Oral irrigator

Abstract

The present invention discloses an oral irrigator having a plunger pump device for pumping a fluid, the plunger pump device comprising: a piston cylinder surrounded by a side wall to form a piston chamber; a piston arranged to reciprocate in the piston chamber and having a first end and a second end opposite to the first end; and a seal material sealingly connected to the piston cylinder, the piston, a first portion of the side wall of the piston cylinder, and the seal material surroundingly form a first cavity, and the piston and the second portion of the side wall of the piston cylinder surroundingly form a second cavity, the first cavity and the second cavity being located at opposite ends of the piston, respectively, and a first through hole is provided to communicate the first cavity with the outside of the first cavity, and as the pressure of the first cavity alternates with the reciprocating movement of the piston in the piston cavity, the fluid in the first cavity can flow out of the first cavity through the first through hole. The oral irrigator of the present invention enhances the waterproof effect and ensures the service life of the seal material.

Description

[Technical Field]

[0001] The present invention relates to the technical field of oral care devices, and in particular to oral irrigators. [Background technology]

[0002] There is a plunger pump-based oral irrigator on the market. It uses a micromotor to drive a drive gear, which drives a driven crown gear, which drives a link. The link is eccentrically connected to the crown gear, and the other end of the link is connected to a piston. The piston is confined within a piston cylinder, and the piston performs linear reciprocating motion within the piston cylinder under the drive of the motor. The piston has a first edge extending away from the motor, and the first edge of the piston and the piston cylinder are tightly fitted, or at least zero-fitted, to achieve static and dynamic sealing between the piston and the piston cylinder. A space with alternating volume is formed between the piston and the piston cylinder above the first edge of the piston. The pressure of the gas or liquid in the space fluctuates periodically, achieving the suction and spraying or / and suction and spraying of the plunger pump.

[0003] There are two embodiments of the piston assembly in current oral irrigators.

[0004] The first type of tail opening remains open, and there is only one seal cavity located above the first edge of the piston between the piston cylinder. During the product's life cycle, high-speed reciprocating friction between the piston and the piston cylinder causes wear on the first edge of the piston and the piston cylinder, resulting in a seal problem between the piston and the piston cylinder. This means that the piston and the piston cylinder are no longer sealed, and liquid or gas located above the first edge of the piston leaks into the tail opening of the piston cylinder. In particular, the leaked liquid may further leak into components such as the battery, motor, and PCBA of the device, causing corrosion and short circuits in the battery, motor, and PCBA, resulting in device failure.

[0005] The second tail opening is fitted with a sealant to seal the piston space between the piston and the piston cylinder, creating two seal cavities between the piston and the piston cylinder: one upper seal cavity above the first edge of the piston, and the other lower seal cavity below the first edge of the piston. Over the product's lifespan, high-speed reciprocating friction between the piston and the piston cylinder causes wear on the first edge of the piston and the piston cylinder, resulting in a seal failure between the piston and the piston cylinder. This means that the upper seal cavity between the piston and the piston cylinder cannot be sealed, allowing liquid or gas above the first edge of the piston to leak into the lower seal cavity in the piston cylinder, increasing the pressure in the lower seal cavity and the resistance of the plunger pump, significantly reducing the mechanical efficiency of the device and resulting in poor device performance. Furthermore, if the amount of gas or liquid leaking from the upper seal cavity to the lower seal cavity continues to increase, the lower seal of the lower seal cavity will burst, causing liquid or gas to leak into spaces other than the piston cylinder.In particular, the leaked liquid will further leak onto components such as the battery, motor, and PCBA of the device, causing corrosion and short circuits in the battery, motor, and PCBA, leading to failure of the device. Summary of the Invention [Problem to be solved by the invention]

[0006] The waterproof reliability of the conventional method is still insufficient and needs to be further improved. [Means for solving the problem]

[0007] In order to overcome the deficiencies of the prior art, the present invention discloses an oral irrigator having a plunger pump device for pumping a fluid, the plunger pump device comprising: a piston cylinder surrounded by a side wall to form a piston chamber; a piston arranged to reciprocate in the piston chamber; and a sealing material sealingly connected to the piston cylinder, wherein the piston, a first portion of the side wall of the piston cylinder, and the sealing material surround each other to form a first cavity, and the piston and a second portion of the side wall of the piston cylinder surround each other to form a second cavity, the first cavity and the second cavity are respectively located at opposite ends of the piston, and a first through hole is provided to connect the first cavity to the outside of the first cavity, and as the piston reciprocates in the piston cavity and the pressure in the first cavity changes alternately, the fluid in the first cavity can flow out of the first cavity through the first through hole.

[0008] Liquid intrusion into the first cavity V1 is usually caused by a broken seal between the piston and the piston cylinder. The provision of the first through-hole allows this liquid to be expelled from the first cavity V1 due to alternating pressure changes within the first cavity V1, thereby ensuring the separation of liquid and electricity. Since the first cavity V1 formed by the sealant does not need to be subjected to the pressure of liquid accumulation, the use of the sealant is extended, thereby improving the overall waterproof level of the oral irrigator.

