Pneumatic metering pump

Abstract

According to the pneumatic metering pump, the feeding valve body and the discharging valve body are connected to the valve seat, so that when fluid is input into the valve bodies, the feeding valve body is opened, and the discharging valve body is closed; when fluid is output outwards from the valve body, the feeding valve body is closed, and the discharging valve body is opened; it is guaranteed that when the valve body outputs fluid outwards, external fluid cannot enter the valve body, and metering errors caused by mixing of the external fluid and the fluid in the valve body are avoided; meanwhile, the throttling valve is arranged to adjust the air inlet amount and the air outlet amount of the air cylinder, the power of the metering pump is adjusted, and therefore the metering pump can adapt to different use environments.

Description

Technical Field

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

[0002] A metering pump, also known as a quantitative pump or a proportional pump, is a pump specifically used for metering and conveying fluids. It relies on the reciprocating motion of the piston in the cylinder to change the volume of the sealed working chamber to achieve fluid delivery. A patent document with application number 202020596889.5 in China and announcement date 2021.3.2 discloses a high-precision fluid pneumatic adjustable metering pump, including a pump body, the pump body is provided with an air inlet and an exhaust port, the pump body is also provided with a liquid inlet, a liquid outlet, and an injection channel, the injection channel is provided with an injection push rod slidably connected thereto, the injection push rod is provided with a first reset elastic member, the end of the injection push rod is in contact with the stroke adjustment rod, a flow control valve is fixed on the stroke adjustment rod, an adjustment fixing seat is provided on the outer side of the stroke adjustment rod, and a flow control cap is provided on the outer side of the flow control valve. The flow rate is adjusted by rotating the flow control cap.

[0003] There is no sealing structure between the liquid inlet and the injection channel of the metering pump, and the medium outside the injection channel cannot be actively injected into the injection channel; when the medium in the injection channel is discharged, the medium outside the injection channel can easily enter the injection channel, thereby causing errors in the metering value of the medium.

[0004] At the same time, since there is no sealing structure between the liquid inlet and the injection channel, when the metering pump measures two media, the new medium will be mixed with the medium that has not been removed from the injection channel. In order to avoid errors in metering accuracy, it is necessary to open the sealing screw to remove the remaining medium in the injection channel, and the structure of the metering pump is complicated; at the same time, the metering pump cannot adjust the output power of the pump body. Utility Model Content

[0005] In view of this, the purpose of the utility model is to provide a pneumatic metering pump, in which the input and output ends of the valve body are provided with sealing structures, so that when fluid is input into the valve body, the feed valve body opens and the discharge valve body closes; when fluid is output from the valve body to the outside, the feed valve body closes and the discharge valve body opens; this ensures that when the valve body outputs fluid to the outside, external fluid cannot enter the valve body, thereby avoiding the mixing of external fluid and fluid in the valve body to cause metering errors; at the same time, a throttle valve is arranged to adjust the air intake and air output of the cylinder, thereby adjusting the power of the metering pump so that it can adapt to different usage environments.

[0006] In order to solve the above technical problems, the technical solution used in the utility model is:

[0007] The utility model discloses a pneumatic metering pump, comprising a valve mechanism, a metering piston cylinder and a pneumatic actuator connected in sequence, wherein the valve mechanism comprises a valve seat, a cavity is arranged in the valve seat, the cavity is communicated with the metering piston cylinder, the pneumatic actuator comprises a cylinder, the cylinder is used to drive the metering piston cylinder to move, a detachable feed valve body and a detachable discharge valve body are arranged on the valve seat; the feed valve body is used to control the on-off of the fluid input in the valve seat, and the discharge valve body is used to control the on-off of the fluid output in the valve seat; the pneumatic actuator also comprises a throttle valve, the throttle valve is connected to the cylinder, and the throttle valve is used to adjust the air intake and air output of the cylinder.

[0008] Preferably, two throttle valves are provided, and the pneumatic piston cylinder is provided with an air inlet pipe joint and an air outlet pipe joint, and the air inlet pipe joint and the air outlet pipe joint are respectively connected to the valve port of a throttle valve.

