CN212610528U

CN212610528U - Chip movable positioning liquid injection structure of PCR instrument

Info

Publication number: CN212610528U
Application number: CN202020392273.6U
Authority: CN
Inventors: 裴颢
Original assignee: Mezhuo Biotechnology Zhejiang Co ltd
Current assignee: Mezhuo Biotechnology Zhejiang Co ltd
Priority date: 2020-03-24
Filing date: 2020-03-24
Publication date: 2021-02-26
Anticipated expiration: 2030-03-24

Abstract

The utility model relates to a chip movable positioning liquid injection structure of a PCR instrument, which comprises a bottom plate, a fixed seat, a bearing platform assembly, a linear guide rail and a bearing platform driving mechanism, wherein the bearing platform assembly is connected with the bottom plate through the linear guide rail; the pushing table component is provided with a nozzle head which is communicated with the pipe body; the fixing seat is arranged on the bottom plate, a heating module is arranged below the corresponding opening of the fixing seat, a chip positioning column is further arranged on the fixing seat, and a second positioning hole is formed in the chip bearing platform corresponding to the chip positioning column. The utility model discloses a with micro-fluidic chip and chip reference column location, realized micro-fluidic chip, fixing base promptly and pushed away the filter tip location of platform subassembly, pushed away the platform subassembly and pushed down the sealed cooperation of the mouth hole with micro-fluidic chip, realize separable area and press the notes liquid.

Description

Chip movable positioning liquid injection structure of PCR instrument

Technical Field

The utility model relates to a medical instrument, in particular to a chip movable positioning liquid injection structure of a PCR instrument.

Background

Polymerase Chain Reaction (PCR) is a molecular biology technique for amplifying and amplifying specific DNA fragments, and can be regarded as special DNA replication in vitro, and the greatest feature of PCR is that a trace amount of DNA can be greatly increased.

In the PCR, DNA is denatured at a high temperature of 95 ℃ in vitro to become a single strand, a primer and the single strand are combined according to the principle of base complementary pairing at a low temperature (usually about 60 ℃), the temperature is adjusted to the optimal reaction temperature (about 72 ℃) of DNA polymerase, and the DNA polymerase synthesizes a complementary strand along the direction from phosphate to pentose.

The basic principle of current digital PCR analysis is to distribute a sample into a large number of droplets, each of which contains one or more samples to be tested, then perform PCR amplification on the samples to be tested, and analyze the droplets after PCR amplification. In PCR, two-phase or three-phase temperature cycling (referred to as "thermal cycling") is repeated to sequentially perform the following reactions: denaturation of the DNA to become single stranded; primer annealing to form denatured single-stranded DNA; and primer extension using thermostable DNA polymerase. This cycle is repeated until a sufficient number of copies is obtained for analysis. At present, there is mainly a continuous flow type PCR method, which has a process of injecting liquid into a microfluidic chip and a process of heating the microfluidic chip, and in the cyclic heating, it is necessary to ensure the liquid in the microfluidic chip to flow, so that it is necessary to ensure the accurate positioning between the microfluidic chip and the liquid injection device and the heating stage, and at the same time, it is necessary to ensure the good contact between the microfluidic chip and the heating stage. However, the current technology has no effective positioning scheme, so that the microfluidic chip is easy to move in the liquid injection process, and the positioning is inaccurate. The efficiency of PCR is reduced, and the sample of PCR is easy to leak or be polluted.

Chinese patent document No. CN 110702588A discloses a digital PCR analysis apparatus and a PCR analysis method in 2020, 1 month and 17 days. The digital PCR analysis apparatus includes: droplet generation module, PCR temperature control module and optical detection module, wherein: the liquid drop generating module is used for generating a liquid drop reaction unit on the microfluidic chip; the PCR temperature control module is used for controlling the temperature of the liquid drop reaction unit generated on the microfluidic chip; and the optical detection module is used for determining the image of the droplet reaction unit on the microfluidic chip. The structure has a plurality of places needing to be perfected on the structure of conveying, positioning and injecting the micro-fluidic chip.

