阅读说明：本技术 一种乳液泵 (Emulsion pump ) 是由 袁群慧 李广兴 周玉 于 2021-07-19 设计创作，主要内容包括：本发明公开了一种乳液泵,包括泵体、第一活塞、第二活塞、第一单向阀和第二单向阀；泵体设有吸入管道、输出管道、进气口和出气口；第一活塞位于泵体内,将泵体的内部分成介质腔和气压腔；吸入管道的一端与介质腔连通,另一端延伸至容器内,输出管道的一端与介质腔连通,另一端伸至泵体外；第一单向阀使介质通过吸入管道单向流入介质腔；第二单向阀使介质单向流入输出管道；进气口将气压腔和外界大气连通,出气口与容器内连通；第二活塞位于气压腔内,第二活塞设有辅助气道,一端与气压腔连通,另一端与出气口选择连通；第一活塞相对于泵体移动时,第二活塞相对于泵体移动将辅助气道与出气口连通。本发明的乳液泵可以提高对容器内介质的保护。(The invention discloses an emulsion pump, which comprises a pump body, a first piston, a second piston, a first one-way valve and a second one-way valve, wherein the pump body is provided with a first piston and a second piston; the pump body is provided with a suction pipeline, an output pipeline, an air inlet and an air outlet; the first piston is positioned in the pump body and divides the interior of the pump body into a medium cavity and an air pressure cavity; one end of the suction pipeline is communicated with the medium cavity, the other end of the suction pipeline extends into the container, one end of the output pipeline is communicated with the medium cavity, and the other end of the output pipeline extends out of the pump body; the first one-way valve enables the medium to flow into the medium cavity in one way through the suction pipeline; the second one-way valve enables the medium to flow into the output pipeline in one way; the air inlet is communicated with the air pressure cavity and the outside atmosphere, and the air outlet is communicated with the inside of the container; the second piston is positioned in the air pressure cavity, the second piston is provided with an auxiliary air passage, one end of the auxiliary air passage is communicated with the air pressure cavity, and the other end of the auxiliary air passage is selectively communicated with the air outlet; when the first piston moves relative to the pump body, the second piston moves relative to the pump body to communicate the auxiliary air passage with the air outlet. The emulsion pump can improve the protection of the medium in the container.)

1. An emulsion pump is characterized by comprising a pump body, a first piston, a second piston, a first one-way valve and a second one-way valve; the pump body is connected with the container and is provided with a suction pipeline, an output pipeline, an air inlet and an air outlet; the first piston is positioned in the pump body and divides the interior of the pump body into a medium cavity and an air pressure cavity; one end of the suction pipeline is communicated with the medium cavity, the other end of the suction pipeline extends into the container, one end of the output pipeline is communicated with the medium cavity, and the other end of the output pipeline extends out of the pump body; the first one-way valve is positioned between the suction pipeline and the medium cavity, so that the medium flows into the medium cavity in one way; the second one-way valve is positioned between the output pipeline and the medium cavity, so that the medium flows into the output pipeline in one way; the air inlet is used for communicating the air pressure cavity with the external air pressure, and the air outlet is communicated with the interior of the container; the second piston is positioned in the air pressure cavity, an auxiliary air passage is arranged on the second piston, one end of the auxiliary air passage is communicated with the air pressure cavity, and the other end of the auxiliary air passage is selectively communicated with the air outlet; wherein when the first piston moves relative to the pump body, the second piston moves relative to the pump body to communicate the auxiliary air passage with the air outlet.

2. A lotion pump according to claim 1, wherein the auxiliary air passage has an end in communication with the air pressure chamber at a higher elevation than an end of the air inlet in communication with ambient air pressure after the pump body is connected to the container.

3. A lotion pump according to claim 1, wherein the second piston divides the pneumatic chamber, a drainage chamber is formed between the first piston and the second piston, and the first piston is provided with a first drainage channel and a second drainage channel; one end of the first drainage channel is communicated with the air pressure cavity, the other end of the first drainage channel is communicated with the drainage cavity, and a third one-way valve is arranged on the first drainage channel to enable liquid to flow into the drainage cavity from the air pressure cavity in a one-way mode; one end of the second liquid discharge channel is communicated with the liquid discharge cavity, the other end of the second liquid discharge channel is communicated with the outside of the pump body, and a fourth one-way valve is arranged on the second liquid discharge channel, so that liquid flows out of the pump body from the liquid discharge cavity in one way.