[0009] According to another aspect of the present invention, the second cavity is provided with an inlet and an outlet, and the oral irrigator includes a liquid storage section that communicates with the inlet of the second cavity via a communicating conduit.

[0010] According to another aspect of the present invention, the first through hole is provided in a first portion of the sealing material and / or the side wall of the piston cylinder, and the first through hole is connected to the outside of the handle portion of the oral irrigator via a connecting pipe, and / or the first through hole is connected to the liquid storage portion or a connecting pipe connecting the liquid storage portion.

[0011] According to another aspect of the present invention, a third cavity V3 is provided adjacent to the second cavity V2, and a first check valve is provided between the third cavity V3 and the second cavity, and the first check valve is arranged to only allow fluid to flow from the second cavity to the third cavity via the discharge port, and the first through hole is connected to the third cavity via a communicating pipe, and a second check valve is provided between the first through hole and the third cavity, and the second check valve is arranged to only allow fluid to flow from the first cavity to the third cavity. Preferably, the plunger pump device further includes a second through hole connecting the first cavity to the outside of the first cavity, and the second through hole is provided with a third check valve, which is positioned to allow only the inflow of external fluid into the first cavity through the second through hole.

[0012] According to yet another aspect of the present invention, the plunger pump device further includes a transmission mechanism having a drive gear fixed to an output shaft of a motor, a driven crown gear meshing with the drive gear, and a link cooperating with the driven crown gear, wherein the link has a connection portion movably connected to a connection cavity of the piston, the link is sealingly joined to the sealing material so as to move at least a portion of the sealing material together with the link, the connection portion has two opposing flat surfaces and a localized spherical surface connecting the opposing flat surfaces, and a pin extends from the flat surfaces and is inserted into a pin hole formed in the piston.

[0013] According to yet another aspect of the present invention, the piston has a first end proximate the first cavity and a second end proximate the second cavity, and the first end and the second end of the piston form a first seal portion and a second seal portion, respectively, that sealingly abut against an inner surface of the piston cylinder's internal cavity.

[0014] Preferably, the piston has a deformable first thin-walled portion located at the first end and a deformable second thin-walled portion located at the second end, the first seal portion being formed on the outer peripheral surface of the end of the first thin-walled portion, and the second seal portion being formed on the outer peripheral surface of the end of the second thin-walled portion.

[0015] Preferably, the first thin portion of the first end portion has a recess, and the position of the recess is provided to correspond to the position of the first through hole.

[0016] The present invention also discloses an oral irrigator having a plunger pump device for pumping a fluid, the plunger pump device comprising a piston cylinder surrounded by a side wall to form a piston chamber, a piston arranged to reciprocate within the piston chamber, and a seal sealingly connected to the piston cylinder, wherein the piston, a first portion of the side wall of the piston cylinder, and the seal form a first cavity, and the piston and a second portion of the side wall of the piston cylinder form a second cavity, and a seal sealingly connected to the first cavity. The second cavities are located at opposite ends of the piston, and the piston has a first end close to the first cavity and a second end remote from the first cavity. The first end and the second end of the piston form a first seal portion and a second seal portion, respectively, sealed against the surface of the internal cavity of the piston cylinder. As the piston reciprocates within the piston chamber, the pressure in the first cavity and the second cavity alternately changes, and the first seal portion and the second seal portion are alternately subjected to pressure.

[0017] According to another aspect of the present invention, the first seal portion and the second seal portion have an interference fit or a zero fit with the inner surface of the piston cylinder, and the remaining outer surface between the first seal portion and the second seal portion has a clearance fit with the inner surface of the piston cylinder.

[0018] According to another aspect of the present invention, the piston has a deformable first thin-walled portion located at the first end and a deformable second thin-walled portion located at the second end, the first seal portion being formed on an outer peripheral end edge of the first thin-walled portion, and the second seal portion being formed on an outer peripheral end edge of the second thin-walled portion.

[0019] Preferably, the ratio of the length to the thickness of the first thin portion and the second thin portion is within a range of 20 to 40 times.

[0020] When the first cavity has a first through-hole, liquid typically enters the first cavity due to a broken seal between the piston and the piston cylinder. The provision of the first through-hole allows this liquid to be expelled from the first cavity due to alternating pressure changes within the first cavity, thereby ensuring the separation of liquid and electricity. Since the first cavity formed by the sealant does not need to be subjected to the pressure of liquid accumulation, the sealant's use period is extended, thereby improving the overall waterproofing level of the oral irrigator.

[0021] When the first through-hole is connected to the nozzle, the oxygen-containing gas from the first cavity is injected into the gingival sulcus, effectively eliminating anaerobic bacteria and maintaining gingival health. Compared to conventional active oxygen injection methods, the alternating pressure change in the first cavity increases the active oxygen injection function and reduces manufacturing costs.