[0009] Preferably, the cylinder includes a cylinder body, a cylinder piston and a cylinder piston rod, the cylinder piston is movably arranged in the cylinder body, one end of the cylinder piston rod extends into the cylinder body and is connected to the cylinder piston rod, and the other end of the cylinder piston rod extends into the metering piston cylinder and is connected to the metering piston head of the metering piston cylinder; the pneumatic actuator also includes a stroke adjustment device, which is movably arranged in the cylinder body and is used to adjust the stroke of the cylinder piston.

[0010] Preferably, the stroke adjustment device includes a cylinder adjustment seat body and a cylinder adjustment screw; the cylinder adjustment seat body is fixed on the cylinder body, one end of the cylinder adjustment screw is threadedly connected to the cylinder adjustment seat body, and the other end of the cylinder adjustment screw passes through the cylinder adjustment seat body and extends into the cylinder body, and the cylinder adjustment screw is used to abut against the cylinder piston to limit the stroke of the cylinder piston.

[0011] Preferably, the feed valve body is provided with a feed port, the accommodating cavity is connected with a feed channel, and the feed valve core is connected with the feed port and the feed channel; an annular feed stopper is provided on the feed valve core, and the cross-sectional area of ​​the feed stopper is larger than the cross-sectional area of ​​the feed port; the elastic reset member is sleeved on the feed valve core and abuts against the feed stopper and the valve seat; under the elastic force of the elastic reset member, the feed stopper closes the feed port.

[0012] Preferably, the discharge valve body is provided with a discharge port, the cavity is connected with a discharge channel, and the discharge valve core is connected with the discharge port and the discharge channel; a ring-shaped discharge blocking portion is provided on the discharge valve core, and the cross-sectional area of ​​the discharge blocking portion is larger than the cross-sectional area of ​​the discharge channel; the elastic reset member is sleeved on the discharge valve core and abuts against the discharge blocking portion and the discharge valve body; under the elastic force of the elastic reset member, the discharge blocking portion closes the discharge channel.

[0013] Preferably, a sealing ring is provided on one side of the blocking portion close to the feed inlet.

[0014] Compared with the prior art, the beneficial effects of the pneumatic metering pump described in the utility model are mainly reflected in: by setting a throttle valve, the air intake and air outlet of the cylinder are adjusted through the throttle valve, the power of the cylinder is adjusted, and thus the power of the metering pump is adjusted, so that it can adapt to different usage environments.

[0015] The cylinder piston rod in the cylinder is directly connected to the metering piston head of the metering piston cylinder, and the metering piston head is directly driven to move back and forth through the action of the cylinder, and the structure is simple.

[0016] In the stroke adjustment device, the cylinder adjustment screw is threadedly connected to the cylinder adjustment seat body. By rotating the cylinder adjustment screw, the position of the end of the cylinder adjustment screw in the cylinder body is changed, thereby adjusting the maximum stroke of the cylinder piston. When the end of the cylinder adjustment screw is close to the fixed end of the cylinder, the movable stroke of the cylinder piston in the cylinder body is large, so that when the cylinder piston moves, the input and output flow rates are large; when the end of the cylinder adjustment screw is close to the movable end of the cylinder, the movable stroke of the cylinder piston in the cylinder body is small, so that when the cylinder piston moves, the input and output flow rates are small; the stroke of the cylinder is adjusted by the stroke adjustment device, thereby adjusting the flow rate of the conveying fluid of the metering pump.

[0017] The feed valve body and the discharge valve body are respectively connected to the valve seat, and sealing structures are provided at the input end and the output end of the valve seat, so that when the fluid is input into the valve seat, the feed valve body opens and the discharge valve body closes; when the fluid is output from the valve seat, the feed valve body closes and the discharge valve body opens; this ensures that when the valve seat outputs the fluid, external fluid cannot enter the valve seat, thereby avoiding the mixing of external fluid and fluid in the valve seat to cause metering errors.

[0018] When the metering piston head moves away from the cavity, the pressure in the cavity decreases, the pressure outside the valve seat is greater than the pressure inside the valve seat, the external fluid pushes the feed valve core to move, the feed stop is separated from the feed valve body, the feed port is connected with the cavity, and the fluid flows into the cavity from the feed port; at the same time, under the action of pressure, the external fluid presses the discharge valve core against the valve body, the discharge valve core closes the discharge channel, and the discharge port is disconnected from the cavity, preventing the fluid in the metering pump from flowing out when the fluid is input.

