Pump body structure of diaphragm pump with stable flow

Abstract

The utility model discloses a pump body structure of a diaphragm pump with stable flow, which comprises a main shell, an inner cavity extending forwards is formed on the top surface of the rear part of the main shell, a first connecting block and a second connecting block are sequentially inserted and sleeved in the inner cavity, the front wall surface of the first connecting block is pressed against the front end surface of the inner cavity, and the rear wall surface of the second connecting block is pressed against the rear end surface of the inner cavity. The front end face of the second connecting block is pressed against the rear end face of the first connecting block, the first connecting block and the second connecting block are fixedly connected in the main shell through bolts, four liquid suction cavities are uniformly distributed in the rear end face of the first connecting block by taking the central axis of the first connecting block as the center, and four mounting holes penetrating front and back are formed in the second connecting block; a feeding through hole and a discharging through hole which are the same in circulation are formed in each liquid suction cavity, it is guaranteed that the discharging amount and the feeding amount are consistent, and each liquid suction cavity is controlled through a liquid inlet one-way valve and a liquid outlet one-way valve, so that control is uniform, conveying is stable, and the problem of channeling of conveyed liquid is solved.

Description

Technical field:

[0001] The utility model relates to the technical field of biopharmaceuticals, and more specifically to a pump body structure of a diaphragm pump with stable flow. Background technology:

[0002] The diaphragm pump uses a thin film to separate the pumped liquid from the piston and the pump cylinder, thereby protecting the piston and the pump cylinder.

[0003] However, in the existing diaphragm pump, the fixed plate (such as Figure 1 As shown in the figure, a plurality of feed cavities are formed on the edge of one end surface of the fixed plate with the central axis as the center, a spherical hole for placing a one-way valve is formed on the bottom surface of the feed cavity, and a plurality of first feed through holes 1a are formed on the bottom surface of the spherical hole, and a bottom spherical hole for placing a one-way valve for discharging is formed in the middle of the other end of the fixed plate, and a plurality of first discharging through holes 2a are formed on the top surface of the bottom spherical hole, and the end of each first discharging through hole 2a extends into the corresponding feed cavity to achieve communication;

[0004] This structure enables the liquid entering all the first feed through holes 1a in each feed cavity to be discharged from the first discharge through hole 2a, and the aperture of the first discharge through hole 2a is smaller than the aperture of all the corresponding first feed through holes 1a, which makes the subsequent discharged liquid inconsistent with the entering liquid, affecting the output flow rate;

[0005] Secondly, all the first discharge holes 2a are controlled by a single one-way valve for discharge, rather than a one-to-one control, which can easily affect the control stability. Specifically, when all the first feed holes 1a corresponding to one of the feed chambers are fed, the covering part of the corresponding one-way valve will be opened, allowing the material to enter the feed chamber. Then, as the material in the feed chamber increases, the corresponding edge of the one-way valve corresponding to the corresponding first discharge hole 2a will be opened to discharge the material. Since the aperture of the first discharge hole 2a is smaller than the aperture of all the corresponding first feed holes 1a, the pressure of the material discharged from the first discharge hole 2a is also large, which may press the surrounding part of the reopened edge of the one-way valve for discharge. The first discharge hole 2a corresponding to the remaining feed chambers may not be completely covered. At this time, the liquid coming out of the first discharge hole 2a will enter the surrounding first discharge holes 2a that are not completely covered, and finally enter the surrounding feed chambers. When the existing diaphragm pump is in operation, it adsorbs and feeds all the feed chambers one by one. Therefore, some liquid will be pre-filled into the feed chambers without adsorbed feed around them, which further reduces the output flow rate and affects the subsequent suction volume of the remaining feed chambers (the corresponding feed chambers already have the liquid that has entered before). This affects the uniformity of its liquid delivery, and the use effect is not ideal. Utility model content:

[0006] The purpose of the utility model is to address the deficiencies of the prior art and to provide a diaphragm pump body structure with a stable flow rate. Each suction chamber is provided with a feed through hole and a discharge through hole with the same flow rate to ensure the consistency of the discharge amount and the feed amount. In addition, each suction chamber is controlled by an inlet one-way valve plate and a liquid outlet one-way valve plate, so that the control is uniform, the delivery is stable, and the problem of liquid being transported crossing the chamber will not occur.

