Multi-channel injection pump

Abstract

The utility model discloses a multi-channel injection pump which aims at overcoming the defect that an existing injection pump is single in function. The liquid pumping and injecting device comprises a flow path switching module, a control module and a liquid pumping and injecting module, the flow path switching module comprises a valve body and a switching diaphragm, the control module comprises a controller and a flow detection structure, and the liquid pumping and injecting module comprises a piston driven by a lead screw sliding block pair; the valve body is provided with a main flow channel and a plurality of liquid changing holes, the switching diaphragm can rotate relative to the valve body, the main flow channel is provided with a main flow channel opening in the center of the valve body, the distances between the liquid changing holes and the main flow channel opening are the same, the liquid changing holes are formed at equal intervals, and the switching diaphragm is provided with a flow channel groove. The runner groove is communicated with the liquid changing hole and the main runner opening; the piston is communicated with the other main runner opening of the main runner; the multi-channel liquid changing hole is matched with the automatic switching liquid changing hole, and the piston is controlled to realize high-precision automation and multi-channel, high-frequency and high-precision liquid transfer.

Description

TECHNICAL FIELD

[0001] The utility model relates to a liquid injection pump, more specifically, it relates to a multi-channel injection pump. BACKGROUND

[0002] As a kind of precision liquid conveying equipment, injection pump is widely used in medical, laboratory and industrial field, especially in high-precision liquid delivery, drug injection and chemical reagent delivery etc.

[0003] The existing injection pump adopts piston to transfer liquid. Some injection pumps adopt the way of built-in liquid storage container to supply liquid, and quantitatively discharge liquid through liquid outlet, and some through single opening for liquid in and out. For the scene needing to accurately inject liquid into several containers and multiple positioning, the above-mentioned liquid injection pump is difficult to meet the needs. A more intelligent multi-channel injection pump is urgently needed.

[0004] Chinese patent CN210343631U, named as a precision screw liquid injection pump, discloses a precision screw liquid injection pump, which comprises a liquid injection pump body, a motor mounting groove, a motor, a piston sleeve, a piston, a screw hole, a screw, a joint bearing, a liquid storage chamber, a liquid storage tank, a liquid guide pipe, a liquid outlet, a plunger, a mounting plate, a connecting bolt and a slot switch, a motor mounting groove is formed on the inner wall of one side of the liquid injection pump body, a motor is fixedly installed in the interior of the motor mounting groove, a piston sleeve is embeddedly installed on the inner wall of the liquid injection pump body on the side of the motor, and a piston is sleeved and fixed in the interior of the piston sleeve.

[0005] The injection pump represented by the above liquid injection pump cannot perform multi-channel liquid injection. UTILITY MODEL CONTENTS

[0006] The utility model overcomes the deficiency of the existing liquid injection pump, provides a multi-channel injection pump, can supply liquid to multiple containers with high precision, and meets the scene of injecting liquid into multiple containers with high frequency.

[0007] In order to solve the above technical problems, the utility model adopts the following technical scheme:

[0008] A multi-channel injection pump, comprising a flow path switching module, a control module and a liquid pumping and injecting module, the flow path switching module comprises a valve body and a switching diaphragm, the control module comprises a controller and a flow detection structure, and the liquid pumping and injecting module comprises a piston driven by a screw block pair;

[0009] The valve body is provided with a main flow channel and a plurality of liquid changing holes, the switching diaphragm can rotate relative to the valve body, the main flow channel is provided with a main flow channel opening at the center of the valve body, the distance from the liquid changing holes to the main flow channel opening is the same, and the liquid changing holes are arranged at equal intervals, the switching diaphragm is provided with a flow channel groove, when the switching diaphragm is attached to the valve body and the flow channel groove is attached to a liquid changing hole, the flow channel groove communicates the liquid changing hole and the main flow channel opening.

[0010] The piston is in communication with another main flow channel opening of the main flow channel;

[0011] The flow detection structure comprises a fixed part and a movable part, the movable part moves away from or approaches the fixed part along with the movement of the piston rod, and the flow detection structure generates a position signal according to the position of the movable part and judges the liquid volume of the piston.

[0012] The injection pump generates negative pressure through the suction of the piston, sucks the liquid into the piston, then generates positive pressure through the reset of the piston, and then pumps out the liquid. The piston port of the piston is connected to the valve body, the liquid outlet of the valve body is used to connect to the external container, and the valve body switches the liquid exchange hole connected to the main flow channel through the switching diaphragm, so as to realize the function of switching the container connected to the piston.

