A dual-channel vertical extrusion peristaltic pump

Abstract

The present invention relates to the technical field of peristaltic pumps, and discloses a dual-channel vertical extrusion peristaltic pump, which includes a pump head. There are two rubber tube guide grooves provided on the pump head, and rubber tubes are installed in the guide grooves; a second extrusion block limiting groove is provided in the middle of the pump head, a first switch block limiting groove is provided at the lower part, a third switch block limiting groove is provided at the upper part, and four full-thread through holes are provided at the four corners; a first switch block, a second extrusion block and a third switch block are provided below the rubber tube. The first switch block, the second extrusion block and the third switch block are connected to three trapezoidal thread drive heads through trapezoidal drive threads, and the three trapezoidal thread drive heads are respectively connected to a first brushless motor, a second brushless motor and a third brushless motor. The present invention can effectively extend the trouble-free service life of the equipment, improve the consistency of the two-channel flow rate, the miniaturization of the equipment and the accuracy of the customized flow rate.

Description

Technical Field

[0001] The invention relates to the technical field of peristaltic pumps, in particular to a dual-path vertical extrusion peristaltic pump. Background Art

[0002] Peristaltic pump is a commonly used fluid conveying device, mainly used for the delivery of various liquids. Compared with traditional centrifugal pumps, peristaltic pumps are widely used in various fields such as flow metering and delivery, small flow liquid delivery, and sampling and dosing of analytical instruments and equipment. They have better flow accuracy and flow stability in fluid delivery.

[0003] Common peristaltic pumps use a motor to drive the extrusion module to alternately squeeze the hose. The hose is elastically closed and opened to transport the liquid. The extrusion module is often a roller and the motor is often a stepper motor. The flow control of common peristaltic pumps generally uses the control of the stepper motor's rotation angle and speed, combined with a reasonable hose diameter to achieve precise control of the flow.

[0004] At present, the traditional technology includes a double-sided extrusion peristaltic pump with end-face inlet (its application number is: 201910671528.4; its publication number is: CN110388312A). The peristaltic pump consists of a fixed part, a rotating part and a plurality of balls, and the fixed part includes a chassis, a main body and a top cover. The peristaltic pump drives the balls to rotate by the rotation of the motor, and alternately squeezes the hose in turn to complete the liquid delivery. However, the peristaltic pump has a complex structure, a large number of rollers, and it is difficult to ensure the consistency of each roller during processing. The pump is expensive and not conducive to miniaturization.

[0005] In addition, a single-position extrusion peristaltic pump is also included (its application number is: 202020725794.9; its publication number is: CN212454762U). The peristaltic pump is composed of a fixed part and a rotating part, and the fixed part includes a chassis and a main body. The peristaltic pump drives the rotating part through the rotation of the motor, and uses the ball on the rotating part to squeeze the specially placed hose to realize the liquid delivery. The single-channel flow of the peristaltic pump is difficult to meet the requirements of multi-channel delivery.

[0006] The above-mentioned existing peristaltic pumps all use the method of alternately squeezing the hose by rollers to complete the liquid transportation. Even during the working interval of the existing peristaltic pumps, when they are not powered on, the hose is always tightly pressed by the rollers, and the hose can only rebound when the motor rotates. In this case, the service life of the hose will be greatly reduced. As the usage time of the hose extends, the elasticity of the hose decays, and the flow rate of the peristaltic pump will also decay accordingly, resulting in inaccurate flow rate or the need to frequently replace the hose to ensure the accuracy of the flow rate. At the same time, because all existing peristaltic pumps use the rolling extrusion method, the hose will be subjected to tangential tensile force, which is likely to cause changes in the wall thickness of the hose. As the usage time extends, the hose will be stretched by rolling extrusion, further affecting the stability and accuracy of the flow rate. In addition, most existing peristaltic pumps use stepper motors. There are also errors in the rotation angle and speed of the stepper motor, and there are problems such as loss of steps in the stepper motor, resulting in flow rate errors. When transporting liquids with equal volume repeatedly, there are relatively large flow rate errors each time. In the case of micro-flow transportation or high requirements for single-flow accuracy, the existing peristaltic pumps are difficult to meet the needs. At the same time, because the service life of the hose of the existing peristaltic pumps is short, it is necessary to frequently replace the hose to ensure the accuracy and stability of the transportation flow rate, which greatly increases the maintenance cost and shortens the fault-free cycle of equipment and instruments. Existing dual-channel peristaltic pumps have problems of unequal flow rates in each channel due to factors such as structural and manufacturing cumulative errors, and it is difficult to meet the requirements of application scenarios where equal flow rates in each channel are required. Summary of the Invention

