CN219932412U - Adjustable diaphragm pump - Google Patents

Abstract

The utility model discloses an adjustable diaphragm pump, which comprises a pump head body, wherein a water inlet cavity, a water outlet cavity and a pressurizing cavity are arranged in the pump head body, the water inlet cavity and the water outlet cavity are respectively communicated with a water inlet and a water outlet, the pressurizing cavity is communicated with the water inlet cavity and the water outlet cavity, a water path communicated with the water outlet cavity is provided with a flow regulating component capable of regulating the water outlet flow according to voltage, the flow regulating component comprises a choke plug and a first reset spring, one end of the first reset spring acts on the inner wall of the pump head body, the other end of the first reset spring acts on the choke plug, and two sides of the choke plug are respectively provided with a first water passing groove and a second water passing groove with different lengths; the water inlet and the water inlet cavity are communicated with a water channel, a negative pressure valve seat for preventing the source water from flowing backwards is arranged on the water channel, a vacuum cavity 39 communicated with the water inlet cavity is arranged in the negative pressure valve seat, and a water sealing sleeve ring and a water locking assembly for controlling the water channel at the water sealing sleeve ring to be sealed or communicated are formed on a water channel communicated with the water inlet and the vacuum cavity 39. The utility model can control the water flow accurately under different voltages.

Description

Adjustable diaphragm pump

Technical Field

The utility model relates to the technical field of fluid transportation, in particular to an adjustable diaphragm pump.

Background

Diaphragm pumps are used as important devices for working on fluids in fluid delivery processes, and are widely used in existing industrial production and human life.

When a diaphragm pump is used in the existing water dispenser system, an atmospheric water tank is usually arranged, and the diaphragm pump pumps water from the water tank and supplies water to a heating unit. The output flow of the diaphragm pump is fixed after the diaphragm pump is started, and the output flow of the diaphragm pump is uncontrollable under different voltages.

Disclosure of Invention

The utility model aims to provide an adjustable diaphragm pump which is used for controlling output flow more accurately under different voltages.

In order to solve the technical problems, the utility model adopts the following scheme:

the adjustable diaphragm pump comprises a pump head body, wherein a water inlet cavity, a water outlet cavity and a pressurizing cavity are arranged in the pump head body, the water inlet cavity and the water outlet cavity are respectively communicated with a water inlet and a water outlet, the pressurizing cavity is respectively communicated with the water inlet cavity and the water outlet cavity through a unidirectional water flow control structure, a water path communicated with the water outlet cavity and the water outlet is provided with a flow regulating assembly capable of regulating the water outlet flow according to voltage, the flow regulating assembly comprises a choke plug and a first reset spring, one end of the first reset spring acts on the inner wall of the pump head body, the other end of the first reset spring acts on the choke plug, the choke plug is in sliding connection with the inner wall of the pump head body, and two sides of the choke plug are respectively provided with a first water passing groove and a second water passing groove with different lengths; the water inlet and the water inlet cavity are communicated with a water channel, a negative pressure valve seat for preventing the source water from flowing backwards is arranged on the water channel, a vacuum cavity communicated with the water inlet cavity is arranged in the negative pressure valve seat, and a water sealing sleeve ring and a water locking assembly for controlling the water channel at the water sealing sleeve ring to be sealed or communicated are formed on a water channel communicated with the water inlet and the vacuum cavity.