Disclosure of Invention

An object of the utility model is to provide a rational in infrastructure, micro-fluidic chip place convenient accurate, can realize compressing tightly the closed liquid, the liquid structure is annotated in the chip activity location of the PCR appearance of heating.

The purpose of the utility model is realized like this:

the utility model provides a chip activity location of PCR appearance annotates liquid structure, includes bottom plate, fixing base, cushion cap subassembly, linear guide and cushion cap actuating mechanism, and the cushion cap subassembly passes through linear guide and is connected with the bottom plate, and cushion cap actuating mechanism sets up on the bottom plate and is connected its characterized in that with the transmission of cushion cap subassembly: the bearing platform assembly comprises a chip bearing platform, an elastic part is arranged between the chip bearing platform and the linear guide rail, an opening is formed in the chip bearing platform, the microfluidic chip is placed above the opening, and a pushing platform assembly moving up and down is further arranged above the opening; the pushing table assembly comprises an installation table and a driving device for pushing the installation table, a nozzle head is arranged on the bottom surface of the installation table, and the nozzle head is communicated with the pipe body; the fixing seat is arranged on the bottom plate, a heating module is arranged below the corresponding opening of the fixing seat, more than two chip positioning columns are further arranged on the fixing seat, and second positioning holes are formed in the chip bearing platform corresponding to the chip positioning columns.

The purpose of the utility model can also adopt the following technical measures to solve:

as a more specific scheme, four luer connectors are distributed on the mounting table in a rectangular mode, each luer connector is connected with the pipe body, the lower end of each luer connector extends out of the bottom surface of the mounting table, the nozzle head is arranged at the lower end of each luer connector, the nozzle head is provided with a through hole, and the through holes are communicated with the pipe bodies. The medium transmitted by the tube body corresponding to each luer connector can be liquid or gas, and is determined according to the practical application.

As a further scheme, the luer connector comprises a male connector, a female connector and a soft sleeve, wherein the center of the male connector is provided with a jack hole penetrating through two ends of the male connector, the female connector is provided with a stepped hole, the stepped hole is communicated with a through hole of the nozzle, the stepped hole is internally provided with a soft sleeve limiting step and a tube limiting step which are distributed up and down, and the tube limiting step is positioned above the through hole; the hose is arranged on the hose limiting step, and the hose body penetrates through the pipe inserting hole and the hose and then is inserted to the pipe limiting step; the mount table corresponds female joint and is equipped with the joint mounting hole, and the joint mounting hole runs through the upper and lower both ends of mount table, and the outer end of female joint still is equipped with the face of filling up, and the face external diameter that fills up is greater than the female joint external diameter, and the mouth protrusion is in the bottom surface of face of filling up, and supreme plug-in connection mounting hole is followed down to the upper end of female joint, and stretch out to the top surface of mount table on, and the upper end and the lock nut of female joint are connected, and the lower extreme of male joint inserts the shoulder hole, and with shoulder hole threaded connection, the cushion cover compresses tightly between the lower extreme of male joint and the.

As a further scheme, the bearing platform assembly further comprises an elastic supporting device, the elastic supporting device comprises a supporting rod, an elastic piece and a fixing groove, the supporting rod is connected to the bottom of the chip bearing platform, and first limiting flanges are arranged on two sides of the bottom of the supporting rod; the fixed slot is connected with linear guide, and the fixed slot top surface is equipped with the fluting, and grooved opening inboard is equipped with the spacing turn-ups of second, and in the fluting was inserted to the bracing piece lower part, first spacing turn-ups kept off with the spacing turn-ups of second mutually, and the elastic component is equipped with a plurality ofly and along bracing piece length direction straight line distribution, and the elastic component setting is between the bottom surface of bracing piece and the fluting bottom surface of fixed slot.

As a further scheme, the elastic supporting devices are provided with a left set and a right set, and one elastic supporting device of each set is arranged at the bottom of the chip bearing platform from left to right; the elastic part is a spring, a positioning cavity is arranged at the bottom of the supporting rod corresponding to the spring, and the upper end of the spring is inserted into the positioning cavity.

