A liquid outlet check valve for a plunger pump, a plunger pump and a high-frequency electrotome

Abstract

The utility model provides a kind of for plunger pump's liquid outlet check valve, plunger pump and high frequency electrotome, wherein liquid outlet check valve includes valve body, spring and plugging piece, plugging piece includes plugging main body and at least two bosses fixed on plugging main body outer circumferential wall and along plugging main body circumferentially spaced arrangement, first lumen, second lumen and third lumen are formed in valve body sequentially communicated along liquid flow direction, spring mounting position is fixed in second lumen, the first end of spring is connected with spring mounting position, the second end of spring is connected with at least two bosses;Natural state, spring is in compression state, and the elastic action of spring drives plugging main body to abut and block first lumen liquid outlet port;The liquid of certain pressure can promote plugging piece to open the liquid outlet port of first lumen, and make liquid discharge after flowing through second lumen and third lumen.Liquid outlet check valve is used in the plunger pump of high frequency electrotome, can effectively prevent the liquid in cylinder body from leaking outward.

Description

Technical Field

[0001] This utility model relates to the field of medical device technology, and in particular to a liquid outlet check valve for a plunger pump, a plunger pump, and a high-frequency electrosurgical unit. Background Technology

[0002] A high-frequency electrosurgical unit (HFEMU) is an electrosurgical instrument that replaces mechanical scalpels for tissue cutting. It heats tissue by generating a high-frequency, high-voltage current at the tip of its effective electrode, achieving tissue separation and coagulation, thus achieving cutting and hemostasis. During use, a suitable neutral electrode plate is required. This plate is attached to a muscle-rich area of ​​the patient, guiding the current collected within the body back to the HFEMU and other instruments, forming a complete high-frequency circuit. This disperses the current during high-frequency surgery, reducing the risk of current concentration, safely collecting and delivering the current to the outside of the body, and protecting the patient's safety.

[0003] Currently, there exists a water-injection type high-frequency electrosurgical unit with a water pump built into the handle. The water injection function of this unit is generally used to inject medical fluid submucosally to elevate lesions, thereby facilitating their removal. The water pump built into the handle is typically a plunger pump, which includes a drive assembly, a plunger assembly, and a cylinder. The plunger assembly is slidably connected to the cylinder, and the drive assembly is drively connected to the plunger assembly. The cylinder has an inlet and an outlet. The inlet communicates with an external infusion bag placed on the high-frequency electrosurgical unit, and the outlet communicates with the distal end of the high-frequency electrosurgical unit for water injection. Both the inlet and outlet are equipped with inlet and outlet check valves.

[0004] The working principle of a plunger pump is as follows: the drive assembly drives the plunger assembly to reciprocate within the cylinder, causing the volume within the cylinder to alternately increase and decrease. When the volume within the cylinder increases, creating negative pressure, the inlet check valve opens and the outlet check valve closes, allowing liquid to enter the cylinder from the infusion bag through the inlet. When the volume within the cylinder decreases, creating positive pressure, the inlet check valve closes and the outlet check valve opens, allowing liquid within the cylinder to flow through the outlet and be ejected from the distal end of the high-frequency electrosurgical unit for water injection into the submucosal tissue. Currently, the outlet check valves used are generally duckbill type check valves, such as... Figure 1 As shown, the inlet end of this duckbill-type one-way valve is a cylindrical connecting pipe, and the outlet end is flat and duckbill-shaped, including two symmetrical elastic lips. In its natural state, a linear gap is formed between the two elastic lips. When the volume inside the cylinder increases, creating a negative pressure, the lips will squeeze together and close under the action of the negative pressure. When the volume inside the cylinder decreases, creating a positive pressure, the fluid pushes the duckbill lips open outward under the action of the positive pressure.

[0005] However, in the use of water-filled high-frequency electrosurgical units (HFOS), when the HFOS is not being used with water, the liquid remaining in the cylinder can easily leak through the gap between the two elastic lips of the duckbill-type check valve, thus affecting the normal cutting and coagulation operation of the HFOS. In particular, the infusion bag is often mounted higher than the operating position of the HFOS, which makes the water level in the infusion bag higher than the water level in the plunger pump cylinder. When the HFOS is not being used with water, the liquid in the infusion bag may enter the cylinder through the inlet check valve due to its own water pressure, further promoting the leakage of liquid in the cylinder through the gap between the two elastic lips of the duckbill-type check valve.

