Filtering sample bottle

Abstract

The utility model relates to the technical field of laboratory supplies, in particular to a filter sample bottle, which comprises an outer tube and an inner tube, the inner pipe can be arranged in the outer pipe and can slide in the axial direction of the outer pipe, a stop part is arranged on the inner side wall of the inner pipe, a flow channel penetrating in the axial direction of the inner pipe is formed in the stop part, and an opening is formed in the end, away from the outer pipe, of the inner pipe; the filtering assembly is arranged in the inner pipe and comprises a filtering membrane and a pressing piece, and the pressing piece presses the filtering membrane on the side, in the axial direction of the inner pipe, of the stopping part; and the bottle cap is arranged on the opening and is used for opening and closing the opening. According to the scheme, the filter membrane is pressed in the inner tube through the pressing piece instead of welding, so that the detection result is prevented from being influenced by a plasticizer left in a filter sample bottle through welding. And the stopping part is arranged on the inner side wall of the inner pipe, so that the bottom end of the inner pipe is prevented from entering the outer pipe and being extruded by the outer pipe to deform, and the inner pipe is radially supported.

Description

Technical Field

[0001] The utility model relates to the technical field of experimental supplies, in particular to a filtering sample bottle. Background Art

[0002] Due to its high analytical efficiency, high sensitivity, wide application range, and small sample volume, HPLC is increasingly widely used, and more and more HPLC analysis methods are included in the pharmacopoeia and various national standards. With the use of HPLC, the use of liquid chromatography filter sample bottles has also increased year by year. The internal parts of the filter sample bottle, such as the parts used for filtration, are welded by ultrasonic waves, which will leave plasticizers in the entire filter sample bottle. These plasticizers may contaminate the filtered sample liquid during use and affect subsequent test results. Utility Model Content

[0003] In view of the above-mentioned shortcomings of the prior art, the purpose of the utility model is to provide a filtering sample bottle to solve the problem that the filtering components in the prior art are assembled by ultrasonic welding, which may leave plasticizers in the filtering sample bottle, contaminating the filtered sample liquid and affecting subsequent test results.

[0004] In order to achieve the above-mentioned purpose and other related purposes, the utility model provides a filtering sample bottle, comprising:

[0005] External pipe;

[0006] The inner tube can be arranged in the outer tube and slide along the axial direction of the outer tube, the inner side wall of the inner tube is provided with a stopper, the stopper is provided with a flow channel penetrating along the axial direction of the inner tube, and one end of the inner tube away from the outer tube is open;

[0007] A filter assembly is arranged in the inner tube, comprising a filter membrane and a pressing member, wherein the pressing member presses the filter membrane onto one side of the stopper along the axial direction of the inner tube;

[0008] A bottle cap is arranged on the opening and is used for opening and closing the opening.

[0009] Optionally, the outer tube has a first inner cavity, one end of the first inner cavity is open, the inner tube is arranged in the outer tube through the first inner cavity, the inner tube has a second inner cavity, the inner tube also has a first end facing the outer tube and a second end away from the outer tube, the stopper is arranged on the side wall of the second inner cavity close to the first end of the inner tube, both ends of the second inner cavity are open, the filter membrane and the clamping piece are both sleeved in the second inner cavity, the filter membrane is located on the side of the stopper facing the outer tube, and the clamping piece is located between the bottom wall of the first inner cavity and the filter membrane, and is used to press the filter membrane against the side of the stopper facing the outer tube.

[0010] Optionally, a limiting portion is provided on the outer wall of the inner tube near its first end, and when the first end of the inner tube enters the first inner cavity, the limiting portion abuts against the side wall of the first inner cavity to limit the inner tube along the axial and radial directions of the outer tube.

[0011] Optionally, the limiting portion is at least three first protrusions uniformly distributed along the circumference of the outer wall of the inner tube; or, the limiting portion is a first protruding ring extending along the circumference of the outer wall of the inner tube.

[0012] Optionally, a guide portion is further provided on the outer side wall of the inner tube close to the first end thereof, and the guide portion is located between the second end of the inner tube and the limiting portion.

[0013] Optionally, the guide portion is a second convex ring extending circumferentially along the outer wall of the inner tube.

