Pneumatic rotary valve metering pump

Abstract

The utility model relates to the technical field of metering pumps, and provides a pneumatic rotary valve metering pump which comprises a rotary valve, a metering mechanism, a driving mechanism, a reversing mechanism and an adjusting screw rod. The rotary valve is provided with a feeding port, a discharging port, a material storage cavity and a three-way valve element. The reversing mechanism comprises a reversing piece, a reversing cylinder body, a reversing piston, a reversing valve element and a reversing cavity. According to the pneumatic rotary valve metering pump provided by the utility model, the action that the three-way valve core is alternately communicated with the material inlet, the material outlet and the material storage cavity is linked with the action that gas of the first gas output port and the second gas output port is alternately conveyed to the first driving cavity and the second driving cavity at the same time, so that the suction or pump-out value is more accurate; according to the metering pump, the volume change of the material storage cavity is more accurate, the metering pump is more accurate due to the combination of the metering pump and the material storage cavity, even if gas transmission power is interrupted, materials sucked or pumped out by the metering pump are accurate, the accuracy can be improved, the structure of the metering pump is simpler, and the cost is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of metering pumps, in particular to a pneumatic rotary valve metering pump. Background Art

[0002] Metering pump is a kind of fluid conveying machinery, and its outstanding feature is that it can maintain a constant flow rate regardless of the discharge pressure. Metering pumps can simultaneously complete the functions of conveying, metering and regulation, thereby simplifying the production process. Using multiple metering pumps, several media can be input into the process flow in accurate proportions for mixing. Due to its own outstanding features, metering pumps have now been widely used in various industrial fields such as petrochemicals, pharmaceuticals, and food.

[0003] The metering pump in the prior art controls the movement stroke of the driving piston in the driving mechanism to make the metering piston of the metering mechanism perform reciprocating sliding motion of the corresponding stroke, thereby alternately changing the volume of the one-way valve storage chamber to inhale or pump out the material and achieve the purpose of quantitatively conveying the material.

[0004] The pneumatic metering pump uses gas as a power source to make the driving piston reciprocate, thereby making the metering piston reciprocate. The reciprocating motion of the driving piston needs to rely on the solenoid valve to alternately control the gas intake on both sides of the driving piston.

[0005] However, in the related pneumatic metering pump technology, the motion control of the metering piston is achieved solely by relying on the solenoid valve and the power gas. The gas transmission power is intermittent, making the motion control of the metering piston difficult and causing the metering value of the material to be sucked in or pumped out to be too much or too little. The metering value has poor accuracy and requires more control components, making the structure of the pneumatic metering pump more complicated, resulting in high manufacturing costs. Utility Model Content

[0006] In view of the shortcomings of the prior art, the utility model provides a pneumatic rotary valve metering pump to solve at least one of the above-mentioned technical defects in the prior art, making the movement control of the metering piston in the pneumatic rotary valve metering pump easier, avoiding excessive or insufficient metering values ​​of the pumped material, improving the accuracy of the metering value, and not requiring more control components, thereby simplifying the structure of the metering pump and reducing manufacturing costs.

[0007] In order to achieve the purpose of the utility model, the utility model provides a pneumatic rotary valve metering pump, which includes:

[0008] The rotary valve has a material inlet, a material outlet, a material storage cavity and a three-way valve core;

[0009] The metering mechanism comprises a metering cylinder and a metering piston, wherein the metering cylinder is connected to the material storage cavity, and the metering piston is slidably connected to the metering cylinder and is suitable for changing the volume of the material storage cavity;

[0010] The driving mechanism comprises a driving member, a driving piston and a driving cylinder, wherein the first end of the driving member is connected to the metering piston, the second end of the driving member is connected to the driving piston, and the driving piston is slidably connected to the driving cylinder.

