A vacuum holding device for use in a chromatograph

Abstract

The utility model discloses a vacuum keeping device for chromatograph, including support, be equipped with the connecting port in the support, the end of support is equipped with screw groove, and the screw groove is equipped with the mounting head of screw connection, the end of mounting head is equipped with capillary, and the end of capillary is equipped with the bushing of bushing, and the bearing of bushing is equipped with the bearing of bushing, and the screw groove is equipped with the taper groove of coaxial, and the taper groove is equipped with the taper pipe of taper groove, and the taper pipe is fixed with mounting head coaxially, and the connecting port is equipped with the sealing groove, and the sealing piece is slidably connected in the sealing groove, and the sealing piece is in contact with the taper pipe, and the outer edge of sealing piece is equipped with the installation cylinder, and the installation cylinder is fixedly connected with support, and the installation cylinder is equipped with a plurality of through grooves. The utility model discloses the collaborative design of screw connection and taper sealing, has improved the convenience and reliability of use significantly, and the screw groove on the support is matched with the external thread on the mounting head, and only needs to rotate mounting head to realize the primary fixation and feeding when installing, and the operation is simple and direct, and need not align the limiting rod and limiting hole simultaneously.

Description

Technical Field

[0001] This utility model relates to the field of chromatography technology, and in particular to a vacuum maintaining device for use in chromatography instruments. Background Technology

[0002] A chromatograph is a device used for chromatographic separation and analysis. It includes an injection system, detection system, recording and data processing system, temperature control system, and mobile phase control system. Modern chromatographs are characterized by stability, sensitivity, versatility, and a high degree of automation. Types include gas chromatographs, liquid chromatographs, and gel permeation chromatography (GPC). These chromatographs are widely used for analyzing the content of specific components in chemical products and polymer materials. GPC can also determine the molecular weight and distribution of polymer materials.

[0003] Currently, chromatographs are connected to mass spectrometers via capillary tubes and vacuum components to couple the chromatographs and mass spectrometers for detecting different isotopes. During operation, a certain vacuum level needs to be maintained. The vacuum interface is one of the main components of the mass spectrometer, mainly for connecting the capillary tube used for sample introduction to the mass spectrometer. Therefore, the requirements for the vacuum interface are also very strict.

[0004] Patent publication number CN211907382U discloses a vacuum interface for a mass spectrometer that facilitates sealing and connection. It includes a support, a capillary tube, and a rubber gasket. The support has a connection port in its center. A limiting rod is welded and fixed to the left side of the mounting head, and a connecting ring penetrating the connection port is located on the left side of the mounting head. A limiting hole is pre-drilled on the surface of the connecting ring, and a mounting plate is integrally formed in the center of the connecting ring. A connecting rod is welded and fixed to the left side of the mounting plate, and a connecting plate is fixed to the left end of the connecting rod. A rubber gasket is adhered and fixed to the left side of the connecting plate to maintain a seal, prevent air ingress, ensure vacuum stability, improve the efficiency of the mass spectrometer, and facilitate automatic sealing of the connection port, making capillary tube replacement convenient. However, this patent requires simultaneous alignment of the limiting rod and the limiting hole during installation, making the operation somewhat cumbersome. Utility Model Content

[0005] The purpose of this invention is to address the shortcomings of existing technologies by proposing a vacuum holding device for chromatographs.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a vacuum maintaining device for a chromatograph, comprising a support, a connection port provided in the support, a threaded groove at the end of the support, a threaded connection of a mounting head in the threaded groove, a capillary tube at the end of the mounting head, a bushing fitted at the end of the capillary tube, a bearing fitted inside the bushing, a conical groove coaxially formed in the threaded groove, a conical tube provided in the conical groove, the conical tube being coaxially fixed with the mounting head, a sealing groove provided in the connection port, a slidably connected sealing element in the sealing groove, the sealing element abutting against the conical tube, an mounting cylinder fitted on the outer edge of the sealing element, the mounting cylinder being fixedly connected to the support, and multiple through grooves formed in the mounting cylinder.

[0007] As a further description of the above technical solution: the sealing element includes a sealing plate that is slidably connected in the sealing groove, and a rubber block is fixedly connected to the outside of the sealing plate.

[0008] As a further description of the above technical solution: a guide rod is horizontally fixed on the inner side of the sealing plate, and a support plate is fixedly connected to the end of the guide rod.

[0009] As a further description of the above technical solution: the support plate is externally fixedly connected to a support ring, the support ring is slidably connected to the tapered groove, and abuts against the tapered tube.

[0010] As a further description of the above technical solution: the inner wall of the sealing groove has multiple equally spaced storage grooves, and a support rod is slidably connected in the storage groove, and the support rod is fixedly connected to the sealing plate.

[0011] As a further description of the above technical solution: a sliding groove is horizontally opened on the inner wall of the storage groove, a slider is slidably connected in the sliding groove, the slider is fixedly connected to the support rod, and a compressed spring is fixed together between the sliding groove and the slider.