[0019] When the metering piston head moves toward the cavity, the pressure in the cavity increases, the pressure outside the valve seat is lower than the pressure inside the valve body, the fluid inside the valve seat pushes the discharge valve core to move, the discharge resistance part is separated from the discharge channel, the discharge port is connected with the cavity, and the fluid in the cavity flows out through the discharge port; at the same time, under the action of pressure, the fluid inside the valve seat pushes the feed valve core to move, the feed resistance part contacts the feed valve body and is pressed against the feed valve body, the feed port is disconnected from the cavity, to prevent fluid from flowing into the metering pump when the fluid is discharged.

[0020] By providing a sealing ring, the sealing effect between the feed stopper and the feed port is further improved, and the reliability is good.

[0021] The utility model adjusts the air intake and air outlet of the cylinder by setting a throttle valve, adjusts the power of the metering pump, and adjusts the maximum stroke of the cylinder by a stroke adjustment device to change the flow rate of the conveying fluid of the metering pump. The above settings can adapt to different usage environments. At the same time, a notch is provided on the feed valve core to increase the flow space between the feed valve core and the feed valve body, thereby improving the flow efficiency of the fluid. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and other purposes, features and advantages of the present invention will become more apparent through a more specific description of the preferred embodiments of the present invention shown in the accompanying drawings. The same reference numerals in all the accompanying drawings indicate the same parts, and the drawings are not intentionally scaled to the actual size, but the focus is on illustrating the subject matter of the present invention.

[0023] Figure 1 It is a three-dimensional schematic diagram of the utility model.

[0024] Figure 2 It is a cross-sectional view of the utility model.

[0025] Figure 3 for Figure 2 Schematic diagram of the feed valve body, discharge valve body and valve seat after separation.

[0026] Figure 4 for Figure 3 Sectional view of AA.

[0027] Figure 5 for Figure 4 Enlarged view of B.

[0028] Figure 6 It is a three-dimensional schematic diagram of the feed valve core in the utility model.

[0029] Description of the drawings: valve mechanism 1, metering piston cylinder 2, pneumatic actuator 3, valve seat 11, feed valve body 12, discharge valve body 13, metering piston head 21, cylinder 31, throttle valve 32, stroke adjustment device 33, chamber 110, feed channel 111, discharge channel 112, feed port 121, feed valve core 122, elastic reset member 123, sealing ring 124, discharge port 131, discharge valve core 132, cylinder Body 311, cylinder piston 312, cylinder piston rod 313, throttle valve seat 321, throttle screw 322, throttle valve core 323, cylinder adjustment seat body 331, cylinder adjustment screw 332, feed stop part 1221, supporting part 1222, accommodating groove 1223, valve core body 1224, 1225, notch 1226, discharge stop part 1321, air inlet pipe joint 3101, air outlet pipe joint 3102. DETAILED DESCRIPTION

[0030] The technical scheme of the utility model is further described in detail below in conjunction with the accompanying drawings and specific embodiments, so that those skilled in the art can better understand the utility model and implement it, but the examples given are not intended to limit the utility model. In the present embodiments, it should be understood that the orientations or positional relationships indicated by terms such as "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", and "outside" are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the utility model, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the utility model.

[0031] It should be noted that when an element is considered to be "connected" to another element, it may be directly connected to the other 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 in this utility model are for illustrative purposes only.

[0032] This embodiment provides a pneumatic metering pump, such as Figures 1 to 6 As shown, it includes a valve mechanism 1, a metering piston cylinder 2 and a pneumatic actuator 3 connected in sequence. The valve mechanism 1 includes a valve seat 11, and a cavity 110 is provided in the valve seat 11. The cavity 110 is connected to the metering piston cylinder 2. A detachable feed valve body 12 and a detachable discharge valve body 13 are provided on the valve seat 11; the feed valve body 12 is threadedly connected to the input end of the valve seat 11, and is used to control the on-off of the fluid input in the valve seat 11; the discharge valve body 13 is threadedly connected to the output end of the valve seat 11, and is used to control the on-off of the fluid output in the valve seat 11. It should be noted that the valve mechanism 1 can be a one-way valve or a three-way valve. In this embodiment, the valve mechanism 1 is a one-way valve.

[0033] The pneumatic actuator 3 includes a cylinder 31 and a throttle valve 32 ; the cylinder 31 is connected to the metering piston cylinder 2 and is used to drive the metering piston cylinder 2 to move.