[0011] The driving piston divides the driving cylinder into a first driving chamber and a second driving chamber;

[0012] an adjusting screw rod, extending into the second driving chamber through a spiral connection, and adapted to adjust the sliding stroke of the driving piston in the driving cylinder;

[0013] The reversing mechanism comprises a reversing member, a reversing cylinder and a reversing piston. The reversing member is connected to the reversing piston. The reversing member slides in the reversing cylinder to make reciprocating motion. The reversing member is drivingly connected to the three-way valve core and is suitable for driving the three-way valve core to rotate.

[0014] The reversing mechanism also has a reversing valve core and a reversing cavity, wherein the reversing cavity is provided with a gas input port, a first gas output port and a second gas output port.

[0015] The reversing piston is connected to the reversing valve core to drive the reversing valve core to reciprocate in the reversing chamber.

[0016] When the reversing valve core moves in the second direction, the reversing member moves in the second direction to drive the three-way valve core to connect the feed port and the storage chamber, the first gas output port is connected to the first drive chamber, and the drive piston slides in the second direction.

[0017] When the reversing valve core moves in the first direction, the reversing member moves in the first direction to drive the three-way valve core to connect the discharge port with the storage chamber, the second gas output port is connected with the second drive chamber, and the drive piston slides in the first direction.

[0018] Preferably, the reversing member comprises a reversing rack and a reversing gear that match each other.

[0019] The reversing rack is connected to the reversing piston, and the reversing gear is coaxially connected to the three-way valve core.

[0020] Preferably, the reversing mechanism is further provided with a refueling nozzle, and the refueling nozzle is connected to the joint where the reversing rack and the reversing gear are connected to each other.

[0021] Preferably, the reversing mechanism is further provided with a sealing sleeve, the sealing sleeve is sleeved on the reversing valve core, and the gas inlet is connected to the space between the sealing sleeve and the reversing valve core.

[0022] When the reversing valve core moves in the second direction, the first gas outlet is connected to the gas inlet.

[0023] When the reversing valve core moves toward the first direction, the second gas output port is communicated with the gas input port.

[0024] Preferably, the reversing mechanism further includes a reversing connecting rod, the reversing connecting rod is passed through the reversing valve core, and the reversing connecting rod is connected to the reversing member.

[0025] Preferably, the connection between the reversing gear and the three-way valve core is coordinated through a spring and a top column.

[0026] Preferably, the reversing piston divides the reversing cylinder into a first reversing drive chamber and a second reversing drive chamber.

[0027] The reversing mechanism is also provided with a first pneumatic interface and a second pneumatic interface, the first pneumatic interface is connected to the first reversing drive chamber, the second pneumatic interface is connected to the second reversing drive chamber, the first pneumatic interface and the second pneumatic interface are alternately supplied with air, and are suitable for driving the reversing piston to reciprocate along the reversing cylinder body.

[0028] Preferably, the driving mechanism further includes a first throttle valve and a second throttle valve.

[0029] The first throttle valve is disposed between the first gas output port and the first driving chamber, and the second throttle valve is disposed between the second gas output port and the second driving chamber.

[0030] Preferably, it further comprises a first connecting air pipe and a second connecting air pipe,

[0031] The first gas output port is connected to the first driving cavity through the first connecting gas pipe.

[0032] The second gas output port is connected to the second driving cavity through the second connecting gas pipe.

[0033] Preferably, the portion of the adjusting screw extending outward is provided with a scale.

