Piston pump drive assembly used in cleaning and nursing equipment

Abstract

A piston pump drive assembly used in cleaning and nursing equipment comprises a piston cylinder 8 and a piston 21. The piston 21 has a head seal portion 211 that movably seals against the inner wall surface of the piston cylinder 8, and the head cavity V2 is provided with a suction port 23 and a spray port 22. The piston pump drive assembly further comprises an electromagnetic drive device comprising a coil 5 and a magnet 20, and an elastic element. The coil 5 is fixed to the piston cylinder 8, and the magnet 20 is fixedly attached to the piston 21 within the cavity. The elastic element is positioned between the piston cylinder 8 and the piston 21 and acts an elastic force on the piston 21 during its movement, with the direction of the elastic force generally parallel to the longitudinal direction. The interior of the piston cylinder 8 can withstand greater internal pressure, and in particular its tail cavity can withstand greater internal pressure, ensuring a secure seal inside the piston cylinder 8.

Description

Technical Field

[0001] The present invention relates to the technical field of cleaning and nursing appliances. More specifically, the present invention relates to a piston pump drive assembly used in cleaning and nursing appliances.

Background Art

[0002] Currently, in personal cleaning and nursing appliances such as oral cleaners circulating in the market, an injection fluid is generated by a piston pump drive mechanism for cleaning. A general piston pump drive mechanism is driven using a micro DC motor as a drive source. Usually, the micro DC motor is connected to a gear group, and a link is eccentrically attached to the driven gear of the gear group. By the link driving the piston, the piston reciprocates linearly in the piston cylinder.

[0003] In order to connect the link and the piston, it is necessary to insert the link into the piston cylinder. Therefore, the space between the link and the piston cylinder needs to be sealed with a sealing material. Since the link is a moving part, in the dynamic seal between the link and the piston cylinder, the sealing material is likely to yield due to fatigue, and as a result, it is likely to cause a sealing failure.

Summary of the Invention

Problems to be Solved by the Invention

[0004] In addition, the rotational speed of the micro motor decreases as the battery voltage decreases, and the two are generally in a linear relationship. When the rotational speed of the motor changes, the number of water pulses per minute of the oral cleaner changes. According to current medical experiment data, an appropriate number of water pulses has a great effect on gum cleaning. However, the number of water pulses fluctuates due to the micro motor being affected by voltage fluctuations, and as a result, it affects the gum cleaning effect of the oral cleaner. Furthermore, the mechanical fitting of the gear group and the link causes the noise of the oral cleaner to increase due to wear and excessive gaps. Therefore, there are still defects in the piston pump drive assembly of existing oral cleaners, and improvement is needed. [Means for solving the problem]

[0005] To solve the shortcomings of the prior art, the piston pump drive assembly according to the present invention comprises a piston cylinder having a cavity formed inside, and a piston having a head seal portion that moves in a sealed manner against the inner wall surface of the piston cylinder, and a piston that is arranged in the cavity of the piston cylinder so as to be reciprocally movable in the longitudinal direction. The cavity comprises a volume-variable head cavity formed adjacent to the head seal portion, and the head cavity is provided with a liquid intake port and a liquid ejection port. The piston pump drive assembly further comprises an electromagnetic drive device and at least one elastic element, the electromagnetic drive device comprising at least one coil which is fixed to the piston cylinder, and the electromagnetic drive device comprising at least one magnet or at least one magnetic conductor, the coil which is fixed to the piston cylinder, the magnet or at least one which is located in the cavity of the piston cylinder and fixedly attached to the piston, the elastic element which is arranged between the piston cylinder and the piston, thereby causing the elastic element to act an elastic force on the piston during the piston's movement. Typically, the direction of the elastic force is generally parallel to the longitudinal direction.

[0006] According to one aspect of the present invention, the electromagnetic drive device comprises at least one magnet and at least one magnetic conductor, wherein the at least one magnet further comprises a first magnet and a second magnet, the first magnet and the second magnet are spaced apart and have like poles facing each other, and the at least one magnetic conductor is disposed between the first magnet and the second magnet.

[0007] According to another aspect of the present 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, an alternating current is applied to the first coil, and a direct current is applied to the second and third coils, wherein the magnetic fields generated by the second and third coils, respectively, by the applied direct currents, have the same polarity at the end faces of the second and third coils facing each other.

[0008] According to one aspect of the present invention, the piston comprises a piston body and an end cap, the piston body having a blind hole that forms a cavity, the blind hole being sealed on the head cavity side and open on the opposite side, the magnet or magnetic conductor being mounted into the cavity from the open side, and the end cap being fitted to the blind hole in a sealed manner so as to hold the magnet or magnetic conductor sealed inside the cavity.

[0009] According to another aspect of the present invention, the piston further comprises a piston bolt for connecting the end cap to the main body, the magnet or magnetic conductor has a central hole, and the magnet or magnetic conductor is fitted onto the piston bolt through the central hole.

[0010] According to another aspect of the present invention, the piston further comprises an elastic retaining member, the elastic retaining member located within the cavity of the piston and provided between the end cap and the magnet or magnetic conductor.

[0011] According to another aspect of the present invention, the piston further comprises a tail seal portion separated from the head seal portion, the piston cylinder comprises a piston cylinder body and a piston cylinder end cap, the piston cylinder end cap is sealed and fixed to the piston cylinder body, the cavity further comprises a tail cavity adjacent to the tail seal portion and the piston cylinder end cap, the elastic element comprises a first coil spring and a second coil spring, each of the first coil spring and the second coil spring in contact with the piston and the piston cylinder, respectively, the elastic forces acting on the piston by the first coil spring and the second coil spring are opposite, the first coil spring is provided in the tail cavity with one end in contact with the piston cylinder end cap, the second coil spring is fitted onto the piston in close proximity to the head cavity with one end in contact with a stepped surface on the inner wall of the piston cylinder and the other end in contact with a stepped surface on the outer surface of the piston.