4. An emulsion pump according to claim 3, wherein the third one-way valve and/or the fourth one-way valve consists of a steel ball and a spring.

5. A lotion pump as claimed in claim 1, further comprising a third piston, a fifth one-way valve and a sixth one-way valve; the third piston is fixedly connected with the first piston and is positioned in the air pressure cavity, the second piston is positioned between the first piston and the third piston, the third piston divides the air pressure cavity, and a suck-back cavity is formed between the third piston and the second piston; the fifth one-way valve is positioned between the back suction cavity and the output pipeline, so that the medium flows into the back suction cavity from the output pipeline in a one-way mode; the sixth one-way valve is positioned between the back suction cavity and the output pipeline, so that the medium flows into the output pipeline from the back suction cavity in one way.

6. A lotion pump according to claim 5, wherein the second piston moves relative to the pump body in a direction towards the third piston as the first piston moves relative to the pump body in a direction to reduce the volume of the media chamber.

7. An emulsion pump according to claim 5, wherein the fifth one-way valve and/or the sixth one-way valve consists of a steel ball and a spring.

8. A lotion pump according to any one of claims 1-7, characterized in that the lotion pump is further provided with a handle; the handle is positioned outside the pump body and is in rotary connection with the pump body; the first piston is rotatably connected with the handle through a first piston rod, the second piston is rotatably connected with the handle through a second piston rod, and the connecting point of the first piston rod and the handle and the connecting point of the second piston rod and the handle are positioned on two sides of the connecting point of the handle and the pump body.

9. A lotion pump according to claim 8, further comprising a piston elastic member; the piston elastic member is located between the pump body and the first piston to drive the first piston to move relative to the pump body in a direction to increase the volume of the medium chamber.

10. An emulsion pump according to any one of claims 1 to 7, wherein the first one-way valve and/or the second one-way valve is/are in the form of a ball valve arrangement.

Technical Field

The invention belongs to the technical field of emulsion pumps, and particularly relates to an emulsion pump.

Background

At present, an emulsion pump is arranged on a container filled with emulsion so that people can obtain the emulsion by pressing a pressure head, the use of people is facilitated, raw materials are saved, and the container provided with the emulsion pump is widely applied to occasions such as household and medical use.

However, the emulsion pump used in the existing container has the following problems in the using process: the emulsion pump can normally work only by keeping the air pressure in the bottle balanced with the atmospheric pressure when in use, so a gap can be left between the pressure head and the pump body, and a channel for air circulation can be left on the emulsion pump, so that sewage can enter a cavity formed by the pressure head and the pump body or enter the bottle from an air flow channel, and the emulsion in the bottle is polluted. In addition, after the emulsion pump is used, emulsion residues exist in the pressure head and the nozzle, the emulsion can flow out of the nozzle and drip down to pollute the environment, and the residual emulsion on the head of the nozzle can cause the nozzle to be blocked after long-term air drying, so that the normal use of the emulsion pump is influenced.

Disclosure of Invention

Aiming at the problems of the existing emulsion pump in the working process, the invention provides an emulsion pump. The emulsion pump comprises a pump body, a first piston, a second piston, a first one-way valve and a second one-way valve; the pump body is connected with the container and is provided with a suction pipeline, an output pipeline, an air inlet and an air outlet; the first piston is positioned in the pump body and divides the interior of the pump body into a medium cavity and an air pressure cavity; one end of the suction pipeline is communicated with the medium cavity, the other end of the suction pipeline extends into the container, one end of the output pipeline is communicated with the medium cavity, and the other end of the output pipeline extends out of the pump body; the first one-way valve is positioned between the suction pipeline and the medium cavity, so that the medium flows into the medium cavity in one way; the second one-way valve is positioned between the output pipeline and the medium cavity, so that the medium flows into the output pipeline in one way; the air inlet is used for communicating the air pressure cavity with the external air pressure, and the air outlet is communicated with the interior of the container; the second piston is positioned in the air pressure cavity, an auxiliary air passage is arranged on the second piston, one end of the auxiliary air passage is communicated with the air pressure cavity, and the other end of the auxiliary air passage is selectively communicated with the air outlet; wherein when the first piston moves relative to the pump body, the second piston moves relative to the pump body to communicate the auxiliary air passage with the air outlet.

