Chromatograph sample introduction connecting assembly

Abstract

The utility model relates to a chromatograph sample introduction connecting component, which comprises a sample introduction needle, a gas source system, a sample introduction pipe and a connecting piece, the connecting piece is arranged between the sample introduction needle and the sample introduction pipe and can be respectively communicated with the sample introduction needle and the sample introduction pipe in a gas tightness manner, the sample introduction pipe is communicated with the gas source system, and a gas tightness sample introduction passage is formed between the sample introduction pipe and the sample introduction needle; according to the chromatographic instrument sample introduction connecting assembly, by arranging the airtight communicating piece, the sealing plug and the sealing partition piece, the sample introduction needle and the sample introduction pipe can be used as independent parts, and the effect that an airtight sample introduction communicating channel can be formed can be achieved; through the extrusion effect of the sealing plug on the sample injection needle, the airtight communication effect of sample injection at the position of the sample injection needle is improved; a sealing ring is arranged at the position, connected with the sample injection pipe, of the airtight communicating piece, so that the airtight effect of the position of the sample injection pipe is improved; meanwhile, parts on the sample injection pipe, the sample injection needle and the connecting piece can be conveniently disassembled, replaced, maintained and the like.

Description

Technical Field

[0001] The utility model relates to the field of chromatographic detection devices, in particular to a chromatograph sample injection connection component. Background Art

[0002] As a detection equipment, pyrolysis gas chromatograph is now widely used in fields such as food research, petrochemical industry, etc. The pyrolysis gas chromatograph consists of two parts, one of which is a pyrolysis instrument for heating and cracking samples, and the other is a gas chromatograph for detecting samples. The two parts are connected to the injection needle through an injection tube to realize sending the pyrolysis gaseous sample to the chromatograph for detection. The mainstream chromatograph detection equipment on the market is a device for vertical injection detection. In order to ensure the sealing effect, the injection needle is directly installed at the sample outlet end of the pyrolysis instrument to form an integrated structure with the pyrolysis instrument. However, although this structure has a good sealing effect, the injection needle and the injection tube are both consumable parts that need to be replaced frequently, and the disassembly and replacement are too cumbersome. However, the injection needle is separated and used alone. Although it is easy to disassemble and replace, the airtightness of its passage cannot be guaranteed. In view of this, it has become an urgent problem to design a connecting component that can separate the injection needle and the injection tube and use them separately and can ensure the airtightness between the two. Utility Model Content

[0003] In order to solve the above technical problems, the utility model discloses a chromatograph injection connection assembly, which includes an injection needle, an air source system, an injection tube, and a connecting piece. The connecting piece is arranged between the injection needle and the injection tube, and can be air-tightly connected to the injection needle and the injection tube respectively. The injection tube is connected to the air source system, and an air-tight injection passage is formed from the injection tube to the injection needle.

[0004] Furthermore, the connecting piece includes an airtight connecting piece having two openings and a gas passage structure. The airtight connecting piece is connected to the injection tube and the injection needle through the two openings respectively, and the injection tube, the airtight connecting piece and the injection needle can form an airtight passage.

[0005] Furthermore, the connecting piece also includes a sealing plug and a sealing barrier. The injection needle is connected to the opening of the airtight connecting piece through the sealing plug. The sealing barrier is arranged between the injection needle and the injection tube, and the sealing barrier is provided with a through hole for the gas sample to pass through, thereby forming an indirect connecting structure that separates the contact between the injection needle and the injection tube.

[0006] Specifically, the end of the sample injection tube abuts against the sealing barrier to form a pressure-sealed structure at the butt joint.

[0007] Specifically, the airtight connecting piece is a variable diameter cylindrical structure in which a gas passage structure is formed by a through channel, the sealing barrier is an annular gasket with thickness, and the outer diameter of the gasket is larger than the minimum diameter of the variable diameter through channel, forming a limiting structure that can be stuck in the through channel, and the injection needle and the injection tube are respectively inserted into the variable diameter through channel from the openings at both ends of the airtight connecting piece and connected to the sealing barrier to form an airtight injection passage.

[0008] Specifically, the airtight connecting piece is a straight tube structure with a gas passage structure formed by a through channel, and the injection needle and the injection tube can be inserted into the through channel from the openings at both ends of the airtight connecting piece respectively to form a two-way connected sleeve structure.

[0009] Specifically, a flange is provided in the through-hole of the airtight connecting piece, and the flange is arranged along the circumferential direction of the inner wall of the through-hole to form a limiting ring in the gas passage structure.