[0012] According to another aspect of the present invention, the first coil spring and the second coil spring are always in a compressed state during the process in which the piston reciprocates within the cavity of the piston cylinder.

[0013] According to another aspect of the present invention, the piston further comprises a tail seal portion separated from the head seal portion, the tail seal portion moves in a sealed manner relative to the inner wall surface of the piston cylinder, and the cavity of the piston cylinder further comprises a tail cavity adjacent to the tail seal portion. Preferably, the tail cavity is provided with at least one communication port.

[0014] According to another aspect of the present invention, at least one communication port comprises an intake port and an exhaust port, wherein the intake port is fitted with an intake check valve to control unidirectional intake of the intake port, and the exhaust port communicates with an injection cavity downstream of the injection nozzle, and the exhaust port is fitted with an exhaust check valve to control unidirectional exhaust of the exhaust port.

[0015] According to another aspect of the present invention, at least one coil is wound around the outer wall surface of the piston cylinder, and the electromagnetic drive device comprises only a magnet, i.e., no magnetic conductor, and the length of the coil in the longitudinal direction is greater than the sum of the length of the magnet in the longitudinal direction and the distance traveled by the magnet in a single longitudinal stroke within the cavity.

[0016] According to another aspect of the present invention, the magnet is arranged such that its magnetic field lines extend in a radial direction perpendicular to the longitudinal direction. Alternatively, the magnet is arranged such that its magnetic field lines are parallel to the direction of the magnetic field lines generated by the coil after an alternating current is passed through the coil.

[0017] According to another aspect of the present invention, an alternating current of frequency f is passed through at least one coil, and an elastic element, a piston, and a magnet or magnetic conductor constitute a resonant body that resonates under the action of current being passed through the coil, preferably the natural frequency fg of the resonant body is in the range of 75% to 125% of the current frequency f of the coil. [Effects of the Invention]

[0018] According to the piston pump drive assembly of the present invention, a magnet and a spring are built into the piston, and a coil surrounding the magnet is provided on the outer wall surface of the piston cylinder. By passing an alternating current through the coil, resonant motion is formed, and the piston reciprocates with high efficiency within the piston cylinder. Since the frequency of the alternating current in the coil is fixed, the motion frequency of the piston follows only the current frequency of the coil, and as a result, the frequency of the piston's reciprocating motion is fixed. This fixes the number of water pulses excited by the piston and ejected from the nozzle per unit time, solving the problem in the prior art where the number of water pulses fluctuates with changes in battery voltage.

[0019] Since the piston is driven to reciprocate by the non-contact electromagnetic force between the magnet and the coil, the impact during driving between moving parts caused by excessive gaps due to movement gaps, wear, etc. is eliminated, and the movement of the piston becomes more stable. By reducing the impact, the high-frequency noise caused by the impact is also reduced.

[0020] According to an aspect of the present invention, a dynamic seal using a link and a sealing material becomes unnecessary. Since the piston cylinder main body and the piston cylinder end cover of the piston cylinder are connected by a fastening member, the inside of the piston cylinder can withstand a larger internal pressure. In particular, its tail cavity can withstand a larger internal pressure, thereby realizing a reliable seal inside the piston cylinder.

Brief Description of the Drawings

[0021] To understand the present invention more completely, the following description of exemplary embodiments can be considered with reference to the accompanying drawings. [Figure 1] FIG. 1 is a schematic view of a piston pump drive assembly and a nozzle used in a cleaning and nursing tool according to a preferred embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view of the piston pump drive assembly and the nozzle shown in FIG. 1 according to a preferred embodiment of the present invention. [Figure 3] FIG. 3 is a cross-sectional view of a piston pump drive assembly according to a first preferred embodiment of the present invention. [Figure 4] FIG. 4 is a cross-sectional view of a piston pump drive assembly according to a first preferred embodiment of the present invention, in which parts of the members are omitted. [Figure 5] FIG. 5 is a schematic view of the water passage and the air passage of a piston pump drive assembly according to a preferred embodiment of the present invention. [Figure 6] FIG. 6 is a schematic view of the water passage and the air passage of a piston pump drive assembly according to another preferred embodiment of the present invention. [Figure 7]FIG. 7 is a schematic diagram of the water and air passages of a piston pump drive assembly according to yet another preferred embodiment of the present invention. [Figure 8] FIG. 8 is a cross-sectional view of a piston pump drive assembly according to a second preferred embodiment of the present invention. [Figure 9] FIG. 9 is a cross-sectional view of a piston pump drive assembly according to a third preferred embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Hereinafter, the present invention will be described in detail with reference to specific embodiments and drawings. In the following description, various details are described to facilitate a full understanding of the present invention. However, it is obvious that the present invention can be implemented in other forms different from the above description, and those skilled in the art can expand and infer according to the actual application situation without departing from the gist of the present invention. Needless to say, the protection scope of the present invention is not limited to the above specific embodiments.

[0023] In the following description, the structure of the cleaning and nursing appliance will be described by taking an oral irrigator as an example. However, it should be understood that the present invention is also applicable to other personal cleaning and nursing appliances that perform cleaning using fluid pulses generated by a piston pump. In the following text, "head side / head end" refers to one end or one side close to the nozzle 1 of the oral irrigator, and "tail side / tail end" refers to one end or one side far from the nozzle 1 of the oral irrigator.

