A pipeline connection structure for liquid chromatograph

Abstract

The utility model discloses a pipeline connection structure of a liquid chromatograph, comprising a connecting pipe with a connecting channel that passes through left and right, characterized in that the left and right ends of the connecting pipe are respectively tightly matched and installed with a pipe sleeve, a pipe seal is arranged in the pipe sleeve, the pipe seal has a sealed connecting channel that passes through left and right, and the pipe seal comprises a closing part and an extending connecting part, the closing part is arranged outside the pipe sleeve to seal and seal the port of the pipe sleeve, the extending connecting part is extended and arranged in the pipe sleeve, the outer wall of the extending connecting part is tightly matched with the inner wall of the pipe sleeve, the end of the extending connecting part is tightly fitted with the end of the connecting pipe, the sealed connecting channel is connected with the connecting channel, a hand-tightening connecting joint is coaxially arranged on the pipe sleeve, and the hand-tightening connecting joint is connected to the matching connecting interface on the instrument to hold the pipe sleeve tightly. The advantage is that the structure is simple, and the "dead volume" generated by the pipeline connection can be effectively avoided, thereby improving the detection effect.

Description

Technical Field

[0001] The utility model relates to a liquid chromatograph, in particular to a pipeline connection structure of the liquid chromatograph. Background Art

[0002] There is often a gap when the pipes in the liquid chromatograph are connected, and the space volume generated by this gap is called "dead volume". The larger the dead volume, the worse the detection effect. Therefore, minimizing the "dead volume" of the pipe connection can improve the detection effect of the instrument. The pipe connection in the traditional structure of the liquid chromatograph usually uses a conical blade ring to seal the connection pipe. The blade ring is pushed into the conical hole set in the pipe connection port to shrink and lock the pipe to achieve the sealing purpose. This structure requires the use of a wrench to turn the push screw to make the blade ring fully shrink and lock the pipe. The operation is more troublesome, and the length of the pipe exposed from the blade ring is fixed. When connecting instruments of different brands or chromatographic columns of different specifications, "dead volume" may be generated due to different interface depths, thus affecting the detection effect. Summary of the invention

[0003] The technical problem to be solved by the utility model is to provide a pipeline connection structure of a liquid chromatograph which has a simple structure and can effectively avoid "dead volume" generated by pipeline connection and affect the detection effect.

[0004] The technical solution adopted by the utility model to solve the above technical problems is:

[0005] A pipeline connection structure of a liquid chromatograph comprises a connecting pipe having a connecting passage that passes through left and right, the left and right ends of the connecting pipe are respectively tightly equipped with pipe sleeves, a pipeline seal is arranged in the pipe sleeve, the pipe seal has a sealed connecting passage that passes through left and right, the pipe seal comprises a closing portion and an extending connecting portion, the closing portion is arranged on the outside of the pipe sleeve to seal and seal the port of the pipe sleeve, the extending connecting portion is extended and arranged in the pipe sleeve, the outer wall of the extending connecting portion is tightly matched with the inner wall of the pipe sleeve, the end of the extending connecting portion is tightly fitted with the end of the connecting pipe, the sealed connecting passage is connected with the connecting passage, a hand-tightening connecting joint is coaxially arranged on the pipe sleeve, and the hand-tightening connecting joint is connected to the matching connecting interface on the instrument to hold the pipe sleeve tightly.

[0006] The connecting channel is coaxial with the sealed connecting channel, and the inner diameter of the connecting channel is equal to the inner diameter of the sealed connecting channel. The consistency of the inner diameter can make the fluid flow evenly in the channel without turbulence, and the chemical components carried in the fluid can also be evenly brought into the detector.

[0007] The outer diameter of the sealing portion is equal to the outer diameter of the tube sleeve. The tube sleeve is designed to be a universal pipeline for liquid chromatography. As long as the tube sleeve is designed to be long enough, it can be adapted to liquid chromatographs and chromatographic columns of various brands, and has good versatility.

[0008] The hand-tightening connection joint comprises a hand-tightening screw, the center of the hand-tightening screw has a through hole that penetrates along the axial direction, the through hole comprises a first through part for penetrating the connecting pipe and a second through part for penetrating the pipe sleeve that are coaxially arranged, the inner diameter of the first through part matches the outer diameter of the connecting pipe, the inner diameter of the second through part matches the outer diameter of the pipe sleeve, the corresponding part of the connecting pipe is arranged in the first through part, the corresponding part of the pipe sleeve is arranged in the second through part, and the end of the pipe sleeve is extended and arranged outside the hand-tightening screw;

[0009] The side of the hand screw is provided with a plug-in installation opening which is connected with the through hole, and the connecting pipe and the pipe sleeve are assembled into the through hole through the plug-in installation opening;

[0010] The hand screw includes a connecting head and a connecting rod with a thread, and the second connecting part is arranged on the connecting rod. The hand screw joint has a simple structure, and a limiting step is formed between the first connecting part and the second connecting part, which forms a limit on the installation position of the hand screw to ensure a stable connection; the plug-in installation opening on the side of the hand screw facilitates the connection and installation between the hand screw and the connecting pipe with the pipe sleeve, and the second connecting part is arranged on the connecting rod with a thread, and after being screwed with the matching interface on the instrument, the pipe sleeve can be held tightly.

