring). The structure prevents air leakage, allowing the flexible airbag 5 to fit tightly against the wiring, thus sealing the inlet. After the equipment is assembled, the circuit board 16 is powered by an external line. After the circuit board 16 starts, it transmits a signal to the stepper motor 14, driving its output shaft to rotate and driving the planetary gear set 18 to work. The planetary gear set 18 reduces and adjusts the speed of the stepper motor 14, thereby driving the rotating table 19, which is fixed to the output gear in the middle, to rotate smoothly. At the same time, the laser sensor 17 at the front end of the positioning plate 15 starts synchronously, and its detection port is aligned with the encoder plate 20 sleeved on the outside of the rotating table 19, capturing rotation data in real time and feeding it back to the circuit board 16. The circuit board 16 precisely controls the operation of the stepper motor 14 according to the feedback data, realizing the fixed-angle rotation of the rotating table 19. When the rotating stage 19 rotates, it rotates synchronously with the base 21 due to its fixed connection, and also cooperates with the fixed stage 23 through the snap-fit ​​groove (the gasket 22 provides flexible filling for the fixed stage 23), thereby driving the upper cover 24 to rotate and completing the sample injection channel switching; the sealed bearing on the outside of the positioning stage 25 reduces rotational friction, and the third sealing ring 7 installed in the first and second protective grooves inside the protective shell 1 ensures the ultra-high pressure sealing performance at the connection between the valve assembly and the sealing assembly; after such switching is completed, the circuit board 16 controls the stepper motor 14 to stop running, and the laser sensor 17 confirms the stationary position of the rotating stage 19 through the encoder board 20, ensuring that subsequent switching can be directly based on the previous data (i.e., retaining process memory), or the previous data can be cleared through the external control system.

[0017] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A high-pressure injection switching valve assembly for a liquid chromatograph, comprising a protective housing (1), characterized in that: The protective shell (1) is equipped with a sealing assembly, and a valve assembly is installed inside the protective shell (1). The sealing assembly includes a mounting groove (8) that is horizontally opened at the front and rear ends above the inner cavity of the protective shell (1). A limiting platform (10) is installed below the mounting groove (8), and a first sealing ring (9) is installed inside the mounting groove (8). A first protective plate (2) that matches the mounting groove (8) and the limiting platform (10) is slidably connected to the upper end of the protective shell (1), and a positioning groove (11) is opened at the rear end of the protective shell (1) and the first protective plate (2).

2. The ultra-high pressure injection switching valve assembly for a liquid chromatograph according to claim 1, characterized in that: The protective shell (1) and the first protective plate (2) are engaged with a second protective plate (3) with a matching positioning groove (11). A cylindrical inlet platform (4) is connected to the upper rear end of one side of the second protective plate (3). A flexible airbag (5) is installed inside the inlet platform (4). A one-way tube (6) is installed in the middle of the front end of the inlet platform (4) connected to the airbag (5). The one-way tube (6) has a built-in spring structure and the one-way end faces forward. A sealing groove (12) is opened on the inner wall of the other side of the second protective plate (3). A second sealing ring (13) is installed in the sealing groove (12).

3. The ultra-high pressure injection switching valve assembly for a liquid chromatograph according to claim 2, characterized in that: The valve assembly includes a stepper motor (14) installed on the bottom surface of the inner shell (1), a positioning plate (15) installed on one side of the top surface of the stepper motor (14), a circuit board (16) installed on the top surface of the positioning plate (15), a laser sensor (17) with the detection port facing downward is installed at the front end of the positioning plate (15), and a planetary gear set (18) is fixedly connected to the output shaft of the stepper motor (14).

4. The ultra-high pressure injection switching valve assembly for a liquid chromatograph according to claim 3, characterized in that: The output gear in the middle of the planetary gear set (18) is fixed to a rotating platform (19). An encoding plate (20) is sleeved on the outside of the rotating platform (19). The encoding plate (20) is placed at the detection end of the laser sensor (17), and a sealed bearing is sleeved on one side of the rotating platform (19).

5. The ultra-high pressure injection switching valve assembly for a liquid chromatograph according to claim 4, characterized in that: A positioning platform (25) is installed on one side of the sealed bearing. The positioning platform (25) is sleeved on the outside of the rotating platform (19). A plurality of equally spaced threaded holes are opened on one side of the positioning platform (25). A first protective groove that matches the positioning platform (25) is opened on one side of the inner cavity of the protective shell (1). A second protective groove is opened on the other side of the first protective groove. A third sealing ring (7) is installed in the first protective groove and the second protective groove.

6. The ultra-high pressure injection switching valve assembly for a liquid chromatograph according to claim 5, characterized in that: The rotating platform (19) is fixedly connected to a base (21) with a U-shaped cross section on one side. A gasket (22) is installed on the inner side of the base (21), and a snap-fit ​​groove is opened on one side of the base (21). A fixed platform (23) is snapped into the snap-fit ​​groove, and a top cover (24) with a matching threaded hole is fixedly connected to one side of the fixed platform (23).

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