CN116498520A

CN116498520A - Piston pump drive assembly for cleaning care implement

Info

Publication number: CN116498520A
Application number: CN202210279666.XA
Authority: CN
Inventors: 戴晓国; 徐振武
Original assignee: Shanghai Shift Electrics Co Ltd
Current assignee: Shanghai Shift Electrics Co Ltd
Priority date: 2022-01-21
Filing date: 2022-03-21
Publication date: 2023-07-28

Abstract

The invention discloses a piston pump drive assembly for a cleaning care implement. The drive assembly includes a piston cylinder and a piston. The piston has a head seal movably sealed against an inner wall surface of the piston cylinder, a liquid inlet and a liquid spray opening being provided in the head chamber, wherein the piston pump drive assembly further comprises an electromagnetic drive device and at least one elastic element, wherein the electromagnetic drive device comprises a coil and a magnet, wherein the coil is fixed relative to the piston cylinder, the magnet is located in the chamber and fixedly attached to the piston, wherein the elastic element is arranged between the piston cylinder and the piston, such that an elastic force can be generated to the piston during movement of the piston by the elastic element, the direction of the elastic force being substantially parallel to the longitudinal direction.

Description

Piston pump drive assembly for cleaning care implement

Technical Field

The present invention relates to the technical field of cleaning and care appliances, and more particularly, to a piston pump drive assembly for use in a cleaning and care appliance.

Background

The piston pump drive mechanism is employed in personal care appliances such as mouthwash which are currently on the market to produce the spray fluid to perform the cleaning action. A common piston driving mechanism is driven by a miniature direct current motor as a driving source. Typically, a miniature dc motor is coupled to a gear set, and a connecting rod is eccentrically mounted on a driven gear of the gear set, and drives a piston to reciprocate in a piston cylinder.

In order to achieve the connection of the connecting rod to the piston, the connecting rod needs to extend into the piston cylinder, and therefore a seal needs to be achieved between the connecting rod and the piston cylinder by means of a seal. Because the connecting rod is a moving part, the dynamic seal between the connecting rod and the piston cylinder is more prone to fatigue yielding of the seal, thereby causing seal failure.

In addition, the rotation speed of the miniature motor can be reduced along with the reduction of the battery voltage, the rotation speed of the miniature motor and the battery voltage are approximately in a linear relation, and the rotation speed of the motor is changed, so that the number of water pulses per minute of the tooth washer can be changed. The current medical experiment data show that the proper water pulse number is helpful to the cleaning of the gingiva, and the micro motor is influenced by the voltage fluctuation to further cause the fluctuation of the water pulse number, thereby influencing the cleaning effect of the tooth flusher on the cleaning of the gingiva. In addition, the mechanical cooperation of the gear set and the connecting rod can cause the noise of the tooth flusher to be larger due to abrasion, overlarge gap and the like. Accordingly, there remains a need for improvements in the piston pump drive assemblies of existing tooth irrigators.

Disclosure of Invention

To overcome the deficiencies in the prior art, the present invention provides a piston pump drive assembly comprising: the piston cylinder is internally provided with a cavity; a piston having a head seal reciprocally disposed within the cavity of the piston cylinder in a longitudinal direction, the head seal sealingly moving relative to an inner wall surface of the piston cylinder, the cavity comprising a variable volume head cavity formed adjacent the head seal, the head cavity being provided with a liquid inlet and a liquid spray, wherein the piston pump drive assembly further comprises an electromagnetic drive means and at least one resilient element, wherein the electromagnetic drive means comprises at least one coil fixed relative to the piston cylinder and further comprises at least one magnet or at least one magnetizer, wherein the coil is fixed relative to the piston cylinder, the magnet or at least one magnetizer being located within the cavity of the piston cylinder and fixedly attached to the piston, wherein the resilient element is disposed between the piston cylinder and the piston such that the resilient element is capable of generating a resilient force on the piston during movement of the piston. Typically, the direction of the elastic force is substantially parallel to the longitudinal direction.

According to one aspect of the invention, the electromagnetic drive comprises at least one magnet and at least one magnetizer; wherein the at least one magnet further comprises a first magnet and a second magnet disposed in spaced apart relation and homopolar opposition, at least one magnetically permeable body disposed between the first magnet and the second magnet.

According to a further aspect of the invention, at least one coil comprises a first coil, a second coil and a third coil, wherein the first coil is located between the second coil and the third coil, the first coil is applied with alternating current, the second coil and the third coil are applied with direct current, wherein the direct current is applied such that the magnetic fields generated by the second coil and the third coil are of the same polarity at the opposite end faces of the second coil and the third coil, respectively.

According to one aspect of the invention, a piston includes a piston body portion having a blind bore forming a cavity, the blind bore being sealed on one side of the head cavity and open on an opposite side, the magnet or the magnetizer being enclosed within the cavity from the open other side, and an end cap portion sealingly fitted to the blind bore to sealingly retain the magnet or the magnetizer within the cavity.

According to another aspect of the present invention, the piston further includes a piston bolt for connecting the end cap portion to the body portion, and the magnet or the magnetizer has a center hole through which the magnet or the magnetizer is fitted over the piston bolt.

According to another aspect of the invention, the piston further comprises a resilient retainer located within the cavity of the piston and disposed between the end cap portion and the magnet or the magnetizer.

According to another aspect of the invention, the piston further comprises a tail seal remote from the head seal, the piston cylinder comprises a piston cylinder body and a piston cylinder end cap sealingly secured to the piston cylinder body, the cavity further comprises a tail cavity adjacent to the tail seal and the piston cylinder end cap, the resilient element comprises a first coil spring and a second coil spring, each of which abuts the piston and the piston cylinder, respectively, the first coil spring and the second coil spring exert opposing resilient forces on the piston, wherein the first coil spring is disposed within the tail cavity, one end of the first coil spring abuts the piston cylinder end cap, the second coil spring is nested adjacent to the head cavity on the piston, one end of the second coil spring abuts a step surface on the piston cylinder inner wall, and the other end of the second coil spring abuts a step surface on the piston outer surface.

