Nebulizer with negative pressure structure

A nebulizer with a negative pressure structure includes a nebulization body, a carrying cavity, a nebulizing element and a negative pressure generating element. The carrying cavity is provided for carrying a nebulized liquid and has a through hole. The nebulizing element is installed at the through hole and includes a piezoelectric driving unit and a nebulizing plate disposed on a side of the piezoelectric driving unit. The negative pressure generating element is formed on the carrying cavity and provided for changing the volume of the carrying cavity or removing air from the carrying cavity to reduce the air pressure in the carrying cavity, so as to nebulize a liquid of low surface tension or high viscosity effectively.

CROSS-REFERENCE TO RELATED APPLICATIONS

This non-provisional application claims priority under 35 U.S.C. §119(a) on Patent Application No(s). 100221854 filed in Taiwan, R.O.C. on Nov. 18, 2011, the entire contents of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to nebulizers, and more particularly to the nebulizer with a negative pressure structure.

2. Description of the Related Art

In general, a conventional nebulizer is comprised of a circular piezoelectric plate, a nebulizing plate, a fixing plate and a cavity. For the nebulization of a liquid having a general surface tension, if the total air and liquid pressure value in the cavity is greater than or equal to the external air pressure value (approximately equal to one 1 atmospheric pressure), the pressure at the inner side and the outer side of the nebulizing plate reaches an equilibrium, and a nebulized liquid stored in the cavity can be attached onto an inner side of the nebulizing plate, so that the nebulized liquid will not spill out from the spray hole, so as to achieve the effects of preventing the spray hole from being clogged easily and nebulizing the liquid effectively.

However, for a liquid having a low surface tension, the surface tension cannot be maintained stably due to the too-low surface tension, so that the liquid will not spill from the inner side to the outer side of the spray hole of the nebulizing plate. If the nebulizing liquid has a spilling speed greater than the nebulization speed, the liquid will spill continuously from the spray hole of the nebulizing plate to cover the surface of the nebulizing plate and result in clogging the spray hole and failing to nebulize the liquid effectively.

If the air pressure in the cavity has a positive pressure value, and the nebulized liquid is attached onto the spray hole of the nebulizing plate, and the external air pressure is smaller than the air pressure and liquid pressure in the cavity, then the nebulized liquid in the cavity will spill out from the spray hole of the nebulizing plate to achieve a pressure equilibrium state. As to the liquid with a low viscosity or a general viscosity, the small molecular weight and coherence force between molecules can be separated during the process of passing droplets of the liquid through the spray hole of the nebulizing plate spray hole, so as to achieve an effective nebulization.

However, as to a liquid of a high viscosity, the liquid has a greater molecular weight and Van der Waals' forces between molecules, the adherence force between molecules drives the liquid to spill out from the spray hole of the nebulizing plate, when the molecules of the liquid pass through the spray hole of the nebulizing plate for anebulization. As a result, the spray hole is covered by the liquid and fails to nebulize the liquid effectively. If a negative pressure state can be maintained in the cavity, the nebulized liquid is attached onto the spray hole of the nebulizing plate, and the external air pressure is greater than the pressure in the cavity, then the external air will move from the hole of the nebulizing plate into the cavity for a pressure equilibrium to reduce the spilling and facilitate the nebulized liquid and the external air to be exchanged by vibrations of the nebulizing plate and nebulize the liquid effectively.

SUMMARY OF THE INVENTION

To achieve the aforementioned objective, the present invention provides a nebulizer with a negative pressure structure comprising a nebulization body, a carrying cavity, a nebulizing element and a negative pressure generating element. The carrying cavity is provided for carrying a nebulized liquid and has a through hole. The nebulizing element is installed at the through hole and includes a piezoelectric driving unit and a nebulizing plate disposed on a side of the piezoelectric driving unit. The negative pressure generating element is formed on the carrying cavity and provided for changing the volume of the carrying cavity or removing air from the carrying cavity to reduce the air pressure in the carrying cavity.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The technical contents of the present invention will become apparent with the detailed description of preferred embodiments and the illustration of related drawings as follows.

With reference toFIGS. 1 to 3for an exploded view of a nebulizer and first and second schematic views of the nebulizer that produces a negative pressure in accordance with the first preferred embodiment of the present invention respectively, the nebulizer1comprises a nebulization body11, a carrying cavity12, a nebulizing element13, a negative pressure generating element14, a slide element15, a printed circuit board16, a battery holder17and a spray hole cover18.

The nebulization body11is made of plastic or metal. In this preferred embodiment, the nebulization body11is substantially in a cylindrical shape and provided for containing the slide element15, the printed circuit board16and the battery holder17. The printed circuit board16is electrically coupled to the nebulizing element13and has a magnetic switch161, and the battery holder17is provided for installing a battery to supply electric power required by the nebulizer1. The spray hole cover18is provided for covering a through hole1211of the carrying cavity, and the through hole1211is provided for installing the nebulizing element13. In addition, the nebulization body11has a slide rail111disposed on an outer wall of the nebulization body11for installing the slide element15thereon. The slide element15has a magnet151used for changing the relative position of the magnetic switch161to turn on or off the nebulizer1.