As a further scheme, the bearing platform assembly further comprises a side plate and a panel, the outer side of the fixing groove is connected with the side plate, and the front end of the fixing groove is connected with the panel; the top end of the side plate is provided with an inner flanging, the left side and the right side of the chip bearing platform are provided with outer flanging, and the top surface of the outer flanging is blocked with the bottom surface of the inner flanging.

As a further scheme, the linear guide rail comprises a fixed block, a guide roller and a slide rail, the fixed block is fixedly connected with the bottom plate, the guide roller is horizontally and rotatably arranged on the fixed block, an annular groove is formed in the periphery of the guide roller, a guide groove is formed in the bottom of the slide rail, a guide convex rib matched with the annular groove is arranged on the inner wall of the guide groove, and the slide rail is connected with the fixed groove. The guide roller can be a rubber wheel, can be better contacted with the slide rail, and reduces the noise during movement.

As a further scheme, the bearing platform driving mechanism is an air cylinder driving mechanism or a lead screw driving mechanism, the lead screw driving mechanism comprises a driving motor, a nut, a lead screw, a guide seat and a connecting lug, the guide seat is arranged on the bottom plate, the top surface of the guide seat is a plane, the bottom surface of the nut is a plane and is in sliding fit with the top surface of the guide seat, the connecting lug is connected between the nut and a side plate of the bearing platform assembly, the front end and the rear end of the guide seat are provided with baffle plates, the lead screw is in threaded connection with the nut and is rotatably arranged between the two baffle plates, and the driving motor is arranged outside one baffle plate and is in transmission connection with the lead.

As a further scheme, the chip bearing platform is provided with a sinking platform for placing the microfluidic chip, the opening is arranged at the bottom of the sinking platform, the edge of the opening is provided with a supporting convex edge, the microfluidic chip and the supporting convex edge are respectively provided with three first positioning holes and three second positioning holes, and the three first positioning holes and the three second positioning holes correspond to each other and are distributed in a triangular shape.

As a further scheme, a directional protrusion is arranged in the sinking platform, a directional groove is arranged on the microfluidic chip corresponding to the directional protrusion, the directional groove and the directional protrusion are in positioning insertion fit, and a first positioning hole is arranged on the microfluidic chip corresponding to the chip positioning column.

The utility model has the advantages as follows:

(1) according to the chip movable positioning liquid injection structure of the PCR instrument, the microfluidic chip, the fixed seat and the nozzle head of the push platform assembly are positioned by positioning the microfluidic chip and the chip positioning column, the push platform assembly is pressed down to be in sealing fit with the nozzle hole of the microfluidic chip, and separable pressurized liquid injection is realized;

(2) the chip movable positioning liquid injection structure of the PCR instrument is provided with a chip bearing platform which moves up and down, a microfluidic chip is placed on the chip bearing platform, and when the microfluidic chip is pressed down by a pushing platform assembly, the microfluidic chip and the chip bearing platform act together to descend and are in positioning fit with a chip positioning column;

(3) the chip bearing platform of the chip movable positioning liquid injection structure of the PCR instrument can also move back and forth, and the microfluidic chip can be conveniently placed by moving the chip bearing platform out of the fixed seat.

The liquid injection pushing platform structure of the PCR instrument is fixed on the mounting platform through the luer connector piece pipe fitting, the mounting platform is pushed to move up and down through the driving device, when the microfluidic chip is placed below the pushing platform assembly, the mounting platform is pushed to move down, the nozzle head of the luer connector can be communicated with the liquid injection port (or the gas inlet/liquid outlet) of the microfluidic chip, and the operation is convenient.

(1) According to the chip positioning liquid injection structure of the PCR instrument, the microfluidic chip and the chip positioning column are positioned, so that the positioning of the microfluidic chip, the fixed seat and the nozzle of the push table assembly is realized, the push table assembly is pressed down to be in sealing fit with the nozzle hole of the microfluidic chip, and separable pressurized liquid injection is realized;

(2) the chip positioning liquid injection structure of the PCR instrument is provided with a chip bearing platform which moves up and down, a microfluidic chip is placed on the chip bearing platform, and when the microfluidic chip is pressed down by a pushing platform assembly, the microfluidic chip and the chip bearing platform act together to descend and are in positioning fit with a chip positioning column;

(3) the chip bearing platform of the chip positioning liquid injection structure of the PCR instrument can also move back and forth, and the microfluidic chip can be conveniently placed by moving the chip bearing platform out of the fixed seat.

