CN217786650U

CN217786650U - Compact sampling mechanism

Info

Publication number: CN217786650U
Application number: CN202222024606.1U
Authority: CN
Inventors: 张福祥; 辛珍阳; 赵琳
Original assignee: Qingdao Zhongchuang Science Apparatus Public Research And Development Service Platform Co ltd; QINGDAO SHENGHAN CHROMATOGRAPHY TECHNOLOGY CO LTD
Current assignee: Qingdao Zhongchuang Science Apparatus Public Research And Development Service Platform Co ltd; QINGDAO SHENGHAN CHROMATOGRAPHY TECHNOLOGY CO LTD
Priority date: 2022-08-02
Filing date: 2022-08-02
Publication date: 2022-11-11
Anticipated expiration: 2032-08-02

Abstract

The utility model relates to an analytical testing instrument accessory technical field, concretely relates to compact sampling mechanism, including bottom plate, mounting bracket, mount pad, sampling component, X to actuating mechanism and Z to actuating mechanism. Through setting up X respectively to actuating mechanism, Z is to actuating mechanism cooperation work, realize the removal that the horizontal X direction promptly and vertical Z side promptly of sample subassembly, make things convenient for the sample subassembly to absorb the sample in a plurality of sample bottles of different positions and realize autoinjection to corresponding detecting instrument, it is more convenient to use, degree of automation is high, improves work efficiency, avoids harmful effects such as artifical too much intervention pollution that leads to the fact the sample. Simultaneously with X to the first motor in the actuating mechanism and Z to the second motor in the actuating mechanism all fixed the setting on the mounting bracket, improved traditional sampling device with drive unit concentrate on the great problem of volume on the sampling subassembly, reduced the whole weight and the occupation space of sampling subassembly, promote the removal efficiency.

Description

Compact sampling mechanism

Technical Field

The utility model relates to an analytical testing instrument accessory technical field, concretely relates to compact sampling mechanism.

Background

The chemical analysis detection technology is widely applied to the fields of food sanitation and safety, environmental monitoring, medicine and health and the like, and the sampling device is taken as an important component in an analytical instrument, is usually used for taking out a sample from a sample bottle and is matched with subsequent liquid pumping equipment to be sent into detection equipment for sample detection and analysis. When most of the existing sampling devices sample a plurality of samples, the sampling assembly can only move up and down in a reciprocating manner to absorb the samples, so that the use is inconvenient; in the prior art, a driving motor in a driving mechanism is usually concentrated on a sampling assembly, the whole mass of the sampling assembly is heavier, the size is larger, the moving efficiency is influenced in the moving process, and the occupied space is larger. Therefore, the prior art needs further improvement based on the above problems.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a compact sampling mechanism to solve the prior art problem that exists among the above-mentioned background art.

For solving the above technical problem, the utility model provides a technical scheme does: the compact sampling mechanism comprises a bottom plate, a mounting frame, a mounting seat, a sampling assembly, an X-direction driving mechanism and a Z-direction driving mechanism, wherein the mounting frame is fixedly arranged on the bottom plate; the sampling assembly is arranged on the mounting seat in a sliding mode and driven to slide by the Z-direction driving mechanism, the Z-direction driving mechanism comprises a second motor, a belt transmission mechanism, a spline shaft, a gear and a rack, the second motor drives the spline shaft to rotate through the belt transmission mechanism, the gear is sleeved on the spline shaft and driven to rotate by the spline shaft, the rack is fixedly arranged on the sampling assembly, and the rack is meshed with the gear to drive the sampling assembly to move in the Z direction; the first motor and the second motor are both fixedly arranged on the mounting frame.

On the basis of the technical scheme, the mounting seat is rotatably provided with a guide wheel, and the outer side wall of the guide wheel is abutted to the mounting frame.

On the basis of the technical scheme, a first sliding rail is fixedly arranged on the mounting seat, a first sliding block is fixedly arranged on one side of the rack, and the first sliding block is matched with and slidably connected with the first sliding rail.

On the basis of the technical scheme, the inner side wall of the gear is symmetrically provided with accommodating grooves, the outer side wall of the spline shaft is correspondingly provided with key grooves, the accommodating grooves and the key grooves are buckled to form accommodating spaces, and balls are arranged in the accommodating spaces.

