Ultrahigh-precision injection pump

Abstract

The utility model provides an ultrahigh-precision injection pump, and belongs to the technical field of injection pumps. The ultrahigh-precision injection pump comprises a pump frame, a sliding block, a motor, a lead screw, a magnetic railing ruler, a circuit board and a magnetic induction chip, the sliding block is arranged on the pump frame in a sliding mode, the motor and the circuit board are both fixed to the pump frame, and one end of the lead screw and an output shaft of the motor are fixed together. Due to the advantage that the absolute positions of the magnetic railing ruler and the magnetic induction chip can be calculated, compared with the design of a traditional rotary encoder, the influence of abrasion of a lead screw and installation errors is avoided, and as time goes on, even if the lead screw is abraded, the pipetting precision is not influenced; compared with a traditional rotary encoder mechanism, the design can greatly improve the pipetting precision and ensure that high-precision operation can still be kept after long-time use, the magnetic railing ruler design can also simplify the assembly steps during production of a traditional rotary encoder, and the production efficiency is improved.

Description

Technical Field

[0001] The present application relates to the technical field of injection pumps, and in particular to an ultra-high precision injection pump. Background Art

[0002] Conventional injection pumps calculate the number of steps by performing relative step calculations using a rotary encoder. The motor pulses and encoder step count form a small closed-loop system. If the grid count and motor pulses are out of sync, it is identified as a lost step and a signal is fed back to the host computer.

[0003] Disadvantages 1. The design principle of the grid code disk is to determine the position of the motor rotation by the light signal of the photoelectric sensor cut by the grid on the code disk. However, when the motor rotation step is very small or the cut grid just stops at the edge of the grid, cumulative errors will occur, thus affecting the pipetting accuracy of the syringe pump.

[0004] Disadvantage 2. The stepper motors used in the syringe pump rotate through pulse signal output. In closed-loop control, the cutting photoelectric signal must have a corresponding conversion relationship with the pulse signal of the control motor. When a decimal that cannot be divided evenly appears in the conversion, the system will default to rounding it up or down to an integer for calculation. The theoretical value will directly affect the pipetting accuracy of the syringe pump.

[0005] Disadvantage 3. Since the code disk is exposed to the outside, when dust or other foreign matter affects the gap of the code disk grid, or partially blocks the photoelectric probe, it will inevitably cause signal interference and affect the operation of the entire feedback loop. Utility Model Content

[0006] In order to make up for the above deficiencies, the present application provides an ultra-high precision syringe pump, which aims to improve the cumulative error caused by a small rotation step of the motor or the cutting grid just stops at the edge of the grid, thereby affecting the pipetting accuracy of the syringe pump. When a decimal that cannot be divided evenly appears in the conversion, the system will default to rounding it up or down to an integer for calculation. The theoretical value will directly affect the pipetting accuracy of the syringe pump. Since the code disk is exposed to the outside, when dust or other foreign matter affects the gap in the code disk grid, or partially blocks the photoelectric probe, it will inevitably cause signal interference, affecting the operation of the entire feedback loop.

[0007] This application is implemented as follows:

[0008] The present application provides an ultra-high precision injection pump, comprising a pump frame, a slider, a motor, a screw, a magnetic scale, a circuit board and a magnetic sensing chip, wherein the slider is slidably arranged on the pump frame, and the motor and the circuit board are both fixed on the pump frame;

[0009] One end of the lead screw is fixed to the output shaft of the motor, the lead screw thread passes through the slider, the magnetic scale is fixed on the slider, the magnetic sensing chip is fixed on the circuit board, the magnetic sensing chip and the circuit board are welded together, and the magnetic scale and the magnetic sensing chip interact with each other in a set area to output position information.

[0010] In one embodiment of the present application, the magnetic scale and the magnetic sensing chip are fitted together at a fixed distance, and the magnetic sensing chip is horizontally arranged on the circuit board.

[0011] In one embodiment of the present application, a threaded hole is provided on the sliding block, and the screw thread passes through the threaded hole.

[0012] In one embodiment of the present application, a through hole is provided on the sliding block, and the pump frame passes through the through hole.

[0013] In one embodiment of the present application, a side plate is further included, wherein the side plate is fixed to the outer wall of the pump frame, and the side plate and the circuit board are arranged correspondingly.

[0014] The beneficial effect of the present application is as follows: the present application obtains an ultra-high precision syringe pump through the above-mentioned design. When in use, the motor works, the rotation of the motor output shaft drives the screw to rotate, and the slider moves under the action of the limit of the pump frame and the screw. The movement of the slider realizes the movement of the magnetic scale. Even if the relative position of the magnetic scale and the magnetic sensing chip changes, the magnetic sensing chip attached to the magnetic scale during movement will confirm the number of steps moved by the change of the magnetic pole. Since the magnetic scale and the slider are directly connected without other transmission mechanisms, the ultra-high progress syringe pump can ensure that there are no other factors affecting the movement accuracy of the screw during transmission. Due to the advantage that the absolute position of the magnetic scale and the magnetic sensing chip can be calculated, compared with the traditional rotary encoder design, it will not be affected by the wear and installation error of the screw. Even if the screw is worn over time, it will not affect the pipetting accuracy. In addition, compared with the traditional rotary encoder mechanism, this design can greatly improve the pipetting accuracy and ensure that high-precision operation can be maintained after long-term use. The magnetic scale design can also simplify the assembly steps during the production of traditional rotary encoders and improve production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] 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.