[0007] The technical solutions of the utility model are as follows:

[0008] A pump body structure of a diaphragm pump with a stable flow rate, comprising a main shell, wherein the rear top surface of the main shell is formed with an inner cavity extending forward, a first connecting block and a second connecting block are inserted into the inner cavity in sequence, a front wall surface of the first connecting block is pressed against the front end surface of the inner cavity, and a front end surface of the second connecting block is pressed against the rear end surface of the first connecting block, the first connecting block and the second connecting block are fixedly connected in the main shell by bolts, a plurality of liquid suction cavities are evenly distributed on the rear end surface of the first connecting block with the central axis of the first connecting block as the center, a plurality of mounting holes penetrating front and back are formed on the second connecting block, the mounting holes correspond to the liquid suction cavities one by one, an edge of the diaphragm body is clamped between the first connecting block and the second connecting block, the diaphragm body covers the corresponding mounting holes and the rear end of the liquid suction cavity, and a rear end of a driving shaft fixed in the middle of the rear end surface of the diaphragm body extends out of the corresponding mounting hole;

[0009] The front end surface of the inner cavity is formed with an outer annular flow groove on the outside and an inner annular flow groove on the inside, and the front part of the main shell is formed with a liquid inlet connection hole and a liquid outlet connection hole, the liquid inlet connection hole is communicated with the outer annular flow groove, and the liquid outlet connection hole is communicated with the inner annular flow groove;

[0010] A liquid inlet one-way valve sheet and a liquid outlet one-way valve sheet are installed on the front wall surface of each liquid suction cavity. A plurality of liquid inlet through holes and liquid outlet through holes are formed on the front wall surface of each liquid suction cavity. The covering sheet of the liquid inlet one-way valve sheet covers all the corresponding liquid inlet through holes, and the covering sheet of the liquid outlet one-way valve sheet covers all the corresponding liquid outlet through holes.

[0011] A front annular groove is formed on the rear wall surface of the first connecting block around the rear end of the liquid suction cavity, a rear annular groove is formed on the front end surface around the front end of the mounting hole of the second connecting block, and a raised ring portion is formed on the front end surface and the rear end surface of the side edge portion of the annular portion of the diaphragm body, and the raised ring portion is nested in the corresponding front annular groove or rear annular groove and clamped between the first connecting block and the second connecting block. This structure realizes the sealing of the liquid suction cavity.

[0012] A spherical concave hole and multiple liquid outlet holes are formed on the front wall surface of the liquid suction chamber, a first mounting through hole is formed in the middle of the inner wall surface of the spherical concave hole, multiple liquid inlet through holes are formed on the inner wall surface of the spherical concave hole, a second mounting through hole is formed on the front wall surface of the liquid suction chamber at one side of the spherical concave hole, a front spherical concave hole is formed on the front end surface of the first connecting block at the front end of the second mounting through hole, and the front ends of all the liquid outlet through holes of the liquid suction chamber extend out of the inner wall surface of the corresponding front spherical concave hole.