[0006] Therefore, there is an urgent need for an improved discharge check valve for plunger pumps, a plunger pump, and a high-frequency electrosurgical unit. Utility Model Content

[0007] (a) Technical problems to be solved

[0008] In view of the problems existing in the above-mentioned technology, the present invention provides solutions to at least some extent. Therefore, the first objective of the present invention is to provide a liquid outlet check valve for a plunger pump, used in a high-frequency electrosurgical unit plunger pump, which can effectively prevent liquid leakage from the cylinder body; the second objective of the present invention is to provide a plunger pump with the above-mentioned liquid outlet check valve; and the third objective of the present invention is to provide a high-frequency electrosurgical unit with the above-mentioned plunger pump.

[0009] (II) Technical Solution

[0010] To achieve the above objectives, the main technical solutions adopted by this utility model include:

[0011] In a first aspect, this utility model provides a liquid outlet check valve for a plunger pump, comprising a valve body, a spring, and a sealing element. The sealing element includes a sealing body and at least two bosses fixed on the outer peripheral wall of the sealing body and spaced apart along the circumference of the sealing body. The valve body has a first cavity, a second cavity, and a third cavity that are sequentially connected along the liquid flow direction. The diameter of the second cavity is larger than the diameter of the liquid outlet of the first cavity. A spring mounting position is fixed in the second cavity. The first end of the spring is connected to the spring mounting position, and the second end of the spring is connected to the at least two bosses.

[0012] In its natural state, the spring is compressed, and the elasticity of the spring causes the sealing body to abut against and seal the outlet of the first cavity; a certain pressure of liquid can push the sealing component to open the outlet of the first cavity, allowing the liquid to flow through the second and third cavities before being discharged.

[0013] Optionally, the first lumen, the second lumen, and the third lumen are coaxially arranged and sequentially along a straight line.

[0014] Optionally, the sealing body is cylindrical, and has a first end close to the liquid outlet of the first tube and a second end away from the liquid outlet of the first tube. At least two protrusions are provided at the first end of the sealing body, and the second end of the spring is sleeved on the sealing body and abuts against the at least two protrusions.

[0015] Optionally, the boss has a first end face and a second end face arranged along the axial direction of the sealing body, the first end face being closer to the liquid outlet of the first cavity than the second end face, and the first end face being flush with the first end face of the sealing body.

[0016] Optionally, the sealing body includes a sealing part and a supporting part. The supporting part is cylindrical and has a first end near the liquid outlet of the first tube and a second end away from the liquid outlet of the first tube. At least two protrusions are provided at the first end of the supporting part, and the second end of the spring is sleeved on the supporting part and abuts against the at least two protrusions. The sealing part is spherical, conical, or frustum-shaped and is smoothly connected to the first end face of the supporting part. The liquid outlet of the first tube has an abutment surface that matches the shape of the sealing part.

[0017] Optionally, the spring mounting position is an annular groove coaxially arranged with the second cavity, the opening of the annular groove facing the liquid outlet of the first cavity, and the first end of the spring is inserted into the annular groove.

[0018] Optionally, the annular groove has an outer annular groove wall and an inner annular groove wall. A through hole is provided on the inner annular groove wall. The through hole extends along the axial direction of the annular groove and penetrates the inner annular groove wall toward the liquid outlet of the first tube.

[0019] Optionally, the valve body includes a first tube and a second tube. A first cavity is formed in the first tube, and an insertion cavity communicating with the first cavity is formed at the end of the first tube. A second cavity and a third cavity are formed in sequence in the second tube. A sealing ring is sleeved on the end of the second tube. The end of the second tube is inserted into the insertion cavity, and the sealing ring seals between the first tube and the second tube.

[0020] Secondly, this utility model provides a plunger pump, including a drive assembly, a plunger assembly, and a cylinder. The plunger assembly is slidably connected to the cylinder, and the drive assembly is drively connected to the plunger assembly. The cylinder has an inlet pipe and an outlet pipe. The inlet pipe is provided with an inlet check valve, and the outlet pipe is provided with an outlet check valve as described above. The drive assembly drives the plunger assembly to reciprocate to change the volume of the cylinder.

[0021] Thirdly, this utility model provides a high-frequency electrosurgical unit, including a handle and a shaft assembly connected sequentially from near to far. The distal end of the shaft assembly forms an operating end, and a plunger pump as described above is installed inside the handle for supplying water to the operating end.