[0024] Each functional component of the oral irrigator is usually housed in a cavity formed by being surrounded by the housing of the handle portion. Specifically, in the cavity of the handle portion, there are housed a pipeline system for conveying fluid, a piston pump drive assembly for imparting cleaning power to the fluid, a power source (usually a rechargeable battery) for supplying power to the piston pump drive assembly, and a corresponding control device.

[0025] Figure 1 shows a schematic diagram of a piston pump drive assembly and nozzle 1 used in a cleaning and nursing tool according to a preferred embodiment of the present invention. Figure 2 shows a longitudinal cross-sectional view of the piston pump drive assembly and nozzle 1. As shown in Figures 1 and 2, the piston pump drive assembly mainly comprises a piston cylinder 8, a piston 21, an electromagnetic drive device, and an elastic element. The piston 21 is housed in the internal cavity of the piston cylinder 8, and due to the action of the electromagnetic force generated by the electromagnetic drive device and the elastic force of the elastic element, the piston 21 reciprocates in the longitudinal direction of the piston 21 relative to the cavity of the piston cylinder 8, thereby realizing a fluid pumping cycle.

[0026] Preferably, the piston cylinder 8 consists of a piston cylinder body and a piston cylinder end cap 9. The piston cylinder body and the piston cylinder end cap 9 are fixed together by one or more fastening members, such as end cap screws 10. The internal cavity of the piston cylinder 8 is generally cylindrical in shape, and as shown in Figure 4, the cavity is composed of cylindrical segments with different inner diameters. The outer shape of the piston 21 generally matches the shape of the cavity of the piston cylinder 8, and the piston 21 also has multiple segments with different outer diameters, thereby allowing the piston 21 to fit inside the cavity of the piston cylinder 8.

[0027] In a preferred embodiment, the piston 21 includes a head seal portion 211 and a tail seal portion 210. The head seal portion 211 and the tail seal portion 210 each have a circumferential head seal surface and a tail seal surface, and both seal surfaces can contact the corresponding inner circumferential surface of the piston cavity to form a fluid seal. As shown in Figure 4, the outer diameter of the head seal portion 211 is smaller than the outer diameter of the tail seal portion 210.

[0028] The cavity formed inside the piston cylinder 8 is divided into a head cavity V2 and a tail cavity V1 by the piston 21. Within this cavity, the head cavity V2 is adjacent to the head seal portion 211, and the tail cavity V1 is adjacent to the tail seal portion 210. The piston cylinder 8 has a spray port 22 and a suction port 23 in the head cavity V2. The spray port 22 is preferably connected to the nozzle 1 via a nozzle connecting component 11 so as to be able to communicate fluid, and a nozzle seal material 16 is provided between the nozzle connecting component 11 and the nozzle 1 to ensure fluid sealing between them. The suction port 23 is provided for introducing a cleaning fluid (e.g., water or other functional cleaning fluid) into the piston cylinder 8.

[0029] During the operation of the piston pump drive assembly, the volumes of the head cavity V2 and tail cavity V1 change with the reciprocating motion of the piston 21. Specifically, when the piston 21 moves toward the tail side of the piston cylinder 8, the volume of the head cavity V2 increases and the volume of the tail cavity V1 decreases, and fluid is drawn into the head cavity V2. When the piston 21 moves toward the head side of the piston cylinder 8, the volume of the head cavity V2 decreases and the volume of the tail cavity V1 increases, and fluid is ejected from the nozzle 22.

[0030] In particular, the motion of the piston 21 relative to the piston cylinder 8 is realized by an electromagnetic drive device. The electromagnetic drive device mainly comprises a coil 5 and a magnet 20. As shown in Figure 2, the coil 5 is wound around the outer wall surface of the piston cylinder 8, preferably positioned between two flanges on the outer wall surface. The magnet 20, on the other hand, is fixed to the piston 21, so that the magnet 20 is housed together with the piston 21 in the cavity of the piston cylinder 8. When the electromagnetic drive device is energized and activated, an electromagnetic force is generated between the coil 5 and the magnet 20, causing the magnet 20 to move relative to the coil 5, and consequently the piston 21 to move relative to the piston cylinder 8.

[0031] Furthermore, an elastic element is placed between the piston cylinder 8 and the piston 21 to enable the reciprocating motion of the piston 21 relative to the piston cylinder 8. Because the elastic element is placed between the piston cylinder 8 and the piston 21, it can act as an elastic force on the piston 21 during its movement. The direction of this elastic force is generally parallel to the longitudinal direction in which the piston moves.

[0032] As shown in Figure 2, in a preferred embodiment of the present invention, the elastic elements are two coil springs 18 and 29, which will hereafter be referred to as the first spring 29 and the second spring 18, respectively.

[0033] The first spring 29 is provided inside the tail cavity V1, with one end of the first spring 29 in contact with the piston cylinder end cover 9, which is also the fixed end of the first spring 29, and the other end of the first spring 29 in contact with the tail end of the piston 21, that is, the end where the tail seal portion 210 is located. Specifically, the first spring 29 can contact the end cover portion 27 of the piston 21.

[0034] In the second cavity V2, which is close to the piston 21, the second spring 18 is fitted onto the smaller diameter segment of the piston 21. As shown in Figure 2, one end of the second spring 18 abuts against the stepped surface of the inner wall of the piston cylinder 8, and this end is also the fixed end of the second spring 18. The other end of the second spring 18 abuts against the stepped surface of the outer surface of the piston 21, and this end is the movable end of the second spring 18. Thus, within the first cavity V1, the first spring 29, provided between the piston 21 and the piston cylinder 8, provides an elastic force to the piston 21, while the second spring 18 is provided between the piston and the piston cylinder 8 at a position closer to the piston head than the first spring 29, and provides an elastic force. The directions of the elastic forces acting on the piston 21 by the first spring 29 and the second spring 18 are opposite.