[0016] Figure 1It is a schematic diagram of the three-dimensional structure of an ultra-high precision injection pump provided in an embodiment of the present application;

[0017] Figure 2 A diagram showing the relationship between a slider, a magnetic sensing chip and a circuit board provided in an embodiment of the present application;

[0018] Figure 3 A schematic diagram of the three-dimensional structure of a slider provided in an embodiment of the present application;

[0019] Figure 4 A diagram showing the relationship between the pump support, motor and screw provided in an embodiment of the present application.

[0020] In the figure: 110 - pump frame; 120 - slider; 130 - motor; 140 - lead screw; 150 - magnetic scale; 160 - circuit board; 170 - magnetic induction chip; 180 - threaded hole; 190 - through hole; 191 - side panel. DETAILED DESCRIPTION

[0021] 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.

[0022] Example

[0023] See also Figure 1 - Figure 4 The present application provides a technical solution: an ultra-high precision injection pump, comprising a pump frame 110, a slider 120, a motor 130, a screw 140, a magnetic scale 150, a circuit board 160 and a magnetic sensing chip 170, wherein the slider 120 is slidably arranged on the pump frame 110, a through hole 190 is opened on the slider 120, and the pump frame 110 passes through the through hole 190, and the arrangement of the through hole 190 exposes a part of the slider 120 outside the pump frame 110, and the motor 130 and the circuit board 160 are both fixed on the pump frame 110;

[0024] One end of the screw rod 140 is fixed to the output shaft of the motor 130, the screw rod 140 is threaded through the slider 120, the slider 120 is provided with a threaded hole 180, the screw rod 140 is threaded through the threaded hole 180, the threaded hole 180 is arranged to facilitate the screw rod 140 to thread through the slider 120, the magnetic scale 150 is fixed on the slider 120, and the magnetic induction chip 170 is fixed on the circuit board 160;

[0025] The magnetic sensing chip 170 and the circuit board 160 are welded together, the magnetic scale 150 and the magnetic sensing chip 170 interact with each other in a set area to output position information, the magnetic scale 150 and the magnetic sensing chip 170 are fitted at a fixed distance, and the magnetic sensing chip 170 is horizontally arranged on the circuit board 160, so the position and distance will be consistent when mutually sensing with the magnetic scale 150. It also includes a side panel 191, which is fixed on the outer wall of the pump frame 110. The side panel 191 and the circuit board 160 are arranged correspondingly, and the setting of the side panel 191 is used to protect the circuit board 160.

[0026] Specifically, the working principle of the ultra-high precision injection pump is as follows: when in use, the motor 130 works, the rotation of the output shaft of the motor 130 drives the screw 140 to rotate, the slider 120 moves under the action of the limit of the pump frame 110 and the screw 140, and the movement of the slider 120 realizes the movement of the magnetic scale 150. Even if the relative position of the magnetic scale 150 and the magnetic sensing chip 170 changes, the magnetic sensing chip 170 attached to the magnetic scale 150 during movement will confirm the number of steps moved by the change of the magnetic pole. Since the magnetic scale 150 and the slider 120 are directly connected, the ultra-high precision injection pump has no other transmission mechanism. It can ensure that no other factors affect the moving accuracy of the lead screw 140 during transmission. Due to the advantage of being able to calculate the absolute position of the magnetic scale 150 and the magnetic sensing chip 170, compared with the traditional rotary encoder design, it will not be affected by the wear and installation error of the lead screw 140. Even if the lead screw 140 is worn over time, it will not affect the pipetting accuracy. In addition, compared with the traditional rotary encoder mechanism, this design can greatly improve the pipetting accuracy and ensure that it can maintain high-precision operation after long-term use. The magnetic scale 150 design can also simplify the assembly steps of the traditional rotary encoder production and improve production efficiency.

[0027] It should be noted that the specific models and specifications of the motor 130, magnetic scale 150, circuit board 160 and magnetic sensing chip 170 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 this field, so it will not be described in detail.

[0028] The power supply and principles of the motor 130 , the magnetic scale 150 , the circuit board 160 and the magnetic sensing chip 170 are clear to those skilled in the art and will not be described in detail herein.

[0029] 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. An ultra-high precision syringe pump, characterized in that: The invention comprises a pump frame (110), a slider (120), a motor (130), a screw rod (140), a magnetic scale (150), a circuit board (160) and a magnetic sensing chip (170), wherein the slider (120) is slidably arranged on the pump frame (110), and the motor (130) and the circuit board (160) are both fixed on the pump frame (110); One end of the lead screw (140) is fixed to the output shaft of the motor (130), the lead screw (140) is threadedly passed through the slider (120), the magnetic scale (150) is fixed on the slider (120), the magnetic sensing chip (170) is fixed on the circuit board (160), the magnetic sensing chip (170) and the circuit board (160) are welded together, and the magnetic scale (150) and the magnetic sensing chip (170) interact with each other in a set area to output position information.

2. An ultra-high precision injection pump according to claim 1, characterized in that: The magnetic scale (150) and the magnetic sensing chip (170) are fitted together at a fixed distance, and the magnetic sensing chip (170) is arranged horizontally on the circuit board (160).

3. An ultra-high precision injection pump according to claim 1, characterized in that: The slider (120) is provided with a threaded hole (180), and the screw rod (140) is threadedly passed through the threaded hole (180).

4. The ultra-high precision injection pump according to claim 1, characterized in that: The sliding block (120) is provided with a through hole (190), and the pump frame (110) passes through the through hole (190).

5. The ultra-high precision injection pump according to claim 1, characterized in that: It also includes a side plate (191), wherein the side plate (191) is fixed on the outer wall of the pump frame (110), and the side plate (191) and the circuit board (160) are arranged correspondingly.

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