[0010] Specifically, the sealing barrier is an annular gasket with thickness and can be clamped by the flange in the through channel. The outer wall diameter of the injection tube is smaller than the inner diameter of the flange and passes through the flange to abut against the sealing barrier. The through hole of the sealing barrier is connected to the injection needle to form an airtight injection passage from the injection tube to the injection needle.

[0011] Specifically, the sealing barrier is a thick annular gasket, and the circumferential edge is fixedly connected to the inner wall of the through-channel of the airtight connecting piece, forming a flange in the gas passage structure that is fixed in position and can limit the insertion depth of the injection needle and the injection tube.

[0012] Specifically, the injection needle includes a needle head and a needle seat, and one end of the needle head is fixedly connected to the needle seat to form a stable end portion with a convex tail portion.

[0013] Specifically, the sealing plug is provided with a channel for the needle to pass through, the diameter of the channel is smaller than the diameter of the needle seat, and an end receiving seat capable of clamping the needle seat is formed at the end of the sealing plug, and the end receiving seat faces the sealing barrier, and the end receiving seat and the sealing barrier together form a accommodating space with a gap in the through channel of the air-tight connecting piece for accommodating the needle seat.

[0014] Specifically, the sealing plug is a connector with an external thread on the outer wall, and the gas passage structure of the airtight connecting piece is provided with an internal thread matching the external thread of the sealing plug, forming a compression structure that can reduce the accommodating space by tightening the thread.

[0015] Specifically, the end portion of the needle seat connected to the needle head is in the shape of a protruding cone, and the end receiving seat is in the shape of a slope concave toward the channel and can fit with the conical surface of the needle seat to form a pressing surface for positioning and sealing.

[0016] Specifically, the contact surface between the sealing barrier and the needle seat is a slope surface that matches each other, forming a sealing pressing surface that can be tightly attached to each other under the extrusion force.

[0017] Furthermore, the connector also includes a sealing ring, which is arranged at the end of the injection tube inserted into the airtight connecting piece, and the sealing ring is in contact with the airtight connecting piece to form a sealed space between the through channel of the airtight connecting piece and the injection tube.

[0018] Specifically, the sealing ring is arranged between the outer wall of the sampling tube and the inner wall of the through-hole of the airtight connecting piece.

[0019] Specifically, the sealing ring is arranged at the port of the through-hole of the airtight connecting piece, and is in contact with the port to form a seal with the sampling tube at the port.

[0020] Specifically, a sealing cap is also provided at one end of the air-tight connecting piece inserted into the sampling tube. The sealing cap is fixedly connected to the end of the air-tight connecting piece, and the sealing cap is provided with a through hole for the sampling tube to pass through and the diameter of the through hole is smaller than the diameter of the sealing ring, forming a clamping piece that can fix the sealing ring to the port of the air-tight connecting piece.

[0021] Specifically, the sealing cap is a nut with an internal thread, and the end of the sealing cap fixedly connected to the airtight connecting piece is provided with an external thread matching the internal thread, forming a compression structure that can generate pressure on the sealing ring through the cooperation of the internal and external threads.

[0022] Specifically, the connecting piece also includes a connecting cap, which is a nut with an internal thread, and the end face is provided with a through hole for the sealing plug connecting end to pass through, and the end of the sealing plug is provided with a convex portion with a diameter larger than the through hole. The connecting cap is movably connected to the sealing plug and can be prevented from falling off by the convex portion of the sealing plug.

[0023] Advantages

[0024] The chromatograph injection connection assembly of the present application achieves the effect of using the injection needle and the injection tube as independent parts and forming an airtight injection connection passage by providing an airtight connecting piece, a sealing plug and a sealing baffle; the airtight connection effect of injection at the injection needle position is improved by the squeezing effect of the sealing plug on the injection needle; the airtight effect at the injection tube position is improved by providing a sealing ring on the airtight connecting piece at the connection position with the injection tube; the structure of connecting the injection needle and the injection tube through the connection assembly of the utility model not only ensures that the injection has a good sealing effect, but also facilitates the disassembly, replacement and maintenance of the injection tube, the injection needle and the parts on the connecting piece. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the structure of the gas path of the chromatograph sample injection connection assembly of the utility model;

[0026] Figure 2 This is a schematic diagram of the structure of the connector of the utility model connecting the injection tube and the injection needle;

[0027] Figure 3 This is a schematic diagram of the connector structure of Example 1 of the chromatograph sample injection connection assembly of the utility model;

[0028] Figure 4 This is a schematic diagram of the connector structure of Example 2 of the chromatograph sample injection connection assembly of the utility model;

[0029] Figure 5 This is a schematic diagram of the connector structure of Example 3 of the chromatograph sample injection connection assembly of the utility model;

[0030] Figure 6 This is one of the structural schematic diagrams of the chromatograph sample injection connection assembly of the utility model;

[0031] Figure 7 This is the second structural schematic diagram of the chromatograph sample injection connection assembly of the utility model;

[0032] Figure 8 This is the third structural schematic diagram of the chromatograph sample injection connection assembly of the utility model;

[0033] Fig. 9 It is a structural schematic diagram of a connection cap of a chromatograph sample injection connection assembly of the utility model.