[0014] Optionally, the distance between the limiting portion and the guiding portion along the axial direction of the inner tube is 2mm-3mm.

[0015] Optionally, an axial distance between the first end of the inner tube and the limiting portion is 1.5 mm-2 mm.

[0016] Optionally, the clamping member is an elastic pressure ring, and the bottom wall of the first inner cavity is provided with a cone, at least part of the outer wall of the cone abuts against the inner wall of the elastic pressure ring, and the end of the cone facing away from the bottom wall of the first inner cavity abuts against the filter membrane, the inner diameter of the elastic pressure ring is 4mm-4.6mm, and the thickness is 1mm, the diameter of the cone gradually decreases in the direction away from the bottom wall of the first inner cavity, and there is an angle of 5 degrees between the bottom wall of the first inner cavity and the side wall of the cone.

[0017] Optionally, the stopper comprises a disk disposed in the second inner cavity, an outer peripheral side wall of the disk is connected to a side wall of the second inner cavity, and a hollow structure is disposed on the disk which runs through the axial direction thereof, and the hollow structure forms the flow channel.

[0018] As described above, the filtering sample bottle of the utility model has the following beneficial effects:

[0019] When this solution is used, first add the filtered sample into the outer tube, and then install the inner tube into the outer tube until the outer bottom of the inner tube is against the inner bottom wall of the outer tube, which can reduce the dead volume. The filtered sample passes through the clamp and the filter membrane to complete the filtration, and finally enters the inner tube through the flow channel. When sampling, the needle is inserted into the inner tube through the bottle cap for sampling. This solution uses a clamp to compress the filter membrane into the inner tube instead of welding, to avoid welding and leaving plasticizer in the filtered sample bottle and affecting the test results. The stopper is arranged on the inner wall of the inner tube, which can prevent the bottom end of the inner tube from entering the outer tube and being squeezed by the outer tube and deformed, and plays a radial supporting role for the inner tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a front view of an embodiment of the utility model;

[0021] Figure 2 for Figure 1 Sectional view at AA;

[0022] Figure 3 It is an exploded schematic diagram of an embodiment of the utility model;

[0023] Figure 4 This is a schematic diagram of the inner tube structure of an embodiment of the utility model.

[0024] Part Number Description

[0025] 1-outer tube; 11-cone; 2-inner tube; 21-stopper; 211-flow channel; 22-limiting part; 23-guide part; 24-first flange; 25-second flange; 3-pressing member; 4-filter membrane; 5-bottle cap; 51-sampling hole; 52-ridge; 6-sealing member. DETAILED DESCRIPTION

[0026] The following is an explanation of the implementation of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific implementations, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0027] It should be noted that the diagrams provided in the present embodiment are only used to illustrate the basic concept of the present invention in a schematic manner, so the diagrams only show the components related to the present invention rather than the number, shape and size of the components in the actual implementation. The type, quantity and proportion of each component in the actual implementation can be changed at will, and the layout of the components may be more complicated. The structure, proportion, size, etc. shown in the diagrams attached to this specification are only used to match the content disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions that the present invention can be implemented, so they have no technical substantive significance. Any modification of the structure, change of the proportional relationship or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the effect and purpose that the present invention can produce. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" cited in this specification are only for the convenience of description and are not used to limit the scope of the implementation of the present utility model. Changes or adjustments to their relative relationships should be regarded as the scope of the implementation of the present utility model without substantially changing the technical content.

[0028] Since the second end of the inner tube 2 of the filtering sample bottle of this embodiment faces upward and the first end faces downward when in use, the "upper" and "top" in this embodiment refer to the direction of the second end of the inner tube 2, and the "lower" and "bottom" refer to the direction of the first end of the inner tube 2, and so on.