[0034] The beneficial effects of the utility model are as follows: the utility model provides a pneumatic rotary valve metering pump, which provides a rotary valve with a rotatable three-way valve core that alternately connects an inlet, an outlet and a storage chamber, and a reversing mechanism including a reversing member, a reversing cylinder, a reversing piston, a reversing valve core and a reversing chamber; the three-way valve core can accurately and alternately connect with the inlet, the outlet and the storage chamber through the reversing member as the reversing piston moves in the reversing cylinder; and under the action of the reciprocating motion of the reversing valve core along the reversing chamber, gas can be alternately transported from the first gas outlet and the second gas outlet to the first driving chamber and the second driving chamber in the driving cylinder body through the input port provided in the reversing chamber, so that the driving piston and the metering piston reciprocate, thereby changing the volume of the storage chamber and realizing the suction or pumping out of the material; because the reversing member is connected to the three-way valve core in driving manner, and the reversing member is connected to the reversing valve core through the reversing piston, the three-way valve The action of the rotary valve whose core alternately connects the feed port, the feed port and the storage chamber, and the action of alternately delivering the gas from the first gas output port and the second gas output port to the first drive chamber and the second drive chamber in the drive cylinder body occur simultaneously in linkage, so that the suction or pumping value of the material can be made more accurate through the three-way valve core, and the volume change of the storage chamber can be made more accurate through the alternation of the gas from the first gas output port and the second gas output port. The combination of the two makes the metering value of the pneumatic rotary valve metering pump more accurate, and even if the gas transmission power is intermittent, the metering value of the material sucked or pumped out by the metering pump will not be too much or too little, which can improve the accuracy of the metering value and make the movement control of the metering piston easier. The alternating control of the gas from the first gas output port and the second gas output port does not require an additional solenoid valve, that is, does not require more control components, so that the structure of the pneumatic rotary valve metering pump becomes simpler and the manufacturing cost is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The above and other purposes, features and advantages of the present invention will become more clear through a more specific description of the preferred embodiments of the present invention shown in the accompanying drawings. The same reference numerals indicate the same parts in all the accompanying drawings, and the drawings are not deliberately scaled to the actual size, but the focus is on illustrating the subject matter of the present application.

[0036] Figure 1 A schematic diagram of the overall structure of a pneumatic rotary valve metering pump provided by an embodiment of the utility model;

[0037] Figure 2 for Figure 1 The top view of

[0038] Figure 3 for Figure 1 Sectional view of AA in the middle;

[0039] Figure 4 for Figure 1 Cross-sectional view of the middle BB;

[0040] Figure 5 for Figure 1 Cross-sectional view of CC;

[0041] Figure 6 Schematic diagram of the internal components of the reversing mechanism.

[0042] In the figure:

[0043] 100, rotary valve; 110, feed inlet; 120, discharge outlet; 130, material storage chamber; 140, three-way valve core;

[0044] 200, metering mechanism; 210, metering cylinder; 220, metering piston;

[0045] 300, driving mechanism; 310, driving member; 320, driving piston; 330, driving cylinder; 331, first driving chamber; 332, second driving chamber; 340, first throttle valve; 350, second throttle valve;

[0046] 400, reversing mechanism; 410, reversing member; 411, reversing rack; 412, reversing gear; 420, reversing cylinder; 421, first reversing drive chamber; 422, second reversing drive chamber; 430, reversing piston; 440, reversing valve core; 450, reversing chamber; 451, gas input port; 452, first gas output port; 4521, first pneumatic interface; 453, second gas output port; 4531, second pneumatic interface; 460, oiling nozzle; 470, sealing sleeve; 480, reversing connecting rod;

[0047] 500, adjusting screw;

[0048] 600, a first connecting air pipe;

[0049] 700, a second connecting air pipe;

[0050] 800, coupling; 810, spring; 820, top column. DETAILED DESCRIPTION

[0051] In order to facilitate the understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings.

[0052] It should be noted that when an element is considered to be "connected" to another element, it may be directly connected to another element and integrated therewith, or there may be an intermediate element at the same time. The terms "installed", "one end", "the other end" and similar expressions used herein are for illustrative purposes only.

[0053] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention pertains. The terms used in the specification herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0054] Combine the following Figures 1 to 6 It should be understood that the following description is only an illustrative embodiment of the present invention and does not constitute any limitation to the present invention.

[0055] See also Figures 1 to 6 An embodiment of the utility model provides a pneumatic rotary valve metering pump, which includes a rotary valve 100, a metering mechanism 200, a driving mechanism 300, a reversing mechanism 400 and an adjusting screw 500.