(1) The cushion cap assembly of the chip movable positioning liquid injection structure of the PCR instrument is driven by the cushion cap driving mechanism to move out of the side of the heating module, so that the micro-fluidic chip can be placed conveniently, and the cushion cap assembly and the micro-fluidic chip can be conveyed to the upper part of the heating module through the cushion cap driving mechanism after the micro-fluidic chip is placed, so that the micro-fluidic chip waits for cyclic heating operation.

(2) The chip bearing platform of the chip movable positioning liquid injection structure of the PCR instrument can move up and down, when the micro-fluidic chip is placed on the chip bearing platform and is positioned right above the heating module, the micro-fluidic chip is pressed downwards, the micro-fluidic chip and the chip bearing platform act together to descend, the micro-fluidic chip can be contacted with the heating module, after the heating is completed (including other operations are completed), the external pressure applying force is removed, the micro-fluidic chip bounces along with the chip bearing platform under the action of the elastic piece, at the moment, the bearing platform driving mechanism drives the bearing platform assembly and the micro-fluidic chip to move out of the side of the heating module, so that the micro-fluidic chip can be taken away conveniently.

Drawings

Fig. 1 is an exploded schematic view of an embodiment of the present invention.

Fig. 2 is a schematic view of the exploded structure of the middle bearing platform assembly of the present invention.

Fig. 3 is another angle structure diagram of fig. 2.

Fig. 4 is a schematic view of the structure of the assembly relationship between the extension state of the platform assembly and the microfluidic chip.

Fig. 5 is a schematic structural view of the pushing platform assembly of the present invention.

Fig. 6 is a schematic view of an exploded structure of the pushing platform assembly of the present invention.

Fig. 7 is another angle structure diagram of fig. 6.

Fig. 8 is a schematic top view of the structure of fig. 7.

FIG. 9 is a schematic sectional view A-A of FIG. 8.

Fig. 10 is an enlarged schematic view of B in fig. 9.

Fig. 11 is a schematic view of the exploded structure of a microfluidic chip used in conjunction with the present invention.

Fig. 12 is a schematic view of the structure of the platform assembly in the retracted state according to the present invention.

Fig. 13 is a schematic top view of the structure of fig. 12.

FIG. 14 is a schematic cross-sectional view of the structure of FIG. 13C-C.

Fig. 15 is an enlarged schematic diagram of the structure at G in the bitmap 14.

Fig. 16 is a schematic sectional view of fig. 13 taken along line D-D.

Fig. 17 is an enlarged schematic view of H in fig. 16.

FIG. 18 is a schematic cross-sectional view of E-E of FIG. 13.

Fig. 19 is a schematic sectional view of fig. 13 showing the structure of F-F.

Detailed Description

The present invention will be further described with reference to the accompanying drawings and examples.

Referring to fig. 1, a chip movable positioning liquid injection structure of a PCR instrument comprises a bottom plate 40, a fixed seat 6, a bearing platform assembly 30, a linear guide rail 8 and a bearing platform driving mechanism 9, wherein the bearing platform assembly 30 is connected with the bottom plate 40 through the linear guide rail 8, the bearing platform driving mechanism 9 is arranged on the bottom plate 40 and is in transmission connection with the bearing platform assembly 30, the bearing platform assembly 30 comprises a chip bearing platform 7, an elastic part is arranged between the chip bearing platform 7 and the linear guide rail 8, an opening 73 is arranged on the chip bearing platform 7, a microfluidic chip 5 is placed above the opening 73, and a push platform assembly 10 which moves up and down is also arranged above the opening 73; the pushing table assembly 10 comprises a mounting table 4 and a driving device for pushing the mounting table 4, wherein a nozzle 143 is arranged on the bottom surface of the mounting table 4, and the nozzle 143 is communicated with the pipe body 2; the fixing seat 6 is arranged on the bottom plate 40, the heating module 20 is arranged below the fixing seat 6 corresponding to the opening 73, more than two chip positioning columns 63 are further arranged on the fixing seat 6, and the chip bearing platform 7 is provided with second positioning holes 72 corresponding to the chip positioning columns 63.