[0034] Legend: 1. Injection needle; 11. Needle; 12. Needle seat; 2. Sealing plug; 21. Channel; 22. End receiving seat; 3. Airtight connecting piece; 31. Flange; 32. Accommodating space; 4. Sealing barrier; 5. Sealing ring; 6. Sealing cap; 61. Through hole; 7. Connecting cap; 8. Gas source system; 9. Injection tube; 10. Connecting piece. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are preferred embodiments of the utility model and should not be regarded as excluding other embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model.

[0036] In the claims, specification and the above-mentioned drawings of the utility model, unless otherwise clearly defined, the use of terms such as "first", "second" or "third" etc. is to distinguish different objects rather than to describe a specific order.

[0037] In the claims, specification and the above-mentioned drawings of the utility model, unless otherwise explicitly defined, directional words, such as the terms "center", "lateral", "longitudinal", "horizontal", "vertical", "top", "bottom", "inside", "outside", "up", "down", "front", "back", "left", "right", "clockwise", "counterclockwise", etc., indicating directions or positional relationships are based on the directions and positional relationships shown in the drawings, and are only for the convenience of describing the utility model and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation or be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the specific protection scope of the utility model.

[0038] In the claims, specification and the above drawings of the utility model, unless otherwise clearly defined, if the term "fixed connection" or "fixed connection" is used, it should be understood in a broad sense, that is, any connection method without a displacement relationship and relative rotation relationship between the two, that is to say, including non-detachable fixed connection, detachable fixed connection, integrated connection and fixed connection through other devices or elements.

[0039] In the claims, specification and drawings of the present utility model, if the terms "include", "have" and their variations are used, they are intended to mean "including but not limited to".

[0040] like Figure 1As shown, the utility model relates to a chromatograph injection connection assembly, which includes an injection needle 1, an air source system 8, an injection tube 9, and a connector 10. The connector 10 is arranged between the injection needle 1 and the injection tube 9, and can be air-tightly connected to the injection needle 1 and the injection tube 9 respectively. The injection tube 9 is connected to the air source system 8, and an air-tight injection passage is formed between the injection tube 9 and the injection needle 1. When in use, the gas source system 8 continuously supplies gas to the equipment. The equipment also includes a thermal cracking heating device, which surrounds the injection tube 9 and heats it. After the sample is added to the injection tube 9, it is gasified by the heating device. The injection tube 9 is connected to the gas source system 8, and the gaseous sample is entrained by the airflow blown out by the gas source system 8 and passes through the connector 10 connected to the injection tube 9 in succession, and then passes through the injection needle 1 connected to the connector 10. The injection needle 1 is inserted into the detection equipment, and the gaseous sample to be detected enters the chromatograph through the above path for detection. Since the sample may be toxic, it is necessary to ensure the airtightness of the process to achieve the purpose of preventing the sample gas from leaking. The connection 10 is provided to prevent the injection tube 9 and the injection needle 1 from direct hard contact Since the injection needle is generally thinner, and the injection tube 9 needs to have a slightly larger inner diameter to add the sample, the combination of the two needs to be filled with sealant or bonded with a lamp to improve the airtightness. However, since the equipment is working at a high temperature, it is easy to cause sample contamination problems. On the other hand, the general injection needle 1 is made of metal and the injection tube 9 is made of glass. The two are in direct contact, and the injection tube 9 is also surrounded by a large-mass thermal cracking device, which is easy to cause damage to the injection tube or the injection needle, affecting the service life of the equipment. Because the injection needle 1 may be blocked, the injection needle needs to be replaced, which will also increase the replacement operation time, resulting in reduced detection efficiency. These problems can be solved by providing a connector 10 between the two.