[0007] To overcome the deficiencies of the above-mentioned existing technologies, the purpose of the present invention is to provide a peristaltic pump that transports liquids in a vertical up-and-down extrusion manner, which has a longer fault-free usage period, smaller flow rate errors between two channels, higher flow rate accuracy, and is more miniaturized.

[0008] To achieve the above purpose, the present invention proposes a dual-channel vertical extrusion peristaltic pump, including a pump head. Two rubber tube guide grooves are provided on the pump head (7), and rubber tubes (2) are installed in the guide grooves. A second extrusion block limiting groove is provided in the middle of the pump head (7), a first switch block limiting groove is provided at the lower part, a third switch block limiting groove is provided at the upper part, and four full-thread through holes are provided at the four corners. A first switch block (10), a second extrusion block (9), and a third switch block (11) are provided below the rubber tube (2). The first switch block (10), the second extrusion block (9), and the third switch block (11) are connected to three trapezoidal thread driving heads (12) through trapezoidal transmission threads, and the three trapezoidal thread driving heads (12) are respectively connected to a first brushless motor (3), a second brushless motor (4), and a third brushless motor (5).

[0009] Preferably, the first switch block (10), the second extrusion block (9), and the third switch block (11) are all provided with limiting bosses, and the height of the limiting bosses is equal to twice the wall thickness of the hose.

[0010] Preferably, the full-thread through hole connects the pump head (7) and the pump cover plate (8) through four second pan head screws (14), four spring washers (6), and four flat washers (15). The pump cover plate (8) is used for limiting and fixing the rubber tube (2), as well as the upper limit of the first switch block (10), the second extrusion block (9), and the third switch block (11).

[0011] Preferably, the rubber tube (2) is connected to four identical hose connectors (1). The two lower hose connectors (1) are liquid inlets, and the two upper hose connectors (1) are liquid outlets.

[0012] Preferably, each of the first brushless motor (3), the second brushless motor (4), and the third brushless motor (5) is connected to the pump head (7) through two first pan head screws (13) + two spring washers (6) + two flat washers (15).

[0013] Preferably, the first brushless motor (3), the second brushless motor (4), and the third brushless motor (5) all adopt brushless reduction motors with the same reduction ratio.

[0014] Preferably, a D-shaped hole is provided in the middle of the trapezoidal thread drive head (12), and D-shaped shafts are provided on the three brushless machines. The D-shaped shafts are inserted into the D-shaped holes.

[0015] Preferably, the pump head (7) is machined from 7075-T6 aluminum alloy profile, and its surface is treated with black anodizing. The aluminum alloy material is light and has high hardness.

[0016] Preferably, the pump cover plate (8) is made of high-transparency acrylic material, which is beautiful and convenient for observing the internal movement of the pump in real time.

[0017] Preferably, the rubber tube (2) is made of BPT material.

[0018] Compared with the prior art, the technical effects and advantages of a dual-channel vertical extrusion peristaltic pump of the present invention are as follows:

[0019] 1. The present invention uses a vertical up-and-down extrusion method to transport liquids. There is no tangential rotational tension on the pump hose, and problems such as elongation and deformation of the hose do not exist. Moreover, through the limit convex platform on the extrusion block, it is ensured that the hose is not over-extruded, and the wall thickness of the hose will not change even after long-term use, thus greatly extending the life of the hose. When the dual-channel vertical extrusion peristaltic pump is powered off or not working, because the extrusion block is at the lower limit, the hose is in a relaxed and uncompressed state. Compared with the existing peristaltic pump where the hose is always pressed tightly by the ball during intermittent operation, the life of the hose is greatly improved. For hoses of the same material, the trouble-free use period of the dual-channel vertical extrusion peristaltic pump is more than 10 times that of the existing peristaltic pump, greatly improving the trouble-free working period of the peristaltic pump.