[0022] In addition, the installation of the second through hole allows the air in the first cavity to be replenished, so that air from outside the piston cylinder can contribute to moving the piston away from the motor, increasing the work of the outside air on the piston and correspondingly reducing the energy consumption of the oral irrigator.

[0023] Furthermore, compared to an embodiment in which the piston has only a single seal portion, the double-seal piston embodiment of the present invention can more reliably form a seal between the piston and the piston cylinder, thereby improving the reliability of leak prevention for the entire plunger pump device. [Brief explanation of the drawings]

[0024] For a more complete understanding of the present invention, the following description of illustrative embodiments may be considered in conjunction with the accompanying drawings, in which:

[0025] [Figure 1] FIG. 1 is a schematic view of the external appearance of an oral irrigator according to a preferred embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view of an oral irrigator according to a preferred embodiment of the present invention, in which a portion of the housing is removed to show the internal structure. [Figure 3] FIG. 3 is a perspective view of a plunger pump device for pumping fluid inside an oral irrigator according to a first preferred embodiment of the present invention. [Figure 4] FIG. 4 is a partial cross-sectional perspective view of a plunger pump device for pumping fluid inside an oral irrigator according to a first preferred embodiment of the present invention. [Figure 5] FIG. 5 is a partial cross-sectional perspective view of a piston and piston cylinder according to a first preferred embodiment of the present invention, in which the piston moves towards the motor. [Figure 6] FIG. 6 is another partial cross-sectional perspective view of the piston and piston cylinder according to the first preferred embodiment of the present invention, in which the piston moves away from the second end of the motor. [Figure 7]FIG. 7 is another partial cross-sectional perspective view of a piston and piston cylinder according to a first preferred embodiment of the present invention, in which the piston cylinder is cut away to show the through-hole. [Figure 8] FIG. 8 is a partial perspective view of the internal duct structure of the oral irrigator according to the first preferred embodiment of the present invention. [Figure 9] FIG. 9 is a partial perspective view of the internal duct structure of the oral irrigator according to the second preferred embodiment of the present invention. [Figure 10] FIG. 10 is a perspective view of a plunger pump device inside an oral irrigator according to a second preferred embodiment of the present invention, in which the piston cylinder is cut away to show the through-hole. [Figure 11] FIG. 11 is a partial perspective view of a plunger pump device inside an oral irrigator according to a second preferred embodiment of the present invention. [Figure 12] FIG. 12 is a partial perspective view of a plunger pump device inside an oral irrigator according to a preferred embodiment of the present invention, from another angle. [Figure 13] FIG. 13 is a cross-sectional perspective view of a piston adapted to a preferred embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0026] The present invention will be described in detail below with reference to specific embodiments and drawings. In the following description, various details are described to facilitate a thorough understanding of the present invention. However, it is clear that the present invention can be embodied in other forms different from the above description. Those skilled in the art can extend or infer the present invention according to actual application situations without departing from the spirit of the present invention. Therefore, it goes without saying that the scope of protection of the present invention is not limited to the specific embodiments described above.

[0027] Figure 1 shows a schematic diagram of the external shape of an oral irrigator according to a preferred embodiment of the present invention. From the external view point, the oral irrigator mainly comprises a liquid reservoir 1 for storing water, a handle 2 suitable for holding with one hand, and an elongated nozzle 3. The nozzle 3 and the liquid reservoir 1 are connected to opposite ends of the handle 2, respectively, thereby detachably connecting these three parts 1, 2, and 3.

[0028] The functional components of the oral irrigator are basically accommodated in a chamber formed by the housing of the handle portion 2. Specifically, the cavity of the handle portion 2 accommodates a conduit system for transporting the fluid, a drive unit for providing cleaning power to the fluid, a plunger pump unit for converting the fluid in the drive unit into cleaning power, a battery 5 for supplying power to the drive unit, and a corresponding control device. In a preferred embodiment of the present invention, the drive unit employs a motor 7. In use, the motor 7 reciprocates the piston of the plunger pump unit within the piston cylinder, sending the liquid contained in the liquid reservoir 1 through the corresponding conduit to the nozzle portion 3 under the reciprocating action of the plunger pump unit, and discharging the liquid from the nozzle portion 3 in a pulsating manner, thereby achieving cleaning of the oral cavity, particularly the teeth and gums.

[0029] A preferred arrangement within the cavity of the handle portion 2 of the oral irrigator is shown in Figure 2. The plunger pump device and battery 5 are held within the cavity of the handle portion 2 by a rack 6. Preferably, the plunger pump device and battery 5 are arranged in parallel.