[0035] During the reciprocating motion of the piston 21 relative to the piston cylinder 8, the first spring 29 and the second spring 18 are always in contact with the piston 21 and maintain a compressed state. For example, as shown in Figure 3, when the piston 21 moves to the position closest to the nozzle 1 and the head cavity V2 is at its smallest size, the second spring 18 is compressed to its maximum extent, and the first spring 29 is also compressed, but close to its relaxed state. Conversely, when the piston 21 moves to the position furthest from the nozzle 1 and the tail cavity V1 is at its smallest size, the first spring 29 is compressed to its maximum extent, and the second spring 18 is also compressed. According to this embodiment, by keeping the first spring 29 and the second spring 18 constantly compressed, noise caused by unnecessary collisions between the piston cylinder 8 and the piston 21 and the springs 18 and 29 can be eliminated.

[0036] Figure 3 shows a specific structure for fixing the magnet 20 inside the piston 21. Preferably, the piston 21 comprises a main body and an end cap 27 fitted to one end of the main body. The main body of the piston 21 has a blind hole that forms a cavity, which is sealed on the head cavity V2 side and open on the opposite side, the tail cavity V1 side. The end cap 27 is attached and fitted to the open side of the blind hole. The magnet 20 is installed into the cavity of the main body from the open side, and then the end cap 27 is fitted into the blind hole in a sealed manner, thereby sealing and holding the magnet 20 inside the cavity. Preferably, in order to seal the piston cavity and prevent liquid from entering and corroding the magnet 20, a magnet sealing material 30 is provided between the end cap 27 and the inner wall surface of the piston cavity, thereby achieving a sealed connection of the end cap 27 to the piston 21.

[0037] The magnet 20 and the cavity of the blind hole have a matching shape, preferably both being cylindrical. The magnet 20 may be a single magnet or multiple separable magnets 20.

[0038] To securely hold the magnet 20 in the cavity of the blind hole, the piston 21 is further provided with a piston bolt 19 for connecting the end cap 27 to the main body, as shown in Figure 2. The piston bolt 19 penetrates the bolt hole in the end cap 27 and extends to the screw hole inside the cavity of the blind hole. The magnet 20 is provided with a central hole, and the magnet 20 is fitted onto the piston bolt 19 through the central hole, thereby holding the magnet 20 between the end cap 27 and the bottom of the blind hole.

[0039] Furthermore, as shown in Figure 2, the piston 21 preferably further comprises an elastic retaining member 28. The elastic retaining member 28 is provided within the cavity of the piston 21 and is installed between the end cap 27 and the magnet 20, thereby holding the magnet 20 and preventing it from moving within the cavity of the piston 21. The elastic retaining member 28 is manufactured from an elastic material such as rubber.

[0040] As shown in Figure 4, in one preferred embodiment, 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 such that it flows into or out of the plane of the paper, as shown in Figure 4. That is, the current in the coil 5 flows around the magnet 20, and the direction of the magnetic field inside the coil 5 formed by the current in the coil 5 is parallel to the longitudinal direction of the magnet. The external magnetic field lines of the magnet 20 penetrate the coil 5.

[0041] When an alternating current of frequency f is passed through coil 5, the external magnetic field lines of magnet 20 cross the energized coil 5, generating a Lorentz force. Since coil 5 is fixed to the piston cylinder 8, and the piston cylinder 8 is stationary relative to the housing of the oral irrigator, coil 5 is constrained and held in a stationary state. A reaction force to the Lorentz force acts on magnet 20, making magnet 20 movable relative to the piston cylinder 8, and magnet 20 is driven by the force acting on it. In the state shown in Figure 4, magnet 20 receives an electromagnetic force to the left and moves to the left. Clearly, if the direction of the current in coil 5 in Figure 4 is reversed, the force acting on magnet 20 will also be reversed, magnet 20 will receive an electromagnetic force to the right and move to the right, thereby achieving reciprocating motion.

[0042] In another alternative embodiment, the magnet 20 in the piston 21 may be positioned such that the direction of its internal magnetic field lines (N', S') is parallel to the direction of the magnetic field lines generated inside the coil 5. In this case, the magnetic field lines of the magnet 20 do not cross the current in the coil. When an alternating current is passed through the coil 5, an alternating magnetic field is generated inside the coil 5, and the direction of the magnetic field lines of the magnetic field inside the coil 5 formed by the current in the coil 5 is roughly parallel to the direction of the magnetic field lines generated by the magnet. For example, in the state shown in Figure 4, the alternating current flowing through the coil 5 generates magnetic field lines from right to left inside the coil 5, while the direction of the magnetic field lines generated by the magnet 20 is from left to right. Therefore, the energizing coil 5 acts a leftward electromagnetic driving force on the magnet 20, driving the magnet to the left and further driving the piston to the left. If the current direction of coil 5 in Figure 4 is reversed, the current in coil 5 generates magnetic field lines from left to right inside coil 5, while the magnetic field lines generated by magnet 20 are from left to right. Therefore, the energized coil 5 acts a rightward electromagnetic driving force on magnet 20, driving magnet 20 to the right, and consequently driving piston 21 to the right.

