Precise metering pump with drip-proof function

Abstract

The utility model discloses a precision metering pump with a drip-proof function, which comprises a shell, a liquid inlet and a liquid outlet are arranged on the shell, a first piston component, a second piston component and a plunger are arranged in the shell, the plunger is connected with the second piston component, and the plunger is connected with the liquid inlet and the liquid outlet. The shell is provided with a first pneumatic driving assembly used for controlling the first piston assembly to move and a second pneumatic driving assembly used for controlling the second piston assembly to move. The pneumatic conveying device has the advantages that the pneumatic conveying device is simple and reasonable in structure and is provided with the first pneumatic driving assembly and the second pneumatic driving assembly, the first pneumatic driving assembly controls the first piston assembly to move, the second pneumatic driving assembly controls the second piston assembly to move, and the first piston assembly moves to convey materials; resorption of substances is achieved, and the situation that the metering accuracy is affected due to dripping leakage of the conveyed substances is prevented.

Description

Technical Field

[0001] The utility model relates to the technical field of metering pump manufacturing, in particular to a precision metering pump with an anti-drip function. Background Art

[0002] A metering pump is a machine that can measure the amount of liquid being transported. It is also called a quantitative pump or a proportional pump. It is widely used in various industries, such as the pharmaceutical industry, food industry, chemical industry, etc.

[0003] For example, the patent application with application number CN201420049067.X and titled "A Pneumatic Plunger Metering Pump" discloses a metering pump structure, including a driving cylinder, a rear end cover of the cylinder, a one-way throttle valve, a pneumatic joint and a micrometer differential head; the rear end cover of the cylinder is arranged on the driving cylinder; the one-way throttle valve includes a cylinder quantity front control valve and a cylinder quantity rear control valve. The cylinder quantity front control valve and the cylinder quantity rear control valve are arranged on the end face of the rear end cover of the cylinder parallel to the cylinder axis direction; the micrometer differential head is arranged in the middle of the end face of the rear end cover of the cylinder perpendicular to the cylinder axis and away from the driving cylinder; the pneumatic joint and the micrometer differential head are arranged on the same end face and are located on both sides of the micrometer differential head. It uses high-pressure gas as the power source for piston movement, but the existing metering pump structure has no back suction function, and there may be a problem of dripping of hanging materials at the injection port after the material injection is completed, resulting in inaccurate dosage accuracy, so its structure needs to be further improved. Utility Model Content

[0004] The purpose of the utility model is to make up for the above-mentioned deficiencies and disclose to the public a precision metering pump with a simple and reasonable structure and a back-suction function and an anti-drip function.

[0005] The technical solution of the utility model is achieved in this way:

[0006] A precision metering pump with an anti-drip function includes a shell, the shell is provided with a liquid inlet and outlet, a first piston assembly, a second piston assembly and a plunger are arranged in the shell, the plunger is connected to the second piston assembly, and a first pneumatic drive assembly for controlling the movement of the first piston assembly and a second pneumatic drive assembly for controlling the movement of the second piston assembly are arranged on the shell.

[0007] The measures to further optimize this technical solution are:

[0008] As an improvement, the shell is equipped with a first micrometer assembly and a second micrometer assembly, the second micrometer assembly is axially provided with a shaft in the central axis direction, a top block is fixed to the tail end of the shaft, and the first micrometer assembly is assembled on the top block.

[0009] As an improvement, the first piston assembly includes a first piston and a first connecting rod, and the shaft is connected to the first connecting rod.

[0010] As an improvement, the second piston assembly includes a second piston and a second connecting rod, and the plunger is connected to the second connecting rod.

[0011] As an improvement, the first micrometer assembly includes a first knob and a first movable sleeve, a locking needle is arranged in the first movable sleeve, and the axial movement of the first movable sleeve is controlled by the first knob.