[0041] like Figure 2 As shown, the connector 10 includes an airtight connecting piece 3, which has two openings and a gas passage structure. The airtight connecting piece 3 connects the injection tube 9 and the injection needle 1 through the two openings, respectively, and the injection tube 9, the airtight connecting piece 3 and the injection needle 1 can form an airtight passage. Through the airtight connecting piece 3, an airtight connecting injection passage is formed between the injection tube 9 and the injection needle 1 without contact;

[0042] like Figures 3 to 5As shown, the connector 10 also includes a sealing plug 2 and a sealing barrier 4. The injection needle 1 is connected to the opening of the airtight connecting piece 3 through the sealing plug 2. The sealing barrier 4 is arranged between the injection needle 1 and the injection tube 9, and a through hole for the gas sample to pass through is provided on the sealing barrier 4, forming an indirect connection structure that separates the injection needle 1 from the injection tube 9. In order to ensure the sealing performance, the sealing plug 2 is used to perform an airtight sealing connection on one end of the injection needle 1. The sealing barrier 4 is arranged between the injection needle 1 and the injection tube 9 to separate the two and avoid damage caused by direct hard contact between the two ends; the end of the injection tube abuts on the sealing barrier to form a pressure-sealed structure at the joint. In addition, the end of the injection tube 9 can also directly abut on the sealing barrier 4 to reduce gas leakage through the pressure of the connection, and one end of the injection needle forms a sealed space in the airtight connecting piece 3 through the sealing plug, with one end facing the injection tube and the other end facing the injection needle, thereby achieving an airtight effect;

[0043] Specifically, the airtight connecting piece 3 is a straight tube structure formed by a through hole to form a gas passage structure. The injection needle 1 and the injection tube 9 can be inserted into the through hole from the openings at both ends of the airtight connecting piece 3 to form a two-way connected sleeve structure. The sleeve structure realizes the communication passage between the injection tube and the injection needle. The specific structure and arrangement of the airtight connecting piece 3 and the sealing baffle 4 are as shown in the following embodiment:

[0044] Example 1

[0045] like Figure 3As shown, a flange 31 is provided in the through-hole of the airtight connecting piece 3, and the flange 31 is arranged along the circumferential direction of the inner wall of the through-hole to form a limit ring in the gas passage structure. The sealing barrier 4 is an annular gasket with thickness, and can be clamped by the flange 31 in the through-hole. The outer wall diameter of the injection tube 9 is smaller than the inner diameter of the flange 31, and passes through the flange 31 to abut against the sealing barrier 4. The through hole of the sealing barrier 4 is connected with the injection needle 1 to form an airtight injection passage from the injection tube 9 to the injection needle 1. In this embodiment, based on the above structure, the airtight connecting piece 3 is a straight-cylindrical two-way structure, and the flange 31 arranged in the cylinder clamps the sealing barrier 4. In this test method, the sealing barrier 4 can use an integrated structure connected with the injection needle 1, or a split structure, that is, an independent and detachable sealing barrier 4. When in use, the sealing barrier 4 is installed in the channel of the airtight connecting piece 3, and is inserted into one end of the connected sampling needle, and the sealing barrier 4 is clamped by the flange 31 in the channel, and then the sampling needle and the sealing plug 2 are installed, and the position of the sampling needle is fixed by the sealing plug 2. For a split or integrated structure, the end of the sampling needle 1 can be abutted against the position of the flange 31 through the sealing barrier 4 by the fixing effect of the plug on the sampling needle 1, or the sealing barrier 4 and the end of the sampling needle 1 can be kept in the same position. The flange 31 in the channel serves as a limiting structure; when in use, the sampling tube 9 keeps the end against the sealing barrier 4 to realize a connected sampling passage, ensuring a certain sealing effect while being connected, and will not be damaged by direct contact between the sampling needle and the tube.

[0046] Example 2

[0047] like Figure 4 As shown, as another embodiment, the difference between this embodiment and embodiment 1 is that the sealing barrier 4 is a thick annular gasket, and the circumferential edge is fixedly connected to the inner wall of the through hole of the airtight connecting piece 3, forming a flange in the gas passage structure that is fixed in position and can limit the insertion depth of the injection needle 1 and the injection tube 9. The sealing barrier 4 is directly fixed in the through hole of the airtight connecting piece 3, and this position can be selected from the middle position of the airtight connecting piece 3. In this embodiment, the position of the sealing barrier 4 remains fixed, even if the injection needle 1 does not keep contacting with the sealing barrier 4, but the injection tube 9 keeps a fixed insertion depth of the airtight connecting piece 3. When in use, the position of the injection needle 1 is fixed by the sealing plug 2, and the end of the injection needle 1 can be in contact with the sealing barrier 4, or the end can be kept at a certain distance from the sealing barrier 4, and the other end is inserted into the injection tube 9, and the end of the injection tube 9 is in contact with the sealing barrier 4, so as to reduce gas sample leakage and realize the sealed injection gas path connection.