[0056] The rotary valve 100 has an inlet 110, an outlet 120, a storage chamber 130 and a three-way valve core 140. The three-way valve core 140 can rotate in the storage chamber 130 so that the inlet 110 and the outlet 120 can be alternately connected to the storage chamber 130.

[0057] The metering mechanism 200 includes a metering cylinder 210 and a metering piston 220. The metering cylinder 210 is connected to the material storage chamber 130, and the metering piston 220 is slidably connected in the metering cylinder 210, which can change the volume of the material storage chamber 130 so that the material storage chamber 130 can inhale or pump out materials to achieve material transportation.

[0058] The driving mechanism 300 includes a driving member 310, a driving piston 320 and a driving cylinder 330. The first end of the driving member 310 is connected to the metering piston 220, the second end of the driving member 310 is connected to the driving piston 320, the driving piston 320 is slidably connected in the driving cylinder 330, and when the driving piston 320 slides, the metering piston 220 also slides in the metering cylinder 210.

[0059] The driving piston 320 divides the interior of the driving cylinder 330 into a first driving chamber 331 and a second driving chamber 332 .

[0060] The adjusting screw 500 extends into the second driving chamber 332 through a spiral connection to adjust the sliding stroke of the driving piston 320 in the driving cylinder 330, which can accurately ensure the sliding stroke of the metering piston 220, thereby improving the accuracy of the volume change of the storage chamber 130 and improving the accuracy of the metering pump.

[0061] The reversing mechanism 400 includes a reversing member 410, a reversing cylinder 420 and a reversing piston 430. The reversing member 410 is connected to the reversing piston 430, and the reversing member 410 reciprocates as the reversing piston 430 slides in the reversing cylinder 420. The reversing member 410 is drivingly connected to the three-way valve core 140, and can drive the three-way valve core 140 to rotate.

[0062] The reversing mechanism 400 further comprises a reversing valve core 440 and a reversing chamber 450. The reversing chamber 450 is provided with a gas input port 451, a first gas output port 452 and a second gas output port 453.

[0063] The reversing piston 430 is connected to the reversing valve core 440 to drive the reversing valve core 440 to reciprocate in the reversing chamber 450 .

[0064] When the reversing valve core 440 moves to the second direction ( Figure 5 When the metering piston 220 moves in the second direction, the volume of the storage chamber 130 increases, and the material can enter the storage chamber 130 through the feed inlet 110, thereby realizing the suction of the material.

[0065] When the reversing valve core 440 moves in the first direction ( Figure 5 , the metering piston 220 also moves in the first direction, the volume of the storage chamber 130 becomes smaller, and the material is discharged from the storage chamber 130 through the discharge port 120, thereby achieving the pumping out of the material.

[0066] The movement of the reversing mechanism 400, the rotational movement of the three-way valve core 140 and the reciprocating movement of the metering piston 220 enable accurate quantitative delivery of the material.