On the basis of the technical scheme, the sampling assembly comprises a shell, a needle seat, a buffer spring and an inner needle, wherein the shell is fixedly arranged on a mounting seat, the needle seat is arranged inside the shell in a sliding mode, the buffer spring is arranged on the needle seat in a sleeved mode, one end of the buffer spring is abutted to the top end inside the shell, the other end of the buffer spring is fixedly arranged on the needle seat, one end of the inner needle is fixedly arranged on the needle seat, and the other end of the inner needle extends to the outside of the shell.

On the basis of the technical scheme, the sampling assembly further comprises an outer needle, the outer needle is fixedly arranged at the bottom end of the shell and is communicated with the interior of the shell, the outer needle is sleeved on the outer side of the inner needle, and the inner needle is connected with the outer needle in a sliding mode.

On the basis of the technical scheme, the shell is provided with the vent hole, a cavity is formed between the bottom end of the needle base and the bottom end inside the shell, and the vent hole and the outer needle are communicated with the cavity.

On the basis of the technical scheme, the mounting seat is fixedly provided with a displacement sensor, the outer side wall of the needle seat is fixedly provided with a sensor stop block and slides in a through groove formed in the shell, and the displacement sensor is matched with the sensor stop block.

On the basis of the technical scheme, the top end of the mounting frame is symmetrically provided with the position sensors, and the mounting seat is fixedly provided with the trigger separation blades corresponding to the position sensors.

The utility model provides a beneficial effect that technical scheme produced lies in:

the utility model discloses in through setting up X respectively to actuating mechanism, Z to actuating mechanism cooperation work, realize that the horizontal X direction and the vertical ascending removal in Z side promptly of taking a sample subassembly, make things convenient for the sample subassembly to absorb the sample in a plurality of sample bottles of different positions and realize the autoinjection to corresponding detecting instrument, it is more convenient to use, degree of automation is high, improves work efficiency, avoids harmful effects such as the pollution that artifical too much intervention caused the sample. Simultaneously with X to the first motor in the actuating mechanism and Z to the second motor in the actuating mechanism all fixed the setting on the mounting bracket, improved traditional sampling device with drive unit concentrate on the great problem of volume on the sampling subassembly, reduced the whole weight and the occupation space of sampling subassembly, promote the removal efficiency.

Drawings

Fig. 1 is a schematic perspective view of the present invention;

fig. 2 is a schematic perspective view of the second embodiment of the present invention;

fig. 3 is a schematic three-dimensional structure of the present invention;

FIG. 4 is a schematic structural view of a sampling assembly of the present invention;

fig. 5 is a schematic view of the internal structure of the sampling assembly of the present invention;

FIG. 6 is a schematic view of the internal structure of the middle gear and spline shaft of the present invention;

FIG. 7 is a schematic structural view of a middle gear of the present invention;

Detailed Description

The invention will be further explained with reference to the following figures and examples:

in the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," and "fixed" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally formed; they may be directly connected or indirectly connected through intervening media, or may be connected through the use of two elements or the interaction of two elements. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

In the description of the present invention, it should be understood that the terms "left", "right", "front", "back", "top", "bottom", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description of the present invention and simplification of description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

Example one

As shown in fig. 1 to 6, a compact sampling mechanism includes a bottom plate 1, a mounting frame 2, a mounting seat 3, a sampling assembly 4, an X-direction driving mechanism 5 and a Z-direction driving mechanism 6, wherein the mounting frame 2 is fixedly disposed on the bottom plate 1, the mounting seat 3 is slidably connected with the mounting frame 2 through the X-direction driving mechanism 5, the X-direction driving mechanism 5 includes a first motor 51, a belt transmission mechanism and a lead screw 52, the first motor 51 drives the lead screw 52 to rotate through the belt transmission mechanism, and the mounting seat 3 is slidably sleeved on the lead screw 52; the sampling assembly 4 is arranged on the mounting base 3 in a sliding manner and driven to slide by the Z-direction driving mechanism 6, the Z-direction driving mechanism 6 comprises a second motor 61, a belt transmission mechanism, a spline shaft 62, a gear 63 and a rack 64, the second motor 61 drives the spline shaft 62 to rotate through the belt transmission mechanism, the gear 63 is sleeved on the spline shaft 62 and driven to rotate by the spline shaft 62, the rack 64 is fixedly arranged on the sampling assembly 4, and the rack 64 is meshed with the gear 63 to drive the sampling assembly 4 to move in the Z direction; the first motor 51 and the second motor 61 are both fixedly arranged on the mounting frame 2.