According to another aspect of the invention, the first coil spring and the second coil spring are always in a compressed state during the reciprocation of the piston within the cavity of the piston cylinder.

According to another aspect of the invention, the piston further comprises a tail seal remote from the head seal, the tail seal being sealingly movable relative to the inner wall surface of the piston cylinder, the cavity of the piston cylinder further comprising a tail cavity adjacent the tail seal. Preferably, the tail cavity is provided with at least one communication port.

According to another aspect of the present invention, at least one communication port includes an air inlet port to which an air inlet check valve for controlling one-way air inlet of the air inlet port is attached, and an air outlet port which communicates into the ejection chamber downstream of the liquid ejection port and to which an air outlet check valve for controlling one-way air outlet of the air outlet port is attached.

According to another aspect of the invention, at least one coil is wound on the outer wall surface of the piston cylinder, and the electromagnetic drive means comprises only a magnet, i.e. no magnetizer, the length of the coil in the longitudinal direction being greater than the sum of the length of the magnet in the longitudinal direction and the length of the single stroke movement of the magnet in the longitudinal direction within the cavity.

According to another aspect of the invention, the magnets are arranged such that the magnetic field lines of the magnets extend in a radial direction perpendicular to the longitudinal direction. Alternatively, the magnets are arranged such that the magnetic lines of force of the magnets are parallel to the direction of the magnetic lines of force generated by the coils after the coils pass an alternating current.

According to another aspect of the invention, at least one coil is passed through an alternating current with a frequency f, the elastic element, the piston and the magnet or the magnetizer constituting a resonator body which resonates under the effect of the current passed through said coil, preferably the natural frequency f of the resonator body _g In the range of 75% -125% of the coil current frequency f.

The piston pump driving assembly is characterized in that a magnet and a spring are arranged in a piston, the outer wall surface of a piston cylinder surrounds a coil of the magnet, alternating current is passed through the coil, so that resonant motion is formed, the piston is driven to reciprocate in the piston cylinder with high efficiency, and the frequency of the alternating current in the coil is fixed, so that the frequency of the reciprocating motion of the piston is fixed only along with the frequency of the coil current, the unit time of water pulses sprayed from a nozzle excited by the piston is fixed, the fixation of the number of the water pulses is realized, and the problem that the water pulses change along with the change of the voltage of a battery in the prior art is solved.

By means of non-contact electromagnetic force between the magnet and the coil to drive the piston to reciprocate, the impact caused by excessive clearance and other factors caused by the clearance and abrasion during driving between the moving parts is eliminated, and the movement of the piston is stable. Since the impact is reduced, high-frequency noise caused by the impact is also reduced.

The scheme of the invention does not adopt dynamic sealing of the connecting rod and the sealing element. The piston cylinder body and the piston cylinder end cover of the piston cylinder are connected through the fastener, so that the interior of the piston cylinder can bear larger internal pressure, and particularly the tail cavity of the piston cylinder can bear larger internal pressure, thereby realizing reliable sealing of the interior of the piston cylinder.

Drawings

For a more complete understanding of the present invention, reference is made to the following description of exemplary embodiments taken in conjunction with the accompanying drawings, in which:

fig. 1 is a schematic view of a piston pump drive assembly and nozzle for a cleaning care implement according to a preferred embodiment of the present invention.

Fig. 2 is a cross-sectional view of the piston pump drive assembly and nozzle shown in fig. 1 in accordance with a preferred embodiment of the present invention.

Fig. 3 is a cross-sectional view of a piston pump drive assembly according to a first preferred embodiment of the invention.

Fig. 4 is a cross-sectional view of a piston pump drive assembly according to a first preferred embodiment of the invention, with component parts omitted.

Fig. 5 is a schematic view of the water and air passages of a piston pump drive assembly according to a preferred embodiment of the present invention.

Fig. 6 is a schematic view of a water and air circuit of a piston pump drive assembly according to another preferred embodiment of the present invention.

Fig. 7 is a schematic view of a water path and an air path of a piston pump driving assembly according to still another preferred embodiment of the present invention.

Fig. 8 is a cross-sectional view of a piston pump drive assembly according to a second preferred embodiment of the invention.

Fig. 9 is a cross-sectional view of a piston pump drive assembly according to a third preferred embodiment of the invention.

List of reference numerals

1 nozzle

2 liquid inlet pipe

3 air inlet pipe

4 gas pipe

5 coil

6 inlet pipe connecting piece

7 gas pipe connecting piece

8,8' piston cylinder

9 piston cylinder end cover

10 end cap screw

11 nozzle connection

12 air inlet pipe connecting piece

13 air inlet pipe one-way valve

14 inlet pipe check valve

15 air pipe one-way valve

16 nozzle seal

17 hydrojet mouth check valve

18 second spring

19 Piston bolt 19',19

20 magnet

20'-1, 20' -2 magnet

20', 20' magnetizer

21 21',21 "piston

22 spray nozzle

23 liquid inlet

24 gas delivery port

25 piston cylinder tail air inlet

26 piston cylinder tail gas outlet

27 end cap portion

28 elastic retainer

29 first spring

30 magnet seal

31 piston cylinder end cap seal

32 inlet tube sealing member

33 gas pipe seal

34 nozzle interface seal

35 air inlet pipe sealing element

210 tail seal

211 head seal

V1 tail cavity

V2 head cavity

V3 spray cavity

2' inlet pipe

4' gas pipe

Detailed Description

The present invention will be further described with reference to specific embodiments and drawings, in which more details are set forth in the following description in order to provide a thorough understanding of the present invention, but it will be apparent that the present invention can be embodied in many other forms than described herein, and that those skilled in the art may make similar generalizations and deductions depending on the actual application without departing from the spirit of the present invention, and therefore should not be construed to limit the scope of the present invention in terms of the content of this specific embodiment.