[0034] The throttle valve 32 is provided with two, and the cylinder 31 is provided with an air inlet pipe joint 3101 and an air outlet pipe joint 3102, and the air inlet pipe joint 3101 and the air outlet pipe joint 3102 are respectively connected to the valve port of a throttle valve 32. The throttle valve 32 is used to adjust the air intake and air outlet of the cylinder 31. By adjusting the air intake and air outlet of the cylinder 31 through the throttle valve 32, the power of the cylinder 31 is adjusted, thereby adjusting the power of the metering pump, so that it can adapt to different use environments.

[0035] The cylinder 31 includes a cylinder body 311, a cylinder piston 312 and a cylinder piston rod 313. The cylinder piston 312 is movably arranged in the cylinder body 311. One end of the cylinder piston rod 313 extends into the cylinder body 311 and is connected to the cylinder piston rod 313. The other end of the cylinder piston rod 313 extends into the metering piston cylinder 2 and is connected to the metering piston head 21 of the metering piston cylinder 2. The cylinder piston rod 313 in the cylinder 31 is directly connected to the metering piston head of the metering piston cylinder 2, and the metering piston head is directly driven to move back and forth through the action of the cylinder 31, and the structure is simple.

[0036] A stroke adjustment device 33 is provided on the cylinder 31, and the stroke adjustment device 33 is movably arranged in the cylinder body 311, and is used to adjust the stroke of the cylinder piston 312. The stroke adjustment device 33 includes a cylinder adjustment seat body 331 and a cylinder adjustment screw 332; the cylinder adjustment seat body 331 is fixed on the cylinder body 311, one end of the cylinder adjustment screw 332 is threadedly connected with the cylinder adjustment seat body 331, and the other end of the cylinder adjustment screw 332 passes through the cylinder adjustment seat body 331 and extends into the cylinder body 311, and the cylinder adjustment screw 332 is used to abut against the cylinder piston 312 to limit the stroke of the cylinder piston 312. In the stroke adjustment device 33, the cylinder adjustment screw 332 is threadedly connected with the cylinder adjustment seat body 331, and the position of the end of the cylinder adjustment screw 332 in the cylinder body 311 is changed by rotating the cylinder adjustment screw 332, thereby adjusting the maximum stroke of the cylinder piston 312. When the end of the cylinder adjusting screw 332 is close to the fixed end of the cylinder 31, the movable stroke of the cylinder piston 312 in the cylinder body 311 is large, so that when the cylinder piston 312 moves, the input and output flow rates are large; when the end of the cylinder adjusting screw 332 is close to the movable end of the cylinder 31, the movable stroke of the cylinder piston 312 in the cylinder body 311 is small, so that when the cylinder piston 312 moves, the input and output flow rates are small; the stroke of the cylinder 31 is adjusted by the stroke adjusting device 33, thereby adjusting the flow rate of the conveying fluid of the metering pump.

[0037] The throttle valve 32 includes a throttle valve seat 321, a throttle screw 322 and a throttle valve core 323; the throttle valve core 323 is arranged on the cylinder body 311, one throttle valve core 323 is connected to the inside of the cylinder body 311 and the intake pipe joint 3101, and the other throttle valve core 323 is connected to the inside of the cylinder body 311 and the outlet pipe joint 3102; the throttle valve seat 321 is arranged above the throttle valve core 323, the throttle screw 322 is penetrated in the throttle valve seat 321 and is threadedly connected to the throttle valve seat 321, and the throttle screw 322 is rotated to change the depth of the end of the throttle screw 322 extending into the throttle valve core 323, thereby adjusting the opening of the throttle valve 32.

[0038] The feed valve body 12 is provided with a feed port 121, the cavity 110 is connected with a feed channel 111, and the feed valve core 122 connects the feed port 121 and the feed channel 111; an annular feed stopper 1221 is provided on the feed valve core 122, and the cross-sectional area of ​​the stopper is larger than the cross-sectional area of ​​the feed port 121; the elastic return member 123 is sleeved on the feed valve core 122 and abuts against the feed stopper 1221 and the valve seat 11; under the elastic force of the elastic return member 123, the feed stopper 1221 presses the feed valve body 12, and the feed stopper 1221 closes the feed port 121.