Four Ruhr connectors 1 are distributed on the mounting table 4 in a rectangular mode, each Ruhr connector 1 is connected with the pipe body 2, the lower end of each Ruhr connector 1 extends out of the bottom surface of the mounting table 4, the nozzle 143 is arranged at the lower end of each Ruhr connector 1, a through hole is formed in the nozzle 143, and the through hole is communicated with the pipe body 2.

The luer connector 1 comprises a male connector 11, a female connector 14 and a soft sleeve 13, wherein the center of the male connector 11 is provided with a plug tube hole 111 penetrating through two ends of the male connector, the female connector 14 is provided with a stepped hole 141, the stepped hole 141 is communicated with a through hole 146 of a nozzle 143, a soft sleeve limiting step 144 and a tube limiting step 145 which are distributed up and down are arranged in the stepped hole 141, and the tube limiting step 145 is positioned above the through hole 146; the soft sleeve 13 is arranged on the soft sleeve limiting step 144, and the tube body 2 penetrates through the insertion tube hole 111 and the soft sleeve 13 and then is inserted into the tube limiting step 145; the mounting table 4 is provided with a connector mounting hole 41 corresponding to the female connector 14, the female connector 14 is inserted into the connector mounting hole 41 and is fixedly connected with the mounting table 4, the lower end of the male connector 11 is inserted into the stepped hole 141 and is in threaded connection with the stepped hole 141, and the soft sleeve 13 is tightly pressed between the lower end of the male connector 11 and the soft sleeve limiting step 144.

The joint mounting hole 41 penetrates through the upper end and the lower end of the mounting table 4, the outer end of the female joint 14 is also provided with a cushion surface 142, the outer diameter of the cushion surface 142 is larger than that of the female joint 14, and the nozzle 143 protrudes out of the bottom surface of the cushion surface 142; the upper end of the female terminal 14 is inserted into the terminal mounting hole 41 from below to above and protrudes onto the top surface of the mounting table 4, and the upper end of the female terminal 14 is connected to the lock nut 12.

The periphery of the upper end of the male connector 11 is provided with anti-skid grains 112.

Four Ruhr joints 1 are distributed on the mounting table 4 in a rectangular mode, and each Ruhr joint 1 is connected with a pipe body 2.

The driving device comprises a cylinder 3, and the outer end of a piston rod 31 of the cylinder 3 is in transmission connection with the mounting table 4.

The outer end of the piston rod 31 is connected with a flange 32, and the flange 32 is connected with the top surface of the mounting table 4.

The bearing platform assembly 30 further comprises an elastic supporting device, the elastic supporting device comprises a supporting rod 77, the elastic part and a fixing groove 79, the supporting rod 77 is connected to the bottom of the chip bearing platform 7, and first limiting flanges 771 are arranged on two sides of the bottom of the supporting rod 77; fixed slot 79 is connected with linear guide 8, the fixed slot 79 top surface is equipped with fluting 791, the opening inboard of fluting 791 is equipped with the spacing turn-ups 793 of second, 77 lower parts of the support rod insert in the fluting 791, and with fluting 791 about sliding fit, first spacing turn-ups 771 keeps off with the spacing turn-ups 793 of second mutually, the elastic component is equipped with a plurality ofly, and along 77 length direction straight line distributions of support rod, the elastic component sets up between the bottom surface of support rod 77 and the fluting 791 bottom surface of fixed slot 79.

The inner wall of the second limiting flange 793 of the fixing groove 79 is provided with an antifriction convex rib 792.

The elastic supporting devices are provided with a left set and a right set, and one elastic supporting device of each set is arranged at the bottom of the chip bearing platform 7 from left to right; the elastic member is a spring 78, a positioning cavity 772 is formed at the bottom of the support rod 77 corresponding to the spring 78, and the upper end of the spring 78 is inserted into the positioning cavity 772.