Preferably, after the pump body is connected with the container, the height of the position of one end, communicated with the air pressure cavity, of the auxiliary air passage is higher than the height of the position, communicated with the outside air pressure, of the air inlet.

Preferably, the second piston divides the air pressure cavity, a liquid discharge cavity is formed between the first piston and the second piston, and the first piston is provided with a first liquid discharge channel and a second liquid discharge channel; one end of the first drainage channel is communicated with the air pressure cavity, the other end of the first drainage channel is communicated with the drainage cavity, and a third one-way valve is arranged on the first drainage channel to enable liquid to flow into the drainage cavity from the air pressure cavity in a one-way mode; one end of the second liquid discharge channel is communicated with the liquid discharge cavity, the other end of the second liquid discharge channel is communicated with the outside of the pump body, and a fourth one-way valve is arranged on the second liquid discharge channel, so that liquid flows out of the pump body from the liquid discharge cavity in one way.

Further preferably, the third one-way valve and/or the fourth one-way valve is composed of a steel ball and a spring.

Preferably, the emulsion pump is also provided with a third piston, a fifth one-way valve and a sixth one-way valve; the third piston is fixedly connected with the first piston and is positioned in the air pressure cavity, the second piston is positioned between the first piston and the third piston, the third piston divides the air pressure cavity, and a suck-back cavity is formed between the third piston and the second piston; the fifth one-way valve is positioned between the back suction cavity and the output pipeline, so that the medium flows into the back suction cavity from the output pipeline in a one-way mode; the sixth one-way valve is positioned between the back suction cavity and the output pipeline, so that the medium flows into the output pipeline from the back suction cavity in one way.

Further preferably, when the first piston moves relative to the cylinder in a direction to reduce the volume of the medium chamber, the second piston moves relative to the cylinder in a direction to approach the third piston.

Further preferably, the fifth one-way valve and/or the sixth one-way valve is composed of a steel ball and a spring.

Preferably, the emulsion pump is also provided with a handle; the handle is positioned outside the pump body and is in rotary connection with the pump body; the first piston is rotatably connected with the handle through a first piston rod, the second piston is rotatably connected with the handle through a second piston rod, and the connecting point of the first piston rod and the handle and the connecting point of the second piston rod and the handle are positioned on two sides of the connecting point of the handle and the pump body.

Further preferably, the emulsion pump is also provided with a piston elastic element; the piston elastic member is located between the pump body and the first piston to drive the first piston to move relative to the pump body in a direction to increase the volume of the medium chamber.

Preferably, the first one-way valve and/or the second one-way valve is in the form of a ball valve structure.

The emulsion pump has the following beneficial technical effects:

1. in the emulsion pump, the pump body is provided with the air inlet and the air outlet, the second piston is provided with the auxiliary air passage, one end of the auxiliary air passage is communicated with the air inlet through the air pressure cavity, and the other end of the auxiliary air passage is communicated with the interior of the container through selective communication with the air outlet. Like this, utilize and set up atmospheric pressure chamber and supplementary air flue between air inlet and gas outlet to and utilize the second piston to communicate supplementary air flue and gas outlet when moving along with first piston, make the inside and external atmospheric pressure state of keeping in the container, guarantee the normal output of this emulsion pump to the medium, and when the second piston moved to stopping to export the medium in the container along with first piston, again with supplementary air flue and gas outlet disconnection intercommunication, thereby reach and prevent that external impurity from directly getting into the container purpose through the air inlet, improve the protection to the medium in the container.

2. In the emulsion pump, the auxiliary air passage is arranged on the second piston rod, and the height position of one end of the auxiliary air passage, which is communicated with the air pressure cavity, is higher than the position of the air inlet on the pump body, so that external sewage entering the air pressure cavity through the air inlet can be effectively prevented from entering the auxiliary air passage, the medium in the container is further protected, and the safety and the reliability of using the emulsion pump are improved.

3. In the emulsion pump, the liquid discharge cavity is arranged between the first piston and the second piston, and the first liquid discharge flow channel, the second liquid discharge flow channel, the third one-way valve and the fourth one-way valve are arranged on the first piston rod, so that external sewage entering the air pressure cavity through the air inlet can be introduced into the liquid discharge cavity and then discharged to the outside of the pump body in the reciprocating movement process of the first piston and the second piston, the possibility that the external sewage enters the container through the air inlet is further reduced, and the protection of media in the container is improved.