In the following description, the structure of the cleaning care appliance is described by way of example as a dental irrigator, but it will be appreciated that the invention is also applicable to other personal cleaning care appliances which are cleaned by means of fluid pulses generated by a piston pump. It should be noted that "head/head" hereinafter refers to the end or side of the nozzle 1 that is closer to the dental appliance, and "tail/tail" refers to the end or side of the nozzle 1 that is farther from the dental appliance.

The various functional components of the dental irrigator are typically housed within a cavity defined by the housing of the handle portion. Specifically, the chamber of the handle portion houses a fluid carrying tubing system, a piston pump drive assembly for providing a cleaning force to the fluid, a power source (typically a rechargeable battery) for providing power to the piston pump drive assembly, and a corresponding control device.

Fig. 1 shows a schematic view of a piston pump drive assembly and nozzle 1 for a cleaning care implement according to a preferred embodiment of the invention. Fig. 2 shows a longitudinal section through the piston pump drive assembly and the nozzle 1. As shown in fig. 1 and 2, the piston pump drive assembly mainly comprises a piston cylinder 8, a piston 21, electromagnetic drive means and an elastic element. The piston 21 is accommodated in an inner cavity of the piston cylinder 8, and the piston 21 can reciprocate in a longitudinal direction of the piston 21 with respect to the cavity of the piston cylinder 8 under the action of electromagnetic force generated by the electromagnetic driving means and elastic force of the elastic member, thereby realizing a circulation operation of pumping fluid.

Preferably, the piston cylinder 8 is constituted by a piston cylinder body and a piston cylinder end cap 9. The piston cylinder body and piston cylinder end cap 9 are secured together by means of one or more fasteners such as end cap screws 10. The internal cavity of the piston cylinder 8 is substantially cylindrical, as shown in fig. 4, and consists of cylindrical sections of different inner diameters. The outer shape of the piston 21 substantially corresponds to the cavity of the piston cylinder 8, the piston 21 also having a plurality of sections of different outer diameters, so that the piston 21 can fit within the cavity of the piston cylinder 8.

In the preferred embodiment, the piston 21 includes a head seal 211 and a tail seal 210. The head seal 211 and the tail seal 210 have circumferential head and tail sealing surfaces, respectively, each of which can form a fluid seal against a corresponding inner circumferential surface of the piston cavity. As shown in fig. 4, the outer diameter of the head seal 211 is smaller than the outer diameter of the tail seal 210.

The cavity formed inside the piston cylinder 8 is divided by the piston 21 to form a head cavity V2 and a tail cavity V1, wherein the head cavity V2 is adjacent to the head seal 211 and the tail cavity V1 is adjacent to the tail seal 210. The piston cylinder 8 is provided with a liquid spraying port 22 and a liquid inlet 23 at the head cavity V2. The liquid spray orifice 22 is preferably connected in fluid communication with the nozzle 1 by a nozzle connection 11, and a nozzle seal 16 may also be provided between the nozzle connection 11 and the nozzle 1 to ensure a fluid tight seal therebetween. While the inlet 23 is provided for letting in a cleaning fluid, such as water or other functional cleaning liquid, into the interior of the piston cylinder 8.

During use of the piston pump drive assembly, the volumes of the head chamber V2 and the tail chamber V1 are variable with the reciprocating movement of the piston 21, in particular, as the piston 21 moves towards the tail of the piston cylinder 8, the volume of the head chamber V2 becomes larger, the volume of the tail chamber V1 becomes smaller, and fluid is drawn into the head chamber V2; as the piston moves toward the head of the cylinder 8, the head chamber V2 becomes smaller in volume and the tail chamber V1 becomes larger in volume, and fluid is ejected from the liquid ejection port 22.

In particular, the movement of the piston 21 relative to the piston cylinder 8 is effected by electromagnetic drive means. The electromagnetic drive mainly comprises a coil 5 and a magnet 20. As shown in fig. 2, the coil 5 is wound around the outer wall surface of the piston cylinder 8, and preferably the coil 5 is interposed between two flanges on the outer wall surface. On the other hand, the magnet 20 is fixed relative to the piston 21 such that the magnet 20 is accommodated in the cavity of the piston cylinder 8 together with the piston 21. When the electromagnetic driving device is electrified and actuated, electromagnetic acting force can be generated between the coil 5 and the magnet 20 to enable the magnet 20 to move relative to the coil 5, so that the piston 21 is driven to move relative to the piston cylinder 8.

Further, in order to achieve a reciprocating movement of the piston 21 relative to the piston cylinder 8, an elastic element is also arranged between the piston cylinder 8 and the piston 21. Since the elastic element is arranged between the piston cylinder 8 and the piston 21, the elastic element can exert an elastic force on the piston 21 during the movement of the piston 21. The direction of the elastic force is substantially parallel to the longitudinal direction of the piston movement.

In the preferred embodiment of the invention, as shown in fig. 2, the elastic element is two helical springs 18 and 29, hereinafter referred to as first spring 29 and second spring 18, respectively.

The first spring 29 is arranged in the tail chamber V1, with one end of the first spring 29 abutting against the piston cylinder end cap 9, which end is also the stationary end of the first spring 29, and the other end abutting against the tail end of the piston 21, i.e. the end of the tail seal 210, in particular the first spring 29 may abut against the end cap portion 27 of the piston 21.