By adopting the technical scheme, on the basis of the existing diaphragm pump, the negative pressure valve seat is arranged on the side surface of the pump head body, when the diaphragm pump does not work, the water locking component controls the water way at the water sealing sleeve ring to be sealed, when the diaphragm pump works, water flow or air in the vacuum cavity is sucked away to form a certain vacuum degree, at the moment, the water locking component controls the water way at the water sealing sleeve ring to be conducted, the conducted flow is related to the vacuum degree in the vacuum cavity, the higher the vacuum degree is, the larger the conducted flow is, the more the water quantity entering the water inlet cavity is, the smaller the vacuum degree is, the smaller the conducted flow is, the water entering the water inlet cavity is, and the vacuum degree in the vacuum cavity can be regulated by regulating the working voltage (power) of the diaphragm pump. The water way that the water outlet cavity and the water outlet are communicated is provided with a choke plug, the choke plug and the inner wall of the pump head body can slide relatively, two sides of the choke plug are respectively provided with a first water passing groove and a second water passing groove with different lengths, after the source water is pumped to the water outlet cavity, the water pressure in the water outlet cavity overcomes the elastic force of a first reset spring, the choke plug is upwards pushed upwards, the longer first water passing groove is communicated with the water outlet, the water outlet flow is the flow passage area where the first water passing groove is communicated with the water outlet, if the working voltage of the diaphragm pump is larger, the water quantity entering the water inlet cavity is more, so that the source water pumped into the water outlet cavity is more, the generated water pressure is larger, the choke plug is continuously upwards moved, the shorter second water passing groove is communicated with the water outlet, and the water outlet flow is the sum of the flow passage areas where the first water passing groove and the second water passing groove are communicated with the water outlet, so that the water outlet flow is more, and the diaphragm pump can be accurately controlled under different voltages.

Preferably, the outside cover of choked flow stopper is equipped with fixed sleeve, and fixed sleeve switch-on goes out the water route between water cavity and the delivery port, and fixed sleeve vertical embedding is in the pump head body, and choked flow stopper reciprocates and control the water flow under play water cavity water pressure and first reset spring combined action.

Preferably, the lower end of the inner wall of the fixed sleeve is provided with a limiting protrusion for limiting downward movement displacement of the choke plug.

Preferably, the water inlet and the water inlet cavity are communicated with a water channel, a negative pressure valve seat for preventing the source water from flowing backwards is arranged on the water channel, the negative pressure valve seat is connected to the side surface of the pump head body, a vacuum cavity communicated with the water inlet cavity is arranged in the negative pressure valve seat, and a water sealing sleeve ring and a water locking assembly for controlling the water channel at the water sealing sleeve ring to be sealed or communicated are formed on a water channel communicated with the water inlet and the vacuum cavity.

Preferably, the water locking assembly comprises a control rod, a pressure sensing plate, a sensing diaphragm and a second reset spring, wherein the periphery of the sensing diaphragm is fixed between the negative pressure valve seat and the valve cover in a sealing manner, the sensing diaphragm and the valve cover form an atmosphere chamber, and the valve cover is provided with an atmosphere hole; the side wall of the control rod is provided with a limiting groove, one end of the control rod is fixedly connected with the middle part of the pressure sensing plate, and the other end of the control rod seals the water sealing lantern ring; one end of the second reset spring acts on the pressure sensing plate, the other end acts on the inner wall of the negative pressure valve seat, and the control rod forms a sealing water sealing sleeve ring or a water locking assembly for controlling the conduction of the water sealing sleeve ring under the combined action of the air pressure in the atmosphere chamber, the pressure in the vacuum chamber and the second reset spring.

Preferably, the control rod circumference cover is equipped with the first sealing washer that is located the restriction groove right side, and first sealing washer compresses tightly between control rod and the internal wall of pump head, and first sealing washer left side is equipped with the packing ring that compresses tightly it, compresses tightly the contact of the lantern ring left side and second reset spring right-hand member.

Preferably, still include backup pad, baffle, shell, eccentric assembly and motor, the shell is connected with the motor upper end, backup pad, baffle set gradually in the shell top from top to bottom, one-way rivers control structure sets up in the backup pad, constitute out the water cavity between backup pad middle part and the pump head body diapire, constitute the intake chamber between backup pad circumference and the pump head body diapire, compress tightly between backup pad and the baffle has the pressure boost diaphragm, pressure boost diaphragm one side undercut forms the pressure boost chamber, the output shaft of motor passes through eccentric assembly drive pressure boost chamber volume variation.

Preferably, the eccentric assembly comprises an eccentric seat, a connecting rod and a pushing frame, wherein the bottom surface of the eccentric seat is eccentrically connected with the output shaft, two ends of the connecting rod are respectively eccentrically connected with the eccentric seat and the pushing frame, and one end of the pushing frame is connected with the bottom end of the pressurizing cavity.

Preferably, a second sealing ring is tightly pressed between the pump head body and the circumference of the supporting plate.