4. In the emulsion pump, the third piston is arranged on the first piston rod, the resorption cavity is arranged between the third piston and the second piston, and the fifth one-way valve and the sixth one-way valve are arranged between the resorption cavity and the output pipeline, so that the medium remained in the output pipeline after the medium is output by the emulsion pump can be resorbed into the resorption cavity through the fifth one-way valve in time and then output to the output pipeline through the sixth one-way valve and output together with the medium in the medium cavity, and the overflow and air drying blockage of the medium in the output pipeline are effectively avoided.

Drawings

FIG. 1 is a schematic sectional view of the emulsion pump of this embodiment;

FIG. 2 is a schematic structural diagram of a first piston, a third piston and a first piston rod of the emulsion pump of this embodiment;

fig. 3 is a schematic structural diagram of the emulsion pump according to the embodiment of the invention, wherein the second piston is arranged between the second piston and the second piston rod.

Detailed Description

The technical solution of the present invention will be further described in detail with reference to the accompanying drawings and embodiments.

Referring to fig. 1 to 3, the lotion pump of the present embodiment includes a pump body 1, a first piston 21, a second piston 22, a first check valve 31, and a second check valve 32. The pump body 1 is detachably and fixedly connected with the container through threads, and a suction pipeline 11, an output pipeline 12, an air inlet 13 and an air outlet 14 are arranged on the pump body 1. The first piston 21 is located inside the cylinder 1 so as to be capable of reciprocating linearly with respect to the cylinder 1, and divides the inside of the cylinder 1 into a medium chamber 151 and an air pressure chamber 152.

One end of the suction pipe 11 communicates with the medium chamber 151 and the other end extends to the inside of the container for introducing the medium in the container into the medium chamber 151. One end of the output pipe 12 is communicated with the medium chamber 151, and the other end extends to the outside of the pump body 1, and is used for outputting the medium in the medium chamber 151. The first check valve 31 is located between the suction pipe 11 and the medium chamber 151 to allow the medium in the container to flow into the medium chamber 151 in a single direction. The second check valve 32 is located between the output pipe 12 and the medium chamber 151, and makes the medium in the medium chamber 151 flow into the output pipe 12 in a single direction. An air inlet 13 is located in the pump body 1 near the upper end to communicate the air pressure chamber 152 with the outside atmosphere, and an air outlet 14 is located in the pump body 1 near the opposite lower end for communication with the interior of the container.

The second piston 22 is located in the pneumatic chamber 152 so as to be capable of reciprocating linear movement relative to the pump body 1, and an auxiliary air passage 221 is provided in the second piston 22. One end of the auxiliary air passage 221 is in communication with the air pressure chamber 152, and the other end extends to the outer circumferential surface of the second piston 22 and is in selective communication with the air outlet 14. When the first piston 21 reciprocates relative to the cylinder 1, the second piston 22 moves relative to the cylinder 1 to communicate the auxiliary air passage 221 with the air outlet port 14.

When the first piston is driven to move in the direction of increasing the volume of the medium cavity in the pump body, the air pressure in the medium cavity is reduced due to the increase of the volume of the first piston, so that the first check valve is opened, the second check valve is closed, the medium in the container flows into the medium cavity through the suction pipeline, meanwhile, the second piston moves to the position where the auxiliary air passage is communicated with the air outlet, so that the air pressure in the container is communicated with the external atmospheric pressure sequentially through the air outlet, the auxiliary air passage, the air pressure cavity and the air inlet, and the medium in the container can flow into the medium cavity rapidly and smoothly; when the first piston is driven to move in the direction of reducing the volume of the medium cavity in the pump body, the air pressure in the medium cavity rises due to the reduction of the volume of the medium cavity, so that the first one-way valve is closed and the second one-way valve is opened, the medium in the medium cavity is driven by the air pressure to be output through the output pipeline 12, and the output operation of the medium in the container is completed.