[0067] It can be understood that the pneumatic rotary valve metering pump provided in the embodiment of the utility model is provided with a rotary valve 100 having a rotatable three-way valve core 140 that alternately connects the feed port 110, the discharge port 120 and the storage chamber 130, and a reversing mechanism 400 including a reversing member 410, a reversing cylinder body 420, a reversing piston 430, a reversing valve core 440 and a reversing chamber 450; the three-way valve core 140 can accurately connect the feed port 110, the discharge port 120 and the storage chamber 130 through the reversing member 410 with the reciprocating motion of the reversing piston 430 in the reversing cylinder body 420. 130 are alternately connected; and under the action of the reciprocating motion of the reversing valve core 440 along the reversing chamber 450, the gas can be alternately delivered from the first gas output port 452 and the second gas output port 453 to the first driving chamber 331 and the second driving chamber 332 in the driving cylinder body 330 through the input port provided in the reversing chamber 450, so that the driving piston 320 and the metering piston 220 can reciprocate, thereby changing the volume of the storage chamber 130 and realizing the suction or pumping out of the material; because the reversing member 410 is driven and connected to the three-way valve core 140, the reversing member 410 is driven and connected to the three-way valve core 140, and the reversing member 410 is driven and connected to the three-way valve core 140. The reversing piston 430 is connected to the reversing valve core 440, so that the three-way valve core 140 alternately connects the feed port 110, the discharge port 120 and the storage chamber 130, and the action of the rotary valve 100 and the action of the gas from the first gas output port 452 and the second gas output port 453 alternately transported to the first drive chamber 331 and the second drive chamber 332 in the drive cylinder body 330 are simultaneously linked, so that the three-way valve core 140 can make the material suction or pumping value more accurate, and the gas from the first gas output port 452 and the second gas output port 453 can be alternately used to make the storage chamber 130 The volume change of the cavity 130 is more accurate. The combination of the two makes the metering value of the pneumatic rotary valve 100 metering pump more accurate. Even if the gas transmission power is intermittent, the metering value of the material sucked in or pumped out by the metering pump will not be too much or too little, which can improve the accuracy of the metering value and make the movement control of the metering piston 220 easier. The alternating gas control of the first gas output port 452 and the second gas output port 453 does not require an additional solenoid valve, that is, no more control components are required, so that the structure of the pneumatic rotary valve 100 metering pump becomes simpler and the manufacturing cost is reduced.

[0068] Specifically, in order to further enable the three-way valve core 140 to rotate more accurately and alternately connect the inlet 110, the outlet 120 and the storage chamber 130, in some embodiments of the present invention, the reversing member 410 includes a reversing rack 411 and a reversing gear 412, and the reversing rack 411 and the reversing gear 412 match each other.

[0069] The reversing rack 411 is connected to the reversing piston 430, and the reversing gear 412 is coaxially connected to the three-way valve core 140. When the reversing rack 411 slides back and forth with the reciprocating motion of the reversing piston 430 in the reversing chamber 450, the reversing gear 412 can rotate back and forth, so that the three-way valve core 140 can also rotate, so as to alternately connect the feed port 110, the discharge port 120 and the storage chamber 130, so as to achieve the suction and pumping of materials.

[0070] Combination Figure 5 Furthermore, in some embodiments of the present invention, the reversing mechanism 400 is also provided with a lubricating nozzle 460, which is connected to the interconnection between the reversing rack 411 and the reversing gear 412, and can lubricate and cool the reversing rack 411 and the reversing gear 412 to reduce the friction resistance of the reversing rack 411 and the reversing gear 412 and improve their service life.

[0071] Combination Figure 5 In some embodiments of the present utility model, the reversing mechanism 400 is further provided with a sealing sleeve 470 , the sealing sleeve 470 is sleeved on the reversing valve core 440 , and the gas input port 451 is connected to the space between the sealing sleeve 470 and the reversing valve core 440 .

[0072] Among them, the sealing sleeve 470 can be a copper sleeve, and there can be multiple copper sleeves. Each adjacent copper sleeve is sealed and connected using a sealing ring. Each copper sleeve is provided with a through hole, and the reversing valve core 440 is provided with recesses and protrusions arranged at intervals on the outside, so that the first gas output port 452 and the second gas output port 453 are alternately connected to the gas input port 451.

[0073] When the reversing valve core 440 moves in the second direction, the first gas output port 452 is connected to the gas input port 451 through a through hole on one of the copper sleeves, and the gas can be input into the first driving chamber 331 from the first gas output port 452 .

[0074] When the reversing valve core 440 moves in the first direction, the second gas output port 453 is connected to the gas input port 451 through the through hole on the other copper sleeve, and the gas can be input into the second driving chamber 332 from the second gas output port 453 .