[0013] The switching diaphragm blocks the inner end face of the valve body, each liquid exchange hole on the valve body is a through hole penetrating through the two end faces, and the switching diaphragm blocks the liquid exchange hole on the valve body, thereby cutting off the communication between the liquid exchange hole and the inside. Because of the flow channel groove on the switching diaphragm, when the flow channel groove rotates to communicate with a liquid exchange hole, the liquid exchange hole communicates with the main flow channel opening. The main flow channel opening communicates with the piston through the main flow channel, thereby realizing the communication between the liquid exchange hole and the piston. Therefore, by rotating the switching diaphragm, the effect of communicating different liquid exchange holes with the valve body is realized. In use, the liquid in the container corresponding to the first liquid exchange hole can be sucked in through the valve body communicating with the first liquid exchange hole. When the switching diaphragm is switched to the second liquid exchange hole, the valve body pumps out the liquid and sends it into the container corresponding to the second liquid exchange hole, thereby realizing the transfer of the liquid.

[0014] For multiple liquid exchange holes, the switching diaphragm can be rotated to switch to different liquid exchange holes, thereby realizing the liquid suction and supply of the containers corresponding to the multiple liquid exchange holes. In order to ensure the accuracy, the flow detection structure judges the liquid volume in the piston according to the displacement of the piston.

[0015] As preferred, the flow path switching module further comprises a flow path switching motor and a rotary bracket, the output shaft of the flow path switching motor is in transmission connection with the rotary bracket and drives the rotary bracket to rotate, the side wall of the rotary bracket is provided with a protrusion, and the side wall of the switching diaphragm is provided with a groove, and the protrusion is embedded in the groove. The switching of the switching diaphragm is realized by the cooperation of the flow path switching motor and the rotary bracket, and the switching diaphragm rotates along with the rotation of the output shaft of the flow path switching motor by the embedding of the protrusion on the rotary bracket and the groove of the switching diaphragm.

[0016] As preferred, the rotary bracket further comprises a locking screw, a top rod, a disc spring and a gasket, the locking screw is threadedly connected with the rotary bracket, the gasket and the switching diaphragm are attached, the disc spring is abutted between the top rod and the gasket, the locking screw is abutted with the top rod, and the locking screw adjusts the protruding amount through the threaded connection with the rotary bracket to adjust the pressure applied by the gasket to the switching diaphragm. The structure is used to ensure the attachment of the switching diaphragm to the valve body to avoid liquid leakage. The locking screw adjusts the protruding amount through the threaded connection, and a certain pre-tightening force between the gasket and the valve body is ensured by pressing the disc spring.

[0017] As preferred, the flow path switching module further comprises an angle control structure, the angle control structure comprises an encoder optical disc coaxially connected with an output shaft of the flow path switching motor and a signal receiver matched with the encoder optical disc, the signal receiver generates a phase angle signal according to the rotation angle of the encoder optical disc, and the signal receiver is communicatively connected with the controller. The current phase angle of the switching diaphragm is determined by the encoder.

[0018] As preferred, the piston comprises a piston cylinder, a piston body, a piston rod and a heating structure, the heating structure is arranged offset to the piston cylinder, the heating structure comprises a self-temperature-controlled heating sheet surrounding the piston cylinder, the heating structure is communicatively connected with the controller, and the controller is provided with a temperature sensor. The self-temperature-controlled heating sheet is used to heat the liquid, and the contraction of the piston body made of PTFE (polytetrafluoroethylene) material at low temperature may cause the sealing performance to be reduced, and the contraction of the piston body is avoided by heating.

[0019] As preferred, the screw rod and nut pair comprises a screw rod and a screw rod nut, the screw rod nut is fixedly connected with a locking pin, the screw rod is drivingly connected with a screw rod motor, the screw rod motor drives the screw rod to rotate, and the locking pin is fixedly connected with the piston rod. The structure realizes the driving of the piston by the screw rod and nut pair.

[0020] As preferred, the screw rod is inserted into the upper bearing block and the lower bearing block, the screw rod is rotatably connected with the upper bearing block and the lower bearing block, and the controller is installed on the upper bearing block and the lower bearing block through the support shaft.