Referring to fig. 1, in the lotion pump of this embodiment, a handle 4 is further provided, and the handle 4 is located outside the pump body 1 and is rotatably connected to the pump body 1 through a rotating shaft 41. Meanwhile, the first piston 21 is provided with a first piston rod 51, one end of the first piston rod 51 is fixedly connected with the first piston 21, and the other end of the first piston rod 51 passes through the air pressure cavity 152 and extends out of the pump body 1, and is rotatably connected with the handle 4 through a pin shaft. The second piston 22 is provided with a second piston rod 52, one end of the second piston rod 52 is fixedly connected with the second piston 22, and the other end of the second piston rod 52 passes through the air pressure cavity 152 to extend out of the pump body 1 and is rotatably connected with the handle 4 through a pin shaft. Wherein the connection point of the first piston rod 51 and the handle 4 and the connection point of the second piston rod 52 and the handle 4 are located on both sides of the connection point of the handle 4 and the pump body 1.

At this time, the first piston rod and the second piston rod are simultaneously in rotating connection with the handle, and a rocker structure driven by the handle is formed, that is, when the driving end of the handle moves downwards along the direction shown in fig. 1, the handle drives the first piston rod to move downwards and drives the second piston rod to move upwards by taking the rotating shaft as a fulcrum, otherwise, when the handle drives the first piston rod to move upwards, the handle simultaneously drives the second piston rod to move downwards, so that synchronous movement control of the first piston and the second piston in the pump body is formed.

Similarly, in other embodiments, other driving mechanisms may be adopted to perform independent driving control on the first piston and the second piston, and the movement of the first piston and the second piston is controlled in a linkage manner through the matching control of the driving mechanisms.

Further, in the emulsion pump of this embodiment, a piston elastic member 6 is further provided. The piston elastic member 6 is a coil spring and is located in the medium chamber 151 between the pump body 1 and the first piston 21 to drive the first piston 21 to move relative to the pump body 1 in a direction to increase the volume of the medium chamber 151.

At this moment, after the driving acting force on the handle is relieved, the first piston can move relative to the pump body under the action of the restoring force of the elastic piston piece, the handle is driven to rotate by the first piston rod, and then the second piston is driven to synchronously move by the second piston rod, so that the automatic resetting of the handle, the first piston and the second piston is realized.

In addition, two connecting grooves 42 are provided on the handle 4 of the present embodiment for accommodating the pin connected to the first piston rod 51 and the pin connected to the second piston rod 52 for reciprocal sliding movement, respectively. Therefore, the handle can smoothly drive the first piston rod and the second piston rod to reciprocate in the linear direction, the jamming of the first piston rod and the second piston rod in the driving process is avoided, and the working stability and reliability of the emulsion pump are improved.

With reference to fig. 1 and 3, in view of the design that the air inlet 13 is disposed in the pump body 1 near the upper end, one end of the auxiliary air channel 221, which is communicated with the air pressure cavity 152, extends to the upper end of the second piston rod 52, so that the height of the end of the auxiliary air channel 221, which is communicated with the air pressure cavity 152, is higher than the height of the position at which the air inlet 13 is communicated with the external air pressure, and the top of the second piston rod 52 is designed to be in the form of a protective cover structure, so as to isolate and protect the auxiliary air channel 221.

Like this, in this emulsion pump's working process, even if there is external sewage to flow into the atmospheric pressure chamber through the air inlet, because the position of supplementary air flue and atmospheric pressure chamber intercommunication is higher than the position of air inlet, so external sewage can fall in the bottom position in atmospheric pressure chamber under the dead weight effect to keep away from supplementary air flue, reached the risk that prevents external sewage and get into the container through the air inlet, improved the protection to the medium in the container.

Referring to fig. 1, in the present embodiment, the second piston 22 is divided into the pneumatic chamber 152, a drain chamber 153 is formed between the first piston 21 and the second piston 22, and the first piston rod 51 is provided with a first drain passage 511 and a second drain passage 512. One end of the first drainage channel 511 is communicated with the air pressure cavity 152, the other end is communicated with the drainage cavity 153, and the third one-way valve 33 is arranged on the first drainage channel 511, so that the liquid flows into the drainage cavity 153 from the air pressure cavity 152 in one way. One end of the second liquid discharge channel 512 is communicated with the liquid discharge cavity 153, the other end extends to be communicated with the outside of the pump body 1, and a fourth one-way valve 34 is arranged on the second liquid discharge channel 512, so that the liquid flows out of the pump body 1 from the liquid discharge cavity 153 in one way.