Preferably, the unidirectional water flow control structure comprises a water inlet unidirectional valve clack and a water outlet unidirectional valve clack, a water inlet hole and a water outlet hole communicated with the pressurizing cavity are arranged on the supporting plate, the water inlet unidirectional valve clack is fixed at the water inlet hole on the supporting plate, and the water outlet unidirectional valve clack is fixed at the water outlet hole on the supporting plate.

The utility model has the beneficial effects that:

1. according to the utility model, under different voltages, the water quantity from the booster cavity pump to the water outlet cavity is different, so that the water pressure in the water outlet cavity is different, the upward moving distance of the choke plug is different, the flow passage area of the water outlet cavity communicated with the water outlet is further different, and finally the water outlet flow is controlled, so that the diaphragm pump can accurately control the water outlet flow under different voltages.

Drawings

Fig. 1 is a schematic structural view of the present utility model.

Reference numerals: the device comprises the following components of a motor, a 02-output shaft, a 03-eccentric seat, a 04-connecting rod, a 05-pushing frame, a 06-shell, a 07-baffle, a 08-pressurizing diaphragm, a 09-supporting plate, a 10-second sealing ring, a 11-water inlet cavity, a 12-negative pressure valve seat, a 13-sensing diaphragm, a 14-valve cover, a 15-compressing sleeve ring, a 16-second return spring, a 17-pressure sensing plate, a 18-flow limiting groove, a 19-control rod, a 20-first sealing ring, a 21-air hole, a 22-air cavity, a 23-water inlet, a 24-water outlet, a 25-fixing sleeve, a 26-first return spring, a 27-flow blocking plug, a 28-second water passing groove, a 29-first water passing groove, a 30-third sealing ring, a 31-water outlet hole, a 32-water inlet hole, a 33-water inlet one-way valve clack, a 34-water outlet one-way valve clack, a 35-pressurizing cavity, a 36-water outlet cavity, a 37-water sealing sleeve ring and a 38-pump head body.

Detailed Description

The present utility model will be described in further detail with reference to examples and drawings, but embodiments of the present utility model are not limited thereto.

In the description of the present utility model, it should be noted that, directions or positional relationships indicated by terms such as "center", "upper", "lower", "left", "right", "vertical", "longitudinal", "lateral", "horizontal", "inner", "outer", "front", "rear", "top", "bottom", etc., are directions or positional relationships based on those shown in the drawings, or are directions or positional relationships conventionally put in use of the inventive product, are merely for convenience of describing the present utility model and for simplifying the description, and are not indicative or implying that the apparatus or element to be referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be construed as limiting the present utility model.

In the description of the present utility model, it should also be noted that, unless explicitly specified and limited otherwise, the terms "disposed," "configured," "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present utility model will be understood in specific cases by those of ordinary skill in the art.

Examples

The adjustable diaphragm pump comprises a pump head body 38, wherein a water inlet cavity 11, a water outlet cavity 36 and a pressurizing cavity 35 are arranged in the pump head body 38, the water inlet cavity 11 and the water outlet cavity 36 are respectively communicated with a water inlet 23 and a water outlet 24, the pressurizing cavity 35 is respectively communicated with the water inlet cavity 11 and the water outlet cavity 36 through a one-way water flow control structure, a water path communicated with the water outlet 24 by the water outlet cavity 36 is provided with a flow regulating component capable of regulating the water outlet flow according to voltage, the flow regulating component comprises a choke plug 27 and a first return spring 26, one end of the first return spring 26 acts on the inner wall of the pump head body 38, the other end acts on the choke plug 27, the choke plug 27 is in sliding connection with the inner wall of the pump head body 38, and two sides of the choke plug 27 are respectively provided with a first water passing groove 29 and a second water passing groove 28 with different lengths; the water inlet 23 is provided with a negative pressure valve seat 12 for preventing the source water from flowing backwards on a water passage communicated with the water inlet cavity 11, a vacuum cavity 39 communicated with the water inlet cavity 11 is arranged in the negative pressure valve seat 12, and a water sealing sleeve ring 37 and a water locking assembly for controlling the water passage at the water sealing sleeve ring 37 to be sealed or communicated are formed on a water passage communicated with the water inlet 23 and the vacuum cavity 39.