[0029] See also Figures 1 to 4 The present embodiment provides a filtering sample bottle, comprising an outer tube 1, an inner tube 2, a filtering assembly and a bottle cap 5. The inner tube 2 can be arranged in the outer tube 1 and slide along the axial direction of the outer tube 1. A stopper 21 is arranged on the inner side wall of the inner tube 2. A flow channel 211 penetrating along the axial direction of the inner tube 2 is arranged on the stopper 21. The end of the inner tube 2 away from the outer tube 1 is open. The filtering assembly is arranged in the inner tube 2, comprising a filter membrane 4 and a pressing member 3. The pressing member 3 presses the filter membrane 3 on one side of the stopper 21 along the axial direction of the inner tube 2. The filtered sample can pass through the pressing member 3 and then through the filter membrane 4. The bottle cap 5 is arranged on the opening of the inner tube 2, and is used to open and close the opening of the inner tube 2. The opening of the inner tube 2 is also referred to as the second end opening of the inner tube 2 below.

[0030] In this embodiment, when in use, first add the filtered sample into the outer tube 1, and then install the inner tube 2 into the outer tube 1 until the outer bottom of the inner tube 2 abuts against the inner bottom wall of the outer tube 1, which can reduce the dead volume. The filtered sample passes through the clamp 3 and the filter membrane 4 to complete the filtration, and then enters the inner tube 2 through the flow channel 211. When sampling, the needle is inserted into the inner tube 2 through the bottle cap 5 for sampling. In this embodiment, the assembly method of pressing the filter membrane 4 into the inner tube 2 by the clamp 3 replaces the welding assembly method, so as to avoid welding leaving plasticizer in the filtered sample bottle and affecting the test results. The stopper 21 is arranged on the inner side wall of the inner tube 2, which can prevent the bottom end of the inner tube 2 from entering the outer tube 1 and being squeezed and deformed by the outer tube, and play a radial supporting role for the inner tube 2.

[0031] In one embodiment, if Figures 1 to 4As shown, the filtration sample bottle includes an outer tube 1, an inner tube 2, a filter membrane 4, a pressing piece 3 and a bottle cap 5. The outer tube 1 and the inner tube 2 are both hollow tubular structures, the hollow part of the outer tube 1 forms a first inner cavity, and the hollow part of the inner tube 2 forms a second inner cavity. The top of the first inner cavity is open, that is, the top of the outer tube 1 is open. Both ends of the second inner cavity are open, that is, both ends of the inner tube 2 are open. The inner tube 2 has a first end facing the outer tube 1 and a second end away from the outer tube 1, that is, the top of the inner tube 2 is the second end, and the bottom end is the first end. The outer diameter of the inner tube 2 is smaller than the inner diameter of the outer tube 1, and the length of the inner tube 2 is greater than the length of the outer tube 1, so that the top of the inner tube 2 can extend out of the first inner cavity. The bottom end of the inner tube 2 enters the first inner cavity, and the inner tube 2 can be movably arranged in the first inner cavity along the axial direction of the outer tube 1. A stopper 21 is provided on the side wall of the second inner cavity near the bottom end of the inner tube 2. The stopper 21 is used to prevent the filter membrane 4 from moving toward the top end of the inner tube 2. The stopper 21 is provided with a flow channel 211 for connecting the two ends of the second inner cavity along the axial direction of the inner tube 2. The filter membrane 4 and the pressing member 3 are both sleeved in the second inner cavity. The filter membrane 4 is located on the side of the stopper 21 facing the outer tube 1, that is, the filter membrane 4 is arranged on the bottom surface of the stopper 21 along the axial direction of the inner tube 2, and the pressing member 3 is located between the bottom wall of the first inner cavity and the filter membrane 4. The outer diameter of the filter membrane 4 and the outer diameter of the pressing member 3 are slightly larger than the inner diameter of the inner tube 2. The pressing member 3 and the filter membrane 4 are interference-fitted in the second inner cavity to ensure the pressing effect of the pressing member 3 on the filter membrane 4 and the filtering effect of the filter membrane 4. The pressing member 3 is used to press the filter membrane 4 against the side of the stopper 21 facing the outer tube 1, that is, the pressing member 3 can press the filter membrane 4 against the bottom surface of the stopper 21 to fix the filter membrane 4 along the axial direction of the inner tube 2, so as to prevent the filter membrane 4 from moving and causing filtration failure, thereby affecting the detection result. The pressing member 3 can be an annular cushion or a cylindrical cushion. The cylindrical cushion is provided with a through hole that penetrates along the axial direction of the inner tube 2, so that the filtered sample can pass through the pressing member 3 along the axial direction of the inner tube 2. The bottle cap 5 is provided on the top opening of the inner tube 2, and is used to open and close the top opening of the inner tube 2. The bottle cap 5 is provided with a sampling hole 51 that penetrates the thickness direction thereof, so as to facilitate the needle to extend into the second inner cavity for sampling. The bottom wall of the first inner cavity abuts against the pressing member 3, which can improve the abutting effect of the pressing member 3 on the filter membrane 4 and reduce the dead liquid volume between the bottom wall of the first inner cavity and the pressing member 3.