At this time, when the first piston and the second piston move relatively to increase the volume of the liquid discharge cavity, the air pressure in the liquid discharge cavity is reduced, the air pressure in the air pressure cavity drives the third one-way valve to open, and liquid remained in the air pressure cavity, such as external sewage flowing in through the air inlet, flows into the liquid discharge cavity through the first liquid discharge channel; when the first piston and the second piston move oppositely and relatively to reduce the volume of the liquid discharge cavity, the air pressure in the liquid discharge cavity is increased, the third one-way valve is closed, the fourth one-way valve is opened, and therefore liquid in the liquid discharge cavity is discharged to the outside of the pump body through the second liquid discharge channel. Therefore, the external sewage flowing into the air pressure cavity through the air inlet can be discharged in time, and the protection of the medium in the container in the use process of the emulsion pump is further improved.

Referring to fig. 1, in the lotion pump of this embodiment, a third piston 23 is further provided, as well as a fifth check valve 35 and a sixth check valve 36. The third piston 23 is located in the pneumatic chamber 152 and is sleeved and fixed on the first piston rod 51 in a parallel relationship with the first piston 21, so as to form a fixed connection relationship with the first piston 21. The second piston 22 is located between the first piston 21 and the third piston 23, and the third piston 23 subdivides the pneumatic chamber 152, forming a suck-back chamber 154 between the third piston 23 and the second piston 22. A fifth one-way valve 35 is located between the suck back chamber 154 and the output conduit 12 to allow one-way flow of media from the output conduit 12 into the suck back chamber 154, and a sixth one-way valve 36 is also located between the suck back chamber 154 and the output conduit 12 to allow one-way flow of media from the suck back chamber 154 into the output conduit 12.

At this time, when the first piston moves towards the direction of increasing the volume of the medium cavity, the second one-way valve is closed due to the fact that the air pressure is increased and decreased when the volume of the medium cavity increases, and meanwhile the third piston moves synchronously with the first piston and moves backwards with the second piston, so that the air pressure is increased and decreased when the volume of the suck-back cavity increases, the fifth one-way valve is opened, the medium remained in the output pipeline is sucked back into the suck-back cavity, and overflow and air drying blockage of the medium remained in the output pipeline are avoided. On the contrary, when the first piston moves towards the direction of reducing the volume of the medium cavity again and outputs the medium in the medium cavity through the output pipeline, the third piston moves synchronously along with the first piston and forms relative movement with the second piston, so that the volume of the suck-back cavity is reduced, the air pressure is increased, the sixth one-way valve is opened, the medium sucked back into the suck-back cavity is output into the output pipeline and is output along with the medium in the medium cavity.

In addition, in this embodiment, first check valve adopts the ball valve structural style that a single steel ball constitutes, when being connected this emulsion pump with the container like this, first check valve utilizes self gravity just can form the conventional shutoff effect to the suction line, and the atmospheric pressure in medium chamber reduces to the container atmospheric pressure can make the medium flow into in the medium chamber through the suction line when the first check valve removal can be promoted, thereby form the automatic start-stop action of first check valve along with first piston motion, thereby improve the simple operation nature of this emulsion pump.

Meanwhile, in the embodiment, the second one-way valve, the third one-way valve, the fourth one-way valve, the fifth one-way valve and the sixth one-way valve are all in a ball valve structure formed by a steel ball and a spring, so that the opening and closing of the corresponding one-way valves can be controlled by utilizing the air pressure change formed by the movement of the corresponding piston relative to the pump body and the acting force of the spring in the corresponding one-way valve, the convenience of control operation is achieved, and the one-way valves can be kept in a normally closed state by means of the spring so as to ensure the reliability and accuracy of actions.

Of course, in other embodiments, according to different design and use conditions, check valves of other structural forms, such as electromagnetic check valves, may also be adopted, and active opening and closing control is performed on each check valve in a remote electric control manner, so as to achieve the effect of remote active control.

Referring to fig. 1 to 3, the emulsion pump of this embodiment is operated and used in the following specific process:

after the emulsion pump and the container are fixedly installed in a threaded manner, the first piston 21 moves in a direction of increasing the volume of the medium cavity 151 under the restoring acting force of the piston elastic member 6, the first piston 21 drives the handle 4 to rotate through the first piston rod 51, the handle 4 drives the second piston 22 to move in a direction close to the medium cavity 151 through the second piston rod 52, so that the first piston 21 finally moves to a position in contact with the second piston 22, as shown in fig. 1, the handle 4 is in a natural balance state, and at this time, the auxiliary air channel 221 and the air outlet 14 are kept in a disconnected relation.