[0048] Example 3

[0049] like Figure 5As shown, as another embodiment, the airtight connecting piece 3 is a variable diameter cylindrical structure in which a gas passage structure is formed by a through channel, and the sealing barrier 4 is an annular gasket with thickness, and the outer diameter of the gasket is larger than the minimum diameter of the variable diameter through channel, forming a limiting structure that can be stuck in the through channel, and the injection needle 1 and the injection tube 9 are respectively inserted into the variable diameter through channel from the openings at both ends of the airtight connecting piece 3 and connected to the sealing barrier 4 to form an airtight injection passage. By using an airtight connecting piece 3 with a variable diameter through-channel, the sealing barrier 4 is placed into the through-channel from the large diameter end of the airtight connecting piece 3 and stuck in the through-channel. In this embodiment, the sealing plug 2 is used to abut the end of the injection needle 1 with the sealing barrier 4, and the sealing barrier 4 is stuck in the channel at a position where it cannot be further advanced, and the injection tube 9 is inserted from the other end and the end is abutted with the sealing barrier 4, so as to achieve the effects of injection connection and airtight connection; in this embodiment, the sealing barrier 4 can use an integrated structure with the injection needle 1, or a split structure; the airtight connecting piece 3 can use a conical variable diameter channel, or a stepped variable diameter channel.

[0050] After repeated experiments and actual use tests, the technical solution of Example 2 is the best embodiment. The fixing structure of the airtight connecting piece 3 and the sealing barrier piece 4 of Example 2 can be used stably and reduce the number of installation steps and parts.

[0051] like Figures 3 to 8 As shown, specifically, the injection needle 1 includes a needle 11 and a needle seat 12, wherein one end of the needle 11 is a tip, and the other end is fixedly connected to the needle seat 12 to form a stable end with a convex tail. When in use, the tip of the needle 11 of the injection needle 1 is inserted into the gasket at the injection port of the chromatograph, and the gasket is resilient to clamp the needle 11 of the injection needle to achieve a sealing effect during the injection process. The needle seat 12 is used to stabilize the overall state of the injection needle 1 when in use and is used as a base.

[0052] The sealing plug 2 is provided with a channel 21 for the needle 11 to pass through, and the diameter of the channel 21 is smaller than the diameter of the needle seat 12. An end receiving seat 22 capable of clamping the needle seat 12 is formed at the end of the sealing plug 2, and the end receiving seat 22 faces the sealing barrier 4. The end receiving seat 22 and the sealing barrier 4 together form a receiving space 32 with a gap in the through-hole of the airtight connecting member 3 for accommodating the needle seat 12. The sealing plug 2 is columnar, and the channel 21 is provided along the center line of the column. When in use, the needle 11 is passed through the channel 21 to avoid the needle 11 from being stuck during use. The connected device is skewed, and after the needle 11 is inserted from the through hole 21 on the sealing plug 2, the end of the sealing plug 2 holding the needle seat 12 is inserted into the through channel of the airtight connecting piece 3. The sealing plug 2 can be made of rubber and has an interference fit with the through channel to achieve a sealing effect. After insertion, the insertion depth of the sealing plug 2 is continued to be pushed forward until the end of the needle seat 12 and the sealing baffle 4 are squeezed and fitted against each other to achieve a hard contact sealing effect. The needle seat 12 and the sealing baffle 4 used in the utility model are both made of metal, such as stainless steel that is not easy to react.

[0053] In order to further enhance the hard contact sealing effect, the sealing plug 2 is a connector with an external thread on the outer wall, and the gas-tight connecting piece 3 is provided with an internal thread matching the external thread of the sealing plug 2 in the gas passage structure, forming a compression structure that can reduce the accommodation space 32 by tightening the thread. The sealing plug 2 uses the same metal material as the gas-tight connecting piece 3, such as stainless steel, and uses internal and external threads to achieve the connection between the sealing plug 2 and the gas-tight connecting piece 3. When in use, the needle seat 12 and the sealing barrier 4 are further compressed by tightening the threads, while maintaining a close hard contact state, avoiding the problem of the soft plug being easy to loosen and difficult to load and unload.