[0032] When the filter sample bottle of this embodiment is used, the filter sample is first added to the outer tube 1, and then the inner tube 2 is loaded from the open end of the first inner cavity of the outer tube 1 until the outer bottom of the inner tube 2 abuts against the bottom wall of the first inner cavity, which can reduce the dead volume. The filter sample passes through the bottom open end of the inner tube 2, the pressing piece 3 and the filter membrane 4 in sequence to complete the filtration, and finally enters the second inner cavity through the flow channel 211. When sampling, the needle is inserted into the second inner cavity through the bottle cap 5 for sampling. The assembly method of this embodiment uses the pressing piece 3 to press the filter membrane 4 into the inner tube 2 instead of the welding assembly method, so as to avoid welding leaving plasticizer in the filter sample bottle and affecting the test results. First, the filter membrane 4 is installed from the bottom open end of the second inner cavity of the inner tube 2, and then the pressing piece 3 is installed from the bottom open end of the second inner cavity of the inner tube 2 and the filter membrane 4 is pressed against the stopper 21. The assembly method of installing from the bottom open end of the second inner cavity of the inner tube 2 can simplify the installation process of the filter membrane 4 and the pressing piece 3, making the assembly and installation of the filter membrane 4 and the pressing piece 3 in the second inner cavity easier, improving the assembly and use stability of the pressing piece 3 and the filter membrane 4, and avoiding the filter membrane 4 falling off and affecting the detection result.

[0033] In one embodiment, if Figures 2 to 4 As shown, a limiting portion 22 is provided on the outer wall of the inner tube 2 near its first end, that is, a limiting portion 22 is provided on the outer wall of the inner tube 2 near its bottom end. When the bottom end of the inner tube 2 enters the first inner cavity, the limiting portion 22 abuts against the side wall of the first inner cavity to limit and fix the inner tube 2 in the first inner cavity along the radial and axial directions of the outer tube 1. Since the outer diameter of the inner tube 2 is smaller than the inner diameter of the outer tube 1, the inner tube 2 may deviate radially and axially along the outer tube 1 in the first inner cavity, especially when centrifuging. The above-mentioned structural arrangement can prevent the inner tube 2 from radially deviating during centrifugation, thereby improving the use stability of the filtration sample bottle of this embodiment.

[0034] In one embodiment, the limiting portion 22 is 1.5 mm to 2 mm away from the bottom of the inner tube 2 along the axial direction of the inner tube 2 . This value can ensure and improve the limiting and sealing effects of the limiting portion 22 .

[0035] In one embodiment, the limiting portion 22 can be disposed on the outer side wall of the bottom end of the inner tube 2 for easy processing.

[0036] In one embodiment, the limiting portion 22 includes at least three first protrusions uniformly distributed along the circumferential direction of the outer wall of the inner tube 2. That is, the limiting portion 22 includes at least three first protrusions arranged on the outer wall near the top of the inner tube 2, and at least three first protrusions are uniformly distributed along the circumferential direction of the outer wall of the inner tube 2. The three first protrusions uniformly distributed along the circumferential direction can achieve the axial and radial limiting of the inner tube 2 along the outer tube 1. The more the number of the first protrusions, the stronger the limiting effect on the inner tube 2, and the stronger the stability of the inner tube 2 in the first inner cavity.