[0012] As an improvement, the second micrometer assembly includes a second knob and a second movable sleeve, the top block is fixed to the second movable sleeve, and the axial movement of the second movable sleeve is controlled by the second knob.

[0013] The first micrometer assembly and the second micrometer assembly are provided with knobs, and the limit position is adjusted by rotating operation, thereby achieving the adjustment of the capacity.

[0014] As an improvement, a buffer cavity is provided in the shell corresponding to the position of the liquid inlet and outlet.

[0015] As an improvement, the cross section of the buffer cavity is an inverted trumpet-shaped structure.

[0016] Providing a buffer chamber can alleviate the instantaneous high pressure at the inlet and outlet.

[0017] As an improvement, a wet cup is provided on the housing, which can play a lubricating role, reduce the wear of the seal caused by the reciprocating motion of the plunger, and increase the service life; in addition, it can prevent the crystallization of the material from affecting the normal operation of the metering pump.

[0018] As an improvement, a sliding sleeve is provided between the housing and the plunger, and a plurality of sealing members are provided between the sliding sleeve and the plunger.

[0019] The advantages of the utility model compared with the prior art are:

[0020] The utility model discloses a precision metering pump with an anti-drip function, which has a simple and reasonable structure. It is provided with a first pneumatic drive component and a second pneumatic drive component. The first pneumatic drive component controls the movement of a first piston component, and the second pneumatic drive component controls the movement of a second piston component. The movement of the first piston component realizes the transportation of a substance, and the movement of the second piston component realizes the back suction of the substance, thereby preventing the dripping of the transported substance from affecting the accuracy of metering. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a cross-sectional structural diagram of the utility model;

[0022] Figure 2 yes Figure 1 Enlarged view of part A in the middle;

[0023] Figure 3 yes Figure 1 Enlarged view of middle part B;

[0024] Figure 4 It is a top view of the utility model.

[0025] The names of the reference numerals in the accompanying drawings of the present utility model are:

[0026] Shell 1, liquid inlet and outlet 1a, buffer chamber 1b, first piston assembly 2, first piston 21, first connecting rod 22, second piston assembly 3, second piston 31, second connecting rod 32, plunger 4, sliding sleeve 41, seal 42, first pneumatic drive assembly 51, second pneumatic drive assembly 52, first micrometer assembly 6, first knob 61, first movable sleeve 62, locking needle 63, second micrometer assembly 7, second knob 71, second movable sleeve 72, shaft 81, top block 82, wet cup 9. DETAILED DESCRIPTION

[0027] The utility model is further described in detail below with reference to the accompanying drawings:

[0028] The following description is used to disclose the utility model so that those skilled in the art can implement the utility model. The preferred embodiments described below are only examples, and those skilled in the art can think of other obvious variations. The basic principles of the utility model defined in the following description can be used for other implementation schemes, variations, improvements, equivalent schemes, and other technical solutions that do not deviate from the spirit and scope of the utility model.

[0029] Those skilled in the art should understand that, in the disclosure of the present invention, the directions or positions indicated by the terms "longitudinal", "lateral", "up", "down", "left", "right", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. are based on the directions or positional relationships shown in the accompanying drawings, which are only simplified descriptions for the convenience of describing the present invention, and do not indicate or imply that the device or component referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, the above terms should not be understood as limitations on the present invention.

[0030] It is to be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0031] like Figures 1 to 4As shown, a precision metering pump with an anti-drip function includes a shell 1, the shell 1 is provided with a liquid inlet and outlet 1a, the shell 1 is provided with a first piston assembly 2, a second piston assembly 3 and a plunger 4, the plunger 4 is connected to the second piston assembly 3, and the shell 1 is provided with a first pneumatic drive assembly 51 for controlling the movement of the first piston assembly 2 and a second pneumatic drive assembly 52 for controlling the movement of the second piston assembly 3.