[0013] The liquid inlet one-way valve sheet and the liquid outlet one-way valve sheet both include a main connecting column, a covering sheet is formed at one end of the main connecting column, an annular protrusion with a conical outer wall is formed on the outer side wall of the other end of the main connecting column, the covering sheet is a spherical surface facing one end face of the main connecting column, the middle part of the main connecting column is clamped in the corresponding first mounting through hole or the second mounting through hole, the covering sheet of the main connecting column is inserted into the spherical concave hole or the front spherical concave hole, the spherical surface of the covering sheet of the main connecting column is tightly attached to the inner wall surface of the spherical concave hole or the front spherical concave hole, the two cooperate, and the covering sheet covers all corresponding liquid outlet through holes or liquid inlet through holes;

[0014] The front end of the main connecting column of the liquid inlet one-way valve plate extends out of the front wall surface of the first connecting block, the annular protrusion of the liquid inlet one-way valve plate is located at the front wall surface of the first connecting block, and the rear end surface of the annular protrusion of the liquid inlet one-way valve plate is pressed against the front wall surface of the first connecting block;

[0015] The rear end of the main connecting column of the liquid outlet one-way valve plate extends out of the rear end of the second mounting through hole, the annular protrusion of the liquid outlet one-way valve plate is in the corresponding liquid suction cavity, and the front end surface of the annular protrusion of the liquid outlet one-way valve plate is pressed against the front wall surface of the corresponding liquid suction cavity.

[0016] The number and inner diameter of all the liquid outlet through holes and all the liquid inlet through holes of each liquid suction cavity are the same, so as to ensure the same flow rate.

[0017] The beneficial effects of the utility model are:

[0018] Each of its liquid suction chambers is provided with a feed through hole and a discharge through hole with the same flow rate to ensure the consistency of the discharge amount and the feed amount, and each of its liquid suction chambers is controlled by an inlet one-way valve plate and a liquid outlet one-way valve plate, so that the control is uniform and the delivery is stable, and there will be no problem of cross-chambering of the delivered liquid, that is, the liquid coming out of one liquid suction chamber will not enter another liquid suction chamber, thereby ensuring the normal and stable delivery of the liquid. Description of the drawings:

[0019] Figure 1 It is a partial structural schematic diagram of a fixed plate in an existing diaphragm pump;

[0020] Figure 2 This is a schematic diagram of the partial structure of the utility model installed on the housing;

[0021] Figure 3 for Figure 2 A partial cross-sectional view of

[0022] Figure 4 for Figure 2 A partial cross-sectional view at a different angle;

[0023] Figure 5 It is a partial structural schematic diagram of the first connecting block of the utility model;

[0024] Figure 6 yes Figure 5 Schematic diagram of the local structure of changing angle. Specific implementation method:

[0025] Example: See Figures 2 to 6 As shown, a pump body structure of a diaphragm pump with stable flow rate includes a main shell 10, which is fixedly connected to the corresponding shell by bolts, and a transmission mechanism is generally installed in the shell, and the rear top surface of the main shell 10 is formed with an inner cavity 11 extending forward, the first connecting block 20 and the second connecting block 30 are inserted into the inner cavity 11 in sequence, the front wall surface of the first connecting block 20 is pressed against the front end surface of the inner cavity 11, and the front end surface of the second connecting block 30 is pressed against the rear end surface of the first connecting block 20, the first connecting block 20 and the second connecting block 30 are fixedly connected to the main shell 10 by bolts, and four suction cavities 21 are evenly distributed on the rear end surface of the first connecting block 20 with the central axis of the first connecting block 20 as the center, and four mounting holes penetrating from front to back are formed on the second connecting block 30, and the mounting holes correspond to the suction cavities 21 one by one, and the edge of the diaphragm body 40 is clamped between the first connecting block 20 and the second connecting block 30, and the diaphragm body 40 covers the The rear end of the driving shaft 41 fixed in the middle of the rear end surface of the diaphragm body 40 extends out of the corresponding mounting hole; wherein, a control motor is installed in the shell, the output shaft of the control motor and the upper fixed rotating plate, the inclined block is fixed on the rotating plate, and the inclined block can be rotated by rotating the rotating plate, and the end of the inclined block extending obliquely forward and the driving shaft 41 of the diaphragm body 40 installed on the main shell 10, which rotates the oblique block by controlling the operation of the motor, so that the driving shaft 41 of the diaphragm body 40 can be pushed forward one by one, so that the diaphragm body 40 is deformed and pushed forward, and at the same time, when the end of the oblique block extending obliquely forward moves away from the driving shaft 41, the elastic restoring force of the diaphragm body 40 makes the diaphragm sheet 40 return to its position backward, and at this time, suction is realized, so that all diaphragm bodies 40 are adsorbed one by one. This principle and structure are the same as those of the existing diaphragm pump and will not be described in detail. There is no specific control motor and other components in the attached drawings.