The bearing platform assembly 30 further comprises a side plate 75 and a panel 74, wherein the outer side of the fixing groove 79 is connected with the side plate 75, and the front end of the fixing groove 79 is connected with the panel 74; the top end of the side plate 75 is provided with an inward flange 751, the left and right sides of the chip platform 7 are provided with outward flanges 76, and the top surfaces of the outward flanges 76 are blocked with the bottom surfaces of the inward flanges 751.

The cap assembly 30 further includes an end cap 710 disposed at a rear end of the fixing groove 79.

The linear guide rail 8 comprises a fixed block 81, a guide roller 82 and a slide rail 83, the fixed block 81 is fixedly connected with the bottom plate 40, the guide roller 82 is horizontally arranged on the fixed block 81 in a rotating mode, an annular groove 821 is arranged on the periphery of the guide roller 82, a guide groove is formed in the bottom of the slide rail 83, a guide convex rib 831 matched with the annular groove 821 is arranged on the inner wall of the guide groove, and the slide rail 83 is connected with the fixed groove 79.

The bearing platform driving mechanism 9 is a screw rod driving mechanism, the screw rod driving mechanism comprises a driving motor 91, a nut 92, a screw rod 93, a guide seat 94 and a connecting lug 95, the guide seat 94 is arranged on the bottom plate 40, the top surface of the guide seat 94 is a plane, the bottom surface of the nut 92 is a plane and is in sliding fit with the top surface of the guide seat 94, the connecting lug 95 is connected between the nut 92 and the side plate 75 of the bearing platform assembly 30, baffle plates are arranged at the front end and the rear end of the guide seat 94, the screw rod 93 is in threaded connection with the nut 92 and is rotatably arranged between the two baffle plates, and the driving motor 91 is arranged outside one baffle plate and is in transmission connection with the screw rod 93.

The chip bearing table 7 is provided with a sinking table for placing the microfluidic chip 5, the opening 73 is arranged at the bottom of the sinking table, the edge of the opening 73 is provided with a supporting convex edge 71, the microfluidic chip 5 and the supporting convex edge 71 are respectively provided with three first positioning holes 53 and three second positioning holes 72, and the three first positioning holes 53 and the three second positioning holes 72 correspond to each other and are distributed in a triangular shape. An orientation protrusion 731 is arranged in the sinking platform, an orientation groove 54 is arranged on the micro-fluidic chip 5 corresponding to the orientation protrusion 731, and the orientation groove 54 is in positioning, inserting and matching with the orientation protrusion 731.

A fixing seat 6 is arranged on the bottom plate 40 below the chip bearing platform 7, the heating module 20 is arranged on the fixing seat 6, three chip positioning columns 63 are arranged on the fixing seat 6, and the three chip positioning columns 63 are in inserting fit with the first positioning holes 53 and the second positioning holes 72. The top end of the chip positioning column 63 is provided with a conical head 631 with a narrow top and a wide bottom. The surface of the conical head is provided with an inclined plane which has a certain guiding function.

The micro-fluidic chip 5 is provided with two liquid injection ports, one gas inlet and one liquid outlet, wherein the liquid injection ports, the gas inlet and the liquid outlet (56 marked in the reference figure 11) are sleeved with silica gel cups 51, the silica gel cups 51 are provided with nozzle holes 52, and the silica gel cups 51 are connected into a whole through silica gel gaskets 511.

The working principle is as follows: the bearing platform assembly 30 extends forwards, the orientation groove 54 of the microfluidic chip 5 is aligned with the orientation protrusion 731 of the chip bearing platform 7 and then placed into the sinking platform of the chip bearing platform 7, the bearing platform assembly 30 moves backwards to a position between the fixed seat 6 and the push platform assembly 10 under the control of the lead screw transmission mechanism, and the second positioning hole 72 of the chip bearing platform 7 is opposite to the center of the chip positioning column 63 of the fixed seat 6. When the mounting table 4 of the push table assembly 10 moves downwards, the microfluidic chip 5 and the chip bearing table 7 are pushed to move downwards at the same time, when the second positioning hole 72 of the chip bearing table 7 and the positioning hole 53 of the microfluidic chip 5 are in contact with the conical head 631 of the chip positioning column 63, the conical head 631 guides the second positioning hole 72, the positioning hole 53 and the chip positioning column 63 to be concentric, so that the bearing table assembly 30, the microfluidic chip 5, the push table assembly 10 and the heating module 20 are positioned completely, the nozzle 143 of the luer 1 of the push table assembly 10 is ensured to be inserted into the nozzle hole 52 of the microfluidic chip 5, the pad surface 142 of the luer 1 is in sealing fit with the silicone rubber cup 51 of the microfluidic chip 5, and operations such as liquid injection and gas supply can be performed at the moment without leakage.

