Corrugated pipe type cavity structure of constant flow pump

Abstract

According to the corrugated pipe type cavity structure of the constant flow pump, when a driving part moves away from a pump head, a liquid cavity is defined by the outer surface of a corrugated pipe and the inner wall of a mounting cavity, and liquid is sucked into the liquid cavity through a liquid inlet; when the driving piece moves close to the pump head, the corrugated pipe is driven to extrude so as to discharge liquid from the liquid cavity through the liquid outlet, the corrugated pipe extends into the mounting cavity, and the external stress environment of the corrugated pipe is more controlled. The mounting cavity is of a rigid structure and can provide physical limiting and supporting for the corrugated pipe, so that transverse expansion or accidental deformation is limited, and errors caused by the flexibility of corrugated pipe materials are avoided. The consistency and predictability of the deformation quantity of the corrugated pipe are effectively controlled, the volume precision of pumped liquid is remarkably improved, and high-precision constant-current control can be achieved easily.

Description

Technical Field

[0001] This application relates to the field of constant flow pumps, and more particularly to a bellows-type cavity structure for a constant flow pump. Background Technology

[0002] Constant flow pumps are widely used in various industries due to their high precision in pumping liquid, achieving adjustable output liquid precision.

[0003] Some constant flow pumps consist of a pump head, a bellows, and a drive structure. The pump head's inlet and outlet channels are connected to the bellows, and one end of the bellows is connected to the drive structure. During the extension and retraction of the drive structure, the bellows is compressed or stretched, causing the pump head's inlet and outlet channels to open or close respectively, thus achieving liquid intake or pumping. Because the bellows uses a pleated wall design, each fold or opening of one pleat pumps out or draws in one unit of liquid, achieving high-precision liquid output.

[0004] However, the existing bellows is located outside the pump head and connected to the pump head at one end. During the extension and retraction of the drive structure, the bellows, due to the flexibility of its material, will deform under the combined action of the drive structure and pressure (the suction liquid is under negative pressure, and the pumped liquid will be affected by the gravity of the liquid). This causes the volume of its internal cavity to change, thus affecting the accuracy of the liquid output and making it difficult to control the suction or pumping of liquid with high precision. Utility Model Content

[0005] In view of this, it is necessary to provide a bellows-type cavity structure for a constant flow pump to solve the above problems.

[0006] Embodiments of this application provide a bellows-type cavity structure for a constant flow pump, comprising:

[0007] The pump head has an inlet, an outlet, and a mounting cavity.

[0008] A bellows, one end of which is fixed to the pump head, and the other end extends into the mounting cavity;

[0009] A driving component is fixedly connected to the bellows to drive the bellows to reciprocate within the mounting cavity;

[0010] When the driving member moves away from the pump head, the outer surface of the bellows and the inner wall of the mounting cavity form a liquid cavity, so as to draw liquid into the liquid cavity through the liquid inlet; when the driving member moves closer to the pump head, it drives the bellows to squeeze, so as to discharge the liquid from the liquid cavity through the liquid outlet.

[0011] In at least one embodiment of this application, the bellows comprises:

[0012] A first mounting part is provided on the pump head;

[0013] The corrugated portion is fixedly connected to the first mounting portion at one end, and the corrugated portion is completely housed within the mounting cavity.

[0014] The second mounting part is fixedly connected to the end of the corrugated part away from the first mounting part, and is also fixedly connected to the driving member. The liquid cavity is formed by the second mounting part, the corrugated part, and the inner wall of the mounting cavity.

[0015] In at least one embodiment of this application, a fixed cavity is formed between the first mounting portion, the second mounting portion, and the corrugated portion, and one end of the driving member extends into the fixed cavity and is fixedly connected to the second mounting portion.

[0016] In at least one embodiment of this application, the extension and retraction direction of the drive member is denoted as the first direction, the extension and retraction direction of the corrugated portion is set along the first direction, and the mounting cavity is opened along the first direction.

[0017] In at least one embodiment of this application, the diameter of the mounting cavity is denoted as a, and the maximum diameter of the corrugated portion is denoted as b, satisfying the relationship a = b.

[0018] In at least one embodiment of this application, the mounting cavity and the corrugated portion are in clearance fit.

[0019] In at least one embodiment of this application, a fixing groove is provided at one end of the pump head near the driving member;

[0020] The bellows-shaped cavity structure of the constant flow pump also includes:

[0021] A fixing plate is installed at one end of the pump head near the drive component, and the first mounting part is located in the fixing groove, with the first mounting part sandwiched between the fixing plate and the pump head.

[0022] In at least one embodiment of this application, a connecting hole is provided on the fixing plate, and the driving member extends through the connecting hole into the fixing cavity.

[0023] In at least one embodiment of this application, the pump head is provided with an inlet channel communicating with the inlet port;

[0024] The bellows-shaped cavity structure of the constant flow pump also includes:

[0025] The first one-way valve assembly is located in the liquid inlet channel to control the connection and closure of the liquid inlet.