In this embodiment, as shown in fig. 1, on the basis of the existing diaphragm pump, the negative pressure valve seat 12 is connected to the side surface of the pump head 38 in a sealing manner, when the diaphragm pump does not work, the water locking assembly controls the water path at the water sealing sleeve ring 37 to seal, water in the water inlet cavity 11 flows back, when the diaphragm pump works, water flow or air in the vacuum cavity 39 is sucked away to form a certain vacuum degree, at this time, the water locking assembly controls the water path at the water sealing sleeve ring 37 to be conducted, the flow after conduction is related to the vacuum degree in the vacuum cavity 39, the higher the vacuum degree is, the larger the flow after conduction is, the water amount entering the water inlet cavity 11 is more, the smaller the vacuum degree is, the flow after conduction is smaller the water entering the water inlet cavity 11 is, and the vacuum degree in the vacuum cavity 39 can be regulated by regulating the working voltage (power) of the diaphragm pump.

In this embodiment, the choke plug 27 is also disposed on the waterway where the water outlet cavity 36 is connected to the water outlet 24, the choke plug 27 may be cylindrical or tapered, and the choke plug 27 and the inner wall of the pump head 38 may slide relatively, two sides of the choke plug 27 are respectively provided with a first water passing channel 29 and a second water passing channel 28 with different lengths, the length of the first water passing channel 29 is greater than that of the second water passing channel 28, the lower ends of the two water passing channels are all level, the heights of the upper ends are different, the pressurizing cavity 35 pumps the source water to the water outlet cavity 36, after the water outlet cavity 36 is pressurized, the water pressure in the water outlet cavity 36 overcomes the elasticity of the first return spring 26, the choke plug 27 is pushed upwards, the longer first water passing channel 29 is connected to the water outlet 24 first water outlet 29, the water outlet flow is the flow channel area where the first water passing channel 29 is connected to the water outlet 24, and if the diaphragm pump has a higher working voltage, so that the source water in the water outlet cavity 36 is more, the generated water pressure is greater, the choke plug 27 continues to move upwards, and the shorter water outlet channel 28 is connected to the second water outlet 24 by the second water passing channel 29, and the water outlet 24 is not connected to the second water outlet 24, so that the flow is more accurate.

Further, a fixing sleeve 25 is sleeved outside the choke plug 27, the fixing sleeve 25 is communicated with a waterway between the water outlet cavity 36 and the water outlet 24, the fixing sleeve 25 is vertically embedded in the pump head body 38, and the choke plug 27 moves up and down under the combined action of the water pressure of the water outlet cavity 36 and the first return spring 26 to control the water outlet flow. Specifically, there is a fixed sleeve 25 embedded in the pump head 38, the fixed sleeve 25 is located at the outer side of the choke plug 27, the side wall of the fixed sleeve 25 is provided with a water passing port connected with the water outlet 24, the choke plug 27 moves up and down along the length direction of the fixed sleeve 25 under the combined action of the water pressure of the water outlet cavity 36 and the first return spring 26, for example, when the voltage is 12V, the water pressure in the water outlet cavity 36 can overcome the elastic force of the first return spring 26, the choke plug 27 is pushed upwards, so that the first water passing channel 29 is firstly connected with the water outlet 24, the water outlet flow is the flow area of the first water passing channel 29, if the voltage is 24V, the water pressure in the water outlet cavity 36 is larger, the distance of the upward movement of the choke plug 27 is larger, at this moment, the second water passing channel 28 is also connected with the water outlet 24, at this moment, the water outlet flow is the sum of the flow areas of the two water passing channels, and the water outlet flow is larger, so that the diaphragm pump can accurately control the water outlet flow under different specific voltages.

Further, a limiting protrusion for limiting the downward movement of the choke plug 27 is provided at the lower end of the inner wall of the fixed sleeve 25. Specifically, in order to avoid the choke plug 27 sliding out from the fixed sleeve 25 during the operation of the diaphragm pump, a circle of limiting protrusions integrally formed with the fixed sleeve 25 are arranged at the inner bottom wall of the fixed sleeve 25, and when the choke plug 27 does not move, the circumferential convex ring of the choke plug 27 contacts with the limiting protrusions, so that the fixed sleeve 25 at the sliding-down position of the choke plug 27 is limited.