Claims

1. The utility model provides a chip activity location of PCR appearance annotates liquid structure, includes bottom plate (40), fixing base (6), cushion cap subassembly (30), linear guide (8) and cushion cap actuating mechanism (9), cushion cap subassembly (30) are connected with bottom plate (40) through linear guide (8), cushion cap actuating mechanism (9) set up on bottom plate (40) and with cushion cap subassembly (30) transmission connection, its characterized in that: the bearing platform assembly (30) comprises a chip bearing platform (7), an elastic piece is arranged between the chip bearing platform (7) and the linear guide rail (8), an opening (73) is formed in the chip bearing platform (7), the microfluidic chip (5) is placed above the opening (73), and a pushing platform assembly (10) which moves up and down is further arranged above the opening (73); the pushing table assembly (10) comprises an installation table (4) and a driving device for pushing the installation table (4), a nozzle head (143) is arranged on the bottom surface of the installation table (4), and the nozzle head (143) is communicated with the pipe body (2); the fixing seat (6) is arranged on the bottom plate (40), the heating module (20) is arranged below the fixing seat (6) corresponding to the opening (73), more than two chip positioning columns (63) are further arranged on the fixing seat (6), and second positioning holes (72) are formed in the chip bearing platform (7) corresponding to the chip positioning columns (63).

2. The chip movable positioning liquid injection structure of the PCR instrument according to claim 1, wherein: four Ruhr joints (1) are distributed on the mounting table (4) in a rectangular mode, each Ruhr joint (1) is connected with the pipe body (2), the lower end of each Ruhr joint (1) extends out of the bottom surface of the mounting table (4), the lower end of each Ruhr joint (1) is provided with the nozzle head (143), the nozzle head (143) is provided with a through hole, and the through holes are communicated with the pipe body (2).

3. The chip movable positioning liquid injection structure of the PCR instrument according to claim 2, wherein: the luer connector (1) comprises a male connector (11), a female connector (14) and a soft sleeve (13), wherein the center of the male connector (11) is provided with a tube inserting hole (111) penetrating through two ends of the male connector, the female connector (14) is provided with a stepped hole (141), the stepped hole (141) is communicated with a through hole (146) of a nozzle head (143), soft sleeve limiting steps (144) and tube limiting steps (145) which are distributed up and down are arranged in the stepped hole (141), and the tube limiting steps (145) are positioned above the through hole (146); the soft sleeve (13) is arranged on the soft sleeve limiting step (144), and the pipe body (2) penetrates through the pipe inserting hole (111) and the soft sleeve (13) and then is inserted into the pipe limiting step (145); the mounting table (4) is provided with joint mounting holes (41) corresponding to the female joint (14), the joint mounting holes (41) penetrate through the upper end and the lower end of the mounting table (4), the outer end of the female joint (14) is further provided with a cushion surface (142), the outer diameter of the cushion surface (142) is larger than that of the female joint (14), a nozzle head (143) protrudes out of the bottom surface of the cushion surface (142), the upper end of the female joint (14) is inserted into the joint mounting holes (41) from bottom to top and extends out of the top surface of the mounting table (4), the upper end of the female joint (14) is connected with a locking nut (92), the lower end of the male joint (11) is inserted into a stepped hole (141) and is in threaded connection with the stepped hole (141), and a soft sleeve (13) is tightly pressed between the lower end of the male joint (11) and a soft sleeve limiting.