[0021] As preferred, the flow detection structure is a capacitive grating position sensor, the movable part is a movable grating, the fixed part is a fixed grating, and the capacitive grating position sensor is communicatively connected with the controller. The capacitive grating position sensor has better stability and detection accuracy, reduces errors caused by optical coupling failure or insufficient accuracy, and ensures the long-term stability and reliability of the injection pump.

[0022] Compared with the prior art, the utility model has the advantages that:

[0023] (1) the liquid changing hole with multiple channels is arranged, the automatic switching liquid changing hole is matched, and the piston is controlled to realize high-precision automation, so that the liquid transfer with multiple channels, high frequency and high precision is realized;

[0024] (2) The position control precision and anti-interference ability are improved through the capacitive grating position sensor;

[0025] (3) Through temperature compensation, the problem of syringe piston shrinkage deformation caused by temperature fluctuation in low temperature environment is effectively reduced, the liquid delivery precision is maintained, and the stability of the syringe pump is improved. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is a schematic view of the utility model;

[0027] Figure 2 is a schematic view of the utility model from another angle;

[0028] Figure 3 is a side view of the utility model;

[0029] Figure 4 is Figure 3 is a sectional view at A-A of the utility model;

[0030] Figure 5 is an exploded view of the utility model;

[0031] Figure 6 is a schematic view of the valve body;

[0032] Figure 7 is a schematic view of the valve body from another angle;

[0033] Figure 8 is a schematic view of the rotary bracket and the switching diaphragm;

[0034] Figure 9 is a schematic view of the valve body and the self-control temperature heating sheet;

[0035] In the figure:

[0036] Flow path switching module 1, control module 2, draw and inject liquid module 3, valve body 4, switching diaphragm 5, main flow channel 6, liquid replacement hole 7, main flow channel opening 8, flow channel groove 9, flow path switching motor 10, rotary bracket 11, protruding block 12, recess 13, set screw 14, top rod 15, disc spring 16, gasket 17, encoder optical disc 18, signal receiver 19, piston assembly 20, self-control temperature heating sheet 21, lead screw 22, lead screw nut 23, lead screw motor 24, upper bearing block 25, lower bearing block 26, movable grid 27, fixed grid 28, lock pin 29, controller 30. DETAILED DESCRIPTION

[0037] The present disclosure will be further described below in conjunction with the drawings and examples.

[0038] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs.

[0039] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0040] In the present disclosure, terms such as "upper", "lower", "left", "right", "front", "rear", "vertical", "horizontal", "side", "bottom", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only relative terms determined for the convenience of describing the structural relationship of each component or element of the present disclosure and do not specifically refer to any component or element of the present disclosure, and should not be construed as a limitation to the present disclosure.

[0041] In the present disclosure, terms such as "fixed connection", "connected", "connected to" should be understood in a broad sense, which may mean a fixed connection, an integral connection or a detachable connection; it may be directly connected or indirectly connected through an intermediate medium. For those related scientific research or technical personnel in the field, the specific meaning of the above terms in the present disclosure can be determined according to specific circumstances and should not be construed as a limitation to the present disclosure.

[0042] Embodiment:

[0043] A multi-channel injection pump, as shown in the figure, includes a flow path switching module 1, a control module 2, and a liquid pumping and injecting module 3. Figure 1 As shown in the figure, the flow path switching module 1 is composed of a valve body 4, a switching diaphragm, a driving mechanism, and a sealing component.

[0044] As shown in the figure, Figures 2 to 4 The flow path switching module 1 is composed of a valve body 4, a switching diaphragm, a driving mechanism, and a sealing component. As shown in the figure, Figure 6 and Figure 7 As shown in the figure and, in some embodiments, the valve body 4 is frustum-shaped. The center of the bottom surface of the valve body 4 is provided with a main flow port 8, and a plurality of liquid changing holes 7 are equidistantly distributed on the periphery. The distance from each hole to the main flow port 8 is equal. Each liquid changing hole 7 penetrates along the height direction of the frustum, and the main flow path 6 is arranged along the radial direction of the frustum. One of the main flow ports 8 turns to the side wall to form another main flow port 8, and the other end is formed on the side wall of the frustum. The switching diaphragm is provided with a flow path groove 9, and the flow path groove 9 is an oblong hole and passes through the center of the switching diaphragm. The switching diaphragm and the bottom surface of the valve body 4 are coaxially arranged and their end faces are in contact.