[0022] (III) Beneficial Effects

[0023] The beneficial effects of this utility model are:

[0024] This utility model provides a liquid outlet check valve for use in the plunger pump of a high-frequency electrosurgical unit. By setting the liquid outlet check valve in the form of a spring and a sealing element, in its natural state, the elasticity of the spring causes the sealing element to abut against and seal the outlet of the first cavity. Liquid inside the cylinder is difficult to leak out through the outlet of the first cavity. The elasticity of the spring counteracts the liquid pressure inside the cylinder. Even if the liquid level in the infusion bag is higher than the liquid level in the plunger pump cylinder, creating pressure within the cylinder, it is difficult to overcome the elasticity of the spring to push open the sealing element and allow the liquid to flow out of the outlet of the first cavity. This effectively prevents liquid leakage from the cylinder when the high-frequency electrosurgical unit is not being used with water. When the internal volume of the cylinder decreases, the compressed liquid can push the sealing element to open the outlet of the first cavity, allowing the liquid to flow through the second cavity and be discharged. This ensures normal liquid supply from the cylinder to the operating end, thus guaranteeing normal water injection for the high-frequency electrosurgical unit. At least two protrusions are spaced apart around the sealing body, serving as a connection to the second end of the spring on one hand, and the spacing between adjacent protrusions on the other hand, facilitating the passage of liquid within the cylinder through the second and third cavities.

[0025] The plunger pump provided by this utility model adopts the above-mentioned liquid outlet check valve, which can effectively prevent liquid from leaking out of the cylinder when the high-frequency electrosurgical unit is not used for water injection.

[0026] The high-frequency electrosurgical unit provided by this utility model uses the aforementioned plunger pump, which can effectively prevent liquid leakage from the cylinder body when the high-frequency electrosurgical unit is not used with water. Attached Figure Description

[0027] This utility model is described with reference to the following drawings:

[0028] Figure 1 This is a three-dimensional structural diagram of a duckbill-type check valve based on the background technology;

[0029] Figure 2 This is a schematic diagram of the high-frequency electrosurgical unit according to Embodiment 1;

[0030] Figure 3 This is a cross-sectional schematic diagram of the high-frequency electrosurgical unit according to Example 1;

[0031] Figure 4 yes Figure 3 Enlarged view of point A in the middle;

[0032] Figure 5 This is a three-dimensional structural schematic diagram of the sealing component according to Embodiment 1.

[0033] [Explanation of Labels in the Attached Image]

[0034] 1: Handle;

[0035] 11: Longitudinal shell; 12: Transverse shell;

[0036] 2: Shaft assembly;

[0037] 31: Drive assembly; 32: Piston assembly; 33: Cylinder block;

[0038] 41: Spring; 42: Sealing component;

[0039] 421: Main sealing element; 422: Protrusion;

[0040] 51: First cavity; 52: Annular groove; 53: Through hole; 55: Second cavity; 56: Third cavity; 57: First tube body; 58: Second tube body; 59: Sealing ring;

[0041] 61: Cylindrical connecting tube; 62: Lip. Detailed Implementation

[0042] To better explain and facilitate understanding of this utility model, a detailed description of its specific embodiments is provided below with reference to the accompanying drawings. In this document, "near" refers to the side closer to the operator, and "far" refers to the side closer to the patient. The directional terms "front," "back," "up," and "down" used in this document are... Figure 2 The orientation is taken as a reference, where the direction from near to far is also the direction from back to front.

[0043] Example 1

[0044] like Figures 2 to 5 As shown, this embodiment provides a high-frequency electrosurgical unit. The high-frequency electrosurgical unit includes a handle 1 and a shaft assembly 2 connected sequentially from near to far. The distal end of the shaft assembly 2 forms an operating end, and a plunger pump for supplying water to the operating end is installed inside the handle 1.

[0045] The plunger pump includes a drive assembly 31, a plunger assembly 32, and a cylinder 33. The plunger assembly 32 is slidably connected to the cylinder 33, and the drive assembly 31 is driveably connected to the plunger assembly 32. The drive assembly 31 drives the plunger assembly 32 to reciprocate, thereby changing the volume of the cylinder 33. The cylinder 33 has an inlet pipe and an outlet pipe. An inlet check valve is installed in the inlet pipe, and an outlet check valve is installed in the outlet pipe. When the volume inside the cylinder 33 increases, creating a negative pressure, the inlet check valve opens and the outlet check valve closes under the negative pressure, allowing liquid to enter the cylinder 33 from the infusion bag through the inlet port. When the volume inside the cylinder 33 decreases, creating a positive pressure, the inlet check valve closes and the outlet check valve opens under the positive pressure, allowing liquid inside the cylinder 33 to flow through the outlet port and be ejected from the distal end of the high-frequency electrosurgical unit.