[0037] In one embodiment, if Figures 2 to 4 As shown, the limiting portion 22 includes a first convex ring extending circumferentially along the outer wall of the inner tube 2, that is, the limiting portion 22 is a first convex ring, and extends circumferentially along the outer wall near the bottom end of the inner tube 2. The surface of the first convex ring in contact with the side wall of the first inner cavity is an arc surface, which can not only play a limiting role on the inner tube 2, but also push the residual filtered sample between the outer wall of the inner tube 2 and the side wall of the first inner cavity to the bottom, play a sealing role, and minimize the volume of the residual filtered sample, thereby improving the filtering effect and the accuracy of the test results. The stopper 21 is arranged on the side wall of the second inner cavity, and after the bottom end of the inner tube 2 enters the first inner cavity and is squeezed and deformed by the outer tube 1, it plays a radial supporting role for the inner tube 2. The position where the inner tube 2 is radially supported is also the position where the first convex ring is located, so that the first convex ring will also be supported radially outward along the inner tube 2, thereby improving the sealing effect of the first convex ring.

[0038] In one embodiment, if Figures 2 to 4 As shown, a guide portion 23 is also provided on the outer wall of the inner tube 2 near its first end, and the guide portion 23 is located between the limiting portion 22 and the second end of the inner tube 2. A guide portion 23 is also provided on the outer wall of the inner tube 2 near the bottom end, and the guide portion 23 is used to guide the inner tube 2 when entering the first inner cavity, so as to facilitate the bottom end of the inner tube 2 to enter the first inner cavity. When other auxiliary equipment is used to press the inner tube 2 into the outer tube 1, if there is no guide portion 23, the inner tube 2 may not be pressed into the outer tube 1 smoothly, and may even cause the inner tube 2 to break directly. The guide portion 23 is located between the top end of the inner tube 2 and the limiting portion 22 along the axial direction of the outer tube 1.

[0039] In one embodiment, if Figures 2 to 4 As shown, the guide portion 23 is a second convex ring extending circumferentially along the outer wall of the inner tube 2, and the outer peripheral side wall of the second convex ring is a plane. That is, the guide portion 23 is a second convex ring extending circumferentially along the inner tube 2, and the surface of the second convex ring in contact with the side wall of the first inner cavity is a plane, and the two sides of the plane along the axial direction of the outer tube 1 are rounded. The width of the second convex ring along the axial direction of the outer tube 1 and the height along the radial direction of the outer tube 1 are both smaller than the first convex ring. The setting of the plane enables the guide portion 23 to play a guiding role while avoiding affecting the axial movement of the inner tube 2 in the first inner cavity, thereby avoiding affecting the filtration of the filtered sample.

[0040] In one embodiment, the specifications of the outer tube 1 and the inner tube 2 of the filter sample bottle are fixed, and the axial distance between the limit portion 22 and the guide portion 23 is 2mm-3mm. The axial distance between the limit portion 22 and the guide portion 23 along the outer tube 1 can be any value between 2mm-3mm, such as 2mm, 3mm, 2.4mm, 2.5mm, etc. The optimal axial distance between the limit portion 22 and the guide portion 23 along the outer tube 1 is 2.4mm. The above-mentioned arrangement can prevent the auxiliary equipment from pressing the inner tube 2 into the first inner cavity, and when the force point of the auxiliary equipment is not mainly concentrated on the inner tube 2, the inner tube 2 cannot accurately enter the first inner cavity, damaging the first inner cavity and causing loss of the auxiliary equipment and the filter sample bottle.

[0041] In one embodiment, if Figure 2 and Figure 3 As shown, the pressing member 3 is an annular elastic pressure ring, and the bottom wall of the first inner cavity is provided with a truncated cone 11 extending along its axial direction. At least part of the outer wall of the truncated cone 11 abuts against the inner wall of the elastic pressure ring to play a pressing role on the pressing member 3, thereby improving the pressing and fixing effect of the pressing member 3 on the filter membrane 4, preventing the filter membrane 4 from falling off, and reducing the dead liquid volume and improving the filtering effect. The end of the truncated cone 11 away from the bottom wall of the first inner cavity abuts against the filter membrane 4, that is, the top surface of the truncated cone 11 abuts against the filter membrane 4, which can reduce the dead liquid volume and improve the filtering effect.