[0030] The plunger pump device mainly includes a piston cylinder 23, a piston 24, and a transmission mechanism connected between the piston 24 and the motor 7. The piston cylinder 23 has a sidewall that surrounds it to form a substantially cylindrical piston chamber, and the piston 24 is disposed to reciprocate within the piston chamber. As shown in FIG. 3, the transmission mechanism includes a drive gear 8 fixed to the output shaft of the motor 7, a driven crown gear 27 meshing with the drive gear 8, and a link 26 movably cooperating with the driven crown gear 27. The link 26 has a connection portion 261 that is movably connected to a connection cavity within the piston 24. The link 26 passes through the seal 21 in a sealing state, and movement of the link 26 can move a portion of the joint between the seal 21 and the link 26. The link 26 is connected to the connection cavity of the piston 24 via cooperation of a pin 25 and a pin hole 244 (see FIG. 5). Specifically, the connection portion 261 of the link 26 has two opposing flat surfaces and a partial spherical surface connecting the opposing flat surfaces, and one pin 25 extends from both ends of the flat surfaces through the connection portion 261, and the pin 25 is inserted into a pin hole 244 formed in the piston 24. The pin 25 is pivotable relative to the piston connection portion 261, and correspondingly, the partial spherical surface of the connection portion 261 is movable relative to the connection cavity of the piston 24. With this transmission mechanism, the rotational motion of the output shaft of the motor 7 is converted into the linear reciprocating motion of the piston 24 inside the piston cylinder 23.

[0031] Next, the configuration of the piston cylinder 23 and the piston 24 according to the first embodiment of the present invention will be described in detail with reference to FIGS.

[0032] 5, when the piston 24 is installed in the piston cylinder 23, at least one sealing portion on the outer surface of the piston 24 makes sealing contact with the inner surface 230 of the side wall of the piston cylinder 23, dividing the piston cavity into at least two cavities, hereinafter referred to as a first cavity V1 and a second cavity V2. The first cavity V1 is formed by being surrounded by the piston 24, a first portion of the side wall of the piston cylinder 23, and a sealing material 21 (also called a leather bowl) connected to the piston cylinder 23. The second cavity V2 is surrounded by the piston 24 and a second portion of the side wall of the piston cylinder 23, and the first cavity V1 and the second cavity V2 are formed at opposite ends of the piston 24, respectively. Here, the "first portion" of the side wall of the piston cylinder 23 refers to a single-step side wall extending from a position on the inner surface of the piston cylinder 23 where a seal is formed against the piston 24 closest to the first end of the piston to an end of the piston cylinder that is closer to the sealing material. For example, if only the outer peripheral edge of the second end of the piston 24 is sealed against the inner surface 230 of the piston cylinder 23, the "first portion" here refers to a single-step side wall extending from a position on the inner surface of the piston cylinder 23 where a seal is formed against the piston 24 closest to the second end of the piston to an end of the piston cylinder that is closer to the sealing material. Correspondingly, the "second portion" of the side wall of the piston cylinder 23 refers to a single-step side wall extending from a position on the inner surface of the piston cylinder 23 where a seal is formed against the piston 24 closest to the second end of the piston to a position closest to the discharge port 16 of the piston cylinder. For example, if only the outer peripheral edge of the second end of the piston 24 is sealed against the inner surface 230 of the piston cylinder 23, the "second portion" here would be a single section of the piston cylinder side wall from the edge of the second end of the piston 24 to a position closest to the discharge port 16 of the piston cylinder 23. It should be understood that the first and second portions of the side wall of the piston cylinder 23 change in response to piston movement and changes in the position of the seal portion of the piston 24, and the volumes of the first cavity V1 and the second cavity V2 change in response to changes in the first and second portions.

[0033] Specifically, the first cavity V1 is formed at a first end of the piston 24 close to the seal member 21, and the second cavity V2 is formed at a second end close to the nozzle portion 3. The first cavity V1 and the second cavity V2 are relatively sealed and separated, and this sealing separation between them is achieved by sealing contact of the piston 24 with the inner surface 230 of the piston cylinder 23.

[0034] 5, the second cavity V2 is provided with an inlet 15 and an outlet 16. The liquid in the liquid reservoir 1 is approach The air is then drawn into the second cavity V2 through the inlet 15 and is then drawn by the piston 24 through the inlet 10 (see FIG. 3) so as to be distributed downstream to the nozzle portion 3 through the outlet 16. approach The second cavity V2 is connected to the outlet 15, i.e., the second cavity V2 constitutes a fluid cavity in which the piston 24 acts. The outlet 16 of the second cavity V2 is connected to the nozzle portion 3 The second cavity V2 is connected to the piston 24, and the fluid that enters the second cavity V2 is discharged from the discharge port 16. The volume of the second cavity V2 changes with the reciprocating motion of the piston 24, realizing the suction and discharge of the fluid. The second cavity V2 constitutes the main injection cavity of the plunger pump device to enable suction and discharge of water.