[0045] As shown in the figure,Figure 4 and Figure 5 As shown, the diaphragm switching is achieved through the flow path switching motor 10. (See reference...) Figure 8 As shown, the flow path switching motor 10 is driven by a rotating bracket 11. The output shaft of the flow path switching motor 10 is connected to a coupling, and the other end of the coupling is connected to the rotating bracket 11, so that the rotating bracket 11 rotates synchronously with the output shaft. The rotating bracket 11 is a rotating body that is larger at the top and smaller at the bottom, and a through hole is provided at its axis. The through hole is also larger at the top and smaller at the bottom. In some embodiments, the wall thickness of the rotating bracket 11 is the same everywhere. The side wall of the rotating bracket 11 has a protrusion 12 extending in the axial direction. The protrusion 12 engages with the groove 13 on the side wall of the switching diaphragm to achieve synchronous rotation. When the flow channel groove 9 is aligned with a specific liquid exchange hole 7, the main flow channel opening 8 is connected to that hole, while other liquid exchange holes 7 are blocked, and the connection is cut off. The angle control of the switching diaphragm is achieved by a combination of an encoder disc 18 and a signal receiver 19. The encoder disc 18 is coaxially set and fixedly connected to the output circle of the drive motor. The encoder disc 18 rotates through the slot of the signal receiver 19 to monitor the rotation phase angle in real time. The signal receiver 19, the flow path switching motor 10, and the controller 30 are electrically connected.

[0046] The sealing system includes a pre-tightening mechanism consisting of a set screw 14, a push rod 15, a disc spring 16, and a gasket 17. The lower sidewall of the through hole in the rotary bracket 11 is threaded, and the thread connects to the set screw 14. By adjusting the screw-in depth of the set screw 14, its vertical position within the through hole can be adjusted. The set screw 14 is fitted with the push rod 15, which is slidably connected within the rotary bracket 11. The push rod 15 abuts against the gasket 17 via the disc spring 16, and the gasket 17 is in contact with the switching diaphragm. The push rod 15 compresses the disc spring 16, generating elastic pressure that causes the gasket 17 to exert a controllable clamping force on the switching diaphragm, ensuring a tight seal with the valve body 4 end face. The gasket 17 firstly ensures the switching diaphragm abuts against the rotary bracket 11, preventing leakage, and secondly, it provides a liquid seal to the switching diaphragm, preventing liquid from flowing out of the flow channel 9.

[0047] The injection module 3 includes a piston assembly 20 and a drive mechanism. The piston assembly 20 includes a cylindrical (uniform cross-section) piston cylinder, a PTFE piston body, and a piston rod. The inlet of the piston assembly 20 communicates with the main flow channel 8 on the side wall of the valve body 4. The drive mechanism is a lead screw motor 24, whose output shaft is a lead screw 22. A lead screw 22 slider is mounted on the lead screw 22, forming a lead screw 22 slider pair. (See reference...) Figure 9As shown, the piston 20 is equipped with a self-regulating heating sheet 21 arranged on the outer periphery of the cylinder, which is controlled in a closed loop by a temperature sensor to maintain the piston 20 body at an appropriate temperature range to prevent liquid leakage caused by cold shrinkage of the piston 20 body. The screw rod slider pair is driven by a screw rod motor 24. The screw rod 22 is rotatably connected to the upper bearing block 25 and the lower bearing block 26 at the upper and lower ends thereof. The screw rod motor 24 drives the screw rod nut 23 to move up and down through the screw rod 22, and the screw rod nut 23 is fixedly connected to the locking pin 29 through fasteners to realize the linear motion of the piston 20 rod. The self-regulating heating sheet 21 and the screw rod motor 24 are electrically connected to the controller 30. The self-regulating heating sheet 21 is attached to the outer wall of the piston 20 cylinder.

[0048] The control module 2 uses a capacitive grating position sensor for flow detection, which includes a movable grating 27 and a fixed grating 28. The movable grating 27 is fixedly connected to the piston 20 rod and the locking pin 29 and moves with the piston 20 rod to form a displacement signal with the fixed grating 28, and the liquid volume is accurately measured through the controller 30. The controller 30 integrates temperature sensing function, coordinates the angle control of the flow path switching motor 10 and the linkage operation of the piston 20 driving system.