The utility model discloses in through setting up X respectively to actuating mechanism 5, Z is to 6 cooperation work of actuating mechanism, realize that the horizontal X direction and vertical the ascending removal in Z side promptly of taking a sample subassembly, make things convenient for the sample of taking a sample subassembly in to a plurality of sample bottles of different positions to absorb and realize autoinjection to corresponding detecting instrument in, it is more convenient to use, degree of automation is high, improve work efficiency, avoid artifical harmful effects such as pollution that too much intervention led to the fact the sample. Simultaneously with X to the first motor 51 in the actuating mechanism 5 and Z to the second motor 62 in the actuating mechanism 6 all fixed the setting on mounting bracket 2, improved traditional sampling device and concentrated the great problem of volume on the sampling subassembly with drive unit, reduced sampling subassembly's whole weight and occupation space, promote the removal efficiency.

Through the arrangement of the X-direction driving mechanism 5, the first motor 51 drives the screw rod 52 to rotate on the mounting frame 2 through the belt transmission mechanism, and can drive the mounting seat 3 with the sampling assembly 4 to move left and right on the mounting frame 2, namely to move transversely in the X direction; through setting up Z to actuating mechanism 6, it is concrete, be provided with keyway 621 on the integral key shaft 62, the gear 63 cover is established in the outside of integral key shaft 62, and the rotation of integral key shaft 62 can drive gear 63 and rotate, rack 64 is fixed to be set up on the lateral wall of mount pad 3, rack 64 and gear 63 mesh, and when gear 63 rotated, rack 64 drove the ascending removal of Z side for the mount pad realization of sampling assembly 4. It should be noted that, the X direction refers to a direction parallel to the lead screw, and the Z direction refers to a direction parallel to the inner needle of the sampling assembly, which is only for convenience of description and understanding of the technical solutions in conjunction with the drawings and does not constitute a limitation to the technical solutions of the present application. As shown in fig. 2, the belt transmission mechanism includes a driving wheel, a belt and a driven wheel, and when the belt transmission mechanism works, the motor drives the driving wheel to rotate, and the driving wheel drives the driven wheel to rotate through the belt, which is one of the transmission mechanisms commonly used by those skilled in the art. In this X-direction drive mechanism 5, the lead screw 52 is disposed coaxially with the driven wheel and is driven to rotate by the driven wheel. The operating principle of the belt transmission mechanism in the Z-direction driving mechanism 6 is the same, and only the components driven by the driven wheel are different, that is, the driven wheel drives the spline shaft 62 to rotate in the Z-direction driving mechanism 6, which will not be described in detail below.

On the basis of the technical scheme, as shown in fig. 2, the top end of the mounting frame 2 is symmetrically provided with position sensors 7, and the mounting base 3 is fixedly provided with trigger separation blades 8 corresponding to the position sensors 7. A trigger baffle 8 is arranged on the mounting seat 3 and is matched with the position sensor 7, so as to limit the movement of the mounting seat 3; more preferably, the position sensor 7 may be a photoelectric sensor, an infrared sensor, or another type of sensor. When the mounting base 3 moves to the end position of the mounting frame 2 on the screw rod 52, the trigger blocking piece 8 is matched with the position sensor 7, the electric signal is transmitted to the control system, the position of the mounting base 3 is positioned, or the first motor 51 is controlled to stop working or move in the opposite direction after receiving the electric signal, the operation step of controlling the trigger signal can be set according to the actual situation, the operation is more convenient, and the automation degree is improved.

On the basis of the above technical solution, as shown in fig. 3, the mounting base 3 is rotatably provided with a guide wheel 9, and the outer side wall of the guide wheel 9 abuts against the mounting frame 2. The guide wheel 9 is arranged on the mounting base 3, so that the guide effect on the reciprocating movement of the mounting base 3 in the X direction can be achieved, and the operation is more stable. Meanwhile, the installation base 3 and the spline shaft 62 in the Z-direction driving mechanism 6 can also realize relative sliding and can also play a role in guiding; therefore, the guide wheel 9 and the spline shaft 62 are matched to work, so that the movement of the mounting base 3 can be guided, and the running process is more stable.

On the basis of the technical scheme, a first sliding rail 10 is fixedly arranged on the mounting base 3, a first sliding block 11 is fixedly arranged on one side of the rack 64, and the first sliding block 11 is matched and slidably connected with the first sliding rail 10. Through the cooperation that sets up first slide rail 10 and first slider 11, can the guide effect, Z is more stable to removing.