[0046] The liquid outlet check valve includes a valve body, a spring 41, and a sealing element 42. The sealing element 42 includes a sealing body 421 and at least two bosses 422 fixed on the outer peripheral wall of the sealing body 421 and spaced apart circumferentially along the sealing body 421. The valve body has a first cavity 51, a second cavity 55, and a third cavity 56 connected sequentially along the liquid flow direction. The diameter of the second cavity 55 is larger than the diameter of the liquid outlet of the first cavity 51. A spring 41 mounting position is fixed in the second cavity 55. The first end of the spring 41 is connected to the spring 41 mounting position, and the second end of the spring 41 is connected to the at least two bosses 422. In its natural state, the spring 41 is in a compressed state. The elastic action of the spring 41 drives the sealing body 421 to abut against and seal the liquid outlet of the first cavity 51. Liquid with a certain pressure can push the sealing element 42 to open the liquid outlet of the first cavity 51, allowing the liquid to flow through the second cavity 55 and the third cavity 56 before being discharged.

[0047] This high-frequency electrosurgical unit, with its liquid outlet check valve configured as a spring 41 and a sealing element 42, allows the spring 41 to spring against and seal the liquid outlet of the first cavity 51 under normal conditions. This makes it difficult for the liquid inside the cylinder 33 to leak out through the liquid outlet of the first cavity 51. The elasticity of the spring 41 counteracts the liquid pressure inside the cylinder 33. Even if the liquid level in the infusion bag is higher than the liquid level in the plunger pump cylinder 33, giving the liquid inside the cylinder 33 a certain pressure, it is difficult to overcome the elasticity of the spring 41 to push open the sealing element 42 and flow out of the liquid outlet of the first cavity 51. This effectively prevents the liquid inside the cylinder 33 from leaking out when the high-frequency electrosurgical unit is not being used with water. The reduced volume of the cylinder 33 compresses the liquid, allowing it to push the sealing element 42 to open the outlet of the first chamber 51. This allows the liquid to flow through the second chamber 55 and be discharged, ensuring normal liquid supply from the cylinder 33 to the operating end, thus guaranteeing normal water injection for the high-frequency electrosurgical unit. At least two protrusions 422, spaced apart around the sealing body 421, serve two purposes: firstly, they connect to the second end of the spring 41; secondly, the spacing between adjacent protrusions 422 facilitates the passage of liquid within the cylinder 33 through the second chamber 55 and the third chamber 56.

[0048] Preferably, in this embodiment, the first cavity 51, the second cavity 55, and the third cavity 56 are coaxially arranged and sequentially along a straight line in the vertical direction. This arrangement results in a simple structure. Due to the limited installation space within the handle 1, the diameter of the first cavity 51 is generally 2-4 mm. The diameter of the outlet of the first cavity 51 is the same as the diameter of the first cavity 51. To ensure the elastic effect of the spring 41, a spring 41 with an outer diameter of 5-10 mm is generally selected, that is, the outer diameter of the spring 41 is larger than the diameter of the outlet of the first cavity 51. Based on this, at least two bosses 422 are arranged at intervals around the sealing body 421, making the structure of the liquid outlet check valve more compact.

[0049] Preferably, in this embodiment, the sealing body 421 is cylindrical, having a first end near the outlet of the first tube 51 and a second end away from the outlet of the first tube 51. At least two protrusions 422 are disposed at the first end of the sealing body 421, and the second end of the spring 41 is sleeved on the sealing body 421 and abuts against the at least two protrusions 422. This arrangement facilitates the stable installation of the spring 41.

[0050] Furthermore, at least two protrusions 422 are evenly spaced along the circumference of the sealing body 421. Furthermore, 3 to 5 protrusions 422 are provided on the outer peripheral wall of the sealing body 421. Specifically, in this embodiment, four protrusions 422 are provided on the outer peripheral wall of the sealing body 421, evenly spaced along the circumference of the sealing body 421.

[0051] Furthermore, the boss 422 has a first end face and a second end face arranged along the axial direction of the sealing body 421. The first end face is close to the liquid outlet of the first cavity 51 relative to the second end face, and the first end face is flush with the first end face of the sealing body 421.

[0052] Preferably, the spring 41 is mounted in an annular groove 52 coaxially with the second cavity 55, with the opening of the annular groove 52 facing the outlet of the first cavity 51, and the first end of the spring 41 is inserted into the annular groove 52. This facilitates the stable installation of the spring 41.