[0026] In at least one embodiment of this application, the first check valve assembly includes:

[0027] The first mounting cylinder has a first fixed channel inside, and the first mounting cylinder has a first hole that communicates with the first fixed channel and the liquid cavity.

[0028] The first elastic element has one end abutting against the inner wall of the first fixed channel;

[0029] The first valve body is located at the other end of the first elastic member.

[0030] In at least one embodiment of this application, the pump head is provided with a liquid outlet channel communicating with the liquid outlet;

[0031] The bellows-shaped cavity structure of the constant flow pump also includes:

[0032] A second one-way valve assembly is located within the liquid outlet channel to control the opening and closing of the liquid outlet. The second one-way valve assembly is in the opposite direction to the first one-way valve assembly.

[0033] In at least one embodiment of this application, the second check valve assembly includes:

[0034] The second mounting cylinder has a second fixed channel inside, and the second mounting cylinder has a second hole that communicates with the second fixed channel and the liquid cavity.

[0035] The second elastic element has one end abutting against the inner wall of the second fixed channel;

[0036] The second valve body is located at the other end of the second elastic member.

[0037] In at least one embodiment of this application, the liquid inlet and the liquid outlet are both located on the peripheral wall of the mounting cavity, and the liquid inlet and the liquid outlet are respectively located on both sides of the bellows. In the axial direction of the driving member, the maximum distance from the liquid inlet to the liquid outlet is denoted as c, and the maximum stroke of the driving member is denoted as d, satisfying the relationship: c≥d.

[0038] The bellows-type cavity structure of the constant flow pump implemented in this embodiment will have at least the following beneficial effects:

[0039] The bellows-type cavity structure of the constant flow pump described above allows for the following configuration: when the driving component moves away from the pump head, the outer surface of the bellows and the inner wall of the mounting cavity form a liquid cavity, allowing liquid to be drawn into the liquid cavity through the inlet; when the driving component moves closer to the pump head, it causes the bellows to be squeezed, discharging the liquid from the liquid cavity through the outlet. The bellows extends into the mounting cavity, resulting in a more controlled external stress environment. The rigid mounting cavity provides physical restraint and support for the bellows, limiting lateral expansion or accidental deformation and avoiding errors caused by the flexibility of the bellows material. This effectively controls the consistency and predictability of the bellows deformation, significantly improving the volume accuracy of the pumped liquid and facilitating high-precision constant flow control. Attached Figure Description

[0040] Figure 1 This is a structural diagram of the bellows-type cavity structure of a constant flow pump;

[0041] Figure 2 This is another structural view of the bellows-type cavity structure of a constant flow pump;

[0042] Figure 3 An exploded view of the bellows-type cavity structure of a constant flow pump;

[0043] Figure 4 This is a cross-sectional view of the bellows-type cavity structure of a constant flow pump.

[0044] Figure 5 A cross-sectional view of the bellows-type cavity structure of a constant flow pump in use;

[0045] Figure 6 This is an exploded view of the first check valve assembly;

[0046] Figure 7 This is an exploded view of the second check valve assembly;

[0047] Figure 8 This is a structural diagram of a bellows;

[0048] Figure 9 This is a cross-sectional view of another embodiment of the bellows-type cavity structure of a constant flow pump.

[0049] Explanation of main component symbols

[0050] 100. The bellows-type cavity structure of the constant flow pump;

[0051] 110, Pump head; 110a, Liquid inlet; 110b, Liquid outlet; 110c, Mounting cavity; 110d, Liquid chamber; 110e, Fixing groove; 110f, Liquid inlet channel; 110g, Liquid outlet channel;

[0052] 120. Bellows; 121. First mounting part; 122. Bellows part; 123. Second mounting part; 120a. Fixing cavity; A. First direction;

[0053] 130. Driving components;

[0054] 140, Fixing plate; 140a, Connecting hole;

[0055] 151. First mounting cylinder; 151a. First fixing channel; 151b. First hole; 152. First elastic element; 153. First valve body;

[0056] 161. Second mounting cylinder; 161a. Second fixing channel; 161b. Second hole; 162. Second elastic element; 163. Second valve body. Detailed Implementation

[0057] The embodiments of this application will now be described with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0058] It should be noted that when a component is considered to be "connected" to another component, it can be directly connected to the other component or may also have an intervening component. When a component is considered to be "placed" on another component, it can be directly placed on the other component or may also have an intervening component. The terms "top," "bottom," "upper," "lower," "left," "right," "front," "back," and similar expressions used in this article are for illustrative purposes only.

[0059] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0060] Embodiments of this application provide a bellows type 120 cavity structure 100 for a constant flow pump, comprising:

[0061] The pump head 110 has an inlet 110a, an outlet 110b and a mounting cavity 110c;

[0062] The bellows 120 is fixed at one end to the pump head 110 and extends into the mounting cavity 110c at the other end.