On the basis of the above technical solution, as shown in fig. 6 and 7, the inside wall of the gear 63 is symmetrically provided with a containing groove 631, the outside wall of the spline shaft 62 is correspondingly provided with a key groove 621, the containing groove 631 and the key groove 621 are buckled to form a containing space, and the containing space is internally provided with the balls 65. Through the way that the accommodating space is formed between the gear 63 and the spline shaft 62 and the balls 75 are used in a matched manner, the spline shaft 62 can drive the gear 63 to rotate, and the gear 63 is matched with the rack 64 to realize the movement of the sampling assembly 4 in the Z direction; in addition, balls are arranged between the spline shaft 62 and the gear 63, the gear 63 can also realize relative sliding relative to the spline shaft 62, when the mounting seat 3 is driven by the X-direction driving mechanism 5 to move in the X direction, the gear 63 and the mounting seat 3 can move synchronously in the X direction on the spline shaft 62 to play a guiding role, and the gear 63 and the mounting seat 9 are matched to play a role in guiding, so that the operation process of the mounting seat 3 in the X direction is more stable. More preferably, as shown in fig. 7, the gear 63 is symmetrically provided with the caps 66 at both sides, and the inner side walls of the caps 66 are provided with the guide rails 661 engaged with the key grooves 621, so as to facilitate the sliding process of the gear 63 and the spline shaft 62.

Therefore the utility model discloses in through setting up gear 63, ball 65 and integral key shaft 62 cooperation structure and realizing the mode of rotation and slip dual movement, the structure is compacter, has reduced traditional rack and pinion structure size greatly, has improved structural rigidity and operational reliability, and the assembly is also more convenient with the use. Because when the traditional mode used drive shaft drive gear to rotate, the structure that adopts usually was equipped with the axle sleeve for the outside cover of drive shaft, and axle sleeve and gear fixed connection, assembly structure is comparatively complicated, and the volume is great, and occupation space is big to also can not realize that lateral shifting plays the guide effect.

Preferably, a position sensor 7 is fixedly arranged at the top end of the mounting seat 3, a trigger baffle 8 is fixedly arranged on one side of the rack 64, and the trigger baffle 8 is arranged corresponding to the position sensor 7. Similarly to the X-direction driving mechanism 5, the Z-direction driving mechanism 6 is also provided with a position sensor 7 for limiting or controlling the movement position and the stroke of the rack 64 and avoiding abnormal situations such as the rack 64 being disengaged from the gear 63; as mentioned above, the triggering principle of the position sensor 7 is the same and will not be described in detail here.

On the basis of the above technical scheme, as shown in fig. 4 and 5, the sampling assembly 4 includes a housing 41, a needle seat 42, a buffer spring 43 and an inner needle 44, the housing 41 is fixedly arranged on the mounting seat 3, the needle seat 42 is slidably arranged inside the housing 41, the buffer spring 43 is sleeved on the needle seat 42, one end of the buffer spring abuts against the top end inside the housing 41, the other end of the buffer spring is fixedly arranged on the needle seat 42, one end of the inner needle 44 is fixedly arranged on the needle seat 42, and the other end of the inner needle extends to the outside of the housing 41. Specifically, a blocking cap is fixedly arranged at the top end of the housing 41, one end of the buffer spring 43 abuts against the bottom end of the blocking cap, and the other end of the buffer spring abuts against the needle seat 42. It should be noted that, in the present invention, the top end of the inner needle 44 is connected to a device for providing auxiliary suction to complete automatic sampling; the top end of the inner needle 44 is connected with the injection pump through a pipeline to realize the automatic suction of the sample and the pumping into the instrument needing to be detected for detection. The detailed structure of the syringe pump can refer to the patent applied by the department: the patent application No. CN202220013673.0 is named as a high-precision high-pressure injection pump, and is not described in detail in the application.

By sleeving the buffer spring 43 on the needle seat 42, the buffer spring 43 is deformed when the inner needle 44 touches other objects, and the working state of the current sampling needle head is further judged; it should be noted that the buffer spring 43 is also deformed when the inner needle 44 pierces the soft rubber pad on the top end of the sample bottle normally, but the deformation amount at this time is not detected, that is, the abnormal deformation amount of the buffer spring 43 is detected, and the deformation amount is preset in advance in the control system of the automatic sample injection device. Through setting up buffer spring 43 and predetermineeing and detect its deformation volume, judge the motion state of interior needle 44 in the sampling subassembly, take place unusual timely processing, effectively protect interior needle 44, prolong its life, reduce maintenance and change, promote work efficiency.