[0042] In one embodiment, the inner diameter of the elastic pressing ring can be any value between 4 mm and 4.6 mm, such as 4 mm, 4.2 mm, 4.6 mm, etc. The thickness of the elastic pressing ring is 1 mm. The above-mentioned elastic pressing ring size value enables the elastic pressing ring to press the filter membrane 4 without affecting the filtration sample passing through the middle of the elastic pressing ring, thereby improving the filtration effect of the filter membrane 4.

[0043] In one embodiment, if Figure 2 As shown, the diameter of the cone 11 gradually decreases in the direction away from the bottom wall of the first inner cavity, that is, the diameter of the cone 11 is smaller at the top and larger at the bottom. The angle formed between the bottom wall of the first inner cavity and the side wall of the cone 11 is 5 degrees, which can smoothly press the inner tube 2 into the outer tube 1. If the angle is set too small, it will be unfavorable for the assembly between the inner tube 2 and the outer tube 1, making the assembly between the inner tube 2 and the outer tube 1 more rigid. If the angle is set too large, the gap between the outer wall of the cone 11 and the inner wall of the elastic pressure ring will be relatively large, the dead volume will be large, and the filtering effect will be affected, and the fixation of the filter membrane 4 will also be affected.

[0044] In one embodiment, if Figures 2 to 4As shown, the stopper 21 includes a disc arranged in the second inner cavity, and the disc is located near the bottom end of the inner tube 2. The outer peripheral side wall of the disc is connected to the side wall of the second inner cavity, and the axis of the disc and the axis of the inner tube 2 are located on the same straight line. The disc can also be integrally formed with the side wall of the second inner cavity. The disc is provided with a hollow structure running through its axial direction, and the hollow structure forms a flow channel 211. The hollow structure can be a through hole of various shapes, and each through hole is not connected to each other, which can improve the radial support of the inner tube 2. The provision of the disc can improve the radial support of the inner tube 2, and since the radial cross-sectional area of ​​the disc is large, it can also improve the support of the filter membrane 4.

[0045] In one embodiment, if Figure 2 As shown, a step extending in the circumferential direction is provided on one side of the stopper 21 toward the bottom end, and the filter membrane 4 is provided on the step. The step can position the filter membrane 4 along the radial direction of the inner tube 2, and facilitates the installation of the filter membrane 4.

[0046] In one embodiment, if Figure 2 and Figure 3 As shown, a sealing member 6 is provided between the sampling hole 51 and the bottle cap 5, and the bottle cap 5 presses the sealing member 6 against the opening of the inner tube 2, so as to seal the opening of the inner tube 2 and the bottle cap 5 to prevent leakage of the filtered sample. The sampling needle can pass through the sealing member 6 and extend into the inner tube 2 for sampling.

[0047] In one embodiment, the sealing member 6 includes sealing cotton, which has a good sealing effect and can absorb the leaked filtered sample.

[0048] In one embodiment, if Figure 2 As shown, the inner wall of the bottle cap 5 is provided with a ridge 52 along the circumferential direction, and the top outer wall of the inner tube 2 is provided with a first flange 24. When the inner tube 2 and the bottle cap 5 are assembled in place, the ridge 52 abuts against the bottom of the first flange 24, limiting the bottle cap 5 and preventing the bottle cap 5 from falling off.

[0049] In one embodiment, if Figure 2 As shown, the top outer wall of the inner tube 2 is provided with a first flange 24 and a second flange 25 in sequence from top to bottom, and there is a gap between the first flange 24 and the second flange 25. When the inner tube 2 and the bottle cap 5 are assembled in place, the ridge 52 is stuck between the first flange 24 and the second flange 25, which limits the bottle cap 5 and prevents it from falling off.

[0050] In one embodiment, the outer wall of the inner tube 2 is provided with exhaust holes penetrating through the thickness direction of the outer wall, which are used to exhaust air outwards when the filtered sample enters the inner tube 2, so that the filtered sample can enter the inner tube 2 faster.

[0051] In one embodiment, there are multiple exhaust holes, which are opened at the same height in the axial direction on the inner tube 2 and are evenly distributed along the circumference. The heights of the exhaust holes opened in the axial direction on the inner tube 2 may be different, which can improve the exhaust effect.