4. The chip movable positioning liquid injection structure of the PCR instrument according to claim 1, wherein: the bearing platform assembly (30) further comprises an elastic supporting device, the elastic supporting device comprises a supporting rod (77), an elastic piece and a fixing groove (79), the supporting rod (77) is connected to the bottom of the chip bearing platform (7), and first limiting flanges (771) are arranged on two sides of the bottom of the supporting rod (77); fixed slot (79) are connected with linear guide (8), fixed slot (79) top surface is equipped with fluting (791), the opening inboard of fluting (791) is equipped with the spacing turn-ups of second (793), bracing piece (77) lower part is inserted in fluting (791), first spacing turn-ups (771) keeps off mutually with the spacing turn-ups of second (793), the elastic component is equipped with a plurality ofly, and along bracing piece (77) length direction straight line distribution, the elastic component sets up between the bottom surface of bracing piece (77) and fluting (791) bottom surface of fixed slot (79).

5. The chip movable positioning liquid injection structure of the PCR instrument according to claim 4, wherein: the elastic supporting devices are provided with a left set and a right set, and one elastic supporting device of each set is arranged at the bottom of the chip bearing platform (7) from left to right; the elastic component is spring (78), and bracing piece (77) bottom is equipped with location chamber (772) corresponding to spring (78), and the upper end of spring (78) inserts in location chamber (772).

6. The chip movable positioning liquid injection structure of the PCR instrument according to claim 4, wherein: the bearing platform assembly (30) further comprises a side plate (75) and a panel (74), the outer side of the fixing groove (79) is connected with the side plate (75), and the front end of the fixing groove (79) is connected with the panel (74); the top end of the side plate (75) is provided with an inner flanging (751), the left side and the right side of the chip bearing platform (7) are provided with outer flanging (76), and the top surface of the outer flanging (76) is blocked with the bottom surface of the inner flanging (751).

7. The chip movable positioning liquid injection structure of the PCR instrument according to claim 4, wherein: linear guide (8) are including fixed block (81), guide roller (82) and slide rail (83), fixed block (81) and bottom plate (40) fixed connection, and guide roller (82) level is rotated and is set up on fixed block (81), and guide roller (82) periphery is equipped with annular groove (821), and the bottom of slide rail (83) is equipped with the guide way, and the inner wall of guide way is equipped with protruding muscle (831) of direction with annular groove (821) complex, slide rail (83) with fixed slot (79) are connected.

8. The chip movable positioning liquid injection structure of the PCR instrument according to claim 1, wherein: cushion cap actuating mechanism (9) are cylinder drive mechanism or lead screw drive mechanism, lead screw drive mechanism includes driving motor (91), nut (92), lead screw (93), guide holder (94) and engaging lug (95), guide holder (94) set up on bottom plate (40), the top surface of guide holder (94) is the plane, the bottom surface of nut (92) is the plane, and with the top surface sliding fit of guide holder (94), engaging lug (95) are connected between curb plate (75) of nut (92) and cushion cap subassembly (30), both ends are equipped with the baffle around guide holder (94), lead screw (93) and nut (92) threaded connection, and rotate and set up between two baffles, driving motor (91) set up outside a baffle, and be connected with lead screw (93) transmission.

9. The chip movable positioning liquid injection structure of the PCR instrument according to claim 1, wherein: the chip bearing platform (7) is provided with a sinking platform for placing the microfluidic chip (5), the opening (73) is arranged at the bottom of the sinking platform, the edge of the opening (73) is provided with a supporting convex edge (71), the microfluidic chip (5) and the supporting convex edge (71) are respectively provided with three first positioning holes (53) and three second positioning holes (72), and the three first positioning holes (53) and the three second positioning holes (72) correspond to each other and are in triangular distribution.

10. The chip movable positioning liquid injection structure of the PCR instrument according to claim 9, wherein: the micro-fluidic chip is characterized in that a directional protrusion (731) is arranged in the sinking platform, a directional groove (54) is arranged on the micro-fluidic chip (5) corresponding to the directional protrusion (731), the directional groove (54) is in positioning, inserting and matching with the directional protrusion (731), and a first positioning hole (53) is further arranged on the micro-fluidic chip (5) corresponding to the chip positioning column (63).