[0026] The front end surface of the inner cavity 11 is formed with an outer annular flow groove 12 on the outside and an inner annular flow groove 13 on the inside, and the front part of the main shell 10 is formed with a liquid inlet connection hole 14 and a liquid outlet connection hole 15, the liquid inlet connection hole 14 is communicated with the outer annular flow groove 12, and the liquid outlet connection hole 15 is communicated with the inner annular flow groove 13;

[0027] A liquid inlet one-way valve sheet 50 and a liquid outlet one-way valve sheet 60 are installed on the front wall surface of each liquid suction cavity 21, and a plurality of liquid inlet through holes 211 and liquid outlet through holes 23 are formed on the front wall surface of each liquid suction cavity 21. The cover sheet of the liquid inlet one-way valve sheet 50 covers all the corresponding liquid inlet through holes 211, and the cover sheet of the liquid outlet one-way valve sheet 60 covers all the corresponding liquid outlet through holes 23. The flow rate of all the liquid outlet through holes 23 and all the liquid inlet through holes 211 of each liquid suction cavity 21 is the same (in this embodiment, the number and aperture of all the liquid outlet through holes 23 and all the liquid inlet through holes 211 of each liquid suction cavity 21 are the same).

[0028] Furthermore, the inner cavity 11 is a cylindrical concave hole, the first connecting block 20 and the second connecting block 30 are circular blocks corresponding to each other in front and back, and their outer side walls are close to or close to the inner side wall of the inner cavity 11. An annular sealing groove is formed on the edge of the front end face of the inner cavity 11, and the first annular sealing ring 1 is nested in the annular sealing groove, and the front end face of the first connecting block 20 is pressed against the first annular sealing ring 1. A second annular groove is formed on the front end face of the inner cavity 11 between the outer annular circulation groove 12 and the inner annular circulation groove 13, and the second annular sealing ring 2 is nested in the second annular groove, and the rear end of the second annular sealing ring 2 is pressed against the front end face of the first connecting block 20. A third annular sealing groove is formed on the front wall surface of the inner annular circulation groove 13 near the middle of the inner cavity 11, and the third annular sealing ring 3 is nested in the third annular sealing groove, and the rear end of the third annular sealing ring 3 is pressed against the front end face of the first connecting block 20.

[0029] The first annular sealing ring 1, the second annular sealing ring 2 and the third annular sealing ring 3 realize the sealing effect of all the suction chambers 21, the outer annular circulation groove 12 and the inner annular circulation groove 13, ensuring that all the suction chambers 21 are not connected to each other and are independently connected to the outer annular circulation groove 12 and the inner annular circulation groove 13.

[0030] Furthermore, a front annular groove is formed on the rear wall surface of the first connecting block 20 around the rear end of the liquid suction chamber 21, a rear annular groove is formed on the front end surface around the front end of the mounting hole of the second connecting block 30, and raised ring portions are formed on the front end surface and the rear end surface of the side portion of the annular portion of the diaphragm body 40. The raised ring portions are nested in the corresponding front annular groove or the rear annular groove and clamped between the first connecting block 20 and the second connecting block 30.

[0031] The front end of the main housing 10 is formed with an upward and downward extending pipe portion 16 , which is communicated with the corresponding liquid inlet connection hole 14 or liquid outlet connection hole 15 .