[0032] The housing 1 is equipped with a first micrometer assembly 6 and a second micrometer assembly 7. The second micrometer assembly 7 is provided with a shaft 81 in the central axial direction. A top block 82 is fixed to the tail end of the shaft 81. The first micrometer assembly 6 is assembled on the top block 82.

[0033] The first piston assembly 2 includes a first piston 21 and a first connecting rod 22 , and the shaft 81 is connected to the first connecting rod 22 .

[0034] The second piston assembly 3 includes a second piston 31 and a second connecting rod 32 , and the plunger 4 is connected to the second connecting rod 32 .

[0035] The first micrometer assembly 6 includes a first knob 61 and a first movable sleeve 62 . A locking pin 63 is arranged in the first movable sleeve 62 . The axial movement of the first movable sleeve 62 is controlled by the first knob 61 .

[0036] The first knob 61 is threadedly connected to the installation part. The first knob 61 is rotated to realize the axial movement of the first knob 61, and drive the axial movement of the first movable sleeve 62 and the locking needle 63, so as to adjust the axial position of the locking needle 63 by the first knob 61, thereby realizing the adjustment of the conveying amount.

[0037] The second micrometer assembly 7 includes a second knob 71 and a second movable sleeve 72 . The top block 82 is fixed to the second movable sleeve 72 . The axial movement of the second movable sleeve 72 is controlled by the second knob 71 .

[0038] Similarly, the second knob 71 is screwed to the mounting portion, and the second knob 71 is rotated to achieve axial movement of the second knob 71 and drive the axial movement of the second movable sleeve 72 to adjust the position of the top block 82, thereby adjusting the back-suction amount.

[0039] A buffer cavity 1b is provided in the housing 1 at a position corresponding to the liquid inlet and outlet 1a.

[0040] The cross section of the buffer chamber 1b is an inverted trumpet-shaped structure.

[0041] The setting of the buffer chamber 1b can buffer the instantaneous high pressure at the inlet and outlet 1a, thereby preventing the instantaneous high pressure from affecting the smooth operation of the pump.

[0042] A wet cup 9 is provided on the housing 1 .

[0043] A sliding sleeve 41 is disposed between the housing 1 and the plunger 4 , and a plurality of sealing members 42 are disposed between the sliding sleeve 41 and the plunger 4 .

[0044] The metering pump has a wide range of application scenarios, such as the delivery of fluid substances such as food liquid and electrolyte. The wet cup 9 can play a lubricating role to reduce friction resistance, reduce the wear of the seal 42 caused by the reciprocating motion of the plunger 4, and increase the service life of the seal 42; in addition, it can also prevent material crystallization from affecting the normal operation of the metering pump.

[0045] Working principle:

[0046] The metering pump of the utility model drives the reciprocating motion of the first piston assembly 2 through the first pneumatic drive assembly 51, drives the reciprocating motion of the second piston assembly 3 through the second pneumatic drive assembly 52, and realizes the movement of the piston through gas circuit switching.

[0047] When aspirating liquid, the second pneumatic drive assembly 52 drives the second piston assembly 3 to move backward together with the first piston assembly 2, and drives the plunger 4 to move backward together, so that a pressure difference is formed in the cavity of the housing 1, thereby sucking the liquid into the pump from the liquid inlet and outlet 1a. The first piston assembly 2 moves backward, which will drive the shaft 81 and the top block 82 to move backward together. When the top block 82 and the locking needle 63 are in contact, the axial position of the locking needle 63 is adjusted by the first knob 61, thereby achieving the adjustment of the delivery amount. In the state of aspirating liquid, the first piston assembly 2 moves backward, and the maximum backward distance of the first piston assembly 2 is limited by the locking needle 63. The locking needle 63 is used for mechanical limiting, thereby controlling the injection amount. The injection amount of the metering pump is changed by controlling the stroke of the first piston assembly 2.