The carrying cavity12is disposed in the nebulization body11and extended upwardly, and the carrying cavity12is comprised of an inner cup body121and an outer cup body122, and the inner cup body121is provided for carrying a nebulized liquid9. The inner cup body121has a containing space formed therein for carrying a nebulized liquid9.

The nebulizing element13is comprised of a piezoelectric driving unit131, a nebulizing plate132and a structure plate (not shown in the figure). The piezoelectric driving unit131can be a piezoelectric driving unit of any type such as a piezoelectric ceramic device, and the structure plate can be used for driving the piezoelectric driving unit131to stably oscillate the nebulizing plate132and facilitate the nebulization process, and the nebulizing plate132is clamped between the piezoelectric driving unit131and the structure plate.

The slide element15is provided for sliding to an ON position or an OFF position on the nebulization body11to turn on or off the nebulizer1respectively.

The negative pressure generating element14is comprised of an inner cup body121and an outer cup body122. The outer cup body122is comprised of a spring141, a one-way exhaust valve142, an air-hole plate143and a pressing portion144. The pressing portion144is disposed at a position of an upper section of the outer cup body122, and the one-way exhaust valve142is installed in the pressing portion144, and the air-hole plate143is installed at a position of a middle section in the outer cup body122. The spring141is installed in the outer cup body122of the carrying cavity12, wherein an end of the spring141abuts the pressing portion144, and the other end of the spring141abuts the air-hole plate143. The external peripheries of the pressing portion144, the one-way exhaust valve142and the one-way exhaust valve142have a O-ring (not shown in the figure) separately, and a sealed space is formed by a contact portion between the inner cup body121and the outer cup body122, and another sealed space is formed by a contact portion between the outer cup body122and the pressing portion144.

In addition, the one-way exhaust valve142can be added and installed on the air-hole plate143, such that a user can press the pressing portion144to decrease the volume occupied by the spring141and push the air occupied in the volume of the spring141out from the one-way exhaust valve142of the pressing portion. The pressing portion144resumes its initial position by the spring141, so that the pressure in the volume occupied by the spring141is reduced to drive and open the one-way exhaust valve142of the air-hole plate143and discharge the air from the inner cup body121to the volume occupied by the spring141. When the pressing portion144is pressed continuously, the air is discharged from the inner cup body121to produce a negative pressure state of the air, so that the one-way exhaust valve142can be added and installed onto the air-hole plate143to prevent the pressing portion144from being pressed repeatedly that may cause an incomplete seal between the outer cup body122and the pressing portion144and also prevent the incomplete seal that may keep the external pressure in the inner cup body121in equilibrium and maintain the in the negative pressure state in the inner cup body121.

Wherein, the outer cup body122has a tenon1221formed at the top of the outer cup body122and provided for latching the inner cup body121, so that the pressing portion144will not fall out from the outer cup body122due to the upwardly exerted resilience force of the spring141.

In addition, an embedding slot1222is formed on an inner side of the outer cup body122, and a protrusion is formed on an outer side of the inner cup body121, and the outer cup body122is sheathed on the inner cup body121, and the protrusion is latched to an end of the embedding slot, so that the outer cup body122is fixed on the inner cup body121. When a user presses the pressing portion144, the spring141is compressed and deformed, and the pressing portion144is moved in a direction towards the inner cup body121. Now, the volume of the carrying cavity12is increased and the air in the carrying cavity12is compressed to increase the pressure in the carrying cavity12and discharged from the one-way exhaust valve142

When the use releases the pressing portion144, the spring resumes its original position to drive the pressing portion144to move in a direction away from the outer cup body122and return the pressing portion144to its original position. Now, the volume of the carrying cavity12is equal to the volume before the inner cup body121is pressed, but some air has been discharged from the one-way exhaust valve142and decreased. In addition, air is allow to enter but not to exit, due to the characteristic of the one-way exhaust valve142, so that the value of the pressure in the carrying cavity12is smaller than the atmospheric pressure and in a negative pressure state.

Since the carrying cavity12is situated in a negative pressure state, therefore when the nebulized liquid in the carrying cavity12is a nebulized liquid (with a viscosity of approximately 1.5˜20 cp which is greater than that of water) with a low surface tension (such as 55 dyne/cm), the air-liquid exchange produces droplets by vibrations based on the principle of nebulization, and the nebulized liquid and external air can achieve the exchange more effectively by the nebulizing plate in the negative pressure state, so as to provide a more effective nebulization.

With reference toFIGS. 4 and 5for the second preferred embodiment of the present invention, the difference between this preferred embodiment and the previous preferred embodiment resides on the structure of the carrying cavity22and the negative pressure generating element24only, and the structure and functions of other elements are the same as those of the first preferred embodiment and thus will not be repeated. InFIGS. 4 and 5, the negative pressure generating element24is an elastic plug covered onto a side of the carrying cavity22and the elastic plug has a one-way exhaust valve241and a latch portion242, and a tenon221is formed at an end of the carrying cavity22and corresponding to the latch portion242, and the one-way exhaust valve241is formed at an end of the elastic plug.