When the handle 4 is pressed, the handle 4 drives the first piston rod 51 to move downward with the rotating shaft 41 as a fulcrum, and drives the first piston 21 to move in a direction of reducing the volume of the medium cavity 151 against the acting force of the piston elastic member 6, so that the volume of the medium cavity 151 is reduced, the air pressure is increased, the first check valve 31 is closed, the second check valve 32 is opened, and the medium in the medium cavity 151 is output through the output pipeline 12.

In this process, on one hand, the handle 4 further uses the rotating shaft 41 as a fulcrum to drive the second piston rod 52 to move upwards, so as to drive the second piston 22 to move towards a direction away from the first piston 21, so that the auxiliary air passage 221 is communicated with the air outlet 14, so that the inner cavity of the container is communicated with the external atmosphere through the air outlet 14, the auxiliary air passage 221, the air pressure cavity 152 and the air inlet 13, so as to maintain a balance relationship between the air pressure in the container and the external air pressure, and on the other hand, the movement of the second piston 22 towards a direction away from the first piston 21 increases the volume of the liquid discharge cavity 153, reduces the air pressure, maintains the air pressure in the air pressure cavity 152 at the atmospheric pressure, so as to open the third one-way valve 33, so that the liquid in the air pressure cavity 152 flows into the liquid discharge cavity 153 through the first liquid discharge passage 511 and the third one-way valve 33. On the other hand, the third piston 23 moves synchronously with the first piston rod 51 downward, so that the second piston 22 and the third piston 23 move relatively to each other, the volume of the suck-back chamber 154 decreases, the air pressure increases, the air pressure in the output pipe 12 is approximately equal to the external atmospheric pressure, the sixth check valve 36 opens, and the medium in the suck-back chamber 154 flows into the output pipe 12 through the sixth check valve 36 and is output together with the medium in the medium chamber 151.

When the handle 4 is bottomed out and the force applied to the handle 4 is released, the first piston 21 stops moving downward and starts moving upward under the restoring force of the piston elastic member 6, so that the volume of the medium chamber 151 increases and the pressure decreases, and the first check valve 31 opens when the air pressure of the first piston 21 moving into the medium chamber 151 decreases to the air pressure in the container, so that the medium in the container flows into the medium chamber 151 through the suction pipe 11 and the first check valve 31 to be discharged again from the medium chamber 151 through the discharge pipe 12.

In the process, before the first piston 21 moves to be in contact with the second piston 22 to enable the handle 4 to be in a balance position and stop moving continuously, on one hand, the first piston 21 moves to drive the handle 4 to rotate reversely through the first piston rod 51, the handle 4 drives the second piston 22 to move towards the direction close to the first piston 21 through the second piston rod 52, and the auxiliary air channel 221 continues to keep a communication relation with the air outlet 14, so that the air pressure in the container is kept in an external atmospheric pressure state, and the medium in the container can smoothly enter the medium cavity 151. On the other hand, when the second piston 22 moves in a direction approaching the first piston 21, the volume of the liquid discharge chamber 153 decreases and the air pressure increases until the air pressure increases to a level at which the fourth check valve 34 opens, and then the liquid in the liquid discharge chamber 153 can be discharged to the outside of the pump body 1 through the second liquid discharge passage 512 and the fourth check valve 34. On the other hand, the third piston 23 moves synchronously with the first piston rod 51 in the upward direction, so that the second piston 22 and the third piston 23 move in the backward direction, the volume of the suck-back chamber 154 increases and the air pressure decreases, and the air pressure of the output pipe 12 is the external atmospheric pressure, so that the fifth check valve 35 opens, the medium remaining in the output pipe 12 flows into the suck-back chamber 154 through the fifth check valve 35, and the suck-back process of the medium remaining in the output pipe 12 is completed.

In the present embodiment, the end of the auxiliary air passage 221 selectively communicated with the air outlet 14 is disposed on the outer circumferential surface of the second piston 22 and is configured as an annular groove structure along the axial direction of the second piston 22, so that the communication relationship between the auxiliary air passage 221 and the air outlet 14 can be always maintained in the process that the second piston 22 reciprocates along with the handle 4 relative to the pump body 1, and the air pressure in the container is maintained in a state opposite to the external atmospheric pressure, so as to ensure the normal output operation of the emulsion pump on the medium.