[0063] The driving component 130 is fixedly connected to the bellows 120 to drive the bellows 120 to reciprocate within the mounting cavity 110c;

[0064] When the drive member 130 moves away from the pump head 110, the outer surface of the bellows 120 and the inner wall of the mounting cavity 110c form a liquid cavity 110d, so that liquid is drawn into the liquid cavity 110d through the liquid inlet 110a; when the drive member 130 moves closer to the pump head 110, it drives the bellows 120 to squeeze, so that liquid is discharged from the liquid cavity 110d through the liquid outlet 110b.

[0065] Please refer to Figures 1-8 In this embodiment, during the liquid suction phase, the drive member 130 moves away from the pump head 110 (i.e., stretches the bellows 120). The bellows 120 is stretched along with the drive member 130, forming a liquid cavity 110d (a closed space) between the outer wall of the bellows 120 and the inner wall of the mounting cavity 110c. Because the pressure inside the liquid cavity 110d decreases at this time, creating a negative pressure, liquid is drawn into the liquid cavity 110d through the inlet 110a of the pump head 110.

[0066] During the discharge phase, the drive unit 130 moves toward the pump head 110 (i.e., compresses the bellows 120). The bellows 120 is compressed, the volume of the liquid chamber 110d decreases, and the liquid is subjected to pressure. The liquid is forced out of the liquid chamber 110d outside the bellows 120 and discharged through the outlet 110b of the pump head 110.

[0067] The bellows 120 extends into the mounting cavity 110c, where its external stress environment is more controlled. The mounting cavity 110c is a rigid structure that provides physical restraint and support for the bellows 120, thereby limiting lateral expansion or accidental deformation and avoiding errors caused by the flexibility of the bellows 120 material. This effectively controls the consistency and predictability of the bellows 120's deformation, significantly improving the volume accuracy of the pumped liquid and facilitating high-precision constant flow control.

[0068] One end of the bellows 120 is fixed to the pump head 110, and the other end is directly connected to the drive component 130, resulting in a short power transmission path and high efficiency.

[0069] The mounting cavity 110c provides a linear motion path, making the movement of the drive component 130 stable and reliable, which is beneficial to the control accuracy of the system's small-volume conveying.

[0070] The positive and negative pressure cycles are formed by the positive and negative movement of the drive unit 130, which correspond to the inhalation and exhalation processes, respectively.

[0071] The pump head 110 is roughly a cylindrical shape with a U-shape, and the inlet 110a, outlet 110b and mounting cavity 110c form a T-shaped structure.

[0072] In at least one embodiment of this application, the bellows 120 includes:

[0073] The first mounting part 121 is provided on the pump head 110;

[0074] The corrugated portion 122 is fixedly connected at one end to the first mounting portion 121, and the corrugated portion 122 is completely housed within the mounting cavity 110c.

[0075] The second mounting part 123 is fixedly connected to the end of the corrugated part 122 away from the first mounting part 121, and is also fixedly connected to the drive member 130. The liquid cavity 110d is formed by the second mounting part 123, the corrugated part 122 and the inner wall of the mounting cavity 110c.

[0076] Please refer to Figures 1-8 In this embodiment, when the drive member 130 moves away from the pump head 110, it drives the second mounting part 123 away from the first mounting part 121, the corrugated part 122 extends, and a sealed space is gradually formed between the outer wall of the corrugated part 122 and the inner wall of the mounting cavity 110c. This space is the liquid cavity 110d, and liquid is drawn in through the liquid inlet 110a.

[0077] When the drive unit 130 moves toward the pump head 110, the corrugated part 122 is compressed, the volume of the liquid chamber 110d decreases, and the liquid is squeezed out from the liquid chamber 110d and discharged through the outlet 110b.

[0078] The entire liquid cavity 110d is formed by three parts: the inner surface of the second mounting part 123, the outer wall of the corrugated part 122, and the inner wall of the mounting cavity 110c, which together form an annular or columnar closed space. The volume changes as the drive member 130 reciprocates, thereby achieving controllable liquid delivery.

[0079] Since the corrugated part 122 is completely housed within the mounting cavity 110c, its deformation is limited by the mounting cavity 110c, thereby avoiding the problem of inconsistent deformation caused by factors such as the softness of the corrugated pipe 120 material and external force interference.

[0080] The bellows 122 achieves linear movement in a specific axial direction (driving direction), improving the consistency of the pumping stroke and thus increasing the volume accuracy of the pumped liquid.

[0081] The liquid chamber 110d is enclosed by three boundaries, with clear geometric limits, which is beneficial for structural designers to control its maximum / minimum volume and helps to achieve small-volume, high-precision fluid control.

[0082] The bellows 120 itself does not have an external exposed surface that is in direct pressure contact with the liquid (as in conventional structures), which makes sealing easier and significantly reduces the risk of leakage.

