Pipette

Abstract

The utility model provides a pipette, and belongs to the technical field of experimental apparatuses. The pipette comprises a frame, an empty cylinder, a motor, a piston, a circuit board, a pressure sensor, a nylon block and a jacking piece, the empty cylinder, the motor and the circuit board are all fixed to the frame, and when the pipette is used, due to the fact that a first small gear is meshed with a large gear, and a second small gear is meshed with a long-strip-shaped toothed rail, movement of the piston is achieved; the first small gear, the large gear, the second small gear and the long-strip-shaped rack rail gear structure are relatively uniform in stress, deformation cannot be generated, the pipetting precision and the service life of the pipetting gun are not affected, and compared with a traditional screw transmission mechanism, the pipetting gun can improve the pipetting precision and prolong the service life of the pipetting gun. The design of the suspension type circuit board can simplify the assembling steps in the production process of a traditional pneumatic gun, improve the production efficiency, reduce the cost of purchasing various parts, reduce the stocking cost, and improve the precision and the service life compared with a traditional injector.

Description

Technical Field

[0001] The present application relates to the technical field of experimental equipment, and in particular to a pipette. Background Art

[0002] The existing pneumatic pipettes are mainly driven by a motor with a screw rod. There are two ways to realize the liquid level detection function. One is to realize it through the pressure difference change of the pressure sensor, and the pressure sensor must be accurately fixed to the air guide hole. The other is to determine the liquid level by interpolating the capacitance sensor monitoring probe and the ground capacitance.

[0003] Disadvantages 1. The structure of the motor driving the lead screw cannot achieve good accuracy, which mainly depends on the control of the motor step angle by the driver. If the processing accuracy of the lead screw fluctuates, it will directly affect the pipetting accuracy. After a long period of stress and wear, the accuracy and life of the lead screw will be greatly reduced.

[0004] Disadvantage 2. The traditional pressure sensor needs to be fixed through a hose or other flexible structure and air holes. The fixing method is complicated and prone to errors, which has a great impact on the error rate of liquid level judgment. Capacitive liquid level detection has higher requirements on the environment. If there are conductive parts such as metal around the probe, it will directly affect the liquid level detection. In addition, capacitive page detection cannot distinguish special situations such as bubbles and clots.

[0005] Disadvantage 3. General pressure sensors only detect the difference to determine the liquid level. There are two types of liquid level detection: active liquid level detection, which can be achieved by traditional methods, and passive liquid level detection, which is difficult to achieve. Utility Model Content

[0006] In order to make up for the above shortcomings, the present application provides a pipette gun, which aims to improve the structure of the motor driving the screw rod. The accuracy cannot be well achieved, which mainly depends on the control of the motor step angle by the driver. If the processing accuracy of the screw rod fluctuates, it will directly affect the pipetting accuracy. After a long period of stress and wear, the accuracy and life of the screw rod will be greatly reduced. The traditional pressure sensor fixing method needs to be fixed by a hose or other flexible structure and air hole. The fixing method is complicated and prone to errors, which has a great impact on the error rate of liquid level judgment. Capacitive liquid level detection has relatively high requirements for the environment. If there are conductive parts such as metal around the probe, it will directly affect the liquid level detection, and capacitive page detection has no way to distinguish special situations such as bubbles and clots. Generally, the pressure sensor only detects the difference to detect and judge the liquid level. There are two situations for liquid level detection. One is active liquid level detection, which can be achieved by traditional methods, but it is difficult to achieve if it is passive liquid level detection.

[0007] This application is implemented as follows:

[0008] The present application provides a pipette gun, comprising a frame, an empty barrel, a motor, a piston, a circuit board, a pressure sensor, a nylon block and a tightening member, wherein the empty barrel, the motor and the circuit board are all fixed on the frame, the piston is inserted in the empty barrel, and the pressure sensor is fixed on the circuit board;

[0009] The pressure sensor is fixedly mounted on the nylon block, the nylon block is inserted into the frame, the tightening piece thread passes through the frame, the tightening piece and the nylon block are arranged correspondingly, the output shaft of the motor and the piston are connected together through a gear transmission part, and the circuit board part is designed as a suspended structure.

[0010] In one embodiment of the present application, a side cover is further included, and the side cover is fixed on the frame.

[0011] In one embodiment of the present application, the gear transmission member includes a first pinion, a large gear, a second pinion and an elongated rack, the first pinion is fixed to the output shaft of the motor, the large gear is rotatably arranged on the frame, and the second pinion is fixed to the large gear;

[0012] The long strip rack is slidably arranged on the frame, the piston and the long strip rack are fixed together, the first pinion is meshed with the large gear, and the second pinion is meshed with the long strip rack.

[0013] In one embodiment of the present application, a special-shaped hole is opened on the circuit board, and the pressure sensor is fixed on the suspended part of the circuit board.