[0032] Furthermore, a spherical recessed hole 22 and a plurality of liquid outlet holes 23 are formed on the front wall surface of the liquid suction chamber 21, a first mounting through hole 221 is formed in the middle of the inner wall surface of the spherical recessed hole 22, a plurality of liquid inlet through holes 211 are formed on the inner wall surface of the spherical recessed hole 22, a second mounting through hole 24 is formed on the front wall surface of the liquid suction chamber 21 at one side of the spherical recessed hole 22, a front spherical recessed hole 25 is formed on the front end surface of the first connecting block 20 at the front end of the second mounting through hole 24, and the front ends of all the liquid outlet through holes 23 of the liquid suction chamber 21 extend out of the inner wall surface of the corresponding front spherical recessed hole 25.

[0033] The liquid inlet one-way valve plate 50 and the liquid outlet one-way valve plate 60 both include a main connecting column 51, a covering plate is formed at one end of the main connecting column 51, and an annular protrusion 52 with a conical outer wall is formed on the outer side wall of the other end of the main connecting column 51, and the covering plate is spherical on one end face facing the main connecting column 51, and the middle part of the main connecting column 51 is clamped in the corresponding first mounting through hole 221 or the second mounting through hole 24, and the covering plate of the main connecting column 51 is inserted into the spherical concave hole 22 or the front spherical concave hole 25, and the spherical surface of the covering plate of the main connecting column 51 is tightly attached to the inner wall surface of the spherical concave hole 22 or the front spherical concave hole 25, and the two cooperate with each other, and the covering plate covers all the corresponding liquid outlet through holes 23 or liquid inlet through holes 211;

[0034] The front end of the main connecting column 51 of the liquid inlet check valve 50 extends out of the front wall surface of the first connecting block 20, the annular protrusion 52 of the liquid inlet check valve 50 is located at the front wall surface of the first connecting block 20, and the rear end surface of the annular protrusion 52 of the liquid inlet check valve 50 is pressed against the front wall surface of the first connecting block 20;

[0035] The rear end of the main connecting column 51 of the liquid outlet one-way valve plate 60 extends out of the rear end of the second mounting through hole 24, the annular protrusion 52 of the liquid outlet one-way valve plate 60 is in the corresponding liquid suction cavity 21, and the front end surface of the annular protrusion 52 of the liquid outlet one-way valve plate 60 is pressed against the front wall surface of the corresponding liquid suction cavity 21.

[0036] Furthermore, an annular groove extending backward is formed in the middle of the annular portion of the diaphragm body 40, and an annular raised circle is formed backward on the rear wall of the middle of the annular portion of the diaphragm body 40 corresponding to the annular groove.

[0037] Working principle: When this embodiment is in use, the control motor installed in the housing is operated to rotate the oblique block, so that the driving shaft 41 of the diaphragm body 40 can be pushed forward one by one, so that the diaphragm body 40 is deformed and pushed forward. At the same time, when the end of the oblique block extending obliquely forward moves away from the driving shaft 41, the elastic restoring force of the diaphragm body 40 causes the diaphragm sheet 40 to return to its position backward. At this time, air suction is achieved, so that all diaphragm bodies 40 are adsorbed one by one.

[0038] When inhaling, the covering piece of the liquid inlet one-way valve plate 50 is deformed and flipped up backwards, and the liquid enters the outer annular circulation groove 12 through the liquid inlet connecting hole 14, and the liquid in the outer annular circulation groove 12 enters the liquid suction chamber 21 from the corresponding liquid inlet through hole 211. When the diaphragm body 40 is reset and rebounds forward, the covering piece of the liquid inlet one-way valve plate 50 returns forward to cover all the corresponding liquid inlet connecting holes 14. At the same time, due to the forward return of the diaphragm body 40, the space in the corresponding liquid suction chamber 21 is reduced, and the internal pressure increases, which will flip the edge of the covering piece of the corresponding liquid outlet one-way valve plate 60 outward, and the liquid in the liquid suction chamber 21 will be discharged from the liquid outlet through hole 23, enter the inner annular circulation groove 13, and finally, be discharged from the liquid outlet connecting hole 15 to realize liquid transportation.