[0075] Of course, in order to arrange the various mechanisms of the pneumatic rotary valve metering pump more reasonably and save the installation space of the metering pump, in this embodiment,

[0076] The first gas output port 452 can be connected to the first driving cavity 331 using a first connecting gas pipe 600.

[0077] The second gas output port 453 can be connected to the second driving cavity 332 using a second connecting gas pipe 700 .

[0078] Combination Figure 5In some embodiments of the present invention, in order to strengthen the connection force between the reversing valve core 440 and the reversing member 410 and the reversing piston 430, and to prevent the metering pump from being damaged due to movement and falling off, in some embodiments of the present invention, the reversing mechanism 400 further includes a reversing connecting rod 480. The reversing connecting rod 480 is inserted through the reversing valve core 440, and the reversing connecting rod 480 is connected to the reversing member 410.

[0079] Combination Figure 4 In some embodiments of the utility model, the connection between the reversing gear 412 and the three-way valve core 140 can also be matched with a spring 810 and a top column 820 to buffer the vibration between the reversing mechanism 400 and the rotary valve 100, thereby improving the metering accuracy of the metering pump. Of course, the coupling 800 with the spring 810 and the top column 820 can also be directly used to connect the reversing mechanism 400 and the rotary valve 100.

[0080] Combination Figure 5 In some embodiments of the present invention, the reversing piston 430 divides the reversing cylinder 420 into a first reversing driving chamber 421 and a second reversing driving chamber 422 .

[0081] The reversing mechanism 400 is also provided with a first pneumatic interface 4521 and a second pneumatic interface 4531. The first pneumatic interface 4521 is connected to the first reversing drive chamber 421, and the second pneumatic interface 4531 is connected to the second reversing drive chamber 422. The first pneumatic interface 4521 and the second pneumatic interface 4531 are alternately air-intaken, which can drive the reversing piston 430 to reciprocate along the reversing cylinder body 420. The first pneumatic interface 4521 and the second pneumatic interface 4531 can be connected to the solenoid valve on the equipment installed with the pneumatic rotary valve metering pump, so that the pneumatic rotary valve metering pump does not need to be provided with a corresponding solenoid valve, which can save manufacturing costs.

[0082] Combination Figure 1 and Figure 2 In some embodiments of the present invention, the driving mechanism 300 further includes a first throttle valve 340 and a second throttle valve 350 .

[0083] The first throttle valve 340 is disposed between the first gas output port 452 and the first driving chamber 331 , and the second throttle valve 350 is disposed between the second gas output port 453 and the second driving chamber 332 .

[0084] The first throttle valve 340 can control the flow rate of the gas entering the first drive chamber 331, and the second throttle valve 350 can control the flow rate of the gas entering the second drive chamber 332, thereby controlling the sliding speed of the drive piston 320, and then controlling the sliding speed of the metering piston 220, so that the rated metering value of the pneumatic rotary valve metering pump can be easily adjusted by simply adjusting the corresponding throttle valve, which is easy to operate.

[0085] Of course, in order to visualize the adjustment of the rated metering value of the pneumatic rotary valve metering pump and make the adjustment simpler and more convenient, in some embodiments of the utility model, the part of the adjusting screw 500 extending to the outside is provided with a scale. When the adjusting screw 500 is rotated to adjust the pneumatic rotary valve metering pump, the metering value can be determined by reading the scale on the adjusting screw 500.