Specifically, a preset distance is set for the movement of the inner needle 44 before use, i.e., the sampling needle moves to a specified distance in the sample bottle in the Z direction; during the actual sampling movement, the following states occur:

if the inner needle 44 of the sampling assembly 4 does not move to a preset distance, the buffer spring 43 is detected to be deformed, which indicates that the sampling needle is pricked on other parts, such as a harder plastic material part at the edge of the top end of the sampling bottle, and a harder part such as a sample rack, and an abnormal alarm is generated to remind a worker to process;

if the inner needle 44 of the sampling assembly 4 moves to a preset distance, the buffer spring 43 is detected to be deformed, which indicates that the sampling needle is inserted into the sample bottle and indicates that the working state is normal;

if the inner needle 44 of the sampling assembly 4 moves to a predetermined distance, the buffer spring 43 is not detected to be deformed, which is indicated as a piercing state, such as a state where no sample bottle is placed or the sampling assembly 4 is biased out of the sample holder 5.

On the basis of the technical scheme, the mounting seat 3 is fixedly provided with the displacement sensor 12, the outer side wall of the needle seat 42 is fixedly provided with the sensor stop 13 and slides in the through groove 411 formed in the shell 41, and the displacement sensor 12 is matched with the sensor stop 13.

Preferably, through setting up displacement sensor 12 and the sensor dog 13 that corresponds the setting, when the position outside the soft cushion of sampling bottle is stinged to interior needle 44 syringe needle, the deformation volume is unusual, and interior needle 44 drives needle file 42 rebound, and buffer spring 43 takes place deformation,

sensor dog

13 and 12 looks adaptations of displacement sensor, and displacement sensor 12 detects out the removal of sensor dog 13, and whether corresponding operating condition to the sampling syringe needle normally judges. The utility model discloses the displacement sensor 12 who uses in is photoelectric sensor, also can adopt infrared sensor or other types's sensor in addition, as long as can detect out needle file 42's removal to judge that buffer spring 43's deformation can.

Example two

On the basis of the technical scheme, the sampling assembly 4 further comprises an outer needle 45, the outer needle 45 is fixedly arranged at the bottom end of the shell 41 and is communicated with the inside of the shell 41, the outer needle 45 is sleeved on the outer side of the inner needle 44, and the inner needle 44 is connected with the outer needle 45 in a sliding manner.

Through the outside cover at interior needle 44 be equipped with outer needle 45, play the guide effect in the motion process that interior needle 44 punctures the sample bottle and takes a sample to because the interior needle 44 is thinner can also avoid shaking and the damage of interior needle 44, strengthen whole sample needle's stability and life.

EXAMPLE III

On the basis of the above technical solution, as shown in fig. 4 and 5, the housing 41 is provided with a vent hole 46, a cavity 47 is formed between the bottom end of the needle holder 42 and the bottom end inside the housing 41, and both the vent hole 46 and the outer needle 45 are communicated with the cavity 47. The vent hole 46 is arranged on the shell 41 and communicated with the outer needle 45, on one hand, the closed sample bottle, namely the top soft rubber pad, is in a completely sealed state before sampling, the inner needle 44 still keeps a sealed state after puncturing the sample bottle, and the volume accuracy of the sample sucked under the negative pressure state is poor, so that the vent hole 46 is communicated with the atmosphere through the outer needle 45, the pressure in the sample bottle can be balanced, the volume of the sucked sample is easy to control, and the accuracy of the sample test result is prevented from being influenced. More preferably, when being applicable to the sample viscosity when great, interior needle 44 absorbs when comparatively difficult, connects high-pressure gas through air vent 46 and impresses in the sample bottle, can assist interior needle 44 and syringe pump to take out the sample that viscosity is great, and application scope is wider. On the other hand, after the syringe needle accomplished once the sample, vent 46 external connection air pump let in gas to its inside, and the air in the vent 46 passes through inside cavity 47 gets into outer needle 45, can clear away the remaining sample in the space between outer needle 45 inside wall and the interior needle 44 lateral wall like this, effectively avoids the sample to remain and causes harmful effects to the concentration isoparametric detection of follow-up other samples, is particularly useful for the trace to detect.