[0054] The end of the needle seat 12 connected to the needle 11 is a protruding cone, and the end receiving seat 22 is a sloped surface concave toward the channel 21, and can fit with the conical surface of the needle seat 12 to form a pressing surface for positioning and sealing; the contact surface between the sealing barrier 4 and the needle seat 12 is a sloped surface that cooperates with each other, forming a sealing pressing surface that can be pressed against each other under extrusion force. By setting a slope structure on the end faces of the two ends of the needle seat, when in use, the sealing plug 2 and the airtight connecting piece 3 are tightened by threads. During the tightening process, the contact slopes of the needle seat 12 and the end receiving seat 22 of the sealing plug 2, as well as the contact slopes of the needle seat 12 and the sealing barrier 4 are pressed against each other by force. The slopes can increase the contact area of ​​the pressing piece and improve the hard contact sealing effect. Through hard contact sealing, the problem of easy aging and poor sealing effect caused by the use of sealing rubber rings in high temperature use environments can be avoided, and the sealing can be ensured while adapting to high temperature use environments, extending the service life, and reducing the frequency of parts replacement.

[0055] Since the injection tube 9 is sealed by abutting the end with the sealing baffle 4, the glass material used in the injection tube 9 cannot ensure the sealing effect by applying a greater extrusion force like the end of the injection needle 1, so further, the connector 10 also includes a sealing ring 5, which is arranged around the end of the injection tube inserted into the airtight connecting piece 3, and the sealing ring 5 is in contact with the airtight connecting piece 3, forming a sealed space between the through-hole of the airtight connecting piece 3 and the injection tube; the sealing ring 5 is arranged between the outer wall of the injection tube and the inner wall of the through-hole of the airtight connecting piece 3. When in use, the sealing ring 5 is arranged in the gap position between the injection tube 9 and the inner wall of the through-hole of the airtight connecting piece 3, and then the injection tube 9 is inserted to abut against the sealing baffle 4, and the sealing ring 5 is made to be close to the outer wall of the injection tube 9 and the inner wall of the through-hole through the elastic deformation of the sealing ring 5, so as to achieve a sealing effect on a small amount of leaked gas at the abutment position of the injection tube.

[0056] As another arrangement of the sealing ring 5, the sealing ring 5 is arranged at the port of the through-hole of the airtight connecting piece 3, and abuts against the port, and forms a seal with the injection tube at the port. The sealing ring 5 is arranged at the opening position of the through-hole of the airtight connecting piece 3, and is fixed, and the inner diameter of the sealing ring 5 is smaller than the outer wall diameter of the injection tube 9. When in use, the injection tube 9 can be directly inserted from the opening position until the end abuts against the sealing baffle 4 to achieve a sealed injection passage effect. This arrangement can solve the problem that the sealing ring 5 will approach the sealing baffle 4 as the injection tube 9 is inserted in the through-hole. This embodiment can keep the position of the sealing ring 5 fixed during use and expose it to the surrounding air. This arrangement can appropriately reduce the temperature of the sealing ring 5 made of heat-resistant silicone / heat-resistant rubber when in use, and improve equipment loss.

[0057] The sealing ring 5 is set at the opening position of the air-tight connecting piece 3, which needs to be glued and fixed, and is not easy to replace. To solve this problem, a sealing cap 6 is further provided at one end of the air-tight connecting piece 3 inserted into the sampling tube. The sealing cap 6 is fixedly connected to the end of the air-tight connecting piece 3, and the sealing cap 6 is provided with a through hole 61 for the sampling tube 9 to pass through and the diameter of the sealing ring 5 is smaller than the diameter of the sealing ring 5, forming a clamping piece that can fix the sealing ring 5 at the port of the air-tight connecting piece 3. When in use, place the sealing ring 5 on the end face of the opening of the airtight connecting piece 3, then cover the sealing cap 6 and press to keep the sealing ring 5 fixed, insert the end of the sampling tube 9 through the hole 61, and pass through the inner diameter of the sealing ring 5 into the through channel of the airtight connecting piece 3 until it abuts against the sealing baffle 4 to achieve a sealed sampling effect. In the process of pressing the sealing ring 5 by this setting method, the sealing ring 5 receives upper and lower extrusion forces, and the sealing ring 5 will produce deformation in both the outer and inner directions, so that the outer circle diameter becomes larger and the inner circle diameter becomes smaller. However, the outer circle deformation is restricted by the sealing cap 6 and cannot expand outward, and the inner circle diameter becomes smaller by a greater amount. Through this deformation, the sealing ring 5 increases the fit of the outer wall of the sampling tube 9, and at the same time increases the fit of the sealing ring 5 with the opening position of the airtight connecting piece 3, further increasing the airtight effect between the sampling tube 9 and the airtight connecting piece 3, and at the same time facilitating the installation and replacement of maintenance parts or wearing parts.