[0043] The first spring 29, the second spring 18, the magnet 20, the piston bolt 19, the elastic retaining member 28, the main body, and the end cap 27 constitute a resonant body. In this embodiment, if the natural frequency of the resonant body is fg, the magnitude of the natural frequency fg is determined by the mass of the resonant body and the combined spring constants of the first spring 29 and the second spring 18. In engineering terms, if fg is within the range of 75% to 125% of the frequency f of the driving force, the resonant body is defined as being in a resonant state under the action of the driving force, and if fg is equal to the frequency f of the driving force, the resonant body is defined as being in a resonant state under the action of the driving force. The driving force is the acting or reacting force between the magnet 20 and the coil 5, and the frequency of the driving force depends on the frequency of the current in the coil 5, i.e., the frequency of the driving force is equivalent to the current frequency f of the coil 5. In this embodiment, the natural frequency fg of the resonant body is within the range of 75% to 125% of the current frequency f of the coil, and the resonant body resonates under the action of the driving force. Preferably, the natural frequency fg of the resonator is within the range of 90% to 110% of the coil current frequency f, and the resonator resonates under the action of a driving force.

[0044] Since the current frequency f of coil 5 is fixed, the motion frequency of piston 21 is also fixed, thereby achieving a fixed number of water pulses. This is more advantageous for gingival health and significantly improves the mechanical efficiency of the piston pump drive assembly in the resonant state.

[0045] When the magnet 20 is positioned inside the coil 5 as shown in Figure 2, it is advantageous to select the longitudinal lengths of the magnet 20 and the coil 5 such that the magnet 20 is always located inside the coil 5 during the motion cycle, in other words, the magnet 20 does not exceed the length range of the coil 5 in the longitudinal direction. For this reason, the longitudinal length of the coil 5 must be greater than the sum of the longitudinal length of the magnet 20 and the distance the magnet 20 moves in one direction relative to the coil 5.

[0046] The magnetic field strength inside coil 5 is proportional to the magnitude of the current in coil 5. When magnet 20 is always located inside coil 5, the magnitude of the electromagnetic force that magnet 20 receives from coil 5 is mainly influenced by the magnitude of the current in coil 5, and the influence of the positional relationship of magnet 20 inside coil 5 is small. As a result, when the resonator resonates due to the electromagnetic force of the current in coil 5, it is not affected by interference from the position of the magnet.

[0047] Next, the piping arrangement structure of the piston pump drive assembly will be described with reference to Figures 4 and 5. The cavity of the piston cylinder 8 comprises a head cavity V2 and a tail cavity V1. The suction port 23 of the head cavity V2 is connected to a water source, such as a liquid reservoir, via a suction pipe 2. Preferably, a suction pipe connector 6 is provided between the suction port 23 and the suction pipe 2, and preferably, a suction pipe seal material 32 is further provided, which seals the suction pipe connector 6 and the piston cylinder body. As shown in Figure 2, a suction pipe check valve 14 is provided between the suction port 23 and the suction pipe connector 6, so that the suction pipe check valve 14 allows fluid from outside the piston cylinder 8 to enter the head cavity V2, but does not allow fluid to flow out of the head cavity V2. A nozzle check valve 17 is also provided at the nozzle 22 of the head cavity V2. As shown in Figure 4, the injection port check valve 17 is provided between the head cavity V2 and the injection cavity V3, which is closer to the nozzle 1 downstream. The injection cavity V3 can be formed by a part of the piston cylinder 8, a part of the nozzle 1, or one end of a connecting part between the two, and the injection cavity V3 opens toward the nozzle 1. The injection port check valve 17 is configured to allow fluid in the head cavity V2 to enter the downstream injection cavity V3, but not to allow fluid in the injection cavity V3 to return to the head cavity V2.

[0048] Furthermore, as shown in Figure 4, the injection cavity V3 is further provided with an air inlet 24. The air inlet 24 is connected to the exhaust port 26 of the tail cavity V1 via an air supply pipe 4. The air inlet 24 and the air supply pipe 4 are connected by an air supply pipe connector 7, and an air supply pipe seal material 33 is provided to prevent fluid leakage. Similarly, an air supply pipe check valve 15 is provided between the air inlet 24 and the connector 17. The air supply pipe check valve 15 is positioned to allow fluid from the tail cavity V1 to enter the injection cavity V3, but to prevent fluid from flowing back out of the cavity V3 along the air supply pipe 4.

[0049] On the other hand, the tail cavity V1 is also provided with at least one port. Specifically, the tail cavity V1 is provided with two ports: an intake port 25 and an exhaust port 26. Preferably, both the intake port 25 and the exhaust port 26 are provided on the side wall of the piston cylinder body. However, it should be understood that in other alternative embodiments, the intake port 25 and / or the exhaust port 26 may be provided on the piston cylinder end cap 9.

[0050] As shown in Figure 4, the exhaust port 26 of the tail cavity V1 is connected to the aforementioned air supply pipe 4. The intake port 25 of the tail cavity V1 is connected to the intake pipe 3 via an intake pipe connecting component 12, and a sealing material 35 is also provided between the connecting component 12 and the piston cylinder 8 to ensure fluid sealing. The intake pipe 3 may communicate with the external environment of the oral irrigator or with the open space inside the oral irrigator. An intake pipe check valve 13 is provided at the connection point between the connecting component 12 and the intake port 25. The intake pipe check valve 13 is positioned to allow fluid from outside the piston cylinder 8 to enter the tail cavity V1, but to prevent fluid from flowing back out of the tail cavity V1.

[0051] As shown in Figure 5, when the piston pump drive assembly is activated, the reciprocating linear motion of the piston 21 changes the pressure in cavities V1 and V2. Under the influence of the pressure difference between atmospheric pressure and the pressure in cavity V2, liquid is drawn from the liquid reservoir into the head cavity V2 along path A in Figure 5. Furthermore, the pressing action of the piston 21 opens the nozzle check valve 17, causing the liquid to enter the injection cavity V3, then enter the nozzle 1, and finally eject from the nozzle 1 along path D. On the other hand, when the piston pump drive assembly is activated, the reciprocating linear motion of the piston changes the pressure in the tail cavity V1. Along path B, which includes the intake pipe 3, gas is drawn from outside the piston cylinder 8 into cavity V1 along the intake pipe 3. Furthermore, the pressing action of the piston causes the gas along path C to open the supply pipe check valve 15 via the supply pipe 4, causing it to enter the injection cavity V3, enter the nozzle 1, and finally eject from the nozzle 1. Thus, the fluid ejected from nozzle 1 becomes a mixture of gas and liquid. The gas here is usually an oxygen-containing gas, and by injecting this oxygen-containing gas deep into the gingival sulcus, anaerobic bacteria are effectively removed, helping to maintain gum health.