[0083] The first mounting part 121 is mounted on the pump head 110 to securely fix one end of the bellows 120 to the structure of the pump head 110, ensuring that the end remains stationary throughout the operation. The first mounting part 121 is approximately an annular structure.

[0084] The corrugated section 122 is the telescopic main body of the bellows 120, possessing good elasticity and compressibility, and is completely housed within the mounting cavity 110c inside the pump head 110. It not only protects the corrugated section 122 from external disturbances but also controls its movement within the geometric boundaries of the mounting cavity 110c. Its structure is generally composed of multiple pleats, each pleat comprising two symmetrically arranged inclined plates.

[0085] The second mounting portion 123 is mounted at the other end of the corrugated portion 122, that is, the end away from the first mounting portion 121, and is fixedly connected to the driving member 130. This structure causes the corrugated portion 122 to reciprocate and extend as the driving member 130 moves, and the second mounting portion 123 is roughly in the shape of a dome.

[0086] In at least one embodiment of this application, a fixed cavity 120a is formed between the first mounting portion 121, the second mounting portion 123 and the corrugated portion 122, and one end of the driving member 130 extends into the fixed cavity 120a and is fixedly connected to the second mounting portion 123.

[0087] Please refer to Figures 1-8 In this embodiment, one end of the drive member 130 extends into the fixed cavity 120a, that is, the drive structure is not exposed to the outside, but is fixed in the bellows 120 structure.

[0088] The extension and retraction of the drive component 130 causes its end to connect with the second mounting part 123, pushing the bellows 120 to extend and retract in the mounting cavity 110c, thereby increasing or decreasing the volume of the liquid cavity 110d and completing the liquid suction and discharge process.

[0089] The drive component 130 and the second mounting part 123 are directly connected in the fixed cavity 120a. The power transmission is linear along the axial direction of the bellows 120. This structure can significantly reduce the lateral deformation of the bellows 120 caused by eccentric force or asymmetrical force in the traditional connection structure, thereby improving the repeatability and control reliability of the bellows 120's extension and retraction.

[0090] In at least one embodiment of this application, the extension and retraction direction of the drive member 130 is denoted as the first direction A, the extension and retraction direction of the corrugated portion 122 is arranged along the first direction A, and the mounting cavity 110c is opened along the first direction A.

[0091] Please refer to Figures 1-8In this embodiment, the drive member 130 reciprocates in the first direction A (axial direction), causing the second mounting part 123 and the corrugated part 122 to extend and retract in the mounting cavity 110c. The corrugated part 122 extends or compresses in the first direction A as the drive member 130 moves, and the mounting cavity 110c itself also extends in the first direction A, so it can fully accommodate the stroke of the corrugated part 122. The liquid cavity 110d expands or contracts in the first direction A accordingly, completing the liquid suction or discharge process.

[0092] All moving parts move in the same direction, avoiding force deviation or torsional transmission, making the power transmission process more efficient and linear, avoiding stress concentration or component misalignment caused by inconsistent directions, and improving the mechanical stability and reliability of the device operation.

[0093] The three components are arranged in a coaxial manner, which helps to modularize and integrate the entire structure, making it easier to integrate the constant flow pump into various space-sensitive devices, such as laboratory instruments, medical pumps, and analytical systems.

[0094] The bellows 120 moves linearly along the driving direction to avoid lateral expansion or uneven deformation. The mounting cavity 110c also extends in this direction. Each expansion and contraction of the bellows 122 can be completed within a stable and regular boundary, which helps to achieve highly repeatable and highly controllable drainage action and ensure constant flow accuracy.

[0095] In at least one embodiment of this application, the diameter of the mounting cavity 110c is denoted as a, and the maximum diameter of the corrugated portion 122 is denoted as b, satisfying the relationship a = b.

[0096] Please refer to Figures 1-8 In this embodiment, the inner diameter a of the mounting cavity 110c is exactly equal to the outer diameter b of the corrugated portion 122, satisfying a = b, and the maximum outer diameter of the corrugated portion 122 is just in contact with the inner wall of the mounting cavity 110c.

[0097] The corrugated portion 122 is completely housed within the mounting cavity 110c. During installation, its outer wall adheres to the inner wall of the mounting cavity 110c, maintaining this contact throughout the reciprocating motion. When the drive member 130 drives the corrugated portion 122 to reciprocate along the axial direction (first direction A) within the mounting cavity 110c, the corrugated portion 122 expands and contracts. The inner wall of the mounting cavity 110c acts as a physical limiting boundary, constraining the radial deformation of the corrugated portion 122 and preventing it from expanding laterally or sinking inward. When the corrugated portion 122 expands, the inner cavity volume increases to absorb liquid; when compressed, the inner cavity volume decreases to discharge liquid. Because the corrugated portion 122 fits tightly with the inner wall of the mounting cavity 110c, it can continuously and stably enclose and form the liquid cavity 110d during the motion, maintaining the integrity and sealing of the liquid flow space.