Near the second cavity V2 of the piston 21, the second spring 18 is fitted over a smaller diameter section of the piston 21, as shown in fig. 2, with one end of the second spring 18 resting against a stepped surface on the inner wall of the piston cylinder 8, this end of the spring 18 also being the stationary end of the second spring 18, and the other end resting against a stepped surface on the outer surface of the piston 21, this end of the spring 18 being the movable end. Thus, in the first chamber V1, the first spring 29 provided between the piston 21 and the piston cylinder 8 applies an elastic force to the piston 21, and the second spring 18 is provided between the piston and the piston cylinder 8 closer to the head of the piston than the first spring 29 applies an elastic force, and the directions of the elastic forces of the first spring 29 and the second spring 18 on the piston 21 are opposite.

The first spring 29 and the second spring 18 remain in compression against the piston 21 throughout the reciprocating movement of the piston 21 relative to the piston cylinder 8. For example, as shown in fig. 3, in which the piston 21 is moved to a position closest to the nozzle 1, the head chamber V2 is at a minimum, at which time the second spring 18 is compressed to a maximum extent, while the first spring 29 is also in a compressed state, but has approached its relaxed state. Conversely, when the piston 21 moves to a position furthest from the nozzle 1, the tail chamber V1 is in a minimum state, at which time the first spring 29 is compressed to a maximum extent, and the second spring 18 is also in a compressed state. According to the present embodiment, the first spring 29 and the second spring 18 are always in the compressed state, and the unnecessary noise generated by the collision of the piston cylinder 8, the piston 21 against the springs 18, 29 can be eliminated.

Fig. 3 shows a specific structure of fixing the magnet 20 to the inside of the piston 21. Preferably, the piston 21 includes a body portion and an end cap portion 27 fitted at one end of the body portion. The body of the piston 21 has a blind bore forming a cavity, the blind bore being sealed on one side of the head cavity V2 and open on the opposite end of the tail cavity V1. The end cap portion 27 is fitted on the opening side of the blind hole. The magnet 20 is fitted into the cavity of the body portion from the open side, and then the end cap portion 27 is sealingly fitted to the blind bore so that the magnet 20 is sealingly retained in the cavity. Preferably, in order to enable the piston cavity to be in a closed state, so as to avoid any liquid from penetrating into the piston cavity and corroding the magnet 20, a magnet sealing member 30 is arranged between the end cover part 27 and the inner wall surface of the piston cavity, so as to realize sealing connection of the end cover part 27 relative to the piston 21.

The magnet 20 and the blind hole cavity have a uniform shape, preferably cylindrical. The magnet 20 may be one magnet or a plurality of separable magnets 20.

In order to keep the magnet 20 fixed relative to the blind hole cavity, the piston 21 plug further comprises a piston bolt 19 for connecting the end cap portion 27 to the body portion, as shown in fig. 2. The piston bolt 19 extends through a bolt hole in the end cap portion 27 to a threaded hole in the interior of the blind cavity. The magnet 20 is provided with a central hole by means of which the magnet 20 is fitted over the piston bolt 19, whereby the magnet 20 is held between the end cap 27 and the bottom of the blind hole.

Furthermore, as shown in fig. 2, the piston 21 preferably further comprises an elastic retainer 28. The elastic holding member 28 is provided in the cavity of the piston 21 between the end cap portion 27 and the magnet 20 so as to hold the magnet 20 from moving in the cavity of the piston 21. The elastic holder 28 is made of an elastomeric material such as rubber, for example.

In a preferred embodiment, as shown in fig. 4, the direction of the internal magnetic field lines of the magnet 20 extends along the radial direction of the magnet, and the direction of the current in the coil 5 is shown in fig. 4 as flowing into or out of the paper, i.e. the current in the coil 5 flows around the magnet 20, the direction of the internal magnetic field of the coil 5 formed by the current in the coil 5 being parallel to the longitudinal direction of the magnet. The external magnetic lines of force of the magnet 20 pass through the coil 5.

When an alternating current of frequency f is passed through the coil 5, the external magnetic lines of force of the magnet 20 cut the current-carrying coil 5, generating lorentz forces. Since the coil 5 is fixed to the piston cylinder 8, the piston cylinder 8 is stationary relative to the housing of the tooth punch, and accordingly the coil 5 is also constrained to remain stationary. The magnet 20 will be subjected to the reaction force of the lorentz force, the magnet 20 can move relative to the piston cylinder 8, the magnet 20 is driven under the force, and in the state of fig. 4, the magnet 20 is subjected to the electromagnetic force to the left, and the magnet 20 moves to the left. Obviously, when the current of the coil 5 in fig. 4 is reversed, the force applied to the magnet 20 is reversed, the magnet 20 is subjected to electromagnetic force to the right, and the magnet 20 moves to the right, thereby realizing reciprocation.

In another alternative embodiment, the magnet 20 in the piston 21 may be arranged such that its internal magnetic flux direction (N ', S') is parallel to the coil internal magnetic flux direction generated by the coil 5. In this case, the magnetic lines of force of the magnet 20 do not cut the coil current carrying. When alternating current passes through the coil 5, an alternating magnetic field is generated inside the coil 5, and the magnetic force line direction of the magnetic field inside the coil 5 formed by the current of the coil 5 is basically parallel to the magnetic force line direction generated by the magnet. For example, in the state of fig. 4, the alternating current flowing through the coil 5 generates magnetic force lines from right to left inside the coil 5, and the direction of the magnetic force lines generated by the magnet 20 is from left to right, and the energizing coil 5 generates electromagnetic driving force to the left on the magnet 20, so as to drive the magnet to move to the left, and further drive the piston to move to the left. When the current of the coil 5 is reversed in fig. 4, the coil 5 generates magnetic force lines from left to right in the coil 5, and the magnetic force lines generated by the magnet 20 are in a direction from left to right, and the energized coil 5 generates electromagnetic driving force to the right on the magnet 20 to drive the magnet 20 to move to the right, and correspondingly drive the piston 21 to move to the right.