[0039] Each of the suction chambers 21 is provided with a feed through hole 212 and a discharge through hole 23 with the same flow rate, ensuring the consistency of the discharge amount and the feed amount, and each of the suction chambers 21 is controlled by a liquid inlet one-way valve plate 50 and a liquid outlet one-way valve plate 60, so that the control is uniform and the delivery is stable, and there will be no problem of cross-chambering of the transported liquid, that is, the liquid coming out of one suction chamber 21 will not enter another suction chamber 21, thereby ensuring the normal and stable delivery of the liquid and a stable delivery volume.

[0040] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A pump body structure of a diaphragm pump with stable flow, comprising a main housing (10), characterized in that: The rear top surface of the main housing (10) is formed with an inner cavity (11) extending forward, the first connecting block (20) and the second connecting block (30) are inserted into the inner cavity (11) in sequence, the front wall surface of the first connecting block (20) is pressed against the front end surface of the inner cavity (11), the front end surface of the second connecting block (30) is pressed against the rear end surface of the first connecting block (20), the first connecting block (20) and the second connecting block (30) are fixedly connected in the main housing (10) by bolts, and the rear end of the first connecting block (20) is fixedly connected to the main housing (10). A plurality of liquid suction cavities (21) are evenly distributed on the end surface with the central axis of the first connecting block (20) as the center, a plurality of mounting holes penetrating front and rear are formed on the second connecting block (30), the mounting holes correspond to the liquid suction cavities (21) one by one, the edge of the diaphragm body (40) is clamped between the first connecting block (20) and the second connecting block (30), the diaphragm body (40) covers the corresponding mounting holes and the rear end of the liquid suction cavity (21), and the rear end of the driving shaft (41) fixed in the middle of the rear end surface of the diaphragm body (40) extends out of the corresponding mounting hole; An outer annular circulation groove (12) and an inner annular circulation groove (13) are formed on the front end surface of the inner cavity (11); a liquid inlet connection hole (14) and a liquid outlet connection hole (15) are formed on the front part of the main shell (10); the liquid inlet connection hole (14) is in communication with the outer annular circulation groove (12), and the liquid outlet connection hole (15) is in communication with the inner annular circulation groove (13); A liquid inlet check valve sheet (50) and a liquid outlet check valve sheet (60) are installed on the front wall surface of each liquid suction cavity (21); a plurality of liquid inlet through holes (211) and liquid outlet through holes (23) are formed on the front wall surface of each liquid suction cavity (21); the cover sheet of the liquid inlet check valve sheet (50) covers all corresponding liquid inlet through holes (211), and the cover sheet of the liquid outlet check valve sheet (60) covers all corresponding liquid outlet through holes (23).

2. The pump body structure of a diaphragm pump with stable flow according to claim 1, characterized in that: The inner cavity (11) is a cylindrical concave hole, the first connecting block (20) and the second connecting block (30) are circular blocks corresponding to each other in front and back, the outer side walls of which are in close contact with or close to the inner side wall of the inner cavity (11), the front end surface edge of the inner cavity (11) is formed with an annular sealing groove, the first annular sealing ring (1) is nested in the annular sealing groove, and the front end surface of the first connecting block (20) is pressed against the first annular sealing ring (1).

3. The pump body structure of a diaphragm pump with stable flow rate according to claim 1, characterized in that: A second annular groove is formed on the front end face of the inner cavity (11) between the outer annular circulation groove (12) and the inner annular circulation groove (13), the second annular sealing ring (2) is nested in the second annular groove, and the rear end of the second annular sealing ring (2) is pressed against the front end face of the first connecting block (20).

4. The pump body structure of a diaphragm pump with stable flow rate according to claim 1, characterized in that: A third annular sealing groove is formed on the front wall surface of the inner annular circulation groove (13) near the middle of the inner cavity (11), and the third annular sealing ring (3) is nested in the third annular sealing groove, and the rear end of the third annular sealing ring (3) is pressed against the front end surface of the first connecting block (20).

