Ceramic precision small-sized constant-displacement pump

Abstract

The present application relates to the technical field of liquid quantitative pumping, and discloses a ceramic precision small-sized quantitative pump, which comprises a plunger sleeve, a plunger and a quantitative pump fixing base, the plunger sleeve is installed at the lower half of the quantitative pump fixing base, the bottom of the plunger sleeve is provided with a through liquid inlet and a through liquid outlet, the plunger is arranged in the plunger sleeve, the bottom of the plunger is provided with a D-shaped end face, the opening of the port in the plane range of the D-shaped end face is opened, and the opening of the port in the cylindrical range is closed by rotating the plunger, the up-and-down movement of the plunger is fixed during rotation, the quantitative pumping and discharging of liquid are realized, the precise quantitative pumping is realized, and the demand of the instrument for continuous, stable and precise quantitative pumping is met.

Description

Technical Field

[0001] This invention relates to the field of liquid metering technology, and in particular to a ceramic precision miniature metering pump. Background Technology

[0002] Many automated instruments currently require continuous quantitative extraction and injection of a certain liquid, which often places high demands on accuracy and stability.

[0003] Currently, the most common pumps on the market that can achieve precise quantitative extraction and discharge of liquids include screw plunger pumps and electromagnetic metering pumps.

[0004] Screw-driven plunger pumps use a motor to rotate a screw, pushing the plunger to achieve extraction and discharge. However, they are typically large and expensive, require solenoid valves to assist in switching the liquid path, and their stability and accuracy are significantly affected by motor step loss. Electromagnetic metering pumps use an electromagnet to control the deformation of a rubber cup to achieve liquid extraction and discharge. Although they are small in size, they require manual adjustment of the metering volume, which is inconvenient. Furthermore, due to the use of rubber components, their accuracy and stability are significantly affected by temperature. To meet the instrument's requirements for continuous, stable, and accurate metering, this invention designs a ceramic precision miniature metering pump. Summary of the Invention

[0005] The purpose of this invention is to provide a ceramic precision miniature metering pump that can meet the instrument's requirements for continuous, stable, and accurate metering.

[0006] To achieve the above objectives, the present invention employs a ceramic precision miniature metering pump, comprising a plunger sleeve, a plunger, and a metering pump mounting base. The plunger sleeve is installed in the lower half of the metering pump mounting base. The bottom of the plunger sleeve has a through inlet and an outlet. The plunger is placed inside the plunger sleeve. The bottom of the plunger has a D-shaped end face. When the plunger is rotated, the outlet within the planar range of the D-shaped end face opens, and the outlet within the cylindrical range closes. While the plunger rotates, it performs a fixed up-and-down movement to achieve metered extraction and discharge of liquid.

[0007] The ceramic precision miniature metering pump also includes a sealing ring, which is disposed on the upper end face of the plunger sleeve.

[0008] The ceramic precision miniature metering pump further includes a bushing, a horizontal shaft, and a bearing. The bushing is disposed at the head of the plunger, one end of the horizontal shaft passes through the bushing, and the bearing is disposed at one end of the horizontal shaft.

[0009] The plunger sleeve has an end face cam, and there is a height difference between the lowest point and the highest point of the end face cam.

[0010] The ceramic precision miniature metering pump also includes a stepper motor, which is mounted on the upper end of the metering pump mounting base.

[0011] The ceramic precision miniature metering pump also includes a sliding connecting sleeve. The output shaft of the stepper motor is fixedly connected to the sliding connecting sleeve. U-shaped grooves are provided on both sides of the lower part of the sliding connecting sleeve, and the U-shaped grooves are engaged with the two ends of the horizontal shaft.

[0012] The ceramic precision miniature metering pump also includes a compression spring, which is disposed between the sliding connecting sleeve and the head of the plunger.

[0013] The ceramic precision miniature metering pump further includes a reverse end face cam, which is disposed above the end face cam, and the end face of the reverse end face cam is adapted to the end face of the end face cam.

[0014] This invention discloses a ceramic precision miniature metering pump. Both the plunger and the plunger sleeve are made of ceramic material, which greatly reduces the impact of temperature on volume, thus ensuring accuracy. The outer wall of the plunger and the inner wall of the plunger sleeve require a high degree of surface finish, with a fitting gap of less than 5μm. This achieves a self-sealing effect while minimizing frictional resistance between the plunger and the plunger sleeve. Furthermore, the plunger sleeve is installed in the lower half of the metering pump mounting base. The bottom of the plunger sleeve has a through-hole inlet and outlet. The bottom of the plunger is formed into a D-shaped end face. When the plunger rotates, the outlet within the planar area of ​​the D-shaped end face opens, and the outlet within the cylindrical area closes. Simultaneously, the plunger performs a fixed-stroke up-and-down movement, enabling quantitative extraction and discharge of liquid, thereby achieving precise metering and meeting the instrument's requirements for continuous, stable, and accurate metering. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the external structure of the ceramic precision miniature metering pump of the present invention.