[0053] More preferably, the annular groove 52 has an outer annular groove wall and an inner annular groove wall, and a through hole 53 is provided on the inner annular groove wall. In this way, by providing a through hole 53 on the inner annular groove wall, the liquid in the cylinder 33 can flow through the through hole 53 to the side of the annular groove 52 away from the liquid outlet of the first cavity 51, and then flow into the third cavity 56.

[0054] Furthermore, the outer annular groove wall is the wall of the second cavity 55. Specifically, the valve body is part of the outlet pipe. This facilitates the processing and manufacturing of the outlet pipe.

[0055] Preferably, the through hole 53 extends axially along the annular groove 52 and penetrates the inner annular groove wall toward the liquid outlet of the first cavity 51. This further facilitates the flow of liquid in the cylinder 33 through the through hole 53 to the side of the annular groove 52 away from the liquid outlet of the first cavity 51, ensuring the water injection function of the high-frequency electrosurgical unit.

[0056] More preferably, the inner annular groove wall has multiple through holes 53, which are evenly distributed circumferentially along the inner annular groove wall. This further facilitates the flow of liquid in the cylinder 33 through the through holes 53 to the side of the annular groove 52 away from the liquid outlet of the first tube 51. Specifically, in this embodiment, the inner annular groove wall has four through holes 53, which are evenly distributed circumferentially along the inner annular groove wall.

[0057] Preferably, the valve body includes a first tube 57 and a second tube 58. A first cavity 51 is formed within the first tube 57, and an insertion cavity communicating with the first cavity 51 is formed at one end of the first tube 57. A second cavity 55 is formed within the second tube 58, and a sealing ring 59 is fitted onto the end of the second tube 58. The end of the second tube 58 is inserted into the insertion cavity, and the sealing ring 59 seals between the first tube 57 and the second tube 58. This valve body configuration facilitates manufacturing and assembly, reducing costs.

[0058] Preferably, there is a gap between the outer edge of the boss 422 and the wall of the second cavity 55, and a gap between the spring 41 and the wall of the second cavity 55. In this way, after the liquid in the cylinder 33 pushes the sealing member 42 to open the outlet of the first cavity 51, the liquid in the cylinder 33 can pass through the gap and flow through the second cavity 55 to the third cavity 56.

[0059] It should be noted that the sealing element 42 can be made of either a rigid or an elastic material. Specifically, in this embodiment, the sealing element 42 is made of rubber.

[0060] Specifically, in this embodiment, the handle 1 includes a longitudinal shell 11 and a transverse shell 12 connected sequentially from bottom to top. The longitudinal shell 11 is used for gripping and forms a longitudinal cavity. The transverse shell 12 forms a transverse cavity that communicates with the longitudinal cavity. The plunger pump is housed in the longitudinal cavity and fixedly connected to the longitudinal shell 11. The shaft assembly 2 is connected to the transverse shell 12. Here, longitudinal refers to the vertical direction, and transverse refers to the front-to-back direction.

[0061] Example 2

[0062] The main difference between this embodiment and Embodiment 1 is:

[0063] The sealing body 421 includes a sealing part and a supporting part. The supporting part is cylindrical and has a first end near the liquid outlet of the first tube 51 and a second end away from the liquid outlet of the first tube 51. At least two protrusions 422 are provided at the first end of the supporting part, and the second end of the spring 41 is sleeved on the supporting part and abuts against the at least two protrusions 422. The sealing part is spherical, conical, or frustum-shaped and smoothly transitions to the end face of the first end of the supporting part. The liquid outlet of the first tube 51 has an abutment surface that matches the shape of the sealing part. In this way, the sealing element 42 abuts against the liquid outlet of the first tube 51, resulting in a good sealing effect.

[0064] Specifically, the sealing part is spherical, and the outlet of the first cavity 51 has a contact surface that matches the shape of the spherical; or, the sealing part is conical, and the outlet of the first cavity 51 has a contact surface that matches the curved surface of the sealing part; or, the sealing part is frustoconical, and the outlet of the first cavity 51 has a contact surface that matches the curved surface of the sealing part.

[0065] The remaining contents are the same as in Example 1, and will not be repeated here.