[0020] 2. The present invention adopts a design of an extrusion block, which can ensure that the flow rates of the two paths are equal, with a flow rate error of ±1 μL for the two paths, and extremely high precision. At the same time, through the sufficient and excessive rotation time of the brushless motor, the strokes of the extrusion block and the switch block are excessive. Through the upper limit position of the pump cover plate and the lower limit position of the pump head limit groove, the consistency of each stroke of the extrusion block and the switch block can be ensured, thereby ensuring the consistency of the amount of each extrusion of the hose. Compared with the existing peristaltic pump that controls the flow rate by controlling the rotation angle of the motor, the dual-channel vertical extrusion peristaltic pump has no problems such as cumulative error, motor out-of-step, and angle error. The repeatability error of the flow rate delivered in each cycle is ≤±2 μL, with extremely high precision, and has advantages that the existing peristaltic pump cannot match in the fields of micro-flow delivery and the requirement of the accuracy of each liquid addition in analytical instrument equipment.

[0021] 3. The present invention adopts a decelerated brushless motor, and the motor life can reach more than tens of thousands of hours, with a high life of the peristaltic pump. Through trapezoidal thread transmission, the transmission is reliable, the structure is simple and practical, and the cost is low, which is convenient for processing and mass production. Moreover, the length, width, and depth of the dual-channel vertical extrusion peristaltic pump are only 76X50X80 mm, with an extremely small volume, which can meet the requirements of miniaturization of equipment.

[0022] 4. The single-time flow rate control of the present invention can customize the size of the flow rate delivered each time by customizing the width of the second extrusion block (the width of the extrusion block determines the length of the extrusion of the rubber tube), and can accurately customize the delivery flow rate, which can better meet the requirements of micro-flow rates under different working conditions than the existing peristaltic pump, and the customized flow rate accuracy is extremely high. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a structural exploded view of a dual-channel vertical extrusion peristaltic pump provided by the present invention;

[0024] Figure 2 is a plan view of a dual-channel vertical extrusion peristaltic pump provided by the present invention;

[0025] Figure 3 is a dual-channel vertical extrusion peristaltic pump provided by the present invention Figure 2 a cross-sectional view taken along line A-A therein;

[0026] Figure 4 is a dual-channel vertical extrusion peristaltic pump provided by the present invention Figure 2 a cross-sectional view taken along line B-B therein;

[0027] Figure 5 is a control flow chart of a dual-channel vertical extrusion peristaltic pump provided by the present invention.

[0028] The reference numerals are: 1 hose joint, 2 rubber tube, 3 first brushless motor, 4 second brushless motor, 5 third brushless motor, 6 spring washer, 7 pump head, 8 pump cover plate, 9 second extrusion block, 10 first extrusion block, 11 third switch block, 12 trapezoidal thread drive head, 13 first pan head screw, 14 second pan head screw, 15 flat washer. Detailed implementation manners

[0029] The following describes the implementation manners of the present invention through specific examples in combination with the accompanying drawings. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific examples, and various details in this specification can also be modified and changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0030] The present invention provides a dual-channel vertical extrusion type peristaltic pump. According to Figures 1-4 as shown, it includes a pump head 7. The pump head 7 is provided with two rubber tube guide grooves, and a rubber tube 2 is installed in the guide grooves; a second extrusion block limiting groove is provided in the middle of the pump head 7, a first switch block limiting groove is provided at the lower part, a third switch block limiting groove is provided at the upper part, and four full-thread through holes are provided at the four corners; a first switch block 10, a second extrusion block 9 and a third switch block 11 are provided below the rubber tube 2. The first switch block 10, the second extrusion block 9 and the third switch block 11 are connected to three trapezoidal thread drive heads 12 through trapezoidal drive threads. The three trapezoidal thread drive heads 12 are respectively connected to a first brushless motor 3, a second brushless motor 4 and a third brushless motor 5. Among them, the full-thread through hole has a specification of M3. The front is used to fix the pump cover plate 8, and the back is used to fixedly install the peristaltic pump as a whole.

[0031] Preferably, the first switch block 10, the second extrusion block 9 and the third switch block 11 are all provided with limiting bosses, and the height of the limiting bosses is equal to 2 times the wall thickness of the hose.