[0039] The discharge valve body 13 is provided with a discharge port 131, the cavity 110 is connected with a discharge channel 112, and the discharge valve core 132 connects the discharge port 131 and the discharge channel 112; an annular discharge blocking portion 1321 is provided on the discharge valve core 132, and the cross-sectional area of ​​the discharge blocking portion 1321 is larger than the cross-sectional area of ​​the discharge channel 112; the elastic reset member 123 is sleeved on the discharge valve core 132 and abuts against the discharge blocking portion 1321 and the discharge valve body 13; under the elastic force of the elastic reset member 123, the discharge blocking portion 1321 presses the valve seat 11, and the discharge blocking portion 1321 closes the discharge channel 112. In this embodiment, the elastic reset member 123 is a spring.

[0040] The side of the feed blocking portion 1221 close to the feed port 121 is provided with a sealing ring 124; the side of the discharge blocking portion 1321 close to the discharge channel 112 is provided with a sealing ring 124. By providing the sealing ring 124, the sealing effect between the feed blocking portion 1221 and the feed port 121 is further improved, and the sealing effect between the discharge blocking portion 1321 and the discharge channel 112 is further improved, and the reliability is good.

[0041] In a preferred embodiment, Figure 3 and Figure 6As shown, a supporting portion 1222 is provided below the feed stopper 1221, and a receiving groove 1223 is formed between the feed stopper 1221 and the supporting portion 1222, and the sealing ring 124 is sleeved on the receiving groove 1223. The sealing ring 124 is sleeved on the receiving groove 1223, and the sealing ring 124 is limited by the feed stopper 1221 and the supporting portion 1222, thereby improving the stability of the sealing ring 124 arranged on the feed valve core 122.

[0042] The feed valve core 122 includes a valve core body 1224 and two or more extensions 1225, the two or more extensions 1225 are arranged around the valve core body 1224, and a gap 1226 is formed between adjacent extensions 1225, and the gap 1226 is arranged along the length direction of the valve core body 1224. In this embodiment, the discharge valve core 132 has the same structure as the feed valve core 122, and will not be described here. The gap 1226 is provided, and the gap 1226 is provided along the length direction of the valve core body 1224, so that the flow space between the feed valve core 122 and the feed valve body 12 is large, thereby improving the flow efficiency of the fluid. In this embodiment, the discharge valve core 132 has the same structure as the feed valve core 122, and will not be described here.

[0043] A feed valve body 12 and a discharge valve body 13 are respectively connected to the valve seat 11, and sealing structures are provided at the input end and the output end of the valve seat 11, so that when fluid is input into the valve seat 11, the feed valve body 12 opens and the discharge valve body 13 closes; when fluid is output from the valve seat 11, the feed valve body closes and the discharge valve body 13 opens; this ensures that when the valve seat 11 outputs fluid, external fluid cannot enter the valve seat 11, thereby avoiding the mixing of external fluid and fluid in the valve seat 11 to cause metering errors.

[0044] The utility model adjusts the air intake and air discharge of the cylinder 31 by setting a throttle valve 32, thereby adjusting the power of the metering pump, and adjusting the maximum stroke of the cylinder 31 by the stroke adjustment device 33, thereby changing the flow rate of the conveying fluid of the metering pump. The above settings can adapt to different usage environments; at the same time, a notch 1226 is provided on the feed valve core 122 to increase the flow space between the feed valve core 122 and the feed valve body 12, thereby improving the flow efficiency of the fluid.

[0045] The working principle of the utility model is as follows: the metering piston head moves away from the cavity 110, the pressure in the cavity 110 decreases, the pressure outside the valve seat 11 is greater than the pressure inside the valve seat 11, the external fluid pushes the feed valve core 122 to move, the feed stop 1221 is separated from the feed valve body 12, the feed port 121 is connected with the cavity 110, and then the fluid flows into the cavity 110 from the feed port 121; at the same time, under the action of pressure, the external fluid presses the discharge valve core 132 against the valve body 11, the discharge valve core 132 closes the discharge channel 112, and the discharge port 131 is disconnected from the cavity 110, so as to prevent the fluid in the metering pump from flowing out when the fluid is input.