[0098] Since the outer wall of the corrugated part 122 is tightly fitted to the inner wall of the mounting cavity 110c, the space of the liquid cavity 110d formed by each expansion and contraction of the corrugated tube 120 is predictable and fixed, avoiding the actual volume deviation caused by the expansion or deformation of the corrugated tube 120, thereby ensuring the stability of the volume of liquid sucked in / out in each working cycle, which helps to achieve precise and controllable micro-fluid output.

[0099] The mounting cavity 110c provides circumferential support, effectively suppressing deformation caused by radial stress, reducing material fatigue and unintended local stress concentration, and helping to extend the service life of the bellows 120.

[0100] It should be noted that in actual use, the maximum diameter of the corrugated part 122 can be slightly smaller than the diameter of the mounting cavity 110c.

[0101] In another embodiment, the corrugated portion 122 and the mounting cavity 110c can be fitted with a clearance.

[0102] In at least one embodiment of this application, the mounting cavity 110c is clearance-fitted with the corrugated portion 122.

[0103] Please refer to Figures 1-8 In this embodiment, the clearance fit provides sufficient axial expansion and contraction space for the bellows 120, avoiding frictional resistance or material jamming caused by excessive tightness. This helps the drive component 130 to smoothly transmit power through the bellows 120, improving the response speed and output stability of the entire pumping process.

[0104] If the corrugated part 122 fits too tightly with the mounting cavity 110c, local wear or tear may occur due to the squeezing and scraping of the corrugated structure. The clearance fit effectively eliminates the above problems, reduces the risk of failure such as material fatigue and fracture, and improves the durability of the pump body.

[0105] The appropriate gap can provide lateral restraint to the corrugated part 122 without affecting expansion and contraction, preventing the corrugated pipe 120 from eccentric shaking or swaying during pumping, thereby ensuring the stability of the liquid chamber 110d molding and helping to improve the volume accuracy and consistency of constant current output.

[0106] In at least one embodiment of this application, a fixing groove 110e is provided at one end of the pump head 110 near the drive member 130;

[0107] The bellows type 120 cavity structure 100 of the constant flow pump also includes:

[0108] A fixing plate 140 is installed at one end of the pump head 110 near the drive member 130, and the first mounting part 121 is located in the fixing groove 110e, and the first mounting part 121 is sandwiched between the fixing plate 140 and the pump head 110.

[0109] Please refer to Figures 1-8 In this embodiment, during assembly, the first mounting part 121 of the bellows 120 is inserted into the fixing groove 110e of the pump head 110, and the fixing plate 140 is installed at the end of the pump head 110 and fixed by screws, buckles, etc. The first mounting part 121 is pressed between the fixing plate 140 and the pump head 110, and is in a stable clamping state. During the operation of the pump, the bellows 120 undergoes expansion and contraction, but the first mounting part 121 always remains stationary and is firmly connected to the pump head 110, playing a role in fixing and sealing. This structure provides reliable end support for the bellows 120 and ensures that liquid will not leak from the interface.

[0110] During the repeated operation of the constant flow pump, the bellows 120 will be subjected to continuous reciprocating mechanical motion and pressure pulsation. The mechanical fixing method using the fixing groove 110e, fixing plate 140 and clamping can effectively prevent the first mounting part 121 from loosening or falling off after long-term operation, ensuring the positioning stability of the bellows 120, thereby maintaining the continuous reliability of the pump body operation.

[0111] The first mounting part 121 is embedded in the fixing groove 110e and pressed into the structure of the pump head 110. The mating clearance can be effectively controlled. The fixing plate 140 applies axial clamping force, which helps to compact the first mounting part 121 and press it tightly against the sealing surface. From a structural perspective, this greatly reduces the risk of liquid leakage from the bellows 120 interface, making it especially suitable for applications that transport corrosive or high-purity liquids (such as medical and chemical experiments).

[0112] The first mounting part 121 is embedded in the fixing groove 110e and pressed in the vertical direction by the fixing plate 140, so that it is restricted up and down and positioned back and forth.

[0113] The fixing groove 110e is an annular groove, and the fixing plate 140 is roughly a rectangular plate.

[0114] In at least one embodiment of this application, the fixing plate 140 is provided with a connecting hole 140a, and the driving member 130 extends through the connecting hole 140a into the fixing cavity 120a.

[0115] Please refer to Figures 1-8In this embodiment, during assembly, the drive member 130 passes through the connecting hole 140a on the fixed plate 140 from the outside of the pump body, the drive member 130 extends into the fixed cavity 120a, and is firmly connected to the second mounting part 123. During the operation of the constant flow pump, the drive member 130 reciprocates (axially extends and retracts), and drives the corrugated part 122 to extend and retract axially through the second mounting part 123. The volume change of the liquid cavity 110d is realized through the extension and retraction of the corrugated tube 120, thus completing the liquid suction and discharge.