[0066] In the description of this utility model, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0067] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0068] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "beneath" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0069] In the description of this specification, the terms "one embodiment," "some embodiments," "embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0070] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make modifications, alterations, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A discharge check valve for a plunger pump, characterized in that, The valve body includes a valve body, a spring (41), and a sealing element (42). The sealing element (42) includes a sealing body (421) and at least two bosses (422) fixed on the outer peripheral wall of the sealing body (421) and spaced apart along the circumference of the sealing body (421). The valve body has a first cavity (51), a second cavity (55), and a third cavity (56) connected sequentially along the liquid flow direction. The diameter of the second cavity (55) is larger than the diameter of the liquid outlet of the first cavity (51). A spring (41) mounting position is fixed in the second cavity (55). The first end of the spring (41) is connected to the spring (41) mounting position, and the second end of the spring (41) is connected to at least two bosses (422). In its natural state, the spring (41) is in a compressed state. The elasticity of the spring (41) drives the sealing body (421) to abut against and seal the liquid outlet of the first cavity (51). Liquid under a certain pressure can push the sealing part (42) to open the liquid outlet of the first cavity (51), allowing the liquid to flow through the second cavity (55) and the third cavity (56) before being discharged.

2. The discharge check valve for a plunger pump according to claim 1, characterized in that, The first cavity (51), the second cavity (55), and the third cavity (56) are coaxially arranged and sequentially along a straight line.

3. The discharge check valve for a plunger pump according to claim 1, characterized in that, The sealing body (421) is cylindrical and has a first end close to the liquid outlet of the first tube (51) and a second end away from the liquid outlet of the first tube (51). At least two protrusions (422) are provided at the first end of the sealing body (421), and the second end of the spring (41) is sleeved on the sealing body (421) and abuts against the at least two protrusions (422).

4. The discharge check valve for a plunger pump according to claim 3, characterized in that, The boss (422) has a first end face and a second end face arranged along the axial direction of the sealing body (421). The first end face is close to the liquid outlet of the first cavity (51) relative to the second end face. The first end face is flush with the first end face of the sealing body (421).

5. The discharge check valve for a plunger pump according to claim 1, characterized in that, The sealing body (421) includes a sealing part and a support part. The support part is cylindrical and has a first end close to the liquid outlet of the first tube cavity (51) and a second end away from the liquid outlet of the first tube cavity (51). At least two bosses (422) are provided at the first end of the support part. The second end of the spring (41) is sleeved on the support part and abuts against the at least two bosses (422). The sealing part is spherical, conical or frustum-shaped. The sealing part is smoothly connected to the first end face of the support part. The liquid outlet of the first tube cavity (51) has an abutment surface that matches the shape of the sealing part.

6. The discharge check valve for a plunger pump according to claim 2, characterized in that, The spring (41) is mounted in an annular groove (52) coaxially with the second tube (55). The opening of the annular groove (52) faces the outlet of the first tube (51), and the first end of the spring (41) is inserted into the annular groove (52).

7. The discharge check valve for a plunger pump according to claim 6, characterized in that, The annular groove (52) has an outer annular groove wall and an inner annular groove wall. A through hole (53) is provided on the inner annular groove wall. The through hole (53) extends axially along the annular groove (52) and penetrates the inner annular groove wall toward the liquid outlet of the first tube (51).

8. The discharge check valve for a plunger pump according to claim 2, characterized in that, The valve body includes a first tube (57) and a second tube (58). A first cavity (51) is formed inside the first tube (57). An insert cavity communicating with the first cavity (51) is formed at the end of the first tube (57). A second cavity (55) and a third cavity (56) are formed inside the second tube (58) in sequence. A sealing ring (59) is fitted at the end of the second tube (58). The end of the second tube (58) is inserted into the insert cavity. The sealing ring (59) seals between the first tube (57) and the second tube (58).

9. A plunger pump, characterized in that, The device includes a drive assembly (31), a plunger assembly (32), and a cylinder (33). The plunger assembly (32) is slidably connected to the cylinder (33), and the drive assembly (31) is drively connected to the plunger assembly (32). The cylinder (33) has an inlet pipe and an outlet pipe. The inlet pipe is equipped with an inlet check valve, and the outlet pipe is equipped with an outlet check valve as described in any one of claims 1 to 8. The drive assembly (31) drives the plunger assembly (32) to reciprocate to change the volume of the cylinder (33).

10. A high-frequency electrosurgical unit, characterized in that, It includes a handle (1) and a shaft assembly (2) connected sequentially from near to far, the far end of the shaft assembly (2) forming an operating end, and a plunger pump as described in claim 9 is installed in the handle (1) for supplying water to the operating end.

Images