[0035] The sealing material 21, which surrounds and forms the first cavity V1, is bowl-shaped, and its bowl-shaped opening is attached to the end of the piston cylinder 23. Preferably, the sealing material 21 can be fixed to the end surface of the piston cylinder 23 via a sealing material fixing block 22. As shown in FIGS. 5 and 6, in order to fit a transmission mechanism having a link 26, the link 26 passes through the bottom of the sealing material 21, and a sealing connection is formed between the sealing material 21 and the link 26. The sealing material 21 is usually made of an elastically deformable and waterproof material such as rubber, and can be formed integrally with the piston cylinder 23, for example, by overmolding. Alternatively, the sealing material 21 and the piston cylinder 23 can be produced separately and then assembled. By providing this sealing material 21, the piston cavity of the piston cylinder 23 is sealed and separated from the space that houses the motor 7, etc. In this way, even if a problem of poor sealing occurs between the piston 24 and the piston cylinder 23 and liquid flows from the piston 24 and the piston cylinder 23 into the first cavity V1, the liquid is blocked by the sealing material 21, and it is possible to prevent the liquid from flowing further into the motor 7 or other control lines 4 and causing damage to electrical components.

[0036] A portion of the seal 21 and the piston 24 can move in accordance with the movement of the link 26. FIGS. 5 and 6 respectively show two positions of the piston 24 relative to the piston cylinder 23. As shown in FIG. 5, the piston 24 moves toward the discharge port 16, with the seal 21 in an expanded state, the second cavity V2 in a maximum volume state, and the first cavity V1 in a minimum volume state. As shown in FIG. 6, the piston 24 moves toward the seal 21, with the seal 21 in a contracted state, the second cavity V2 in a minimum volume state, and the second cavity V2 in a maximum volume state. At the same time, the internal pressures of the first cavity V1 and the second cavity V2 alternately change with the reciprocating movement of the piston 24 within the piston chamber and the expansion and contraction of the seal 21.

[0037] According to a first preferred embodiment of the present invention, the first cavity V1 is in communication with the outside through a first through hole 30. As shown in FIGS. 5 and 7, the first through hole 30 is formed by penetrating the side wall of the piston cylinder 23 that defines the first cavity V1. In general, the diameter of the first through hole 30 is clearly smaller than the inner diameter of the piston cylinder 23. In another alternative embodiment, the first through hole 30 may be provided in the seal 21 instead of the side wall of the piston cylinder 23, and is preferably provided in a portion of the seal 21 that does not deform as the piston 24 moves. In another alternative embodiment, the first through hole 30 may be arranged to penetrate both the side wall of the piston cylinder 23 and the seal 21 at the same time.

[0038] The first through-hole 30 may be connected to the space in the oral irrigator where the liquid flow path is located, the liquid reservoir 1, or a liquid conduit therein. In the first embodiment, as shown in FIG. 8 , the first through-hole 30 can be connected to the liquid reservoir 1 outside the handle portion 2 via a connecting tube 9 and a connecting connector 12 located outside the first cavity V1. Preferably, the liquid reservoir 1 of the oral irrigator can be connected to the handle portion 2 via a liquid reservoir holder 11 shown in FIG. 11 , and the liquid reservoir holder 11 is provided with a liquid reservoir holder connecting hole 14 for connecting the connecting connector 12. Preferably, a sealant 13 for connecting the connector may be provided at the end of the connecting connector 12 to achieve a waterproof sealed connection between the connecting connector 12 and the connecting hole 14.

[0039] In other alternative embodiments, the first through-hole 30 communicates directly or indirectly with the outside air of the handle portion 2, or communicates with another location that does not require waterproofing.

[0040] If liquid infiltrates into the first cavity V1 formed by the sealing material, the piston 24, and the piston cylinder 23 (usually due to a breakdown in the seal between the piston 24 and the piston cylinder 23), the provision of the first through-hole 30 allows this liquid to be discharged from the first cavity V1 by alternating changes in pressure within the first cavity V1, thereby ensuring separation of the liquid and electricity. Since there is no need to be subjected to the pressure of a liquid pool in the first cavity V1 formed by the sealing material 21, the use of the sealing material 21 is extended, thereby improving the overall waterproof level of the oral irrigator.

[0041] Next, an oral irrigator according to a second preferred embodiment of the present invention will be described with reference to FIGS.

[0042] As shown in FIG. 10, the basic structure of the piston 24′ and the piston cylinder 23′ in the second preferred embodiment is similar to that of the first preferred embodiment, in which the piston 24′ and the piston cylinder 23′ cooperate with each other to form a first cavity V1 and a second cavity V2, both of which are provided with bowl-shaped sealing members 21, and will not be repeated here.

[0043] The difference from the first embodiment is that the first cavity V1 is provided with two through holes, a through hole 32 and a through hole 34. As shown in Fig. 10, the through hole 32 and the through hole 34 are both provided through the side wall of the piston cylinder 23', so that the inside of the first cavity V1 communicates with the outside of the cavity. Preferably, the two through holes 32 and 34 are provided at opposite ends along the inner diameter of the piston cylinder 23'.

[0044] It should be understood that in other alternative embodiments, one or both of the through holes 32 and 34 may be positioned to penetrate the seal 21, or may be positioned to penetrate the side wall of the piston cylinder 23' and the seal 21 simultaneously.