Further, the water locking assembly comprises a control rod 19, a pressure sensing plate 17, a sensing diaphragm 13 and a second return spring 16, wherein the periphery of the sensing diaphragm 13 is fixed between the negative pressure valve seat 12 and the valve cover 14 in a sealing manner, the sensing diaphragm 13 and the valve cover 14 form an atmosphere chamber 22, and the valve cover 14 is provided with an atmosphere hole 21; the side wall of the control rod 19 is provided with a limiting groove 18, one end of the control rod 19 is fixedly connected with the middle part of the pressure sensing plate 17, and the other end is sealed with a water sealing sleeve ring 37; one end of the second return spring 16 acts on the pressure sensing plate 17, the other end acts on the inner wall of the negative pressure valve seat 12, and the control rod 19 forms a sealing water sealing sleeve ring 37 or a water locking assembly for controlling the conduction of the sealing water sleeve ring 37 under the combined action of the air pressure in the air cavity 22, the pressure in the vacuum cavity 39 and the second return spring 16.

Further, a first sealing ring 20 positioned on the right side of the limiting groove 18 is circumferentially sleeved on the control rod 19, the first sealing ring 20 is tightly pressed between the control rod 19 and the inner wall of the pump head body 38, a tightly pressed sleeve ring 15 for tightly pressing the first sealing ring 20 is arranged on the left side of the first sealing ring 20, and the left side of the tightly pressed sleeve ring 15 is contacted with the right end of the second reset spring 16.

Specifically, when the diaphragm pump does not work, the sum of the pressure in the vacuum cavity 39 and the acting force of the elastic force of the second return spring 16 on the sensing diaphragm 13 is larger than the acting force of the air pressure in the atmosphere cavity 22 on the sensing diaphragm 13, the control rod 19 seals the water sealing collar 37 under the combined action of the acting forces, and the right end of the control rod 19 is sealed by the first sealing ring 20, so that the water in the water inlet cavity 11 cannot flow backwards; when the diaphragm pump works, water flow or air in the vacuum cavity 39 is sucked away to form a certain vacuum degree, at this time, the sum of the pressure in the vacuum cavity 39 and the acting force of the elastic force of the second return spring 16 on the sensing diaphragm 13 is smaller than the acting force of the air pressure in the atmosphere cavity 22 on the sensing diaphragm 13, and the control rod 19 moves rightwards (in the direction of the choke plug 27) under the combined action of the acting forces until the water inlet 23 is communicated with the vacuum cavity 39 through the limiting groove 18. When the flow limiting groove 18 of the control rod 19 just exceeds the first sealing ring 20 to the right, the flow passage of the water inlet 23 communicated with the vacuum cavity 39 through the flow limiting groove 18 is smaller, the flow rate entering the water inlet cavity 11 is smaller, if the control rod 19 continues to move to the right, the right side of the part of the control rod 19 with the flow limiting groove 18 moves to a longer distance, the flow passage area of the water inlet 23 communicated with the vacuum cavity 39 through the flow limiting groove 18 is increased, the flow rate of the water inlet cavity 11 is increased, the control rod 19 returns to the original state when the diaphragm pump stops working, and the first sealing ring 20 seals the water sealing ring 37. Therefore, by adjusting the working voltage (power) of the diaphragm pump, the vacuum in the vacuum chamber 39 can be adjusted, and the distance of the control rod 19 moving right is further adjusted, so that the function of adjusting the flow entering the water inlet chamber 11 is achieved, and the water locking assembly can prevent the water in the water inlet chamber 11 from flowing backwards after the diaphragm pump stops working.