[0052] Figure 6 shows a schematic diagram of the fluid piping of a piston pump drive assembly according to another preferred embodiment. The difference from the embodiment shown in Figure 5 is that the tail cavity V1 does not communicate with the injection cavity V3, but has a communication port. This communication port communicates with the atmosphere via the air supply pipe 4' and may communicate directly with the outside of the irrigator housing, or with a space inside the irrigator housing that communicates with the atmosphere. Preferably, it is connected to a space inside the housing that is not affected by water. In this embodiment, there is no need to provide a check valve or flow limiting element in the communication path of the air supply pipe 4'.

[0053] When using a piston pump drive assembly having an air supply pipe 4' that communicates with the atmospheric environment, as the piston 21 moves, the liquid in the liquid reservoir enters the head cavity V2 from the suction pipe 2' along arrow E. At the same time, as shown by the bidirectional arrow F in Figure 6, the gas in the tail cavity V1 alternately enters and exits the tail cavity V1 as the piston 21 reciprocates. The air supply pipe 4' that communicates with the atmosphere has the effect of reducing the pressure fluctuation range in the tail cavity V1. If the liquid that should be held in the head cavity V2 leaks into the tail cavity V1 due to a poor seal between the piston and the piston cavity, at least a portion of the liquid in the tail cavity V1 will be discharged from the tail cavity V1 via the air supply pipe 4'.

[0054] Figure 7 shows a schematic diagram of the water and air channels of a piston pump drive assembly according to another preferred embodiment. In the arrangement of water and air channels shown in Figure 7, the tail cavity V1 does not have a port that communicates fluidly with the outside of the cavity. In this case, the tail cavity V1 forms a substantially isolated space. In this structure, when the piston 21 reciprocates relative to the piston cylinder 8, the pressure inside the tail cavity V1 changes significantly. However, since the piston cylinder end cover 9 can be fixed to the tail end of the piston cylinder 8 by end cover screws 10, and preferably a sealing material 31 is provided between the end cover 9 and the piston cylinder body, this structure can withstand large cavity pressures and maintain airtight isolation between the tail cavity V1 and the outside of the piston cylinder 8.

[0055] Figure 8 shows a cross-sectional view of a piston pump drive assembly according to a second preferred embodiment of the present invention. As shown in Figure 8, the arrangement of the piston cylinder 8', piston 21', and elastic elements in the piston pump drive assembly is similar to that of the piston pump drive assembly of the first embodiment, so a detailed explanation is omitted here.

[0056] In the embodiment shown in Figure 8, the electromagnetic drive device 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, the coil 5' is held between opposing flanges integrally formed on the outer wall surface of the piston cylinder 8' and spaced apart. The magnets 20'-1 and 20'-2 are provided in a cavity formed inside the piston 21', and these two magnets 20'-1 and 20'-2 are positioned at a predetermined distance apart and have like poles facing each other, with a magnetic conductor 20' provided between them.

[0057] In this context, "magnets" typically refer to permanent magnets containing nickel or cobalt, while "magnetic conductors" refer to permeable materials other than permanent magnets, such as annealed iron or steel.

[0058] The method of holding magnets 20'-1, 20'-2, and magnetic conductor 20' within the internal cavity of piston 21' is similar to the first preferred embodiment, where magnets 20'-1 and 20'-2 each have a central hole, the central holes of the two magnets are aligned, and the magnetic conductor 20' between magnets 20'-1 and 20'-2 also has a central hole, the piston bolt 19' passes through the central holes of these three components, and these three components are held in place by an end cap.

[0059] As can be seen from the longitudinal cross-sectional structure shown in Figure 8, in the longitudinal direction, the coil 5' is positioned approximately in the center between the two magnets 20'-1 and 20'-2. The longitudinal length of the coil 5' is preferably selected such that at least a portion of at least one of the magnets 20'-1, 20'-2 is outside the longitudinal occupancy range of the coil 5'. The magnets 20'-1 and 20'-2 preferably have the same shape and size, and the magnets and magnetic conductors 20' preferably have the same diameter.

[0060] When using the drive device of this preferred embodiment, when an alternating current of frequency f is passed through the coil 5', the direction of the current in the coil 5' becomes either inflow into the plane of the paper or outflow from the plane of the paper, as shown in Figure 8. Since the same poles of the two magnets 20'-1 and 20'-2 face each other, the magnetic field lines from the magnets 20'-1 and 20'-2 extend from their opposing ends, then change direction and extend radially, penetrating the energizing coil 5'. The magnetic field lines of the two magnets 20'-1 and 20'-2 cross the energizing coil 5', generating a Lorentz force. Since the coil 5' is constrained and held in a stationary state, a reaction force of the Lorentz force acts on the two magnets 20'-1 and 20'-2 at this time, driving them to reciprocate relative to the piston cylinder 8.