[0045] One end of the through-hole 32 is connected to the interior of the first cavity V1, and the other end leads to the outside of the first cavity V1 of the piston cylinder 23′. The through-hole 32 is provided as a one-way passage that allows only the inflow of outside air into the piston cylinder 23′ and does not allow the fluid in the first cavity V1 to flow to the outside. For this reason, the through-hole 32 may be provided with a check valve. As shown in FIG. 10, the check valve 33 is preferably provided at the middle position of the through-hole 32. As shown in FIG. 10, the through-hole 32 has a portion located on the side wall of the piston cylinder 23′ and another portion located from the outside of the piston cylinder 23′ to the interface at the side wall of the piston cylinder 23′. The through-holes 32 of the two portions are aligned, and the check valve 33 is installed between the two portions. The through-hole 32 may directly lead to the outside of the housing of the handle portion 2 or may open to a water-free space within the handle portion.

[0046] On the other hand, in the second embodiment, the through hole 34 is provided to connect the first cavity V1 to a third cavity V3, which is an additional injection cavity. Preferably, communication between the first cavity V1 and the through hole 34 of the third cavity V3 is achieved by a communication pipe 9'. As shown in FIG. 10 , specifically, the fluid in the first cavity V1 flows into the third cavity V3 through the through hole 34, the communication pipe 9', and the discharge hole 31 located in the third cavity V3. In a preferred embodiment, the third cavity V3 is formed by a single-stage cylindrical tube extending from the end of the piston cylinder 23' where the discharge port 16 is located toward the nozzle portion, and a port connecting the third cavity V3 to the through hole 34 is provided in the side wall of the cylindrical tube. In an alternative embodiment, the cylindrical tube can be formed as part of the nozzle portion 3. Between the nozzle portion and the third cavity V3, a seal 36 is preferably provided so as to determine a watertight seal between them.

[0047] The third cavity V3 is adjacent to the second cavity V2, and the outlet 16 of the second cavity V2 faces the third cavity V3. The third cavity V3 is also separated from the nozzle portion 3 and the second cavity V2 by a check valve 29. Therefore, the liquid sent to the second cavity V2 opens the check valve 29 at a certain pressure, enters the third cavity V3, and can then flow to the nozzle portion 3. The check valve is arranged to only allow the liquid to flow from the second cavity V2 to the third cavity V3 and not allow the liquid to flow back from the third cavity V3 to the second cavity V2. Meanwhile, a check valve 35 is also provided in the flow path between the first cavity V1 and the third cavity V3 to allow the fluid in the first cavity V1 to enter the third cavity V3 through the through-hole 34 and to prevent the fluid from entering the first cavity V1 of the piston cylinder 23' in the reverse direction. As shown in Fig. 10, the check valve 35 is provided near the side wall of the third cavity V3, i.e., at the discharge hole 31. In other alternative embodiments, the check valve 35 may be provided in the through-hole 34 or in the middle of the communicating pipe 9'.

[0048] In the second embodiment, the principles of water suction and spraying in the second cavity V2 are similar to those in the first embodiment. When the piston moves toward the motor 7, the volume of the second cavity V2 increases, the pressure decreases, and the water in the liquid storage section 1 is sucked into the second cavity V2 through the check valve 28 by atmospheric pressure, and the check valve 29 closes. When the piston moves away from the motor 7, the volume of the second cavity V2 decreases, the pressure increases, the check valve 28 closes, and the check valve 29 opens. The liquid in the second cavity V2 flows through the outlet 16 (shown in FIG. 11) into the lumen of the nozzle section 3, passes through the nozzle section, and enters the oral cavity, circulating back and forth in this manner.

[0049] In particular, during use, when the piston moves toward the motor 7, the volume of the piston entering the first cavity V1 is greater than the volume of the seal material 21 leaving the first cavity V1, so that the movement of the piston in this direction reduces the volume of the first cavity V1, the pressure in the first cavity V1 increases, the check valve 33 closes, and the air outside the piston cylinder 23′ cannot enter the first cavity V1 through the through-hole 32, and the fluid in the first cavity V1 (usually the fluid is air, and only if there is leakage due to the movable seal between the piston and the piston cylinder 23′ will some liquid be contained in the first cavity V1) communication pipe 9' and enters the third cavity V3 via the check valve 35. In this way, the second fluid from the first cavity V1 is added to the fluid originally in the liquid reservoir 1 discharged through the nozzle 3, and the fluid discharged from the nozzle 3 becomes a gas, a liquid, or a mixture of gas and liquid. The second fluid is usually an oxygen-containing gas, and injecting the oxygen-containing gas into the gingival sulcus effectively eliminates anaerobic bacteria and maintains gingival health. Compared to conventional active oxygen addition methods, the alternating pressure change in the first cavity V1 increases the active oxygen addition function and reduces manufacturing costs.