[0116] The drive component 130 enters the bellows 120 directly through the connecting hole 140a on the fixed plate 140 (fixed cavity 120a). The connection path is short and there is no intermediate transfer mechanism, so the power transmission is more direct, the response is fast and there is no lag, which helps to achieve high-frequency and high-precision fluid control.

[0117] The connecting hole 140a is the only channel through which the drive component 130 passes, which facilitates a highly reliable seal through components such as sealing rings and rubber sleeves. This effectively prevents liquid or mist inside the pump body from leaking into the space where the drive structure is located, and also prevents external dust and impurities from entering the pump cavity, thereby enhancing the pump body's sealing performance and system safety.

[0118] The connecting hole 140a is a circular through hole.

[0119] In at least one embodiment of this application, the pump head 110 has an inlet channel 110f communicating with the inlet port 110a;

[0120] The bellows type 120 cavity structure 100 of the constant flow pump also includes:

[0121] The first one-way valve assembly is located in the liquid inlet channel 110f to control the connection and closure of the liquid inlet 110a.

[0122] Please refer to Figures 1-8 In this embodiment, during the liquid suction stage (the drive unit 130 moves away from the pump head 110 and the bellows 120 extends), the bellows 120 extends to form a negative pressure, the volume of the liquid chamber 110d increases, and the internal pressure decreases. Under the action of the pressure difference, the external liquid enters through the inlet 110a to the inlet channel 110f, and the first one-way valve opens, allowing the liquid to flow into the liquid chamber 110d.

[0123] During the discharge stage (the drive unit 130 approaches the pump head 110, and the bellows 120 is compressed), the bellows 120 is compressed, the pressure in the liquid chamber 110d rises, and the liquid is squeezed out. At this time, the first one-way valve automatically closes due to the reverse pressure to prevent the liquid from flowing back into the inlet channel 110f. The liquid is discharged through the outlet 110b, realizing one-way flow.

[0124] The first one-way valve group only allows liquid to flow in one direction and closes the reverse path. This structure ensures that during each liquid suction / discharge process, the liquid can only enter from the inlet 110a and cannot be discharged in the reverse direction. This effectively prevents the liquid from being drawn back or causing flow errors when the bellows 120 is compressed or vibrated, and improves the metering accuracy and stability of the constant flow pump.

[0125] During each aspiration operation, liquid can only flow into the liquid chamber 110d after the valve group is opened. During the drainage phase, the valve group is closed, and all the internal liquid is discharged to the outlet 110b, avoiding residue and mixing. This fluid control method helps to achieve precise micro-volume metering and highly repeatable drainage control.

[0126] The liquid inlet channel 110f is a circular channel.

[0127] In at least one embodiment of this application, the first check valve assembly includes:

[0128] The first mounting cylinder 151 has a first fixed channel 151a inside, and the first mounting cylinder 151 has a first hole 151b that communicates with the first fixed channel 151a and the liquid cavity 110d.

[0129] The first elastic element 152 has one end abutting against the inner wall of the first fixed channel 151a;

[0130] The first valve body 153 is located at the other end of the first elastic member 152.

[0131] Please refer to Figures 1-8 In this embodiment, during the liquid suction stage (the bellows 120 extends), the driving member 130 pulls the bellows 120 to extend, the volume of the liquid chamber 110d increases, forming a negative pressure. The valve body is driven by the pressure difference to move outward (away from the fixed end of the first elastic member 152), the first hole 151b opens, and the liquid flows from the inlet 110a through the first mounting cylinder 151, the first fixed channel 151a, and the first hole 151b into the liquid chamber 110d.

[0132] During the drainage stage (compression of bellows 120), the bellows 120 is compressed, the pressure in the liquid chamber 110d increases, and the pressure acts in the opposite direction on the first valve body 153, causing it to compress towards the first elastic element 152. Under the combined action of the elastic force of the first elastic element 152 and the reverse hydraulic pressure, the first valve body 153 abuts against the inner wall of the first fixed channel 151a, closing the first hole 151b, preventing liquid from flowing back from the liquid chamber 110d to the inlet channel 110f, thus realizing the one-way valve control function.

[0133] The first elastic element 152 provides the first valve body 153 with active reset capability, so that even after the pump body stops running, the valve can remain closed, effectively preventing liquid backflow or backflow caused by factors such as gravity, residual pressure, and rebound, and improving the delivery stability of the constant flow pump.

[0134] The first mounting cylinder 151 is the outer shell of the valve body assembly. It forms a first fixed channel 151a inside for liquid flow. The first mounting cylinder 151 is cylindrical and hollow in the middle. A first hole 151b is provided on the wall of the mounting cylinder to connect the inside of the fixed channel with the liquid chamber 110d. It is an opening for liquid inflow / guidance. The first hole 151b is a circular through hole. A first elastic element 152 (such as a spring) is installed in the first fixed channel 151a, with one end abutting against the inner wall of the mounting cylinder. The first valve body 153 is provided at the other end of the elastic element. It moves with the compression or release of the elastic element to open or close the first hole 151b or the liquid channel, and plays a check valve role. The first valve body 153 is a ball valve.