[0017] Figure 2 This is a view of the concealed metering pump mounting base according to Embodiment 1 of the present invention.

[0018] Figure 3 This is a cross-sectional view of Embodiment 1 of the present invention.

[0019] Figure 4 This is an end-face cam view of Embodiment 1 of the present invention.

[0020] Figure 5 This is a view of the concealed metering pump mounting base in Embodiment 2 of the present invention.

[0021] Figure 6 This is a cross-sectional view of Embodiment 2 of the present invention.

[0022] 1. Stepper motor; 2. Slotted optocoupler; 3. Metering pump mounting base; 4. Sliding connecting sleeve; 5. End face cam; 6. Plunger sleeve; 7. Compression spring; 8. Bearing; 9. Horizontal shaft; 10. Sealing ring; 11. Plunger; 12. Sealing plug; 13. Reverse end face cam. Detailed Implementation

[0023] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0024] In the description of this invention, it should be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, in the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0025] Please see Figures 1 to 4 Example 1: This invention provides a ceramic precision miniature metering pump, including a plunger sleeve 6, a plunger 11, and a metering pump mounting base 3. The plunger sleeve 6 is installed in the lower half of the metering pump mounting base 3. The bottom of the plunger sleeve 6 has a through inlet and an outlet. The plunger 11 is placed inside the plunger sleeve 6. The bottom of the plunger 11 has a D-shaped end face. When the plunger 11 is rotated, the outlet within the planar range of the D-shaped end face opens, and the outlet within the cylindrical range closes. While the plunger 11 rotates, it performs a fixed up-and-down movement to achieve metered extraction and discharge of liquid.

[0026] The ceramic precision miniature metering pump also includes a sealing ring 10, which is disposed on the upper end face of the plunger sleeve 6.

[0027] The ceramic precision miniature metering pump also includes a bushing, a horizontal shaft 9, and a bearing 8. The bushing is located at the head of the plunger 11, one end of the horizontal shaft 9 passes through the bushing, and the bearing 8 is located at one end of the horizontal shaft 9.

[0028] The plunger sleeve 6 has an end face cam 5, and there is a height difference between the lowest point and the highest point of the end face cam 5.

[0029] The ceramic precision miniature metering pump also includes a stepper motor 1, which is mounted on the upper end of the metering pump mounting base 3.

[0030] The ceramic precision miniature metering pump also includes a sliding connecting sleeve 4. The output shaft of the stepper motor 1 is fixedly connected to the sliding connecting sleeve 4. U-shaped grooves are provided on both sides of the lower part of the sliding connecting sleeve 4, and the U-shaped grooves are engaged with the two ends of the horizontal shaft 9.

[0031] The ceramic precision miniature metering pump also includes a compression spring 7, which is disposed between the sliding connecting sleeve 4 and the head of the plunger 11.

[0032] The sliding connecting sleeve 4 has a butterfly-shaped protrusion, and a sensing groove is formed on the butterfly protrusion.

[0033] The ceramic precision miniature metering pump also includes a slotted optical coupler 2, which is mounted on one side of the metering pump mounting base 3.

[0034] The lowest and highest points of the end face of the end face cam 5 each retain a section of horizontal plane.

[0035] A sealing plug 12 is provided at the bottom of the metering pump mounting base 3.

[0036] In this embodiment, both the plunger 11 and the plunger sleeve 6 are made of ceramic material, which greatly reduces the influence of temperature on volume and thus ensures accuracy. The outer wall of the plunger 11 and the inner wall of the plunger sleeve 6 require a high degree of smoothness, and their fitting gap is less than 5μm, which can form a self-sealing effect while ensuring that the frictional resistance between the plunger 11 and the plunger sleeve 6 is small. In addition, the plunger sleeve 6 is installed in the lower half of the metering pump mounting base 3. The bottom of the plunger sleeve 6 has a through inlet and outlet. The bottom of the plunger 11 is made into a D-shaped end face at the corresponding position. When the plunger 11 rotates, the opening within the planar range of the D-shaped end face opens and the opening within the cylindrical range closes. The plunger 11 rotates while making a fixed up-and-down movement, which can realize the quantitative extraction and discharge of liquid, thereby achieving accurate quantification and meeting the instrument's requirements for continuous, stable and accurate quantification.