[0014] In one embodiment of the present application, a mounting groove is provided on the frame, and the nylon block is inserted into the mounting groove.

[0015] In one embodiment of the present application, a threaded hole is provided on the frame, and the tightening member threadably passes through the threaded hole.

[0016] The beneficial effects of the present application are as follows: the present application obtains a liquid transfer gun through the above-mentioned design. When in use, since the pressure sensor is installed on the suspension structure of the circuit board, the pressure sensor can change its position up, down, left, and right relative to the circuit board body. The pressure sensor is adjusted to the most suitable position and perfectly fits the air hole. The nylon block is inserted into the frame, the pressure sensor is held, and the top tightening piece is rotated. One end of the top tightening piece is fixed in the frame by squeezing the nylon block. The fixing method of the pressure sensor is simple and fast. When liquid transfer is required, the motor works, and the output shaft of the motor drives the first pinion to rotate. Since the first pinion is meshed with the large gear, and the second pinion is meshed with the long rack, the movement of the piston is realized. The first pinion, the large gear, the second pinion and the long rack gear structure are subjected to relatively uniform force, and no deformation will occur to affect the pipetting accuracy and the life of the pipette. Compared with the traditional screw transmission mechanism, the pipette can improve its pipetting accuracy and service life. The design of the suspended circuit board can simplify the assembly steps of the traditional pneumatic gun production, improve production efficiency, and reduce the cost of purchasing multiple components and inventory costs. Compared with the traditional syringe, the accuracy and life are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the implementation methods of the present application, the drawings required for use in the implementation methods will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 It is a schematic diagram of the three-dimensional structure of a pipette provided in an embodiment of the present application;

[0019] Figure 2 A diagram showing the relationship between the frame, gear transmission, pressure sensor and nylon block provided for the embodiment of the present application;

[0020] Figure 3 A schematic diagram of the three-dimensional structure of a gear transmission member provided in an embodiment of the present application;

[0021] Figure 4 A diagram showing the relationship between the long rack rail, the piston and the empty cylinder provided in the embodiment of the present application;

[0022] Figure 5 A schematic diagram of the three-dimensional structure of the framework provided in the implementation manner of the present application.

[0023] In the figure: 110 - side cover; 120 - frame; 130 - empty cylinder; 140 - motor; 150 - gear transmission member; 151 - first small gear; 152 - large gear; 153 - second small gear; 154 - long rack; 160 - piston; 170 - circuit board; 180 - special-shaped hole; 190 - pressure sensor; 191 - nylon block; 192 - tightening member; 193 - mounting groove; 194 - threaded hole. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solutions and advantages of the implementation methods of this application clearer, the technical solutions in the implementation methods of this application will be clearly and completely described below in conjunction with the drawings in the implementation methods of this application. Obviously, the described implementation methods are part of the implementation methods of this application, not all of the implementation methods. Based on the implementation methods in this application, all other implementation methods obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0025] Example

[0026] See also Figure 1 - Figure 5 The present application provides a technical solution: a pipette gun, comprising a frame 120, an empty cylinder 130, a motor 140, a piston 160, a circuit board 170, a pressure sensor 190, a nylon block 191 and a tightening member 192, wherein the empty cylinder 130, the motor 140 and the circuit board 170 are all fixed on the frame 120, and further comprising a side cover 110, wherein the side cover 110 is fixed on the frame 120, and the side cover 110 is arranged to further protect the components in the frame 120, the piston 160 is inserted in the empty cylinder 130, and the pressure sensor 190 is fixed on the circuit board 170;

[0027] The pressure sensor 190 is fixedly mounted on the nylon block 191. The pressure sensor 190 has two air holes, one of which is connected to the air hole of the frame 120, and the other is connected to the atmosphere. The differential signal can be used to determine both positive pressure jumps and negative pressure jumps. This design can achieve accurate liquid level detection at different altitudes. The nylon block 191 is inserted into the frame 120. The frame 120 is provided with a mounting groove 193. The nylon block 191 is inserted into the mounting groove 193. The setting of the mounting groove 193 is convenient for The nylon block 191 is assembled into the frame 120, the pressing piece 192 is threadedly penetrated through the frame 120, a threaded hole 194 is provided on the frame 120, and the pressing piece 192 is threadedly penetrated through the threaded hole 194. The setting of the pressing piece 192 is convenient for tightening and fixing the nylon block 191 in the frame 120. The pressing piece 192 in this embodiment is a bolt, and the pressing piece 192 and the nylon block 191 are correspondingly arranged. The output shaft of the motor 140 and the piston 160 are connected together through the gear transmission member 150.