[0032] Preferably, the pump head 7 and the pump cover plate 8 are connected by four second pan head screws 14, four spring washers 6 and four flat washers 15. The pump cover plate 8 is used for limiting and fixing the rubber tube 2 and the upper limit of the first switch block 10, the second extrusion block 9 and the third switch block 11. Among them, the specification of the second pan head screw is M3×14mm, and the specification of the flat washer is M3.

[0033] Preferably, the rubber tube 2 is connected to four identical hose joints 1. The two lower hose joints 1 are liquid inlets, and the two upper hose joints 1 are liquid outlets.

[0034] Preferably, each of the first brushless motor 3, the second brushless motor 4, and the third brushless motor 5 is connected to the pump head 7 by two first pan head screws 13 + two spring washers 6 + two flat washers 15. The specification of the first pan head screw is M3×8mm, and the specification of the spring washer is M3.

[0035] Preferably, the first brushless motor 3, the second brushless motor 4, and the third brushless motor 5 all adopt brushless reduction motors with the same reduction ratio.

[0036] Preferably, a D-shaped hole is provided in the middle of the trapezoidal thread drive head 12, and D-shaped shafts are provided on the three brushless machines. The D-shaped shafts are inserted into the D-shaped holes.

[0037] Preferably, the pump head 7 is machined from 7075-T6 aluminum alloy profile, and its surface is treated with black anodizing. The aluminum alloy material is light and has high hardness.

[0038] Preferably, the pump cover 8 is made of high-transparency acrylic material, which is beautiful and convenient for real-time observation of the internal movement of the pump.

[0039] Preferably, the rubber tube 2 is made of BPT material.

[0040] The working process of the present invention is as follows:

[0041] A dual-channel vertical extrusion peristaltic pump of the present invention completes liquid delivery from bottom to top by alternately vertically moving up and down the second extrusion block 9, the first switch block 10, and the third switch block 11 to squeeze the rubber tube. The second extrusion block 9 is used for extrusion and transportation of the flow path, and the first switch block 10 and the third switch block 11 are used for control of the opening and closing of the flow path. The second extrusion block 9, the first switch block 10, and the third switch block 11 are driven to rotate forward and backward by three brushless motors, and then drive the trapezoidal thread drive head to rotate forward and backward through the D-shaped hole connection to complete the up and down movement. The trapezoidal thread drive head 12 is in trapezoidal thread drive with the second extrusion block 9, the first switch block 10, and the third switch block 11, and then the rotational movement is converted into a vertical up and down linear movement by the limit groove on the pump head.

[0042] The forward and reverse control lines of the first brushless motor 3, the second brushless motor 4, and the third brushless motor 5 control the forward and reverse rotation through high and low levels. By default, high level is for forward rotation and low level is for reverse rotation. When the brushless motor rotates forward, the second extrusion block 9, the first switch block 10, and the third switch block 11 move vertically upward; when the brushless motor rotates in reverse, the second extrusion block 9, the first switch block 10, and the third switch block 11 move vertically downward.

[0043] When the brushless motor rotates forward for a time period T, the extrusion block and the switch block move vertically upward and are in the high position, and the high position is limited by the upper limit on the pump cover plate 8; when the brushless motor rotates backward for a time period T, the extrusion block and the switch block move vertically downward and are in the low position, and the low position is limited by the limit groove on the pump head 7. The time period T of the rotation of the brushless motor is sufficient and excessive, which fully ensures that the vertical movement stroke of the extrusion block and the switch block can reach the high or low position each time. When the extrusion block and the switch block are in the high or low position, the brushless motor is stalled, the motor starts the stall protection and powers off, the rotation stops, and it powers on again and resumes rotation at the next start cycle.

[0044] The single - time flow control of this peristaltic pump can customize the flow rate of each delivery by customizing the width of the second extrusion block 9 (the width of the extrusion block determines the length of the extrusion of the rubber tube 2). Combining with the appropriate pipe diameter and wall thickness of the rubber tube 2, the flow rate of the liquid delivered each time can be accurately controlled.

[0045] As Figure 5 shown, the control flow of the present invention is as follows:

[0046] When the double - path vertical extrusion type peristaltic pump of the present invention is just powered on, it executes the initialization program and enters the initialization state; the initialization state is state 1. The peristaltic pump is in state 1 when it is powered off or not delivering liquid.