[0012] As a further description of the above technical solution: a magnet is fixedly connected to the end of the support rod, and an iron sheet is fixedly connected inside the storage groove.

[0013] This utility model has the following beneficial effects:

[0014] 1. Compared with existing technologies, this vacuum holding device for chromatographs significantly improves ease of use and reliability through the synergistic design of threaded connection and conical seal. Specifically, the threaded groove on the support matches the external thread on the mounting head. During installation, only rotating the mounting head is needed to achieve initial fixation and feeding, making the operation simple and intuitive. This overcomes the cumbersome problem of needing to align the limiting rod and limiting hole simultaneously in the prior art. At the same time, the conical tube, which is coaxially fixed with the mounting head, is screwed in and gradually pressed against the seal. This conical sealing method can form an annular linear sealing band during the tightening process. Compared with planar seals, it can generate a larger sealing specific pressure under the same preload, thus achieving high-efficiency airtightness while maintaining mechanical connection, effectively ensuring the vacuum stability of the vacuum interface.

[0015] 2. Compared with existing technologies, this vacuum holding device for chromatographs enhances the sealing effect and service life of the device through a unique elastic reset and multi-point support structure. The sealing plate in the sealing element can slide within the sealing groove, and its back is connected to the support plate via a guide rod. The support ring outside the support plate is slidably connected within the conical groove and abuts against the conical tube, forming a stable force transmission path and ensuring that the clamping force of the conical tube can be evenly applied to the sealing element. More importantly, the sealing plate is slidably connected to the receiving groove via multiple support rods, and the slider at the end of the support rod slides within the groove and compresses the spring. This design makes the entire sealing element an elastic floating system. The system features a unique design. When the tapered tube is compressed, the seal can undergo a slight backward displacement to buffer the pressure. When the mounting head is removed and the tapered tube is withdrawn, the compressed spring automatically pushes the seal back to its original position, achieving automatic reset and preventing possible jamming or wear between the seal and the inner wall of the connection. In addition, the magnet at the end of the support rod attracts the iron sheet in the receiving groove, providing an additional auxiliary reset force. This further ensures that the seal can be stably reset in the non-working state, maintaining the normally closed state of the interface and preventing vacuum leakage. This elastic adaptive mechanism not only optimizes the sealing contact but also reduces the risk of permanent deformation during long-term use, extending the service life of the device. Attached Figure Description

[0016] Figure 1 This is a perspective view of the overall structure of a vacuum holding device for a chromatograph proposed in this utility model;

[0017] Figure 2 This is a main sectional view of the overall structure of a vacuum holding device for a chromatograph proposed in this utility model;

[0018] Figure 3 This invention proposes a vacuum holding device for use in a chromatograph. Figure 2 Enlarged view of the structure at point A in the middle.

[0019] Legend:

[0020] 1. Support; 2. Mounting head; 3. Bushing; 4. Capillary tube; 5. Threaded groove; 6. Bearing; 7. Tapered groove; 8. Tapered tube; 9. Support ring; 10. Through groove; 11. Mounting cylinder; 12. Rubber block; 13. Sealing plate; 14. Guide rod; 15. Support plate; 16. Iron sheet; 17. Storage groove; 18. Magnet; 19. Sealing groove; 20. Support rod. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0022] Reference Figures 1 to 3 This utility model provides a vacuum holding device for a chromatograph: it includes a support 1, a connection port inside the support 1, a threaded groove 5 at the end of the support 1, a threaded connection to a mounting head 2 inside the threaded groove 5, a capillary tube 4 at the end of the mounting head 2, a bushing 3 at the end of the capillary tube 4, a bearing 6 inside the bushing 3, a conical groove 7 coaxially opened inside the threaded groove 5, a conical tube 8 inside the conical groove 7, the conical tube 8 being coaxially fixed with the mounting head 2, a sealing groove 19 inside the connection port, a sliding connection to a sealing element inside the sealing groove 19, the sealing element abutting against the conical tube 8, an mounting cylinder 11 sleeved on the outer edge of the sealing element, the mounting cylinder 11 being fixedly connected to the support 1, and multiple through grooves 10 opened in the mounting cylinder 11;

[0023] The sealing element includes a sealing plate 13 slidably connected within a sealing groove 19, a rubber block 12 fixedly connected to the outer side of the sealing plate 13, a guide rod 14 horizontally fixed to the inner side of the sealing plate 13, a support plate 15 fixedly connected to the end of the guide rod 14, a support ring 9 fixedly connected to the outer side of the support plate 15, the support ring 9 slidably connected to a conical groove 7 and abutting against a conical tube 8, a plurality of equidistantly distributed receiving grooves 17 axially opened on the inner wall of the sealing groove 19, a support rod 20 slidably connected within the receiving grooves 17, the support rod 20 fixedly connected to the sealing plate 13, a horizontally opened sliding groove on the inner wall of the receiving grooves 17, a slider slidably connected within the sliding grooves, the slider fixedly connected to the support rod 20, a compressed spring fixedly fixed between the sliding grooves and the slider, a magnet 18 fixedly connected to the end of the support rod 20, and an iron sheet 16 fixedly connected inside the receiving grooves 17.