[0061] In an electromagnetic drive device having two opposing magnets 20'-1 and 20'-2, the magnetic resistance is reduced compared to the first preferred embodiment, resulting in a greater magnetic field strength at coil 5'. Also, because the length of coil 5' is shorter than the length of the magnetic conductor 20', magnetic field lines flowing out or into the circumferential direction of the magnetic conductor 20' pass through coil 5'. Since the magnetic field lines form a closed curve, in this embodiment, magnetic field lines in the opposite direction to those passing through coil 5' move away from coil 5'. Because the force acting on coil 5' by the magnetic field lines in the opposite direction is relatively small, the electromagnetic drive device of the second preferred embodiment can exhibit better driving efficiency.

[0062] Similar to the first preferred embodiment, two magnets 20'-1, 20'-2, a magnetic conductor, a piston including a piston bolt, an elastic retaining member, a main body, and an end cap, and springs at both ends constitute a resonator. If the natural frequency of the resonator is fg, then fg should be set within the range of 75% to 125% of the current frequency f of the coil 5'. Preferably, the natural frequency fg of the resonator is within the range of 90% to 110% of the current frequency f of the coil, thereby causing the resonator to resonate under the action of a driving force.

[0063] Figure 9 shows a cross-sectional view of a piston pump drive assembly according to a third preferred embodiment of the present invention. As shown in Figure 9, the arrangement of the piston cylinder 8”, piston 21”, and elastic elements in the piston pump drive assembly is similar to that of the piston pump drive assemblies of the first and second embodiments, so a detailed explanation is omitted here.

[0064] In particular, in the piston pump drive assembly of the third preferred embodiment, three coils, 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", with the first coil 5"-1 positioned between the second coil 5"-2 and the third coil 5"-3. An alternating current is applied to the first coil 5"-1, and a direct current is applied to the second coil 5"-2 and the third coil 5"-3. The second coil 5"-2 and the first coil 5"-1, and the third coil 5"-3 and the first coil 5"-1 can be separated by flanges integrally formed with the piston cylinder 8". Preferably, the longitudinal lengths of the second coil 5"-2 and the third coil 5"-3 are both 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.

[0065] In the third embodiment, instead of the magnet 20 of the first embodiment, a magnetic conductor 20" is attached to the piston 21". The magnetic conductor 20" may be a cylindrical, integral component. In other alternative embodiments, the magnetic conductor may be formed by connecting and combining multiple magnetic conductors 20" in series.

[0066] Preferably, the longitudinal length of the magnetic conductor 20" is greater than or equal to the sum of the longitudinal lengths of the first, second, and third coils.

[0067] As shown in Figure 9, a central hole is provided in the center of the magnetic conductor 20'', and this central hole is concentric with the outer cylindrical surface of the magnetic conductor 20''. The piston bolt 19'' passes through this central hole, thereby permanently housing the entire magnetic conductor 20'' within the cavity of the piston 21''.

[0068] During 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, when direct current is passed through the second coil 5"-2 and the third coil 5"-3, both ends of the magnetic conductor behave similarly to a permanent magnet, and the magnetic poles of the opposing end faces of the second coil 5"-2 and the third coil 5"-3 become identical due to the application of direct current. The magnetic field lines generated by these coils pass through the first coil 5"-1, which is located between them along the radial direction of the magnetic conductor, and interact with the magnetic field lines generated by the alternating current passed through the first coil 5"-1, resulting in a reciprocating force.

[0069] According to the drive assembly of the third embodiment, the magnet is replaced by a coil to which a DC current is applied, which can further reduce the overall cost of the assembly.

[0070] Similar to the first preferred embodiment, the magnetic conductor 20”, the piston 21”, including the piston bolt, elastic retaining member, main body, and end cap, and the springs at both ends constitute a resonant body. If the natural frequency of the resonant body is fg, then fg should be set within the range of 75% to 125% of the AC current frequency f of the first coil 5”-1. Preferably, the natural frequency fg of the resonant body is within the range of 90% to 110% of the coil current frequency f, thereby causing the resonant body to resonate under the action of the driving force.

[0071] Other variations of the preferred embodiments described above are also possible. For example, only one spring may be provided as the elastic element of the piston pump drive assembly. Specifically, only a spring 18 fitted onto the piston may be provided. Alternatively, for example, the piston cylinder 8 may have only a head cavity, and the piston 21 may have only one seal portion having a circumferential sealing surface. The tail end of the piston cylinder 8 may be left open without forming a cavity.

[0072] Furthermore, the specific location and structure of the check valves installed in each pipeline can be changed according to the pipeline connection structure and extension direction.

[0073] While the present invention has been disclosed in preferred embodiments as described above, it is not limited thereto, and those skilled in the art can make possible changes and modifications without departing from the spirit and scope of the invention. Accordingly, any modifications, equivalent changes and modifications made to the above embodiments based on the technical substance of the invention, without departing from the technical concept of the invention, fall within the scope of protection set forth in the claims of the invention. [Explanation of Symbols]

[0074] 1 nozzle 2 liquid suction tubes 3 Intake pipes 4. Airway 5 coils 6. Water intake pipe connection parts 7. Air supply tube connection parts 8,8',8" piston cylinder 9 Piston Cylinder End Covers 10-end cap screws 11 Nozzle connection parts 12 Intake pipe connection parts 13. Intake manifold check valve 14. Water intake pipe check valve 15. Air supply duct check valve 16 Nozzle Seal Material 17 Spray nozzle check valve 18. Second spring 19,19',19" piston bolt 20 magnets 20'-1, 20'-2 magnets 20', 20" magnetic conductor 21,21',21" pistons 22 spouts 23 liquid suction port 24 air vents 25 Piston Cylinder Tail Section Intake 26-piston cylinder tail section exhaust port 27 end cover 28 Elastic retaining member 29. First spring 30 Magnetic Seal Materials 31 Piston Cylinder End Cap Seal Material 32. Water intake pipe sealant 33 Air supply tube sealing material 34 Nozzle Connection Port Sealing Material 35 Intake pipe sealant 210 tail seal section, 211 Head seal section V1 Tail Cavity V2 Head Cavity V3 Injection Cavity 2' water suction pipe 4' Air supply tube