The first spring 29, the second spring 18, the magnet 20, and the piston including the piston bolt 19, the elastic holder 28, the body portion, and the end cap portion 27 constitute a resonator body. At this time, the natural frequency of the resonator body is f _g Natural frequency f of resonator _g The magnitude of (2) depends on the mass of the resonator body and the combined spring stiffness coefficients of the first spring 29 and the second spring 18. When f _g Between 75% and 125% of the driving force frequency f, the resonance body is defined as being in resonance state under the action of the driving force, when f _g When the frequency f of the driving force is equal, the resonator body is in a resonance state under the driving force. The driving force is the force or reaction between the magnet 20 and the coil 5, the frequency of the driving force being dependent on the frequency of the current in the coil 5, i.e. the driving force frequency is equal to the coil 5 current frequency f. In the present embodiment, the natural frequency f of the resonator body _g Between 75% and 125% of the coil current frequency f, the resonator body resonates under the action of the driving force, preferably the natural frequency fg of the resonator body is between 90% and 110% of the coil current frequency f, and the resonator body resonates under the action of the driving force.

Since the frequency f of the current of the coil 5 is fixed, the frequency of the movement of the piston 21 is fixed, thereby realizing the fixation of the number of water pulses, which is more beneficial to the health of gums, and the mechanical efficiency of the piston pump driving assembly is greatly improved in the resonance state.

Advantageously, when the magnet 20 is arranged inside the coil 5 as shown in fig. 2, the length of the magnet 20 and the longitudinal direction of the coil 5 should be chosen such that the magnet 20 is always inside the coil 5 during the movement period, in other words, the length of the magnet 20 in the longitudinal direction does not exceed the length range of the coil 5. For this purpose, the length of the coil 5 in the longitudinal direction should be greater than the sum of the longitudinal length of the magnet 20 and the distance of movement of the magnet 20 relative to the coil 5 in one direction.

The magnetic field intensity inside the coil 5 is proportional to the magnitude of the current in the coil 5, and in the case that the magnet 20 is always inside the coil 5, the magnitude of the electromagnetic force from the coil 5 is mainly influenced by the magnitude of the current in the coil 5 on the magnet 20, but the positional relationship with the magnet 20 inside the coil 5 is not great, so that the position of the magnet is not disturbed when the resonator resonates under the electromagnetic force of the current in the coil 5.

Next, a piping arrangement structure of the piston pump drive assembly is described with reference to fig. 4 and 5. The cavity of the piston cylinder 8 comprises a head cavity V2 and a tail cavity V1. The inlet 23 of the head chamber V2 is connected to a water source, such as a reservoir, via the inlet pipe 2. A water inlet pipe connection 6 is preferably provided between the inlet 23 and the inlet pipe 2, and a water inlet pipe seal 32 is preferably also provided, which seal 32 provides a seal between the water inlet pipe connection 6 and the piston cylinder body. As shown in fig. 2, the inlet pipe check valve 14 is provided between the inlet port 23 and the inlet pipe connection 6, so that the inlet pipe check valve 14 allows only fluid outside the piston cylinder 8 to enter the head chamber V2, but does not allow fluid to flow out of the head chamber V2. A liquid jet one-way valve 17 is also provided at the liquid jet port 22 of the head chamber V2, as shown in fig. 4, the liquid jet one-way valve 17 being provided between the head chamber V2 and the ejection chamber V3 downstream thereof closer to the nozzle 1. The ejection chamber V3 may be formed by a part of the piston cylinder 8, a part of the nozzle 1 or an end of a connection between them, the ejection chamber V3 opening into the nozzle 1. The liquid-jet one-way valve 17 is provided to allow the fluid in the head chamber V2 to enter the downstream ejection chamber V3, but not allow the fluid in the ejection chamber V3 to return to the head chamber V2.

In addition, as shown in fig. 4, a gas delivery port 24 is further provided at the injection cavity V3, and the gas delivery port 24 is connected to a gas outlet 26 of the tail cavity V1 through the gas delivery pipe 4. The gas delivery port 24 is connected with the gas delivery pipe 4 through a gas delivery pipe connecting piece 7, and a gas delivery pipe sealing piece 33 is further arranged to avoid fluid overflow. Similarly, a gas delivery pipe check valve 15 is provided between the gas delivery port 24 and the connector 17. The air delivery pipe check valve 15 is arranged to allow only fluid in the tail chamber V1 to enter the ejection chamber V3, but to prevent fluid from flowing back out of the chamber V3 along the air delivery pipe 4.

On the other hand, the tail chamber V1 is also provided with at least one port. Specifically, the tail chamber V1 is provided with two ports: an air inlet 25 and an air outlet 26. Preferably, both the air inlet 25 and the air outlet 26 are provided on the side wall of the piston cylinder body. It should be appreciated that in other alternative embodiments, the air inlet 25 and/or the air outlet 26 may be provided on the piston cylinder end cap 9.