[0037] The technology for achieving the combined rotational and vertical movement of the plunger 11 is as follows:

[0038] The plunger 11 has a bushing at its head, and a horizontal shaft 9 runs through the bushing perpendicularly to it. A bearing 8 is located at one end of the horizontal shaft 9. An end face cam 5 is mounted on the upper surface of the plunger sleeve 6. There is a height difference between the lowest and highest points of the end face. When the plunger 11 rotates, the vertical projection of the bearing 8 on its horizontal shaft 9 always falls on the end face of the end face cam 5. The stepper motor 1 is mounted on the upper end of the metering pump mounting base 3, and the output shaft of the stepper motor 1 is fixed to the sliding connecting sleeve 4. The sliding connecting sleeve 4 has a disc-shaped boss and U-shaped grooves on both sides of its lower part. The U-shaped grooves fit perfectly into the two ends of the horizontal shaft 9 at the head of the plunger 11, allowing the motor torque to be output to the plunger 11 while the horizontal shaft 9 slides up and down within the U-shaped grooves.

[0039] A compression spring 7 is installed between the sliding connecting sleeve 4 and the head of the plunger 11. The compression spring 7 continuously provides a force to make the plunger 11 move downward, so that the bearing 8 of the head of the plunger 11 is always in close contact with the end face of the end face cam 5.

[0040] When the stepper motor 1 drives the plunger 11 to rotate, the bearing 8 always moves in close contact with the end face of the end face cam 5. When it moves from the lowest point to the highest point of the end face, the bearing 8 moves upward, causing the plunger 11 to lift and move upward to draw in liquid. When the bearing 8 moves from the highest point to the lowest point of the end face cam 5, the bearing 8 moves downward, and the compression spring 7 presses the plunger 11 down, causing it to move downward and discharge liquid. In this way, the combined motion of the plunger 11 rotating and moving up and down can be achieved.

[0041] The slotted optocoupler 2 is installed on one side of the metering pump mounting base 3. The disc-shaped boss on the sliding connecting sleeve 4 has a sensing groove. The boss is located in the groove of the slotted optocoupler 2. The sliding connecting sleeve 4 rotates synchronously with the plunger 11. The reset position is determined by the slotted optocoupler 2.

[0042] When the bearing 8 on the plunger 11 moves to the lowest point of the end face cam 5, the plunger 11 is in the reset position. At this time, the planar cut of the D-shaped end face at the bottom of the plunger 11 is parallel to the direction of the liquid inlet and liquid outlet of the plunger sleeve 6. The liquid inlet and the liquid outlet are both located within the cylindrical surface range of the D-shaped end face, that is, the liquid inlet and the liquid outlet are both in a closed state.

[0043] The lowest and highest points of the end face cam 5 each retain a section of horizontal plane, which is used to cooperate with the D-shaped end face at the bottom of the plunger 11. When the liquid inlet or outlet is not within the plane range of the D-shaped end face, the plunger 11 does not move up and down.

[0044] The plunger 11 rotates once to complete one extraction and one discharge of liquid. The quantitative volume is determined by the difference between the cross-sectional area of ​​the plunger 11 and the height of the end face cam 5. Once these two parameters are fixed, continuous, accurate and repeatable quantitative measurement can be achieved.

[0045] A ceramic precision miniature metering pump, as long as the stepper motor 1 completes one full circular motion, that is, rotates from the reset position back to the reset position, it will definitely complete one metered extraction and metered discharge of liquid, and is not affected by the stepper motor 1 losing steps.

[0046] Please see Figure 5 and Figure 6 Example 2: This invention provides a ceramic precision miniature metering pump, including a plunger sleeve 6, a plunger 11, and a metering pump mounting base 3. The plunger sleeve 6 is installed in the lower half of the metering pump mounting base 3. The bottom of the plunger sleeve 6 has a through inlet and an outlet. The plunger 11 is placed inside the plunger sleeve 6. The bottom of the plunger 11 has a D-shaped end face. When the plunger 11 is rotated, the outlet within the planar range of the D-shaped end face opens, and the outlet within the cylindrical range closes. While the plunger 11 rotates, it performs a fixed up-and-down movement to achieve metered extraction and discharge of liquid.

[0047] The ceramic precision miniature metering pump also includes a sealing ring 10, which is disposed on the upper end face of the plunger sleeve 6.

[0048] The ceramic precision miniature metering pump also includes a bushing, a horizontal shaft 9, and a bearing 8. The bushing is disposed at the head of the plunger 11, one end of the horizontal shaft 9 passes through the bushing, and the bearing 8 is disposed at one end of the bushing.

[0049] The plunger sleeve 6 has an end face cam 5, and there is a height difference between the lowest point and the highest point of the end face cam 5.