Further, still include backup pad 09, baffle 07, shell 06, eccentric assembly and motor 01, shell 06 is connected with motor 01 upper end, backup pad 09, baffle 07 from top to bottom sets gradually in shell 06 top, unidirectional water flow control structure sets up on backup pad 09, constitute out water cavity 36 between backup pad 09 middle part and the pump head body 38 diapire, be equipped with third sealing washer 30 between backup pad 09 and the pump head body 38, be used for sealed out water cavity 36 circumference, constitute intake chamber 11 between backup pad 09 circumference and the pump head body 38 diapire, compress tightly between backup pad 09 and the baffle 07 and have pressure boost diaphragm 08, pressure boost diaphragm 08 one side undercut forms pressure boost chamber 35, motor 01's output shaft 02 passes through eccentric assembly drive pressure boost chamber 35 volume variation.

Further, the eccentric assembly comprises an eccentric seat 03, a connecting rod 04 and a pushing frame 05, wherein the bottom surface of the eccentric seat 03 is eccentrically connected with the output shaft 02, two ends of the connecting rod 04 are eccentrically connected with the eccentric seat 03 and the pushing frame 05 respectively, and one end of the pushing frame 05 is connected with the bottom end of the pressurizing cavity 35.

Further, a second sealing ring 10 is pressed between the pump head 38 and the supporting plate 09 in the circumferential direction.

Further, the unidirectional water flow control structure comprises a water inlet unidirectional valve clack 33 and a water outlet unidirectional valve clack 34, a water inlet hole 32 and a water outlet hole 31 which are communicated with the pressurizing cavity 35 are arranged on the supporting plate 09, the water inlet unidirectional valve clack 33 is fixed at the water inlet hole 32 on the supporting plate 09, and the water outlet unidirectional valve clack 34 is fixed at the water outlet hole 31 on the supporting plate 09. Specifically, when the diaphragm pump works, the motor 01 drives the eccentric seat 03 to eccentrically rotate, the pushing frame 05 drives the pressurizing diaphragm 08 to compress or expand the volume of the pressurizing cavity 35, when the volume of the pressurizing cavity 35 is increased, source water is sucked into the water inlet cavity 11 from the water inlet 23, then the water inlet hole 32 pushes up the water inlet one-way valve clack 33, the source water enters the pressurizing cavity 35, when the volume of the pressurizing cavity 35 is reduced, the source water is pressed to the water outlet hole 31 and pushes up the water outlet one-way valve clack 34, the source water is pumped to the water outlet cavity 36, the elasticity of the second return spring 16 is overcome, the choke plug 27 is pushed up upwards, the water amount entering the water outlet cavity 36 is continuously according to different voltages, so that the water pressure of the water outlet cavity 36 is different, the upward moving distance of the choke plug 27 is different, and the final water outlet amount is also different, and the diaphragm pump can accurately control the water outlet flow under different voltages.

The foregoing description of the preferred embodiment of the utility model is not intended to limit the utility model in any way, but rather to cover all modifications, equivalents, improvements and alternatives falling within the spirit and principles of the utility model.

Claims (9)

1. The utility model provides an adjustable diaphragm pump, includes pump head body (38), is equipped with intake chamber (11), play water cavity (36), booster cavity (35) in pump head body (38), intake chamber (11), play water cavity (36) are put through with water inlet (23), delivery port (24) respectively, booster cavity (35) are put through with intake chamber (11), play water cavity (36) respectively through one-way rivers control structure, characterized in that, be equipped with the flow regulating assembly that can adjust the water flow according to the voltage on the water route that goes through with delivery port (24) in play water cavity (36), flow regulating assembly includes choked flow plug (27) and first reset spring (26), first reset spring (26) one end acts on pump head body (38) inner wall, the other end acts on choked flow plug (27), choked flow plug (27) and pump head body (38) inner wall sliding connection, choked flow plug (27) both sides are equipped with first water tank (29) and second water tank (28) that the length is different respectively; the water inlet (23) and the water inlet cavity (11) are communicated with a water channel, a negative pressure valve seat (12) for preventing source water from flowing backwards is arranged on the water channel communicated with the water inlet cavity (11), a vacuum cavity (39) communicated with the water inlet cavity (11) is arranged in the negative pressure valve seat (12), and a water sealing sleeve ring (37) and a water locking assembly for controlling water channel sealing or conduction at the water sealing sleeve ring (37) are formed on a water channel communicated with the water inlet (23) and the vacuum cavity (39).