Having shown and described the basic principles and essential features of the invention, it will be apparent to those skilled in the art that the invention is not limited to the details of the foregoing exemplary embodiments, and that the embodiments are thus to be considered as exemplary and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Furthermore, it should be understood that although the present specification describes embodiments, not every embodiment includes only a single embodiment, and such description is for clarity purposes only, and it is to be understood that all embodiments may be combined as appropriate by one of ordinary skill in the art to form other embodiments as will be apparent to those of skill in the art from the description herein.

Claims

1. The compact sampling mechanism is characterized by comprising a bottom plate (1), a mounting frame (2), a mounting seat (3), a sampling assembly (4), an X-direction driving mechanism (5) and a Z-direction driving mechanism (6), wherein the mounting frame (2) is fixedly arranged on the bottom plate (1), the mounting seat (3) is in sliding connection with the mounting frame (2) through the X-direction driving mechanism (5), the X-direction driving mechanism (5) comprises a first motor (51), a belt transmission mechanism and a lead screw (52), the first motor (51) drives the lead screw (52) to rotate through the belt transmission mechanism, and the mounting seat (3) is sleeved on the lead screw (52) in a sliding manner; the sampling assembly (4) is arranged on the mounting seat (3) in a sliding mode and driven to slide by the Z-direction driving mechanism (6), the Z-direction driving mechanism (6) comprises a second motor (61), a belt transmission mechanism, a spline shaft (62), a gear (63) and a rack (64), the second motor (61) drives the spline shaft (62) to rotate through the belt transmission mechanism, the gear (63) is sleeved on the spline shaft (62) and driven to rotate by the spline shaft (62), the rack (64) is fixedly arranged on the sampling assembly (4), and the rack (64) is meshed with the gear (63) to drive the sampling assembly (4) to move in the Z direction; the first motor (51) and the second motor (61) are both fixedly arranged on the mounting frame (2).

2. A compact sampling mechanism according to claim 1 characterized in that a guide wheel (9) is rotatably arranged on the mounting base (3), the outer side wall of the guide wheel (9) is abutted with the mounting frame (2).

3. The compact sampling mechanism of claim 1, characterized in that a first sliding rail (10) is fixedly arranged on the mounting seat (3), a first sliding block (11) is fixedly arranged on one side of the rack (64), and the first sliding block (11) is matched with and slidably connected with the first sliding rail (10).

4. The compact sampling mechanism of claim 1, characterized in that the gear (63) has a symmetrical receiving groove (631) on the inner side wall, the spline shaft (62) has a corresponding key groove (621) on the outer side wall, the receiving groove (631) is fastened with the key groove (621) to form a receiving space, and the receiving space has a ball (65) therein.

5. The compact sampling mechanism of claim 1, wherein the sampling assembly (4) comprises a housing (41), a needle seat (42), a buffer spring (43), and an inner needle (44), the housing (41) is fixedly arranged on the mounting seat (3), the needle seat (42) is slidably arranged inside the housing (41), the buffer spring (43) is sleeved on the needle seat (42) and one end of the buffer spring abuts against the top end inside the housing (41), the other end of the buffer spring is fixedly arranged on the needle seat (42), one end of the inner needle (44) is fixedly arranged on the needle seat (42), and the other end of the inner needle extends to the outside of the housing (41).

6. The compact sampling mechanism of claim 5, characterized in that the sampling assembly (4) further comprises an outer needle (45), the outer needle (45) is fixedly arranged at the bottom end of the housing (41) and is communicated with the inside of the housing (41), the outer needle (45) is sleeved on the outer side of the inner needle (44), and the inner needle (44) is slidably connected with the outer needle (45).

7. The compact sampling mechanism of claim 6, characterized in that the housing (41) is provided with a vent hole (46), a chamber (47) is formed between the bottom end of the needle seat (42) and the bottom end of the inside of the housing (41), and the vent hole (46) and the outer needle (45) are both communicated with the chamber (47).

8. A compact sampling mechanism according to claim 5 characterized in that a displacement sensor (12) is fixedly arranged on the mounting seat (3), a sensor stop (13) is fixedly arranged on the outer side wall of the needle seat (42) and slides in a through groove (411) formed in the housing (41), and the displacement sensor (12) is matched with the sensor stop (13).

9. The compact sampling mechanism of claim 1, characterized in that the top end of the mounting frame (2) is symmetrically provided with position sensors (7), and the mounting base (3) is fixedly provided with trigger baffles (8) corresponding to the position sensors (7).