[0050] The ceramic precision miniature metering pump also includes a stepper motor 1 and a sliding connecting sleeve 4. The stepper motor 1 is mounted on the upper end of the metering pump mounting base 3. The output shaft of the stepper motor 1 is fixedly connected to the sliding connecting sleeve 4. U-shaped grooves are provided on both sides of the lower part of the sliding connecting sleeve 4, and the U-shaped grooves are engaged with the two ends of the horizontal shaft 9.

[0051] The ceramic precision miniature metering pump also includes a reverse end face cam 13, which is disposed above the end face cam 5, and the end face of the reverse end face cam 13 is adapted to the end face of the end face cam 5.

[0052] In this embodiment, based on Example 1, the compression spring 7 between the sliding connecting sleeve 4 and the head of the plunger 11 is not installed. Instead, a reverse end face cam 13 is installed at a certain distance directly above the end face cam 5. The end face of the reverse end face cam 13 faces downward and has the same shape as the lower end face cam 5. The distance between the upper and lower end faces is slightly larger than the outer diameter of the bearing 8.

[0053] When the stepper motor 1 drives the plunger 11 to rotate, the bearing 8 can only move in the end face track formed by the two end face cams 5 and the reverse end face cam 13. That is, the plunger 11 is forced to move upward or downward, so that the combined motion of the plunger 11 rotating and moving up and down can be realized.

[0054] The two solutions, Example 1 and Example 2, each have their own key technical features:

[0055] Example 1 uses the compression spring 7 to eliminate the backlash between the bearing 8 and the end face cam 5, achieving a very high quantitative accuracy, which is suitable for situations with small displacement and high accuracy requirements.

[0056] Example 2 adopts a double-end cam track structure. As long as the torque of the stepper motor 1 is sufficient, the plunger 11 will definitely move up and down, which can withstand greater pumping pressure and is suitable for situations where the displacement is large and the precision requirements are not particularly high.

[0057] In summary, the ceramic precision miniature metering pump of the present invention has minimal influence on the change of cavity volume due to temperature, resulting in precise metering; furthermore, the rotation and up-and-down movement of the plunger 11 can be achieved by a single motor; the ceramic precision miniature metering pump is small in size and simple in structure; the ceramic precision miniature metering pump can achieve continuous and precise metering extraction and discharge; and the ceramic precision miniature metering pump has good airtightness.

[0058] The above description discloses only one preferred embodiment of the present invention, and should not be construed as limiting the scope of the present invention. Those skilled in the art will understand that all or part of the processes of the above embodiments can be implemented, and equivalent changes made in accordance with the claims of the present invention are still within the scope of the invention.

Claims

1. A ceramic precision miniature metering pump, characterized in that, The device includes a plunger sleeve, a plunger, and a metering pump mounting base. The plunger sleeve is installed in the lower half of the metering pump mounting base. The bottom of the plunger sleeve has a through inlet and an outlet. The plunger is placed inside the plunger sleeve. The bottom of the plunger has a D-shaped end face. When the plunger is rotated, the outlet within the planar range of the D-shaped end face opens, and the outlet within the cylindrical range closes. While the plunger rotates, it performs a fixed up-and-down movement to achieve metered extraction and discharge of liquid. The ceramic precision miniature metering pump also includes a bushing, a horizontal shaft, and a bearing. The bushing is disposed at the head of the plunger, one end of the horizontal shaft passes through the bushing, and the bearing is disposed at one end of the horizontal shaft. The ceramic precision miniature metering pump also includes a stepper motor, which is mounted on the upper end of the metering pump mounting base; The ceramic precision miniature metering pump also includes a sliding connecting sleeve. The output shaft of the stepper motor is fixedly connected to the sliding connecting sleeve. U-shaped grooves are provided on both sides of the lower part of the sliding connecting sleeve, and the U-shaped grooves are engaged with both ends of the horizontal shaft. The sliding connecting sleeve is provided with a butterfly-shaped protrusion, and a sensing groove is provided on the butterfly protrusion; The ceramic precision miniature metering pump also includes a slotted optical coupler, which is mounted on one side of the metering pump mounting base.

2. The ceramic precision miniature metering pump as described in claim 1, characterized in that, The ceramic precision miniature metering pump also includes a sealing ring, which is disposed on the upper end face of the plunger sleeve.

3. The ceramic precision miniature metering pump as described in claim 1, characterized in that, The plunger sleeve has an end face cam, and there is a height difference between the lowest point and the highest point of the end face cam.

4. The ceramic precision miniature metering pump as described in claim 3, characterized in that, The ceramic precision miniature metering pump also includes a compression spring, which is disposed between the sliding connecting sleeve and the head of the plunger.

5. The ceramic precision miniature metering pump as described in claim 4, characterized in that, The ceramic precision miniature metering pump also includes a reverse end face cam, which is disposed above the end face cam, and the end face of the reverse end face cam is adapted to the end face of the end face cam.

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