[0058] Specifically, the sealing cap 6 is a nut with an internal thread, and the end of the sealing cap 6 fixedly connected to the airtight connecting piece 3 is provided with an external thread matching the internal thread, forming a compression structure that can generate pressure on the sealing ring through the cooperation of the internal and external threads. The use of the internal and external threads can increase the tight fixing effect between the sealing cap 6 and the airtight connecting piece 3, ensuring that the airtight effect of the sealing ring 5 is maintained.

[0059] like Fig. 9 As shown, in order to increase the fixing effect when the connector 10 is connected to the chromatograph, the connector 10 also includes a connecting cap 7, which is a nut with internal threads, and the end face is provided with a through hole for the connection end of the sealing plug 2 to pass through, and the end of the sealing plug 2 is provided with a convex portion with a diameter larger than the through hole, and the connecting cap 7 is movably connected to the sealing plug 2, and can be blocked from falling off by the convex portion of the sealing plug 2. When in use, the airtight connecting piece 3 and the injection tube 9 associated with the sealing plug 2 are fixed to the chromatograph needle injection position through the connecting cap 7, and the position has a protruding external thread end. Tighten the connecting cap 7 so that the convex portion of the sealing plug 2 is pressed against the end of the external thread end. This is because the injection needle 1 has been inserted into the chromatograph from the sealing gasket position on the external thread end, and the equipment is started to start the injection detection work, and the pyrolysis instrument and the injection connection assembly are fixed to the chromatograph injection detection position through the connecting cap 7.

[0060] Obviously, the above-mentioned embodiments of the present invention are merely examples for clearly explaining the present invention, and are not intended to limit the embodiments of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the embodiments here. All obvious changes or modifications derived from the technical solution of the present invention are still within the scope of protection of the present invention.

Claims

1. A chromatograph sample injection connection assembly, characterized in that: The invention comprises an injection needle (1), an air source system (8), an injection tube (9), and a connecting piece (10). The connecting piece (10) is arranged between the injection needle (1) and the injection tube (9), and can be respectively connected to the injection needle (1) and the injection tube (9) in an airtight manner. The injection tube (9) is connected to the air source system (8), and an airtight injection passage is formed between the injection tube (9) and the injection needle (1).

2. The chromatograph sample injection connection assembly according to claim 1, characterized in that: The connecting piece (10) comprises an airtight connecting piece (3), wherein the airtight connecting piece (3) has two openings and a gas passage structure, and the airtight connecting piece (3) is connected to the injection tube (9) and the injection needle (1) respectively through the two openings, and the injection tube (9), the airtight connecting piece (3) and the injection needle (1) can form an airtight passage.

3. The chromatograph sample injection connection assembly according to claim 2, characterized in that: The connecting member (10) further comprises a sealing plug (2) and a sealing barrier member (4); the injection needle (1) is connected to the opening of the airtight connecting member (3) via the sealing plug (2); the sealing barrier member (4) is arranged between the injection needle (1) and the injection tube (9); and a through hole is provided on the sealing barrier member (4) for the gas sample to pass through, thereby forming an indirect connection structure that separates the contact between the injection needle (1) and the injection tube (9).

4. The chromatograph sample injection connection assembly according to claim 3, characterized in that: The end of the sample injection tube (9) abuts against the sealing barrier (4), forming a pressure-sealed structure at the butt joint.

5. The chromatograph sample injection connection assembly according to claim 3, characterized in that: The airtight connecting piece (3) is a variable diameter cylindrical structure with a gas passage structure formed by a through-hole, the sealing barrier (4) is an annular gasket with a thickness, and the outer diameter of the gasket is larger than the minimum diameter of the variable diameter through-hole, forming a limit structure that can be stuck in the through-hole, and the injection needle (1) and the injection tube (9) are respectively inserted into the variable diameter through-hole from the openings at both ends of the airtight connecting piece (3) and connected to the sealing barrier (4), forming an airtight injection passage.

6. The chromatograph sample injection connection assembly according to claim 3, characterized in that: The airtight connecting piece (3) is a straight tube structure with a gas passage structure formed by a through hole, and the injection needle (1) and the injection tube (9) can be respectively inserted into the through hole from the openings at both ends of the airtight connecting piece (3) to form a two-way connected sleeve structure.

7. The chromatograph sample injection connection assembly according to claim 6, characterized in that: A flange (31) is provided in the through-hole of the airtight connecting piece (3), and the flange (31) is arranged along the circumferential direction of the inner wall of the through-hole to form a limiting ring in the gas passage structure.