[0135] In at least one embodiment of this application, the pump head 110 is provided with a liquid outlet channel 110g communicating with the liquid outlet 110b;

[0136] The bellows type 120 cavity structure 100 of the constant flow pump also includes:

[0137] The second one-way valve assembly is located within the liquid outlet channel 110g to control the opening and closing of the liquid outlet 110b. The second one-way valve assembly is in the opposite direction to the first one-way valve assembly.

[0138] Please refer to Figures 1-8 In this embodiment, during the liquid suction stage (when the drive unit 130 is away from the pump head 110), the bellows 120 extends, the liquid chamber 110d is under negative pressure, the first one-way valve opens, and liquid flows into the liquid chamber 110d from the inlet channel 110f. The second one-way valve is closed to prevent external liquid from flowing back into the liquid chamber 110d.

[0139] During the drainage stage (drive unit 130 is close to pump head 110), bellows 120 is compressed, the volume of liquid chamber 110d decreases, the internal pressure increases, the first check valve closes to prevent liquid from flowing back to inlet 110a, the second check valve opens, and the liquid is discharged through outlet channel 110g and outlet 110b.

[0140] By installing a second one-way valve assembly within the liquid outlet channel 110g, liquid is only allowed to be discharged during the drainage stage, effectively preventing backflow of liquid after drainage, ensuring complete discharge of liquid in each drainage action, preventing residual liquid accumulation, avoiding flow error, and improving the accuracy of pumped liquid volume.

[0141] After the liquid is drained, the bellows 120 may cause liquid backflow due to the rebound of the compressed state. The presence of the second check valve can automatically close the outlet path to prevent the drained liquid from flowing back into the pump body.

[0142] The liquid outlet channel 110g is a circular channel.

[0143] In at least one embodiment of this application, the second check valve assembly includes:

[0144] The second mounting cylinder 161 has a second fixing channel 161a inside, and the second mounting cylinder 161 has a second hole 161b that communicates with the second fixing channel 161a and the liquid cavity 110d.

[0145] The second elastic element 162 has one end abutting against the inner wall of the second fixed channel 161a;

[0146] The second valve body 163 is located at the other end of the second elastic member 162.

[0147] Please refer to Figures 1-8 In this embodiment, during the drainage stage (the drive component 130 moves toward the pump head 110, and the bellows 120 is compressed), the volume of the liquid chamber 110d decreases, the internal liquid is forced out, and the liquid pressure pushes the second valve body 163 to overcome the elastic force of the second elastic component 162. The second valve body 163 leaves the sealing position and opens the second hole 161b. The liquid smoothly flows from the liquid chamber 110d through the second hole 161b and the second fixed channel 161a to the outlet 110b.

[0148] During the liquid suction stage (the drive component 130 moves away from the pump head 110 and the bellows 120 extends), a negative pressure is formed in the liquid chamber 110d. The second valve body 163 is subjected to the combined action of the reverse pressure difference and the reset force of the second elastic component 162, which causes it to spring back and fit against the sealing surface, closing the second hole 161b and preventing the discharged liquid from flowing back into the liquid chamber 110d, thus achieving unidirectional fluid control.

[0149] It should be noted that the second mounting cylinder 161 is roughly a cylindrical shape with a through-hole in the middle, the second elastic element 162 is a spring, the second fixing channel 161a is a circular channel, and the second hole 161b is a circular through-hole; the second valve body 163 is a ball valve, and the second valve body 163 is set close to the bellows 120, and the first valve body 153 is set close to the bellows 120. The first valve body 153 and the second valve body 163 are symmetrically arranged about the driving element 130. The driving element 130 is a telescopic rod, and its power source can be a telescopic motor, a telescopic cylinder, etc.

[0150] In at least one embodiment of this application, the inlet 110a and the outlet 110b are both located on the peripheral wall of the mounting cavity 110c, and the inlet 110a and the outlet 110b are respectively located on both sides of the bellows 120. In the axial direction of the drive member 130, the maximum distance from the inlet 110a to the outlet 110b is denoted as c, and the maximum stroke of the drive member 130 is denoted as d, satisfying the relationship: c≥d.

[0151] Please refer to Figure 9 In this embodiment, in the axial direction of the drive member 130, since the maximum distance from the liquid inlet 110a to the liquid outlet 110b is greater than or equal to the maximum stroke of the drive member 130, it is convenient for the liquid to flow in the liquid chamber 110d, thereby playing the role of venting, so as to ensure the output accuracy of the bellows-type cavity structure 100 of the constant flow pump.