[0048] During injection, the first piston assembly 2 and the second piston assembly 3 move forward, and the second piston assembly 3 drives the plunger 4 to move forward together, thereby pumping the liquid in the cavity out of the pump. During injection, the shaft 81, the top block 82 and the first piston assembly 2 move forward together until the top block is blocked by the second knob 71 and stops moving forward, and the first piston assembly 2 continues to move forward.

[0049] Due to the limitation of the second micrometer assembly 7, a gap will be generated between the first piston assembly 2 and the second piston assembly 3 during the injection. After the injection is completed, the first pneumatic drive assembly 51 drives the first piston assembly 2 to continue to maintain the original forward movement trend, and the air circuit of the second pneumatic drive assembly 52 is switched, so that the second piston assembly 3 moves backward. At this time, the liquid outlet circuit is not closed. Through the backward movement of the second piston assembly 3, the liquid hanging at the liquid inlet and outlet 1a and the residual liquid in the pipeline are sucked back. When the second piston assembly 3 touches the first piston assembly 2, the liquid outlet circuit is closed, the liquid suction circuit is opened, and then the air circuit of the first pneumatic drive assembly 51 is switched, so that the first piston assembly 2 and the second piston assembly 3 move backward together to suck liquid.

[0050] The above are only preferred embodiments of the present invention, and do not limit the implementation mode and protection scope of the present invention. Those skilled in the art should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the description and illustrations of the present invention should be included in the protection scope of the present invention.

Claims

1. A precision metering pump with an anti-drip function, comprising a housing (1), wherein the housing (1) is provided with a liquid inlet and outlet (1a), wherein: A first piston assembly (2), a second piston assembly (3) and a plunger (4) are arranged in the housing (1); the plunger (4) is connected to the second piston assembly (3); and a first pneumatic drive assembly (51) for controlling the movement of the first piston assembly (2) and a second pneumatic drive assembly (52) for controlling the movement of the second piston assembly (3) are arranged on the housing (1).

2. A precision metering pump with anti-drip function according to claim 1, characterized in that: The housing (1) is equipped with a first micrometer assembly (6) and a second micrometer assembly (7); a shaft (81) is arranged in the central axial direction of the second micrometer assembly (7); a top block (82) is fixed to the tail end of the shaft (81); and the first micrometer assembly (6) is assembled on the top block (82).

3. A precision metering pump with anti-drip function according to claim 2, characterized in that: The first piston assembly (2) comprises a first piston (21) and a first connecting rod (22), and the shaft (81) is connected to the first connecting rod (22).

4. The precision metering pump with anti-drip function according to claim 3 is characterized in that: The second piston assembly (3) comprises a second piston (31) and a second connecting rod (32), and the plunger (4) is connected to the second connecting rod (32).

5. The precision metering pump with anti-drip function according to claim 4 is characterized in that: The first micrometer assembly (6) comprises a first knob (61) and a first movable sleeve (62). A locking pin (63) is arranged inside the first movable sleeve (62). The axial movement of the first movable sleeve (62) is controlled by the first knob (61).

6. A precision metering pump with anti-drip function according to claim 5, characterized in that: The second micrometer assembly (7) comprises a second knob (71) and a second movable sleeve (72), the top block (82) is fixed to the second movable sleeve (72), and the axial movement of the second movable sleeve (72) is controlled by the second knob (71).

7. A precision metering pump with anti-drip function according to any one of claims 1 to 6, characterized in that: A buffer chamber (1b) is provided in the housing (1) at a position corresponding to the liquid inlet and outlet (1a).

8. The precision metering pump with anti-drip function according to claim 7 is characterized in that: The cross section of the buffer chamber (1b) is an inverted trumpet-shaped structure.

9. A precision metering pump with anti-drip function according to claim 8, characterized in that: A wet cup (9) is provided on the shell (1).

10. A precision metering pump with anti-drip function according to claim 9, characterized in that: A sliding sleeve (41) is provided between the housing (1) and the plunger (4), and a plurality of sealing members (42) are provided between the sliding sleeve (41) and the plunger (4).

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