[0028] The gear transmission member 150 includes a first pinion 151, a large gear 152, a second pinion 153 and a strip rack 154. The first pinion 151 is fixed to the output shaft of the motor 140, the large gear 152 is rotatably arranged on the frame 120, the second pinion 153 is fixed to the large gear 152, the strip rack 154 is slidably arranged on the frame 120, the piston 160 and the strip rack 154 are fixed together, the first pinion 151 is meshed with the large gear 152, the second pinion 153 is meshed with the strip rack The rail 154 is meshed, and the first pinion 151, the large gear 152, the second pinion 153 and the long strip rack 154 cooperate with each other to multiply the torque and accuracy of the motor 140. The gear structure is relatively evenly stressed and will not deform to affect the pipetting accuracy and the life of the pipette gun. The circuit board 170 is partially designed as a suspended structure, and a special-shaped hole 180 is opened on the circuit board 170. The pressure sensor 190 is fixed on the suspended part of the circuit board 170. The setting of the special-shaped hole 180 makes part of the circuit board 170 suspended.

[0029] Specifically, the working principle of the pipette gun is as follows: when in use, since the pressure sensor 190 is installed on the suspension structure of the circuit board 170, the pressure sensor 190 can change its position up, down, left, and right relative to the main body of the circuit board 170. The pressure sensor 190 is adjusted to the most suitable position and perfectly fits the air hole, and the nylon block 191 is inserted into the frame 120. The pressure sensor 190 is held, and the top tightening member 192 is rotated. One end of the top tightening member 192 is fixed in the frame 120 by squeezing the nylon block 191. The fixing method of the pressure sensor 190 is simple and fast. When pipetting is required, the motor 140 works, and the output shaft of the motor 140 drives the first pinion 151 Rotation, as the first pinion 151 and the large gear 152 are meshed, and the second pinion 153 and the long rack 154 are meshed, the movement of the piston 160 is realized, and the gear structure of the first pinion 151, the large gear 152, the second pinion 153 and the long rack 154 is relatively evenly stressed, and will not cause deformation to affect the pipetting accuracy and the life of the pipette. Compared with the traditional screw transmission mechanism, the pipette can improve its pipetting accuracy and service life. The design of the suspended circuit board 170 can simplify the assembly steps of traditional pneumatic guns, improve production efficiency, and reduce the cost of purchasing multiple components, reduce inventory costs, and improve accuracy and life compared to traditional syringes.

[0030] It should be noted that the specific models and specifications of the motor 140, circuit board 170 and pressure sensor 190 need to be selected and determined according to the actual specifications of the device, and the specific selection calculation method adopts the existing technology in the field, so it will not be described in detail.

[0031] The power supply and principles of the motor 140 , the circuit board 170 , and the pressure sensor 190 are clear to those skilled in the art and will not be described in detail herein.

[0032] The above description is only an embodiment of the present application and is not intended to limit the scope of protection of the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present application. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

Claims

1. A pipette, characterized in that: The invention comprises a frame (120), an empty cylinder (130), a motor (140), a piston (160), a circuit board (170), a pressure sensor (190), a nylon block (191) and a tightening member (192); the empty cylinder (130), the motor (140) and the circuit board (170) are all fixed on the frame (120); the piston (160) is inserted into the empty cylinder (130); and the pressure sensor (190) is fixed on the circuit board (170); The pressure sensor (190) is fixedly mounted on the nylon block (191), the nylon block (191) is inserted into the frame (120), the pressing member (192) is threadedly inserted through the frame (120), the pressing member (192) and the nylon block (191) are arranged correspondingly, the output shaft of the motor (140) and the piston (160) are connected together by a gear transmission member (150), and the circuit board (170) is partially designed as a suspended structure.

2. A pipette according to claim 1, characterized in that: It also includes a side cover (110), wherein the side cover (110) is fixed on the frame (120).

3. A pipette according to claim 1, characterized in that: The gear transmission member (150) comprises a first pinion (151), a large gear (152), a second pinion (153) and an elongated rack (154); the first pinion (151) is fixed on the output shaft of the motor (140); the large gear (152) is rotatably disposed on the frame (120); and the second pinion (153) is fixed on the large gear (152); The long strip rack (154) is slidably arranged on the frame (120), the piston (160) and the long strip rack (154) are fixed together, the first small gear (151) and the large gear (152) are meshed, and the second small gear (153) and the long strip rack (154) are meshed.

4. A pipette according to claim 1, characterized in that: The circuit board (170) is provided with a special-shaped hole (180), and the pressure sensor (190) is fixed on the suspended part of the circuit board (170).

5. A pipette according to claim 1, characterized in that: The frame (120) is provided with a mounting groove (193), and the nylon block (191) is inserted into the mounting groove (193).

6. A liquid transfer gun according to claim 1, characterized in that: The frame (120) is provided with a threaded hole (194), and the pressing member (192) is threadedly passed through the threaded hole (194).

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