[0086] In this specification, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0087] In the description of this specification, the description with reference to the terms "preferred embodiment", "further embodiment", "some embodiments", "other embodiments" or "specific example" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0088] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A pneumatic rotary valve metering pump, characterized in that: include: The rotary valve has a material inlet, a material outlet, a material storage cavity and a three-way valve core; The metering mechanism comprises a metering cylinder and a metering piston, wherein the metering cylinder is connected to the material storage cavity, and the metering piston is slidably connected to the metering cylinder and is suitable for changing the volume of the material storage cavity; The driving mechanism comprises a driving member, a driving piston and a driving cylinder, wherein the first end of the driving member is connected to the metering piston, the second end of the driving member is connected to the driving piston, and the driving piston is slidably connected to the driving cylinder. The driving piston divides the driving cylinder into a first driving chamber and a second driving chamber; an adjusting screw rod, extending into the second driving chamber through a spiral connection, and adapted to adjust the sliding stroke of the driving piston in the driving cylinder; The reversing mechanism comprises a reversing member, a reversing cylinder and a reversing piston. The reversing member is connected to the reversing piston. The reversing member slides in the reversing cylinder to make reciprocating motion. The reversing member is drivingly connected to the three-way valve core and is suitable for driving the three-way valve core to rotate. The reversing mechanism also has a reversing valve core and a reversing cavity, wherein the reversing cavity is provided with a gas input port, a first gas output port and a second gas output port. The reversing piston is connected to the reversing valve core to drive the reversing valve core to reciprocate in the reversing chamber. When the reversing valve core moves in the second direction, the reversing member moves in the second direction to drive the three-way valve core to connect the feed port and the storage chamber, the first gas output port is connected to the first drive chamber, and the drive piston slides in the second direction. When the reversing valve core moves in the first direction, the reversing member moves in the first direction to drive the three-way valve core to connect the discharge port with the storage chamber, the second gas output port is connected with the second drive chamber, and the drive piston slides in the first direction.

2. The pneumatic rotary valve metering pump according to claim 1, characterized in that: The reversing member includes a reversing rack and a reversing gear that match each other. The reversing rack is connected to the reversing piston, and the reversing gear is coaxially connected to the three-way valve core.

3. The pneumatic rotary valve metering pump according to claim 2, characterized in that: The reversing mechanism is also provided with a refueling nozzle, and the refueling nozzle is connected to the mutual connection and cooperation position of the reversing rack and the reversing gear.

4. The pneumatic rotary valve metering pump according to claim 1, characterized in that: The reversing mechanism is further provided with a sealing sleeve, which is sleeved on the reversing valve core, and the gas inlet is connected to the space between the sealing sleeve and the reversing valve core. When the reversing valve core moves in the second direction, the first gas outlet is connected to the gas inlet. When the reversing valve core moves toward the first direction, the second gas output port is communicated with the gas input port.

5. The pneumatic rotary valve metering pump according to claim 4, characterized in that: The reversing mechanism further includes a reversing connecting rod, the reversing connecting rod is penetrated through the reversing valve core, and the reversing connecting rod is connected to the reversing member.

6. The pneumatic rotary valve metering pump according to claim 2, characterized in that: The connection between the reversing gear and the three-way valve core is matched through a spring and a top column.

7. The pneumatic rotary valve metering pump according to claim 1, characterized in that: The reversing piston divides the reversing cylinder into a first reversing drive chamber and a second reversing drive chamber. The reversing mechanism is also provided with a first pneumatic interface and a second pneumatic interface, the first pneumatic interface is connected to the first reversing drive chamber, the second pneumatic interface is connected to the second reversing drive chamber, the first pneumatic interface and the second pneumatic interface are alternately supplied with air, and are suitable for driving the reversing piston to reciprocate along the reversing cylinder body.

8. The pneumatic rotary valve metering pump according to claim 1, characterized in that: The driving mechanism further includes a first throttle valve and a second throttle valve. The first throttle valve is disposed between the first gas output port and the first driving chamber, and the second throttle valve is disposed between the second gas output port and the second driving chamber.

9. The pneumatic rotary valve metering pump according to any one of claims 1 to 8, characterized in that: Also includes a first connecting air pipe and a second connecting air pipe, The first gas output port is connected to the first driving cavity through the first connecting gas pipe. The second gas output port is connected to the second driving cavity through the second connecting gas pipe.

10. The pneumatic rotary valve metering pump according to claim 1, characterized in that: The portion of the adjusting screw rod extending outward is provided with a scale.

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