[0049] The valve body 4, the screw rod motor 24, the flow path switching motor 10, the upper bearing block 25 and the lower bearing block 26 are all mounted on a support plate, and the PCB board on which the movable grating 27 and the controller 30 are installed is mounted through the upper bearing block 25 and the lower bearing block 26. The PCB board is electrically connected and communicates with the screw rod motor 24, the flow path switching motor 10 and the self-regulating heating sheet 21 in a wired manner.

[0050] System working principle:

[0051] Through the butt joint of the flow channel groove 9 and the different liquid exchange holes 7, multi-channel liquid path switching is realized. When the piston 20 is pumping, negative pressure is formed to suck liquid in the selected channel, and when pressurized, the liquid is output through the switched channel. Displacement detection and temperature compensation work together to ensure the infusion accuracy under different working conditions. The encoder positioning and capacitive grating sensor data linkage form a closed loop control system.

[0052] The above-described embodiments are only preferred schemes of the present application and do not limit the present application in any form. Other variants and modifications can be made without exceeding the technical solutions recited in the claims.

Claims

1. A multi-channel syringe pump, characterized in that, It includes a flow path switching module, a control module, and a liquid injection module. The flow path switching module includes a valve body and a switching diaphragm. The control module includes a controller and a flow detection structure. The liquid injection module includes a piston driven by a lead screw and slider pair. The valve body is provided with a main channel and several fluid exchange holes. The switching diaphragm can rotate relative to the valve body. The main channel has a main channel opening at the center of the valve body. The distance from the fluid exchange holes to the main channel opening is the same and each fluid exchange hole is equally spaced. The switching diaphragm is provided with a flow channel groove. When the switching diaphragm is in contact with the valve body and the flow channel groove is in contact with a fluid exchange hole, the flow channel groove connects the fluid exchange hole and the main channel opening. The piston is connected to another main channel opening of the main channel; The flow detection structure includes a fixed part and a movable part. The movable part moves away from or closer to the fixed part as the piston rod moves. The flow detection structure generates a position signal based on the position of the movable part and determines the liquid volume of the piston.

2. A multi-channel syringe pump according to claim 1, characterized in that, The flow path switching module also includes a flow path switching motor and a rotary bracket. The output shaft of the flow path switching motor is connected to the rotary bracket and drives the rotary bracket to rotate. The side wall of the rotary bracket is provided with protrusions, and the side wall of the switching diaphragm is provided with grooves. The protrusions and grooves are fitted together.

3. A multi-channel syringe pump according to claim 2, characterized in that, The rotary bracket also includes a set screw, a push rod, a disc spring, and a washer. The set screw is threadedly connected to the rotary bracket, the washer and the switching diaphragm are in contact, the disc spring abuts between the push rod and the washer, and the set screw abuts against the push rod. The set screw adjusts the extension amount through its threaded connection with the rotary bracket to adjust the pressure applied by the washer to the switching diaphragm.

4. A multi-channel syringe pump according to claim 2, characterized in that, The flow path switching module also includes an angle control structure, which includes an encoder disc coaxially connected to the output shaft of the flow path switching motor and a signal receiver that works with the encoder disc. The signal receiver generates a phase angle signal based on the rotation angle of the encoder disc and communicates with the controller.

5. A multi-channel syringe pump according to claim 1, characterized in that, The piston includes a piston cylinder, a piston body, a piston rod, and a heating structure. The heating structure is offset from the piston cylinder. The heating structure includes a self-temperature-controlled heating element surrounding the piston cylinder. The heating structure is communicatively connected to a controller, and the controller is equipped with a temperature sensor.

6. A multi-channel syringe pump according to claim 1, characterized in that, The lead screw and slider assembly includes a lead screw and a lead screw nut. The lead screw nut is fixedly connected to a locking pin. The lead screw is driven by a lead screw motor, which drives the lead screw to rotate. The locking pin is fixedly connected to a piston rod.

7. A multi-channel syringe pump according to claim 6, characterized in that, The lead screw is inserted into the upper bearing block and the lower bearing block, and the lead screw is rotatably connected to the upper bearing block and the lower bearing block. The controller is mounted on the upper bearing block and the lower bearing block via a support shaft.

8. A multi-channel syringe pump according to claim 1, characterized in that, The flow detection structure is a capacitive grating position sensor, in which the moving part is the moving grating and the fixed part is the fixed grating. The capacitive grating position sensor is communicatively connected to the controller.

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