[0152] When the bellows 120 extends to its maximum stroke, the end of its internal liquid chamber 110d just reaches or has not yet fully reached the foremost position of the outlet 110b. In the initial stage of the pumping cycle (especially during startup), the gas will be preferentially pushed towards the front end of the liquid chamber 110d (i.e., the side near the outlet). Since the outlet 110b is located at the top or side wall of the cavity in front of the bellows 120, the gas will be preferentially discharged through the outlet 110b when under pressure. At the same time, because the driving stroke does not exceed the distance between the inlet and outlet 110b (c≥d), the bellows 120 will not push the gas back towards the inlet 110a during the entire operation, avoiding gas back suction and facilitating the complete expulsion of the gas from the pump body.

[0153] The above description is merely an embodiment of this application. It should be noted that those skilled in the art can make improvements without departing from the inventive concept of this application, but these improvements all fall within the protection scope of this application.

Claims

1. A bellows-type cavity structure for a constant flow pump, characterized in that, include: The pump head has an inlet, an outlet, and a mounting cavity. A bellows, one end of which is fixed to the pump head, and the other end extends into the mounting cavity; A driving component is fixedly connected to the bellows to drive the bellows to reciprocate within the mounting cavity; When the driving component moves away from the pump head, the outer surface of the bellows and the inner wall of the mounting cavity form a liquid cavity, so as to draw liquid into the liquid cavity through the liquid inlet; When the drive unit moves close to the pump head, it drives the bellows to squeeze, so as to discharge the liquid from the liquid chamber through the outlet.

2. The bellows-type cavity structure of the constant flow pump according to claim 1, characterized in that, The bellows includes: A first mounting part is provided on the pump head; The corrugated portion is fixedly connected to the first mounting portion at one end, and the corrugated portion is completely housed within the mounting cavity. The second mounting part is fixedly connected to the end of the corrugated part away from the first mounting part, and is also fixedly connected to the driving member. The liquid cavity is formed by the second mounting part, the corrugated part, and the inner wall of the mounting cavity.

3. The bellows-type cavity structure of the constant flow pump according to claim 2, characterized in that, A fixed cavity is formed between the first mounting part, the second mounting part, and the corrugated part. One end of the driving member extends into the fixed cavity and is fixedly connected to the second mounting part.

4. The bellows-type cavity structure of the constant flow pump according to claim 2, characterized in that, The extension and retraction direction of the drive component is denoted as the first direction, the extension and retraction direction of the corrugated part is set along the first direction, and the mounting cavity is opened along the first direction.

5. The bellows-type cavity structure of the constant flow pump according to claim 2, characterized in that, Let a be the diameter of the mounting cavity and b be the maximum diameter of the corrugated part, satisfying the relationship a = b.

6. The bellows-type cavity structure of the constant flow pump according to claim 2, characterized in that, The mounting cavity is clearance-fitted with the corrugated part.

7. The bellows-type cavity structure of the constant flow pump according to claim 3, characterized in that, A fixing groove is provided at one end of the pump head near the driving component; The bellows-shaped cavity structure of the constant flow pump also includes: A fixing plate is installed on one end of the pump head near the driving member, and the first mounting part is located in the fixing groove. The first mounting part is sandwiched between the fixing plate and the pump head. A connecting hole is provided on the fixing plate, and the driving member extends through the connecting hole into the fixing cavity.

8. The bellows-type cavity structure of the constant flow pump according to claim 1, characterized in that, The pump head has an inlet channel that communicates with the inlet port; The bellows-shaped cavity structure of the constant flow pump also includes: A first one-way valve assembly is located in the liquid inlet channel to control the opening and closing of the liquid inlet. The first check valve assembly includes: The first mounting cylinder has a first fixed channel inside, and the first mounting cylinder has a first hole that communicates with the first fixed channel and the liquid cavity. The first elastic element has one end abutting against the inner wall of the first fixed channel; The first valve body is located at the other end of the first elastic member.

9. The bellows-type cavity structure of the constant flow pump according to claim 8, characterized in that, The pump head has a liquid outlet channel that communicates with the liquid outlet. The bellows-shaped cavity structure of the constant flow pump also includes: A second one-way valve assembly is located in the liquid outlet channel to control the opening and closing of the liquid outlet. The second one-way valve assembly is in the opposite direction to the first one-way valve assembly. The second check valve assembly includes: The second mounting cylinder has a second fixed channel inside, and the second mounting cylinder has a second hole that communicates with the second fixed channel and the liquid cavity. The second elastic element has one end abutting against the inner wall of the second fixed channel; The second valve body is located at the other end of the second elastic member.

10. The bellows-type cavity structure of the constant flow pump according to claim 1, characterized in that, Both the liquid inlet and the liquid outlet are located on the peripheral wall of the mounting cavity, and the liquid inlet and the liquid outlet are located on both sides of the bellows. In the axial direction of the drive component, the maximum distance from the liquid inlet to the liquid outlet is denoted as c, and the maximum stroke of the drive component is denoted as d, satisfying the relationship: c≥d.

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