2. An adjustable diaphragm pump according to claim 1, wherein a fixed sleeve (25) is sleeved outside the choke plug (27), the fixed sleeve (25) is communicated with a waterway between the water outlet cavity (36) and the water outlet (24), the fixed sleeve (25) is vertically embedded in the pump head body (38), and the choke plug (27) moves up and down under the combined action of the water pressure of the water outlet cavity (36) and the first return spring (26) and controls the water outlet flow.

3. An adjustable diaphragm pump according to claim 2, wherein the lower end of the inner wall of the fixed sleeve (25) is provided with a limit protrusion for limiting the downward displacement of the choke plug (27).

4. An adjustable diaphragm pump according to claim 1, characterized in that the water locking assembly comprises a control rod (19), a pressure sensing plate (17), a sensing diaphragm (13) and a second return spring (16), the periphery of the sensing diaphragm (13) is sealed and fixed between a negative pressure valve seat (12) and a valve cover (14), the sensing diaphragm (13) and the valve cover (14) form an atmosphere chamber (22), and the valve cover (14) is provided with an atmosphere hole (21); a limiting groove (18) is arranged on the side wall of the control rod (19), one end of the control rod (19) is fixedly connected with the middle part of the pressure sensing plate (17), and the other end is sealed with a water sealing lantern ring (37); one end of the second return spring (16) acts on the pressure sensing plate (17), the other end acts on the inner wall of the negative pressure valve seat (12), and the control rod (19) forms a sealing water sealing sleeve ring (37) or a water locking assembly for controlling the conduction of the water sealing sleeve ring (37) under the combined action of air pressure in the air cavity (22), the pressure in the vacuum cavity (39) and the second return spring (16).

5. An adjustable diaphragm pump according to claim 4, wherein the control rod (19) is circumferentially sleeved with a first sealing ring (20) positioned on the right side of the limiting groove (18), the first sealing ring (20) is tightly pressed between the control rod (19) and the inner wall of the pump head body (38), the left side of the first sealing ring (20) is provided with a tightly pressed collar (15) for tightly pressing the first sealing ring, and the left side of the tightly pressed collar (15) is contacted with the right end of the second return spring (16).

6. The adjustable diaphragm pump according to claim 1, further comprising a supporting plate (09), a partition plate (07), a housing (06), an eccentric assembly and a motor (01), wherein the housing (06) is connected with the upper end of the motor (01), the supporting plate (09) and the partition plate (07) are sequentially arranged above the housing (06) from top to bottom, a unidirectional water flow control structure is arranged on the supporting plate (09), a water outlet cavity (36) is formed between the middle part of the supporting plate (09) and the bottom wall of the pump head body (38), a water inlet cavity (11) is formed between the circumference of the supporting plate (09) and the bottom wall of the pump head body (38), a pressurizing diaphragm (08) is tightly pressed between the supporting plate (09) and the partition plate (07), one side of the pressurizing diaphragm (08) is downwards sunken to form a pressurizing cavity (35), and an output shaft (02) of the motor (01) drives the pressurizing cavity (35) to change in volume through the eccentric assembly.

7. The adjustable diaphragm pump of claim 6, wherein the eccentric assembly comprises an eccentric seat (03), a connecting rod (04) and a pushing frame (05), the bottom surface of the eccentric seat (03) is eccentrically connected with the output shaft (02), two ends of the connecting rod (04) are eccentrically connected with the eccentric seat (03) and the pushing frame (05) respectively, and one end of the pushing frame (05) is connected with the bottom end of the pressurizing cavity (35).

8. An adjustable diaphragm pump according to claim 6, characterized in that a second sealing ring (10) is pressed between the pump head body (38) and the support plate (09) in the circumferential direction.

9. An adjustable diaphragm pump according to claim 6, characterized in that the unidirectional water flow control structure comprises a water inlet unidirectional valve flap (33) and a water outlet unidirectional valve flap (34), a water inlet hole (32) and a water outlet hole (31) which are communicated with the pressurizing cavity (35) are arranged on the supporting plate (09), the water inlet unidirectional valve flap (33) is fixed at the water inlet hole (32) on the supporting plate (09), and the water outlet unidirectional valve flap (34) is fixed at the water outlet hole (31) on the supporting plate (09).