5. The pump body structure of a diaphragm pump with stable flow rate according to claim 1, characterized in that: A front annular groove is formed on the rear wall surface of the first connecting block (20) around the rear end of the liquid suction chamber (21), a rear annular groove is formed on the front end surface around the front end of the mounting hole of the second connecting block (30), and a raised ring portion is formed on the front end surface and the rear end surface of the side portion of the annular portion of the diaphragm body (40), and the raised ring portion is nested in the corresponding front annular groove or the rear annular groove and clamped between the first connecting block (20) and the second connecting block (30).

6. The pump body structure of a diaphragm pump with stable flow rate according to claim 1, characterized in that: The front end of the main housing (10) is formed with an upward and downward extending pipe portion (16), and the extending pipe portion is communicated with the corresponding liquid inlet connection hole (14) or liquid outlet connection hole (15).

7. The pump body structure of a diaphragm pump with stable flow rate according to claim 1, characterized in that: A spherical concave hole (22) and a plurality of liquid outlet through holes (23) are formed on the front wall surface of the liquid suction cavity (21); a first mounting through hole (221) is formed in the middle of the inner wall surface of the spherical concave hole (22); a plurality of liquid inlet through holes (211) are formed on the inner wall surface of the spherical concave hole (22); a second mounting through hole (24) is formed on the front wall surface of the liquid suction cavity (21) at one side of the spherical concave hole (22); a front spherical concave hole (25) is formed on the front end surface of the first connecting block (20) at the front end of the second mounting through hole (24); and the front ends of all the liquid outlet through holes (23) of the liquid suction cavity (21) extend out of the inner wall surface of the corresponding front spherical concave hole (25).

8. The pump body structure of a diaphragm pump with stable flow rate according to claim 7, characterized in that: The liquid inlet check valve plate (50) and the liquid outlet check valve plate (60) both comprise a main connecting column (51), a covering plate formed at one end of the main connecting column (51), an annular protrusion (52) with a conical outer wall formed on the outer side wall of the other end of the main connecting column (51), a spherical surface of the covering plate facing the end face of the main connecting column (51), a middle portion of the main connecting column (51) being clamped in the corresponding first mounting through hole (221) or the second mounting through hole (24), the covering plate of the main connecting column (51) being inserted into the spherical concave hole (22) or the front spherical concave hole (25), the spherical surface of the covering plate of the main connecting column (51) being in close contact with the inner wall surface of the spherical concave hole (22) or the front spherical concave hole (25), the two being matched, and the covering plate covering all corresponding liquid outlet through holes (23) or liquid inlet through holes (211); The front end of the main connecting column (51) of the liquid inlet check valve (50) extends out of the front wall surface of the first connecting block (20), the annular protrusion (52) of the liquid inlet check valve (50) is located at the front wall surface of the first connecting block (20), and the rear end surface of the annular protrusion (52) of the liquid inlet check valve (50) is pressed against the front wall surface of the first connecting block (20); The rear end of the main connecting column (51) of the liquid outlet one-way valve plate (60) extends out of the rear end of the second mounting through hole (24), the annular protrusion (52) of the liquid outlet one-way valve plate (60) is located in the corresponding liquid suction cavity (21), and the front end surface of the annular protrusion (52) of the liquid outlet one-way valve plate (60) is pressed against the front wall surface of the corresponding liquid suction cavity (21).

9. The pump body structure of a diaphragm pump with stable flow rate according to claim 1, characterized in that: An annular groove extending backwards is formed in the middle of the annular portion of the diaphragm body (40), and an annular raised ring is formed backwards on the rear wall of the middle of the annular portion of the diaphragm body (40) corresponding to the annular groove.

10. The pump body structure of a diaphragm pump with stable flow rate according to claim 1, characterized in that: The flow rates of all the liquid outlet through holes (23) and all the liquid inlet through holes (211) of each liquid suction cavity (21) are the same.

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