[0050] When the piston moves away from the motor 7, the volume of the piston entering the first cavity V1 is smaller than the volume of the sealing material 21 leaving the first cavity V1. As a result, the volume of the first cavity V1 increases due to the movement of the piston in this direction, and the pressure in the first cavity V1 decreases accordingly. The check valve 33 opens, and air outside the piston cylinder 23′ enters the first cavity V1 through the through-hole 32. At the same time, the check valve 35 closes, preventing the fluid (usually liquid) present in the third cavity V3 from flowing back into the first cavity V1. In this way, air is filled into the first cavity V1, replenishing the amount of air in the first cavity V1 and making the air in the first cavity V1 available for use in the next cycle. The outside air enters the first cavity V1 and blows air into the third cavity V3 again, thus circulating back and forth in this manner. Air from outside the piston cylinder 23' helps to move the piston 24' away from the motor 7. As the work of the outside air on the piston 24' increases, the energy consumption of the oral irrigator decreases accordingly.

[0051] FIG. 13 shows a piston 24 with a double seal structure that can improve the sealing effect by alternating the pressure in the first cavity V1.

[0052] In particular, the first end and second end of the piston 24 form a first seal portion 242 and a second seal portion 240 that are sealed against the inner surfaces of the piston cylinders 23 and 23', respectively, and as the piston 24 moves back and forth within the piston cavities, the pressure in the first cavity V1 and the second cavity V2 alternately changes so that the first seal portion 242 and the second seal portion 240 are alternately subjected to pressure.

[0053] As shown in FIG. 13 , the piston 24 has a first thin-walled portion 243 located at a first end and a second thin-walled portion 241 located at a second end. The first seal portion 242 is formed on the outer peripheral edge of the first thin-walled portion 243, and the second seal portion 240 is formed on the outer peripheral edge of the second thin-walled portion 241. In other words, the two seal portions 240 and 242 of the piston are adjacent to the first cavity V1 and the second cavity V2, respectively. The inner sidewall surface 230 of the piston cylinder 23′ has the shape of the outer surface of a cylinder or a small-angle cone. Preferably, the outer surface of the cone is less than 15 degrees. The outer surface of the piston 24 has the shape of the outer surface of a cylinder or a small-angle cone. The first seal portion 242 and the second seal portion 240 of the piston 24 both have an interference fit, or at least a zero fit, with the inner side wall surface 230 of the piston cylinder 23', thereby forming a seal between the seal portions 240, 242 on the outer peripheral end edge and the inner side wall surface 230, preventing fluid flow between the first cavity V1 and the second cavity V2.

[0054] In particular, the shape, dimensions, and material selection of the first thin-walled portion 243 and the second thin-walled portion 241 ensure that they are deformable. "Deformable" here means that the thin-walled portion is flexible or tends to bend relative to the rest of the piston due to fluid pressure; in other words, the first thin-walled portion 243 and the second thin-walled portion 241 are non-rigid. To achieve the deformability of the thin-walled portions, preferably, the ratio of the length L to the thickness T of each of the first thin-walled portion 243 and the second thin-walled portion 241 is in the range of 20-40, as shown in FIG. 13.

[0055] In an alternative embodiment, the seals 240, 242 may be achieved by the deformable properties of the elastic material itself.

[0056] As shown in FIG. 13 , the first seal portion 242 and the second seal portion 240 are located at both ends of the piston 24. Except for the contact between the first seal portion 242 and the second seal portion 240 and the piston cylinder 23′, there is a moving gap between the other outer surface of the piston 24 and the inner sidewall surface 230 of the piston cylinder 23′, i.e., a clearance fit. Therefore, when viewed from the overall external shape, the seal portions 240 and 242 at the two ends of the piston 24 are “warped” relative to the middle of the piston. When the piston 24 moves toward the motor 7, the increased pressure in the first cavity V1 presses the first thin-walled portion 243 of the piston so that the first seal portion 242 at the first thin-walled portion 243 tightly contacts the inner surface of the piston cylinder 23′, strengthening the seal between the piston and the piston cylinder 23′. When the piston 24 moves away from the motor 7, the high pressure in the second cavity V2 presses the second thin-walled portion 241 of the piston 24, so as to make the second sealing portion 240 fit more tightly against the inner surface of the piston cylinder, strengthening the seal between the piston and the piston cylinder 23′. Therefore, by alternately changing the pressure in the first cavity V1 and the second cavity V2, the technical solution of the present invention ensures that at least one sealing portion is under pressure, and therefore can provide a more reliable seal between the piston and the piston cylinder than a technical solution in which the piston has only one sealing portion.

[0057] To explain further, when a piston having two sealing portions 240 and 242 as shown in Figure 13 is used, the first cavity V1 is formed by the sealing material, the end face of the piston 24 on the side of the first thin-walled portion 243, and a portion from the end face of the first thin-walled portion 243 of the piston 24 to a portion of the piston cylinder side wall of the sealing material (this portion of the side wall is the first portion of the side wall of the piston cylinder), and the second cavity V2 is formed by the end face of the piston 24 on the side of the second thin-walled portion 241 and a portion from the end of the second thin-walled portion 241 of the piston 24 to a portion of the piston cylinder side wall of the discharge port 16 (this portion of the side wall is the second portion of the side wall of the piston cylinder).