[0046] The metering piston head moves toward the cavity 110, the pressure in the cavity 110 increases, the pressure outside the valve seat 11 is lower than the pressure inside the valve body, the fluid inside the valve seat 11 pushes the discharge valve core 132 to move, the discharge resistance portion 1321 is separated from the discharge channel 112, the discharge port 131 is connected with the cavity 110, and the fluid in the cavity 110 flows out through the discharge port 131; at the same time, under the action of pressure, the fluid inside the valve seat 11 pushes the feed valve core 122 to move, the feed resistance portion 1221 contacts and presses on the feed valve body 12, and the feed port 121 is disconnected from the cavity 110, to prevent fluid from flowing into the metering pump when the fluid is discharged.

[0047] When the power of the cylinder needs to be adjusted, the throttle valve is rotated to change the opening of the throttle valve, and the air intake and exhaust of the cylinder are adjusted, thereby adjusting the power of the cylinder; when the delivery flow of the cylinder needs to be adjusted, the cylinder adjusting screw 332 is rotated to change the position of the end of the cylinder adjusting screw 332 in the cylinder body 311, and the maximum stroke of the cylinder piston 312 is adjusted; thereby adjusting the delivery flow of the cylinder.

[0048] 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.

[0049] In the description of this specification, the description with reference to the terms "preferred embodiment", "further embodiment", "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.

[0050] 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 metering pump, comprising a valve mechanism, a metering piston cylinder and a pneumatic actuator connected in sequence, wherein the valve mechanism comprises a valve seat, a cavity is provided in the valve seat, the cavity is communicated with the metering piston cylinder, the pneumatic actuator comprises a cylinder, the cylinder is used to drive the metering piston cylinder to move, and is characterized in that: A detachable feed valve body and a detachable discharge valve body are provided on the valve seat; the feed valve body is used to control the on-off of the fluid input in the valve seat, and the discharge valve body is used to control the on-off of the fluid output in the valve seat; the pneumatic actuator also includes a throttle valve, which is connected to the cylinder and is used to adjust the air intake and air output of the cylinder.

2. The pneumatic metering pump according to claim 1, characterized in that: The throttle valves are provided with two, and the pneumatic piston cylinder is provided with an air inlet pipeline joint and an air outlet pipeline joint, and the air inlet pipeline joint and the air outlet pipeline joint are respectively connected to the valve port of a throttle valve.

3. The pneumatic metering pump according to claim 1, characterized in that: The cylinder includes a cylinder body, a cylinder piston and a cylinder piston rod. The cylinder piston is movably arranged in the cylinder body. One end of the cylinder piston rod extends into the cylinder body and is connected to the cylinder piston rod. The other end of the cylinder piston rod extends into the metering piston cylinder and is connected to the metering piston head of the metering piston cylinder. The pneumatic actuator also includes a stroke adjustment device, which is movably arranged in the cylinder body and is used to adjust the stroke of the cylinder piston.

4. The pneumatic metering pump according to claim 3, characterized in that: The stroke adjustment device includes a cylinder adjustment seat body and a cylinder adjustment screw; the cylinder adjustment seat body is fixed on the cylinder body, one end of the cylinder adjustment screw is threadedly connected to the cylinder adjustment seat body, and the other end of the cylinder adjustment screw passes through the cylinder adjustment seat body and extends into the cylinder body. The cylinder adjustment screw is used to abut against the cylinder piston to limit the stroke of the cylinder piston.

5. The pneumatic metering pump according to claim 1, characterized in that: The feed valve body is provided with a feed port, the cavity is connected with a feed channel, and the feed valve core is connected with the feed port and the feed channel; an annular feed stopper is provided on the feed valve core, and the cross-sectional area of ​​the feed stopper is larger than the cross-sectional area of ​​the feed port; the elastic reset member is sleeved on the feed valve core and abuts against the feed stopper and the valve seat; under the elastic force of the elastic reset member, the feed stopper closes the feed port.

6. The pneumatic metering pump according to claim 5, characterized in that: The discharge valve body is provided with a discharge port, the cavity is connected with a discharge channel, and the discharge valve core is connected with the discharge port and the discharge channel; an annularly arranged discharge blocking portion is provided on the discharge valve core, and the cross-sectional area of ​​the discharge blocking portion is larger than the cross-sectional area of ​​the discharge channel; the elastic reset member is sleeved on the discharge valve core and abuts against the discharge blocking portion and the discharge valve body; under the elastic force of the elastic reset member, the discharge blocking portion closes the discharge channel.

7. The pneumatic metering pump according to claim 5, characterized in that: A sealing ring is arranged on one side of the feed stopper close to the feed inlet.

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