As shown in fig. 4, the air outlet 26 of the tail chamber V1 is connected to the air delivery pipe 4. The air inlet 25 of the rear chamber V1 is connected to the air inlet pipe 3 via an air inlet pipe connection 12 and a seal 35 is also provided between the connection 12 and the piston cylinder 8 to ensure a fluid-tight seal. The air inlet pipe 3 can be open to the environment outside the tooth-rinsing device, and also to the open space inside the tooth-rinsing device. At the location where the connection piece 12 is connected with the air inlet 25, an air inlet pipe one-way valve 13 is provided, which air inlet pipe one-way valve 13 is arranged to allow only fluid outside the piston cylinder 8 to enter the tail chamber V1, but not to allow fluid in the tail chamber V1 to flow back out.

When the piston pump driving assembly is operated as shown in fig. 5, liquid is drawn into the head chamber V2 from the reservoir along the path a in fig. 5 by the pressure difference between the atmospheric pressure and the pressure in the chamber V2 due to the change in the pressures in the chambers V1 and V2 caused by the reciprocating linear motion of the piston 21, and the liquid opens the liquid-spraying-port check valve 17 into the spraying chamber V3 due to the pushing action of the piston 21, thereby entering the nozzle 1, and finally being ejected through the nozzle 1 along the path D. On the other hand, when the piston pump driving assembly works, gas is pumped into the cavity V1 from the outside of the piston cylinder 8 along the path B including the gas pipe 3 due to the change of the pressure in the tail cavity V1 caused by the reciprocating linear motion of the piston, and is injected into the injection cavity V3 through the gas pipe 4 along the path C due to the pushing action of the piston by opening the gas pipe one-way valve 15 through the gas pipe 3 and then enters the nozzle 1, and finally is injected out through the nozzle 1. Thus, the fluid ejected from the nozzle 1 will be a mixture of gas and liquid, where the gas is typically an oxygen-containing gas, and the injection of the oxygen-containing gas into the gingival sulcus is effective in removing anaerobic bacteria and helps to maintain gingival health.

Fig. 6 shows a schematic view of a fluid circuit of a piston pump drive assembly according to another preferred embodiment. The difference from the embodiment shown in fig. 5 is that the tail chamber V1 is not in communication with the ejection chamber V3, but has a communication port which communicates through the gas pipe 4' to the atmosphere, either directly to the outside of the shell of the dental irrigator or to a space inside the shell of the dental irrigator which communicates with the outside atmosphere, preferably to a space inside the shell which is not affected by water. In this embodiment, there is no need to provide a one-way valve or a flow restriction element in the communication path of the delivery tube 4'.

In use of the piston pump drive assembly with the delivery tube 4 'communicating with the atmosphere, liquid in the reservoir will enter the head chamber V2 along the inlet tube 2' along arrow E as the piston 21 moves, while gas in the tail chamber V1 will alternately enter and exit the tail chamber V1 as shown by the double arrow F in fig. 6 as the piston 21 reciprocates. The atmospheric delivery pipe 4' serves to reduce the amplitude of the pressure variation in the tail chamber V1. If the liquid that would have been held in the head chamber V2 leaks into the tail chamber V1 due to a failure of the seal between the piston and the piston chamber, at least a portion of the liquid in the tail chamber V1 will be sent out of the tail chamber V1 through the transfer tube 4'.

Fig. 7 shows a schematic view of the water and air paths of a piston pump drive assembly according to another preferred embodiment. In the waterway and airway arrangement shown in FIG. 7, the tail chamber V1 does not have ports that are in fluid communication with the outside of the chamber. In this case, the tail chamber V1 actually forms an isolated space. With this construction, the pressure in the tail chamber V1 will vary drastically with the reciprocating movement of the piston 21 relative to the piston cylinder 8. However, since the piston cylinder end cap 9 can be fixed to the rear end of the piston cylinder 8 by the end cap screw 10, preferably a seal 31 is provided between the end cap 9 and the piston cylinder body, this structure can withstand a large cavity pressure and maintain the airtight isolation of the rear cavity V1 from the outside of the piston cylinder 8.

Fig. 8 shows a cross-sectional view of a piston pump drive assembly according to a second preferred embodiment of the invention. As shown in fig. 8, the arrangement of the piston cylinder 8', the piston 21' and the elastic member in the piston pump drive assembly is similar to that of the piston pump drive assembly of the first embodiment, and will not be repeated here.

In the embodiment shown in fig. 8, the electromagnetic drive in the piston drive assembly comprises a coil 5' and magnets 20' -1 and 20' -2. The coil 5 'is wound around the outer wall surface of the piston cylinder 8', and preferably, spaced apart flanges are integrally formed on the outer wall surface of the piston cylinder 8', the coil 5' being held between the opposed flanges. The magnets 20'-1 and 20' -2 are disposed in a cavity portion formed inside the piston 21', the two magnets 20' -1 and 20'-2 being disposed at a distance from each other and being homopolar opposite each other with the magnetizer 20' disposed therebetween.

The magnet herein generally refers to a permanent magnet containing nickel or cobalt, and the magnetizer refers to a magnetically conductive material other than the permanent magnet, such as annealed iron and steel.

The manner in which the magnet 20'-1, the magnet 20' -2 and the magnetizer 20 'are held within the cavity in the piston 21' is similar to that in the first preferred embodiment, the magnet 20'-1 and the magnet 20' -2 each have a central hole, the central holes of the two magnets are aligned, and the magnetizer 20 'in the middle of the magnet 20' -1 and the magnet 20'-2 is also provided with the same central hole, and the piston bolt 19' passes through the central holes of the three and holds the three together by means of the end cap portion.

As can be seen from the longitudinal cross-sectional structure shown in fig. 8, the coil 5' is arranged at a position substantially midway between the two magnets 20' -1 and 20' -2 in the longitudinal direction. The length of the coil 5 'in the longitudinal direction is preferably chosen such that at least a portion of the at least one magnet 20' -1, 20'-2 is outside the range occupied by the coil 5' in the longitudinal direction. Magnet 20' -1 and magnet 20' -2 preferably have the same shape and size, and magnet and magnetizer 20' preferably have the same diameter.