8. The chromatograph sample injection connection assembly according to claim 7, characterized in that: The sealing barrier (4) is an annular gasket with a thickness and can be clamped by the flange (31) in the through-hole. The outer wall diameter of the injection tube (9) is smaller than the inner diameter of the flange (31) and passes through the flange (31) to abut against the sealing barrier (4). The through hole of the sealing barrier (4) is connected to the injection needle (1), forming an airtight injection passage from the injection tube (9) to the injection needle (1).

9. The chromatograph sample injection connection assembly according to claim 6, characterized in that: The sealing barrier (4) is a thick annular gasket, and its circumferential edge is fixedly connected to the inner wall of the through-hole of the airtight connecting piece (3), forming a flange in the gas passage structure that is fixed in position and can limit the insertion depth of the injection needle (1) and the injection tube (9).

10. The chromatograph sample injection connection assembly according to any one of claims 3 to 9, characterized in that: The injection needle (1) comprises a needle head (11) and a needle seat (12); one end of the needle head (11) is fixedly connected to the needle seat (12) to form a stable end with a convex tail.

11. The chromatograph sample injection connection assembly according to claim 10, characterized in that: The sealing plug (2) is provided with a passage (21) for the needle (11) to pass through, the diameter of the passage (21) being smaller than the diameter of the needle seat (12), an end receiving seat (22) capable of clamping the needle seat (12) is formed at the end of the sealing plug (2), the end receiving seat (22) faces the sealing barrier (4), and the end receiving seat (22) and the sealing barrier (4) together form a receiving space (32) with a spacing therebetween in the through-hole of the airtight connecting piece (3) for accommodating the needle seat (12).

12. The chromatograph sample injection connection assembly according to claim 11, characterized in that: The sealing plug (2) is a connecting piece with an external thread on its outer wall, and the gas passage structure of the airtight connecting piece (3) is provided with an internal thread matching the external thread of the sealing plug (2), forming a compression structure that can reduce the accommodating space (32) by tightening the thread.

13. The chromatograph sample injection connection assembly according to claim 11, characterized in that: The end portion of the needle seat (12) connected to the needle head (11) is in the shape of a protruding cone, and the end receiving seat (22) is in the shape of a slope that is concave toward the channel (21) and can fit with the conical surface of the needle seat (12) to form a positioning and sealing pressing surface.

14. The chromatograph sample injection connection assembly according to claim 12, characterized in that: The contact surface between the sealing barrier (4) and the needle seat (12) is a mutually matching slope surface, forming a sealing pressing surface that can be tightly attached to each other under the extrusion force.

15. The chromatograph sample injection connection assembly according to claim 2, characterized in that: The connecting piece (10) further comprises a sealing ring (5), which is arranged around the end of the sample injection tube inserted into the airtight connecting piece (3), and the sealing ring (5) is in contact with the airtight connecting piece (3), so as to form a sealed space between the through-hole of the airtight connecting piece (3) and the sample injection tube.

16. The chromatograph sample injection connection assembly according to claim 15, characterized in that: The sealing ring (5) is arranged between the outer wall of the sample injection tube and the inner wall of the through-hole of the airtight connecting piece (3).

17. The chromatograph sample injection connection assembly according to claim 15, characterized in that: The sealing ring (5) is arranged at the port of the through-hole of the airtight connecting piece (3) and is in contact with the port to form a seal with the injection tube at the port.

18. The chromatograph sample injection connection assembly according to claim 17, characterized in that: The end of the airtight connecting piece (3) inserted into the injection tube is also provided with a sealing cap (6), the sealing cap (6) is fixedly connected to the end of the airtight connecting piece (3), and the sealing cap (6) is provided with a through hole (61) for the injection tube to pass through and the diameter of which is smaller than the diameter of the sealing ring (5), forming a pressing piece capable of fixing the sealing ring (5) to the port of the airtight connecting piece (3).

19. The chromatograph sample injection connection assembly according to claim 18, characterized in that: The sealing cap (6) is a nut with an internal thread, and the end of the sealing cap (6) fixedly connected to the airtight connecting piece (3) is provided with an external thread matching the internal thread, forming a compression structure capable of generating pressure on the sealing ring (5) through the cooperation of the internal and external threads.

20. The chromatograph sample injection connection assembly according to claim 3, characterized in that: The connecting piece (10) further comprises a connecting cap (7), which is a nut with an internal thread and an end surface provided with a through hole for the connecting end of the sealing plug (2) to pass through, and an end portion of the sealing plug (2) is provided with a convex portion having a diameter greater than the through hole, and the connecting cap (7) is movably connected to the sealing plug (2) and can be prevented from falling off by the convex portion of the sealing plug (2).

Images