[0052] In one embodiment, the outer tube 1 includes an expanded diameter section and a round tube section sequentially arranged from top to bottom, so as to facilitate the inner tube 2 to enter the outer tube 1 .

[0053] In one embodiment, a fixing convex ring is provided on the outer wall of the middle part of the inner tube 2 along its axial direction, the side of the fixing convex ring close to the top end of the inner tube 2 is a vertical surface, and the side close to the bottom end of the inner tube 2 is an inclined surface, and the height of the inclined surface gradually decreases along the bottom end of the inner tube 2. The fixing convex ring enables the inner tube 2 to have a better axial and radial limiting effect in the first inner cavity along the outer tube 1.

[0054] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the technology may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed in the present invention shall still be covered by the claims of the present invention.

Claims

1. A filtering sample bottle, characterized in that: include: External pipe; The inner tube can be arranged in the outer tube and slide along the axial direction of the outer tube, the inner side wall of the inner tube is provided with a stopper, the stopper is provided with a flow channel penetrating along the axial direction of the inner tube, and one end of the inner tube away from the outer tube is open; A filter assembly is arranged in the inner tube, comprising a filter membrane and a pressing member, wherein the pressing member presses the filter membrane onto one side of the stopper along the axial direction of the inner tube; A bottle cap is arranged on the opening and is used for opening and closing the opening.

2. The filtering sample bottle according to claim 1, characterized in that: The outer tube has a first inner cavity, one end of which is open, the inner tube is arranged in the outer tube through the first inner cavity, the inner tube has a second inner cavity, and the inner tube also has a first end facing the outer tube and a second end away from the outer tube, the stopper is arranged on the side wall of the second inner cavity close to the first end of the inner tube, both ends of the second inner cavity are open, the filter membrane and the pressing piece are both sleeved in the second inner cavity, the filter membrane is located on the side of the stopper facing the outer tube, and the pressing piece is located between the bottom wall of the first inner cavity and the filter membrane, and is used to press the filter membrane against the side of the stopper facing the outer tube.

3. The filtering sample bottle according to claim 2, characterized in that: A limiting portion is provided on the outer side wall of the inner tube near its first end. When the first end of the inner tube enters the first inner cavity, the limiting portion abuts against the side wall of the first inner cavity to limit the inner tube along the axial and radial directions of the outer tube.

4. The filtering sample bottle according to claim 3, characterized in that: The limiting portion is at least three first protrusions uniformly distributed along the circumference of the outer wall of the inner tube; or, the limiting portion is a first protruding ring extending along the circumference of the outer wall of the inner tube.

5. The filtering sample bottle according to claim 3 or 4, characterized in that: A guide portion is also provided on the outer side wall of the inner tube close to the first end thereof, and the guide portion is located between the second end of the inner tube and the limiting portion.

6. The filtering sample bottle according to claim 5, characterized in that: The guide portion is a second convex ring extending circumferentially along the outer side wall of the inner tube.

7. The filtering sample bottle according to claim 5, characterized in that: The distance between the limiting portion and the guiding portion along the axial direction of the inner tube is 2mm-3mm.

8. The filtering sample bottle according to claim 3, characterized in that: An axial distance between the first end of the inner tube and the limiting portion is 1.5 mm-2 mm.

9. The filtering sample bottle according to claim 2, characterized in that: The clamping piece is an elastic pressure ring, and the bottom wall of the first inner cavity is provided with a frustum, at least part of the outer wall of the frustum abuts against the inner wall of the elastic pressure ring, and the end of the frustum facing away from the bottom wall of the first inner cavity abuts against the filter membrane, the inner diameter of the elastic pressure ring is 4mm-4.6mm, and the thickness is 1mm, the diameter of the frustum gradually decreases in the direction away from the bottom wall of the first inner cavity, and there is an angle of 5 degrees between the bottom wall of the first inner cavity and the side wall of the frustum.

10. The filtering sample bottle according to claim 2, characterized in that: The stopper comprises a disk arranged in the second inner cavity, the outer peripheral side wall of the disk is connected to the side wall of the second inner cavity, and the disk is provided with a hollow structure running through the axial direction thereof, and the hollow structure forms the flow channel.

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