When the driving device of the preferred embodiment is used, an alternating current with frequency f is passed through the coil 5', and the direction of the current in the coil 5' is shown in fig. 8 as flowing into or out of the paper. Since the two magnets 20' -1 and 20' -2 are homopolar opposed, the magnetic lines of force generated by the magnets 20' -1 and 20' -2, after extending from their opposed ends, are diverted to extend radially through the current carrying coil 5'. The magnetic lines of force of the two magnets 20'-1 and 20' -2 cut the current carrying coil 5 'and generate lorentz forces, and since the coil 5' is constrained to remain stationary, the two magnets 20'-1 and 20' -2 will now be subjected to the reaction forces of the lorentz forces and thereby be driven in a relative reciprocating motion with respect to the piston cylinder 8.

The electromagnetic driving device having the two magnets 20'-1 and 20' -2 arranged opposite to each other has a magnetic field strength at the coil 5 'increased due to a decrease in magnetic resistance as compared with the first preferred embodiment, and the electromagnetic driving device of the second preferred embodiment can produce a better driving efficiency because the coil 5' passes through magnetic lines of force flowing out or flowing in from the circumferential direction of the magnetic conductor body as the length of the coil 5 'is smaller than that of the magnetic conductor body, and because the magnetic lines of force are closed curves, in the present embodiment, magnetic lines of force opposite to the magnetic lines of force passing through the coil 5' are relatively smaller away from the coil 5 'due to the force generated by the magnetic lines of force opposite to the coil 5'.

Similarly to the first preferred embodiment, the two magnets 20'-1 and 20' -2, the magnetizer, the piston including the piston bolt, the elastic retainer, the body portion, the end cap portion, and the springs at both ends constitute a resonance body having a natural frequency f _g F is as follows _g It should be between 75% and 125% of the current frequency f on the coil 5', preferably the natural frequency fg of the resonator body is between 90% and 110% of the coil current frequency f, which causes the resonator body to resonate under the influence of the driving force.

Fig. 9 shows a cross-sectional view of a piston pump drive assembly according to a third preferred embodiment of the invention. As shown in fig. 9, the arrangement of the piston cylinder 8", the piston 21" and the elastic element in the piston pump drive assembly is similar to that in the piston pump drive assemblies of the first and second embodiments, and will not be repeated here again.

In particular, in the piston pump drive assembly of the third preferred embodiment, three coils, namely, a first coil 5"-1, a second coil 5" -2, and a third coil 5"-3, are wound around the outer wall surface of the piston cylinder 8", wherein the first coil 5"-1 is located between the second coil 5" -2 and the third coil 5 "-3. The first coil 5"-1 applies an alternating current, and the second coil 5" -2 and the third coil 5"-3 apply a direct current. The second coil 5"-2 and the first coil 5" -1 and the third coil 5"-3 and the first coil 5" -1 may be separated by a flange integrally formed with the piston cylinder 8 ". Preferably, the longitudinal lengths of the second coil 5"-2 and the third coil 5" -3 are shorter than the length of the first coil 5"-1, and the longitudinal lengths of the second coil 5" -2 and the third coil 5"-3 are the same.

Instead of the magnet 20 in the first embodiment, in the third embodiment, a magnetizer 20 "is attached to the opposing piston 21", and the magnetizer 20 "may be a cylindrical integral piece. In other alternative embodiments, the magnetic conductors may be combined by connecting sections of magnetic conductors 20 "together in series.

Preferably, the length of the magnetic conductor 20″ in the longitudinal direction is greater than or equal to the longitudinal length and sum of the first, second and third coils.

As shown in fig. 9, the magnetizer 20 "has a central hole in the middle, which is cylindrically centered with the outer circumference of the magnetizer 20", through which the piston bolt 19 "passes, whereby the entire magnetizer 20" is fixedly accommodated in the cavity of the piston 21 ".

In use, alternating current is applied to the first coil 5"-1, and direct current is applied to the second coil 5" -2 and the third coil 5 "-3. In this case, after the second coil 5"-2 and the third coil 5" -3 are subjected to direct current, both ends of the magnetizer act like permanent magnets, and after the direct current is applied, the magnetic poles of the opposite end faces of the second coil 5"-2 and the third coil 5" -3 are identical, magnetic force lines generated by the magnetic poles pass through the first coil 5"-1 located in the middle of the second coil and the third coil along the radial direction of the magnetizer, and interact with the magnetic force lines generated by the first coil 5" -1 through alternating current, so that reciprocating force is generated.

With the drive assembly of the third embodiment, the magnets are replaced with coils to which direct current is applied, so that the overall assembly cost is further reduced.

Similarly to the first preferred embodiment, the magnetizer 20", the piston 21" including the piston bolt, the elastic retainer, the body portion, the end cap portion, and the springs at both ends constitute a resonance body having a natural frequency f _g F is as follows _g It should be between 75% and 125% of the alternating current frequency f at the first coil 5"-1, preferably the natural frequency fg of the resonator body is between 90% and 110% of the coil current frequency f, which causes the resonator body to resonate under the influence of the driving force.

Other variations of the preferred embodiments described above are possible. For example, the elastic element of the piston pump drive assembly may be provided with only one spring, in particular may comprise only the spring 18 which is fitted over the piston. For another example, the piston cylinder 8 may comprise only a head chamber and the piston 21 only comprises one seal with a circumferential sealing surface. At the rear end of the piston cylinder 8, which may be in an open state, no cavity is formed.

In addition, the specific position and configuration of the check valve provided in each pipe may also be changed according to the connection structure and the extending direction of the pipe.