[0047] State 1 is the liquid suction state of the double - path vertical extrusion type peristaltic pump, that is, when the third switch block is in the high position, the rubber tube 2 here is pressed and in the closed state, the first switch block 10 is in the low position, the rubber tube 2 here is in the open state, and the second extrusion block 9 moves from the high position to the low position, and the rubber tube 2 here changes from the pressed state to the open state, and the liquid is sucked due to the elasticity of the rubber tube 2.

[0048] State 2 is the liquid discharge state of the double - path vertical extrusion type peristaltic pump, that is, when the first switch block is in the high position, the rubber tube 2 here is pressed and in the closed state, the third switch block 11 is in the low position, the rubber tube 2 here is in the open state, and the second extrusion block 9 moves from the low position to the high position, and the rubber tube 2 here changes from the open state to the pressed state, and the liquid is discharged due to the incompressibility of the liquid.

[0049] One complete infusion working cycle of the double - path vertical extrusion type peristaltic pump 1 is to execute state 2 and then state 1, that is, to discharge liquid first and then suck liquid, and so on in a cycle to complete the pulsed liquid delivery.

Claims

1. A dual-channel vertical extrusion peristaltic pump, comprising a pump head (7), characterized in that: Two rubber tube guiding grooves are provided on the pump head (7), and rubber tubes (2) are installed in the guiding grooves; a second extrusion block limiting groove is provided in the middle of the pump head (7), a first switch block limiting groove is provided at the lower part, a third switch block limiting groove is provided at the upper part, and four full-thread through holes are provided at the four corners; below the rubber tube (2), there are a first switch block (10), a second extrusion block (9) and a third switch block (11), and the first switch block (10), the second extrusion block (9), and the third switch block (11) are connected to three trapezoidal thread driving heads (12) through trapezoidal driving threads, and the three trapezoidal thread driving heads (12) are respectively connected to a first brushless motor (3), a second brushless motor (4), and a third brushless motor (5); The number of the second extrusion blocks (9) is one, and the number of the rubber tubes (2) is two; The first switch block (10), the second extrusion block (9), and the third switch block (11) all move vertically up and down; The first switch block (10), the second extrusion block (9), and the third switch block (11) are not inclined along the axial direction of the rubber tube (2); The first switch block (10), the second extrusion block (9), and the third switch block (11) are all provided with limiting bosses, and the height of the limiting bosses is equal to twice the wall thickness of the hose; The four full-thread through holes connect the pump head (7) and the pump cover plate (8) through four second pan head screws (14), four spring washers (6), and four flat washers (15); The pump cover plate (8) is used for limiting and fixing the rubber tube (2) and the upper limit of the first switch block (10), the second extrusion block (9), and the third switch block (11).

2. The dual-channel vertical extrusion peristaltic pump according to claim 1, characterized in that: The rubber tube (2) is connected to four identical hose connectors (1), and the two lower hose connectors (1) are liquid inlets, and the two upper hose connectors (1) are liquid outlets.

3. The dual-channel vertical extrusion peristaltic pump according to claim 1, wherein: For the first brushless motor (3), the second brushless motor (4), and the third brushless motor (5), each brushless motor is connected to the pump head (7) through two first pan head screws (13) + two spring washers (6) + two flat washers (15).

4. A dual-channel vertical extrusion peristaltic pump according to claim 1 or 3, characterized in that: The first brushless motor (3), the second brushless motor (4), and the third brushless motor (5) all adopt brushless reduction motors with the same reduction ratio.

5. A dual-channel vertical extrusion peristaltic pump according to claim 1, characterized in that: A D-shaped hole is provided in the middle of the trapezoidal thread driving head (12), and the three brushless motors are provided with D-shaped shafts, and the D-shaped shafts are inserted into the D-shaped holes.

6. The double-channel vertical extrusion peristaltic pump according to claim 1, wherein: The pump head (7) is machined from 7075-T6 aluminum alloy profile and its surface is treated with black anodization.

7. A dual-channel vertical extrusion peristaltic pump according to claim 1, characterized in that: The pump cover plate (8) is made of high-transparency acrylic material.

8. A dual-channel vertical extrusion peristaltic pump according to claim 1, characterized in that: The rubber tube (2) is made of BPT material.

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