[0024] Working principle: When not installed, the seal is in its initial position facing inwards towards the connection port (i.e., towards the vacuum chamber) under the action of the internal spring. At this time, the seal (especially the rubber block 12 on it) may partially block the connection port, forming a normally closed state, which helps to prevent a large amount of outside air from rushing into the vacuum system. The operator aligns the capillary tube 4 with the bushing 3 and bearing 6, and the mounting head 2 fixed thereto, with the connection port of the support 1. Since a threaded connection is used, it is not necessary to precisely align the limiting rod and limiting hole as in the patent in the background art. Simply screw the thread at the end of the mounting head 2 into the threaded groove 5 of the support 1. When the mounting head 2 is rotated, it moves forward in a straight line under the guidance of the thread; the tapered tube 8, which is fixed coaxially with the mounting head 2, moves forward together. The tip of the tapered tube 8 first contacts the sealing element transmission mechanism composed of the support ring 9, support plate 15, guide rod 14 and sealing plate 13. As the tightening continues, the tapered surface of the tapered tube 8 continues to advance along the inclined surface of the support ring 9, generating a huge radial force; this force is transmitted through the support ring 9, support plate 15, and guide rod 14, and finally to the sealing plate 13, pushing the entire sealing element to overcome the elastic force of the rear spring and move towards the bottom of the sealing groove 19 (i.e., away from the vacuum chamber);

[0025] When capillary tube 4 needs to be replaced or maintained, simply rotate the mounting head 2 in the reverse direction. As the mounting head 2 retracts, the tapered tube 8 also moves backward, releasing the pressure on the seal. At this time, the compressed spring loses its external pressure, and its stored elastic potential energy is released, pushing the slider and support rod 20 outward, thereby pushing the entire seal (sealing plate 13, rubber block 12, etc.) back to its initial position. The attraction force between magnet 18 and iron sheet 16 plays an auxiliary role in the reset process, ensuring that the seal can be reset quickly, stably and completely, preventing it from getting stuck halfway due to friction or oil. After the seal is reset, it partially or completely covers the connection port again, quickly isolating the vacuum chamber from the external environment, minimizing the time and amount of air entering the vacuum system during disassembly, effectively protecting the vacuum state of the mass spectrometer, and improving the efficiency of subsequent vacuuming.

[0026] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A vacuum maintaining device for a chromatograph, comprising a support (1) having a connection port therein, characterized in that: The support (1) has a threaded groove (5) at its end, and a mounting head (2) is threadedly connected in the threaded groove (5). The mounting head (2) has a capillary tube (4) at its end, and a bushing (3) is fitted at the end of the capillary tube (4). A bearing (6) is fitted in the bushing (3). A tapered groove (7) is coaxially opened in the threaded groove (5). A tapered tube (8) is provided in the tapered groove (7). The tapered tube (8) is coaxially fixed with the mounting head (2). A sealing groove (19) is provided in the connection port. A sealing element is slidably connected in the sealing groove (19). The sealing element abuts against the tapered tube (8). An mounting cylinder (11) is fitted on the outer edge of the sealing element. The mounting cylinder (11) is fixedly connected to the support (1). The mounting cylinder (11) has multiple through grooves (10).

2. A vacuum maintaining device for a chromatograph according to claim 1, characterized in that: The seal includes a sealing plate (13) that is slidably connected in the sealing groove (19), and a rubber block (12) is fixedly connected to the outside of the sealing plate (13).

3. A vacuum maintaining device for a chromatograph according to claim 2, characterized in that: The inner side of the sealing plate (13) is horizontally fixed with a guide rod (14), and the end of the guide rod (14) is fixedly connected to a support plate (15).

4. A vacuum maintaining device for a chromatograph according to claim 3, characterized in that: The support plate (15) is externally fixedly connected to a support ring (9), which is slidably connected to the tapered groove (7) and abuts against the tapered tube (8).

5. A vacuum maintaining device for a chromatograph according to claim 2, characterized in that: The inner wall of the sealing groove (19) has multiple equidistantly distributed storage grooves (17), and a support rod (20) is slidably connected in the storage groove (17). The support rod (20) is fixedly connected to the sealing plate (13).

6. A vacuum maintaining device for a chromatograph according to claim 5, characterized in that: The inner wall of the storage groove (17) is horizontally opened with a sliding groove, and a slider is slidably connected in the sliding groove. The slider is fixedly connected to the support rod (20), and a compressed spring is fixed between the sliding groove and the slider.

7. A vacuum maintaining device for a chromatograph according to claim 5, characterized in that: A magnet (18) is fixedly connected to the end of the support rod (20), and an iron sheet (16) is fixedly connected inside the storage groove (17).

Images