[0011] The hand-tightening screw is provided with a hand-tightening operation joint, which has a connection hole that penetrates along the axial direction and matches with the connection pipe, and the side of the hand-tightening operation joint is provided with a plug-in opening that is connected with the connection hole, and the corresponding part of the connection pipe is assembled into the connection hole through the plug-in opening, and the connection head is recessed with a positioning cavity, and the positioning cavity is coaxially connected with the through-hole, and the hand-tightening operation joint includes a hand-tightening part and a positioning part that are coaxially arranged in sequence along the axis, and the positioning part is tightly embedded in the positioning cavity, and an anti-dropout positioning piece is extended on the positioning part at a position corresponding to the plug-in installation opening, and the anti-dropout positioning piece is staggered with the plug-in opening, and the anti-dropout positioning piece is extended into the plug-in installation opening. The hand-tightening operation joint can be used to increase the torque and prevent the hand-tightening screw from falling off, so as to ensure the stable installation between the hand-tightening screw and the connection pipe.

[0012] The positioning part is a polygonal structure, and the positioning cavity cooperates with the positioning part to realize an anti-rotation connection between the two, ensuring that the hand screw can be driven to rotate synchronously when the hand-tightening operation joint is manually tightened.

[0013] The hand-tightening operation joint is made of rubber material, and the outer side of the hand-tightening part is provided with anti-skid patterns for increasing friction. The cost is low and the hand-tightening operation is easy.

[0014] The pipeline seal is made of PEEK material. The pipeline seal is made of PEEK (polyetheretherketone) material. The strength and toughness of the PEEK material itself determine the stability of the fixed seal, and metal lubrication is not required.

[0015] The connecting pipe and the pipe sleeve are fixed by welding, and the connection is stable.

[0016] Compared with the prior art, the advantages of the utility model are: simple structure, pipe sleeves are tightly installed on the two ends of the connecting pipe, and a pipeline seal is tightly arranged in the pipe sleeve. The port of the pipe sleeve is sealed and closed by the closing part of the pipe seal, and the extending connecting part of the pipe seal is tightly fitted with the end of the connecting pipe. After the hand-tightening connecting joint is connected to the matching connecting interface on the instrument, the pipe sleeve is tightened to achieve further tight fit between the connecting pipe and the pipeline seal and the pipe sleeve. After the connection, the "dead volume" is theoretically zero; in addition, the hand-tightening connecting joint does not need to rely on tools to operate, and the sealing connection can be achieved by hand-tightening, making the connection more convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a cross-sectional structural diagram of the first embodiment of the utility model;

[0018] Figure 2 for Figure 1 Schematic diagram of the cross-sectional structure with the hand screws removed;

[0019] Figure 3 It is a schematic cross-sectional structure diagram of the pipeline seal in the utility model;

[0020] Figure 4 It is a front view structural diagram of the hand-tightening screw in the utility model;

[0021] Figure 5 It is a schematic cross-sectional structure diagram of the hand-tightening screw in the utility model;

[0022] Figure 6 It is a partial front view structural diagram of the second embodiment of the utility model;

[0023] Figure 7 This is a front view structural diagram of a hand-tightening operation joint in the second embodiment of the utility model;

[0024] Figure 8 This is a schematic cross-sectional view of the hand-tightening operation joint in the second embodiment of the present utility model;

[0025] Fig. 9 It is a front view structural schematic diagram of the hand-tightening operating joint and the hand-tightening screw in the second embodiment of the utility model. DETAILED DESCRIPTION

[0026] The present invention will be described in further detail below in conjunction with the accompanying drawings.

[0027] Embodiment 1: As shown in the figure, a pipeline connection structure of a liquid chromatograph comprises a connecting pipe 1 having a connecting channel 11 which passes through left and right, and the left and right ends of the connecting pipe 1 are respectively tightly equipped with a pipe sleeve 2, and a pipe seal 3 is arranged in the pipe sleeve 2. The pipe seal 3 has a sealed connecting channel 31 which passes through left and right, and the pipe seal 3 comprises a closing portion 301 and an extending connecting portion 302. The closing portion 301 is arranged on the outside of the pipe sleeve 2 to seal and seal the port of the pipe sleeve 2, and the extending connecting portion 302 is extended and arranged in the pipe sleeve 2. The outer wall of the extending connecting portion 302 is tightly matched with the inner wall of the pipe sleeve 2, and the end of the extending connecting portion 302 is tightly fitted with the end of the connecting pipe 1, and the sealed connecting channel 31 is connected with the connecting channel 11, and a hand-tightening connecting joint 4 is coaxially arranged on the pipe sleeve 2. After the hand-tightening connecting joint 4 is connected to the matching connecting interface on the instrument, the pipe sleeve 2 is tightly held.