While the invention has been described in terms of preferred embodiments, it is not intended to be limiting, but rather to the invention, as will occur to those skilled in the art, without departing from the spirit and scope of the invention. Therefore, any modification, equivalent variation and modification of the above embodiments according to the technical substance of the present invention fall within the protection scope defined by the claims of the present invention.

Claims

1. A piston pump drive assembly for a cleaning care implement comprising:

a piston cylinder (8) having a cavity formed therein;

a piston (21) having a head seal (211) which is arranged in the cavity of the piston cylinder so as to be reciprocatingly movable in the longitudinal direction, the head seal being sealingly movable with respect to an inner wall surface of the piston cylinder,

the cavity comprises a head cavity (V2) with a variable volume, the head cavity (V2) is formed adjacent to the head sealing part, the head cavity (V2) is provided with a liquid inlet (23) and a liquid spraying opening (22),

it is characterized in that the piston pump drive assembly further comprises an electromagnetic drive device and at least one elastic element,

wherein the electromagnetic drive apparatus includes:

at least one coil fixed relative to the piston cylinder: and

at least one magnet or at least one magnetizer located within the cavity and fixedly attached to the piston,

wherein the elastic element is arranged between the piston cylinder and the piston such that an elastic force can be generated on the piston during movement of the piston by the elastic element.

2. The piston pump drive assembly as in claim 1, wherein said electromagnetic drive means comprises at least one magnet and at least one magnetizer;

the at least one magnet further comprises a first magnet and a second magnet, the first magnet and the second magnet being arranged spaced apart and homopolar opposite,

the at least one magnetically permeable body is disposed between the first magnet and the second magnet.

3. The piston pump drive assembly as in claim 1, wherein said at least one coil comprises a first coil, a second coil, and a third coil, wherein said first coil is positioned between said second coil and said third coil,

the first coil is applied with alternating current, the second coil and the third coil are applied with direct current, and the applied direct current enables the polarities of magnetic fields generated by the second coil and the third coil to be the same at the opposite end faces of the second coil and the third coil.

4. The piston pump drive assembly as claimed in claim 1, wherein said piston (21) comprises a body portion and an end cap portion (27), said body portion having a blind bore forming a cavity, said blind bore being sealed on one side of said head cavity and open on an opposite side, said magnet or said magnetizer being housed within said cavity from said open other side,

the end cap portion is sealingly mated to the blind bore to sealingly retain the magnet or the magnetizer within the cavity.

5. The piston pump drive assembly as in claim 4, wherein said piston further comprises a piston bolt for connecting said end cap portion to said body portion, said magnet or said magnetizer having a central bore through which said magnet or said magnetizer is nested on said piston bolt.

6. The piston pump drive assembly as in claim 4 or 5, wherein said piston further comprises a resilient retainer (28) located within said cavity of said piston and disposed between said end cap portion and said magnet or said magnetizer.

7. The piston pump drive assembly as in claim 1, wherein said piston further comprises a tail seal remote from said head seal, said piston cylinder including a piston cylinder body and a piston cylinder end cap sealingly secured to said piston cylinder body, said cavity further comprising a tail cavity (V1) adjacent said tail seal and said piston cylinder end cap,

the elastic element comprises a first helical spring (29) and a second helical spring (18), each of which abuts against the piston and the piston cylinder, respectively, the elastic forces exerted by the first helical spring and the second helical spring on the piston being opposite,

wherein the first spiral spring (29) is arranged in the tail cavity (V1), one end of the first spiral spring is abutted against the piston cylinder end cover,

the second spiral spring (18) is sleeved on the piston close to the head cavity (V2), one end of the second spiral spring is abutted against the step surface on the inner wall of the piston cylinder, and the other end of the second spiral spring is abutted against the step surface on the outer surface of the piston.

8. The piston pump drive assembly of claim 7, wherein said first coil spring (29) and said second coil spring (18) are always in compression during reciprocation of said piston within said cavity of said piston cylinder.

9. The piston pump drive assembly of claim 1, wherein the piston further comprises a tail seal (210) remote from the head seal, the tail seal being sealingly movable relative to the inner wall surface of the piston cylinder, the cavity of the piston cylinder further comprising a tail cavity (V1) adjacent the tail seal, and/or

The tail cavity is provided with at least one communication port.

10. The piston pump drive assembly as defined in claim 8, wherein said at least one communication port comprises an inlet port and an outlet port,

wherein the air inlet port is attached with an air inlet one-way valve for controlling the air inlet port to perform one-way air inlet,

the air outlet port is communicated into an injection cavity (V3) downstream of the liquid injection port (22), and an air outlet one-way valve for controlling the air outlet port to perform one-way air outlet is attached to the air outlet port.

11. The piston pump drive assembly as in claim 1, wherein said at least one coil is wound on an outer wall surface of said piston cylinder and said electromagnetic drive means includes only said at least one magnet, and wherein a length of said coil in said longitudinal direction is greater than a sum of a length of said at least one magnet in said longitudinal direction and a single stroke length distance of said magnet in said cavity in said longitudinal direction.

12. The piston pump drive assembly as defined in claim 11, wherein,

the magnets are arranged such that the magnetic lines of force of the magnets extend in a radial direction perpendicular to the longitudinal direction, or

The magnets are arranged such that the magnetic lines of force of the magnets are parallel to the direction of the magnetic lines of force generated by the coils after the coils pass an alternating current.

13. The piston pump drive assembly as in claim 1, wherein said at least one coil passes an alternating current of frequency f,

the elastic element, the piston and the at least one magnet or the at least one magnetizer form a resonance body which resonates under the action of the current passing through the coil, and the natural frequency f of the resonance body _g In the range of 75% -125% of the coil current frequency f.