Claims

1. A piston pump drive assembly used in cleaning and nursing equipment, A piston cylinder (8) with a cavity formed inside, The piston cylinder comprises a head seal portion (211) that moves in a sealed manner against the inner wall surface of the piston cylinder, and a piston (21) that is arranged within the cavity of the piston cylinder so as to be reciprocally movable in the longitudinal direction. In a piston pump drive assembly, the cavity comprises a variable-volume head cavity (V2) formed adjacent to the head seal portion, and the head cavity (V2) is provided with a liquid intake port (23) and a liquid injection port (22), The piston pump drive assembly further comprises an electromagnetic drive device and at least one elastic element, Among them, the electromagnetic drive device is At least one coil fixed to the piston cylinder, The system comprises at least one magnet or at least one magnetic conductor located within the cavity and fixedly attached to the piston, The piston pump drive assembly used in cleaning and nursing equipment is characterized in that the elastic element is positioned between the piston cylinder and the piston, thereby causing the elastic element to act as an elastic force on the piston during the piston's movement.

2. The electromagnetic drive device comprises at least one magnet and at least one magnetic conductor. The at least one magnet further comprises a first magnet and a second magnet, wherein the first magnet and the second magnet are spaced apart and have like poles facing each other. The piston pump drive assembly according to claim 1, characterized in that the at least one magnetic conductor is disposed between the first magnet and the second magnet.

3. The 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. An alternating current is applied to the first coil, and a direct current is applied to the second and third coils. The piston pump drive assembly according to claim 1, characterized in that the magnetic fields generated by the second coil and the third coil, respectively, by the applied DC current, have the same polarity at the end faces of the second coil and the third coil facing each other.

4. The piston (21) comprises a main body and an end cap (27), the main body having a blind hole that forms a cavity, the blind hole being sealed on the head cavity side and open on the opposite side, the magnet or magnetic conductor being mounted into the cavity from the open side. The piston pump drive assembly according to claim 1, characterized in that the end cover portion is fitted in a sealed manner into the blind hole so as to seal and hold the magnet or magnetic conductor within the cavity.

5. The piston pump drive assembly according to claim 4, wherein the piston further comprises a piston bolt for connecting the end cap portion to the main body portion, the magnet or magnetic conductor has a central hole, and the magnet or magnetic conductor is fitted onto the piston bolt through the central hole.

6. The piston pump drive assembly according to claim 4 or 5, wherein the piston further comprises an elastic retaining member (28), the elastic retaining member being located within the cavity of the piston and provided between the end cap and the magnet or magnetic conductor.

7. The piston further comprises a tail seal portion separated from the head seal portion, the piston cylinder comprises a piston cylinder body and a piston cylinder end cap, the piston cylinder end cap is sealed and fixed to the piston cylinder body, and the cavity further comprises a tail cavity (V1) adjacent to the tail seal portion and the piston cylinder end cap. The elastic element comprises a first coil spring (29) and a second coil spring (18), the first coil spring and the second coil spring each contact the piston and the piston cylinder, respectively, and the elastic forces acting on the piston by the first coil spring and the second coil spring are opposite to each other. Within this, the first coil spring (29) is provided in the tail cavity (V1), with one end of it in contact with the piston cylinder end cover. The piston pump drive assembly according to claim 1, characterized in that the second coil spring (18) is fitted onto the piston in close proximity to the head cavity (V2), with one end of the coil spring contacting a stepped surface on the inner wall of the piston cylinder and the other end contacting a stepped surface on the outer surface of the piston.

8. The piston pump drive assembly according to claim 7, characterized in that the first coil spring (29) and the second coil spring (18) are always in a compressed state during the process in which the piston reciprocates within the cavity of the piston cylinder.

9. The piston further comprises a tail seal portion (210) separated from the head seal portion, the tail seal portion moves in a sealed manner relative to the inner wall surface of the piston cylinder, and the cavity of the piston cylinder further comprises a tail cavity (V1) adjacent to the tail seal portion, and / or The piston pump drive assembly according to claim 1, characterized in that the tail cavity is provided with at least one communication port.

10. At least one communication port includes an intake port and an exhaust port, Within that, an intake check valve is installed in the intake port to control the one-way intake of the intake port. The piston pump drive assembly according to claim 8, characterized in that the exhaust port communicates with the injection cavity (V3) downstream of the injection nozzle (22), and the exhaust port is fitted with an exhaust check valve that controls the unidirectional exhaust of the exhaust port.

11. The piston pump drive assembly according to claim 1, characterized in that the at least one coil is wound around the outer wall surface of the piston cylinder, the electromagnetic drive device comprises only the at least one magnet, and the length of the coil in the longitudinal direction is greater than the sum of the length of the at least one magnet in the longitudinal direction and the distance traveled by the magnet in a single longitudinal stroke within the cavity.

12. The magnet is arranged such that its magnetic field lines extend in the radial direction perpendicular to the longitudinal direction, or The piston pump drive assembly according to claim 11, characterized in that the magnet is arranged such that its magnetic field lines are parallel to the direction of the magnetic field lines generated by the coil after an alternating current is passed through the coil.

13. An alternating current with frequency f is passed through at least one of the coils. The piston pump drive assembly according to claim 1, characterized in that the elastic element, the piston, and the at least one magnet or the at least one magnetic conductor constitute a resonant body that resonates under the action of current being passed through the coil, and the natural frequency fg of the resonant body is in the range of 75% to 125% of the current frequency f of the coil.

Images