[0028] In this specific embodiment, the connecting channel 11 is coaxial with the sealed connecting channel 31, and the inner diameter of the connecting channel 11 is equal to the inner diameter of the sealed connecting channel 31. The consistency of the inner diameter can make the fluid flow evenly in the channel without turbulence, and the chemical components carried in the fluid can also be evenly brought into the detector.

[0029] In this specific embodiment, the outer diameter of the sealing portion 301 is equal to the outer diameter of the tube sleeve 2. Designed as a universal pipeline for liquid chromatography, as long as the tube sleeve 2 is designed to be long enough, it can be adapted to liquid chromatographs and chromatographic columns of various brands, and has good versatility.

[0030] In this specific embodiment, the hand-tightened connection joint 4 includes a hand-tightened screw, the center of which has a through hole 41 that penetrates axially, the through hole 41 includes a first through portion 411 coaxially arranged for inserting the connecting pipe 1 and a second through portion 412 coaxially arranged for inserting the pipe sleeve 2, the inner diameter of the first through portion 411 matches the outer diameter of the connecting pipe 1, the inner diameter of the second through portion 412 matches the outer diameter of the pipe sleeve 2, the corresponding part of the connecting pipe 1 is arranged in the first through portion 411, the corresponding part of the pipe sleeve 2 is arranged in the second through portion 412, and the end of the pipe sleeve 2 is extended and arranged outside the hand-tightened screw;

[0031] The side of the hand screw is provided with a plug-in installation opening 42 which is connected with the through hole 41, and the connecting pipe 1 and the pipe sleeve 2 are assembled into the through hole 41 through the plug-in installation opening 42;

[0032] The hand screw includes a connecting head 401 and a threaded connecting rod 402, and a second connecting portion 412 is arranged on the connecting rod 402. The above-mentioned hand screw joint has a simple structure, and a limiting step is formed between the first connecting portion 411 and the second connecting portion 412, which forms a limit on the installation position of the hand screw to ensure a stable connection; the plug-in installation opening 42 on the side of the hand screw facilitates the connection and installation between the hand screw and the connecting pipe 1 with the pipe sleeve 2, and the second connecting portion 412 is arranged on the threaded connecting rod 402, and after being screwed with the matching interface on the instrument, the pipe sleeve 2 can be held tightly.

[0033] In this specific embodiment, the pipeline seal 3 is made of PEEK material. The connecting pipe 1 and the pipeline seal 3 are made of PEEK material. The strength and toughness of the PEEK material itself determine the stability of the fixed seal, and metal lubrication is not required.

[0034] In this specific embodiment, the connecting pipe 1 and the pipe sleeve 2 are fixed by welding. The connection is stable.

[0035] Embodiment 2: The other parts are the same as Embodiment 1, except that a hand-tightening operating joint 5 is provided on the hand-tightening screw, and the hand-tightening operating joint 5 has a connecting hole 51 which penetrates axially and matches with the connecting pipe 1, and a plug-in opening 52 which is connected with the connecting hole 51 is provided on the side of the hand-tightening operating joint 5, and the corresponding part of the connecting pipe 1 is assembled into the connecting hole 51 through the plug-in opening 52, and a positioning cavity 4011 is recessed in the connecting head 401, and the positioning cavity 4011 is coaxially connected with the through-hole 41, and the hand-tightening operating joint 5 includes a hand-tightening portion 501 and a positioning portion 502 which are coaxially arranged in sequence along the axis, and the positioning portion 502 is tightly embedded in the positioning cavity 4011, and an anti-slip positioning piece 53 is extended at the position of the positioning portion 502 corresponding to the plug-in installation opening 42, and the anti-slip positioning piece 53 is staggered with the plug-in opening 52, and the anti-slip positioning piece 53 extends into the plug-in installation opening 42. The joint 5 can be used to increase the torque and prevent the hand screw from falling off by hand-tightening, thereby ensuring stable installation between the hand screw and the connecting pipe 1.

[0036] In this specific embodiment, the positioning portion 502 is a polygonal structure, and the positioning cavity 4011 cooperates with the positioning portion 502 to achieve an anti-rotation connection between the two, ensuring that the hand screw can be driven to rotate synchronously when the hand-tightening operation joint 5 is manually tightened.