[0058] As shown in Figure 13, the first seal portion 242 and the second seal portion 240 at the two ends of the piston are both formed with perfectly circular edges. However, in an alternative embodiment, as shown in Figure 11, the first thin-walled portion 243 at the first end has a recess that is positioned to correspond to the through-hole, allowing for a double seal and through-hole structure when miniaturizing the piston and piston cylinder.

[0059] Although the present invention has been disclosed in the above preferred embodiments, it is not intended to limit the present invention, and those skilled in the art can make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, any modifications, equivalent changes and alterations made to the above embodiments based on the contents that do not deviate from the technical solution of the present invention and the technical essence of the present invention fall within the scope of protection defined in the claims of the present invention. [Explanation of symbols]

[0060] 1 Liquid storage unit 2 Handle 3 Nozzle section 4 Control Lines 5 Battery 6 racks 7 Motor 8 Drive Gear 9 Communication pipe 9' Communication pipe 10 Suction tube 11 Liquid reservoir holder 12 Communication connector 13 Connecting connector sealant 14 Liquid storage unit holder communication hole 15 Entrance 16 Outlet 21 Sealing material 22 Sealing material fixing block 23 Piston Cylinder 23' Piston Cylinder 24 pistons 24' Piston 25-pin 26 Links 261 Connection 27 Driven crown gear 28 Check valve 29 Check valve 30 First through hole 31 Discharge hole 32 penetration hole 33 Check valve 34 Through hole 35 Check valve 36 Sealing material 230 Inner surface of piston cylinder 240 Second seal part 241 Second thin section 242 First seal part 243 First thin section 244 pins hole V1 First cavity V2 Second cavity V3 Third cavity

Claims

1. 1. An oral irrigator having a plunger pump device for pumping a fluid, comprising: The plunger pump device a piston cylinder surrounded by a side wall to form a piston chamber; a piston reciprocally disposed within the piston chamber; a seal member sealingly connected to the piston cylinder; Equipped with the piston, a first portion of the piston-cylinder sidewall, and the seal surround each other to form a first cavity, and the piston and a second portion of the piston-cylinder sidewall surround each other to form a second cavity, the first cavity and the second cavity being located at opposite ends of the piston, respectively. In oral irrigators, a first through-hole that connects the first cavity to an outside of the first cavity; As the pressure in the first cavity alternates with the reciprocating movement of the piston in the piston chamber, the fluid in the first cavity can flow out of the first cavity through the first through-hole, The second cavity is provided with a discharge port, A third cavity (V3) is provided adjacent to the second cavity (V2), a first check valve (29) is provided between the third cavity and the second cavity; the first check valve is arranged to allow fluid to flow only from the second cavity through the outlet into the third cavity; The first through hole (34) communicates with the third cavity via a communication pipe, a second check valve (35) is provided between the first through hole and the third cavity; the second check valve is positioned to allow fluid to flow only from the first cavity to the third cavity; the plunger pump device further includes a second through-hole that connects the first cavity to an outside of the first cavity; The second through hole is provided with a third check valve (33), the third check valve is arranged to allow only the inflow of an external fluid into the first cavity through the second through-hole. Oral irrigator.

2. The second cavity has an inlet and an outlet, The oral irrigator is characterized in that it includes a liquid storage section that communicates with the inlet of the second cavity via a communication conduit. The oral irrigator according to claim 1.

3. the first through-hole is provided in a first portion of the sealing material and / or a side wall of the piston cylinder, and the first through hole communicates with the outside of the handle portion of the oral irrigator via a communication pipe, and / or the first through hole communicates with the liquid storage portion or a communication pipe line connecting the liquid storage portion. The oral irrigator according to claim 2.

4. The plunger pump device further includes a transmission mechanism having a drive gear fixed to an output shaft of a motor, a driven crown gear meshing with the drive gear, and a link cooperating with the driven crown gear; the link has a connection portion movably connected to a connection cavity of the piston, the link being sealingly joined to the seal so as to move at least a portion of the seal with the link; the connecting portion has two opposing flat surfaces and a local spherical surface connecting the opposing flat surfaces, a pin extending from the flat surfaces, and the pin being inserted into a pin hole formed in the piston. The oral irrigator according to claim 1.

5. the piston has a first end proximate the first cavity and a second end proximate the second cavity; the first end and the second end of the piston form a first seal portion and a second seal portion, respectively, that sealingly abut against an inner surface of the internal cavity of the piston cylinder. The oral irrigator according to claim 1 or 2.

6. the piston has a deformable first thin-walled portion located at the first end and a deformable second thin-walled portion located at the second end, the first seal portion being formed on an outer peripheral surface of an end of the first thin-walled portion, and the second seal portion being formed on an outer peripheral surface of an end of the second thin-walled portion. The oral irrigator according to claim 5.

7. The first thin-walled portion of the first end portion has a recess, and the position of the recess is provided to correspond to the first through hole. The oral irrigator according to claim 6.

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