[0037] In this specific embodiment, the hand-tightening operation joint 5 is made of rubber material, and the outer side of the hand-tightening part 501 is provided with an anti-slip pattern 55 for increasing friction. The cost is low and the hand-tightening operation is easy.

[0038] During the specific assembly, the pipe sleeve 2 with the pipeline seal 3 is welded and fixed to the connecting pipe 1, so that the pipeline seal 3 is tightly attached to the end of the connecting pipe 1, and then the hand screw is installed on the pipe sleeve 2, and then the hand screw operation joint 5 is installed, the installation position of the hand screw is locked, and finally the hand screw is screwed into the matching connection interface on the instrument.

Claims

1. A pipeline connection structure of a liquid chromatograph, comprising a connecting pipe having a connecting channel extending from left to right, characterized in that The left and right ends of the connecting pipe are respectively tightly equipped with pipe sleeves, a pipe seal is arranged in the pipe sleeve, and the pipe seal has a sealed connecting channel running through the left and right sides. The pipe seal includes a closing portion and an insert connecting portion. The closing portion is arranged on the outside of the pipe sleeve to seal and close the port of the pipe sleeve, and the insert connecting portion is inserted into the pipe sleeve. The outer wall of the insert connecting portion is tightly matched with the inner wall of the pipe sleeve, and the end of the insert connecting portion is tightly fitted with the end of the connecting pipe. The sealed connecting channel is connected with the connecting channel. A hand-tightening connecting joint is coaxially arranged on the pipe sleeve. After the hand-tightening connecting joint is connected to the matching connecting interface on the instrument, the pipe sleeve is tightly held.

2. A pipeline connection structure for a liquid chromatograph as claimed in claim 1, characterized in that The connecting channel is coaxial with the sealing connecting channel, and the inner diameter of the connecting channel is equal to the inner diameter of the sealing connecting channel.

3. A pipeline connection structure for a liquid chromatograph as claimed in claim 1, characterized in that The outer diameter of the sealing portion is equal to the outer diameter of the pipe sleeve.

4. A pipeline connection structure for a liquid chromatograph as claimed in claim 1, characterized in that The hand-tightening connection joint comprises a hand-tightening screw, the center of the hand-tightening screw has a through hole that penetrates along the axial direction, the through hole comprises a first through part for penetrating the connecting pipe and a second through part for penetrating the pipe sleeve that are coaxially arranged, the inner diameter of the first through part matches the outer diameter of the connecting pipe, the inner diameter of the second through part matches the outer diameter of the pipe sleeve, the corresponding part of the connecting pipe is arranged in the first through part, the corresponding part of the pipe sleeve is arranged in the second through part, and the end of the pipe sleeve is extended and arranged outside the hand-tightening screw; The side of the hand screw is provided with a plug-in installation opening which is connected with the through hole, and the connecting pipe and the pipe sleeve are assembled into the through hole through the plug-in installation opening; The hand screw comprises a connecting head and a connecting rod portion with threads, and the second connecting portion is arranged on the connecting rod portion.

5. A pipeline connection structure for a liquid chromatograph as claimed in claim 4, characterized in that The hand-tightening screw is provided with a hand-tightening operating joint, and the hand-tightening operating joint has a connecting hole that penetrates axially and cooperates with the connecting pipe. The side of the hand-tightening operating joint is provided with a plug-in opening that is connected to the connecting hole. The corresponding part of the connecting pipe is assembled into the connecting hole through the plug-in opening. A positioning cavity is recessed in the connecting head, and the positioning cavity is coaxially connected with the through-hole. The hand-tightening operating joint includes a hand-tightening portion and a positioning portion that are coaxially arranged in sequence along the axis. The positioning portion is tightly embedded in the positioning cavity. An anti-slip positioning piece is extended from the positioning portion at a position corresponding to the plug-in installation opening. The anti-slip positioning piece is staggered with the plug-in opening, and the anti-slip positioning piece extends into the plug-in installation opening.

6. A pipeline connection structure for a liquid chromatograph as claimed in claim 5, characterized in that The positioning portion is a polygonal structure, and the positioning cavity matches the positioning portion.

7. A pipeline connection structure for a liquid chromatograph as claimed in claim 5, characterized in that The hand-tightening operation joint is made of rubber material, and the outer side surface of the hand-tightening part is provided with an anti-slip pattern for increasing friction.

8. A pipeline connection structure for a liquid chromatograph as claimed in claim 1, characterized in that The pipeline sealing element is made of PEEK material.

9. A pipeline connection structure for a liquid chromatograph as claimed in claim 1, characterized in that The connecting pipe and the pipe sleeve are fixed by welding.

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