When the elastic plug is plugged into the carrying cavity22, both sides of the elastic plug are compressed and the elastic plug is deformed to retract the latch portion242and plug the elastic plug into an inner side of the tenon221. Now, the air originally situated in the carrying cavity22is pushed out from the one-way exhaust valve241by elastic plug. When the elastic plug is released, the elastic plug is no longer compressed and it returns to its original form. Now, the latch portion242is latched to an inner side of the tenon221to close the carrying cavity22and avoid air leakage. Some air is discharged from the one-way exhaust valve241while plugging the elastic plug, and the volume of the carrying cavity22substantially remains the same before and after the elastic plug is plugged, so that the pressure in the carrying cavity22is smaller than the atmospheric pressure and becomes a negative pressure state which facilitate the nebulized liquid and external air to have an exchange by the nebulizing plate for an effective nebulization.

With reference toFIGS. 6 and 7for the third preferred embodiment of the present invention, the difference between this preferred embodiment and the previous preferred embodiments resides on the structure of the carrying cavity32and the negative pressure generating element34only, and the structure and functions of other elements are the same as those of the previous preferred embodiments and thus will not be repeated.

InFIGS. 6 and 7, the carrying cavity is comprised of an inner cup body321and an outer cup body322, and the negative pressure generating element34is comprised of an embedding slot341, a protrusion342and a one-way exhaust valve343, and the embedding slot341is a curve groove formed on the inner cup body321, and the protrusion342is disposed on an inner side of the outer cup body322and latched into the embedding slot341, and the outer cup body322is fixed onto the inner cup body321. However, the present invention is not limited to the arrangement of this preferred embodiment only, but the embedding slot341can also be formed on an outer side of the inner cup body321or an inner side of the outer cup body322, and the protrusion342can be disposed on an inner side of the outer cup body322or an outer side of the inner cup body321and opposite to the embedding slot341, and the protrusion342is latched into the corresponding embedding slot341. The one-way exhaust valve343is installed at the top of the outer cup body322.

When the outer cup body322is pulled in a direction away from the inner cup body321, the protrusion342is moved along the groove of the embedding slot341and latched to the bottom of the embedding slot341. Now, the volume of the carrying cavity32is increased, and the one-way exhaust valve343has the features of allowing air to exit only but not enter, so that the number of air molecules in the carrying cavity32remains unchanged, and the carrying cavity32produces a negative pressure state to facilitate an exchange of the nebulized liquid and external air for a nebulization.

With reference toFIGS. 8 and 9for the fourth preferred embodiment of the present invention, the difference between this preferred embodiment and the previous preferred embodiments resides on the structure of the carrying cavity42and the negative pressure generating element44only, and the structure and functions of other elements are the same as those of the previous preferred embodiments and thus will not be repeated.

InFIGS. 8 and 9, the carrying cavity42is comprised of an inner cup body421and an outer cup body422, and the negative pressure generating element44is comprised of a telescopic body441, a one-way exhaust valve442, a latch groove443and a protrusion444, and the telescopic body441and the one-way exhaust valve442are disposed at the top of the outer cup body422, and the protrusion444is disposed on an inner side of the inner cup body421or an outer side of the outer cup body422, and the latch groove443is formed on an inner side of the outer cup body422or an outer side of the inner cup body421and opposite to the protrusion444, and the protrusion444is latched into the latch groove443. Wherein, the telescopic body441is made of plastic and has an elastic property when it is pulled and pushed.

When the telescopic body441is pulled in a direction away from the inner cup body421, the telescopic body441is propped open and expanded outwardly, so that the volume of carrying cavity42becomes bigger. Since the one-way exhaust valve442only allows the air to exit but not enter, therefore the number of molecules of the air in the carrying cavity42remains unchanged, and the pressure of the air in the carrying cavity42is smaller than the atmospheric pressure, so as to produce a negative pressure state and facilitate an exchange of the nebulized liquid and outside air by the nebulizing plate for a nebulization.

With reference toFIGS. 10 and 11for the fifth preferred embodiment of the present invention, the difference between this preferred embodiment and the previous preferred embodiments resides on the structure of the carrying cavity52and the negative pressure generating element54only, and the structure and functions of other elements are the same as those of the previous preferred embodiments and thus will not be repeated.

InFIGS. 10 and 11, the carrying cavity52is disposed in the nebulization body and extended upwardly, and the carrying cavity52is comprised of an inner cup body521and an outer cup body522, and the inner cup body521is provided for carrying a nebulized liquid9. The inner cup body521has a containing space formed therein for carrying the nebulized liquid9. The outer cup body522is fixed on an outer wall of the inner cup body521, and the negative pressure generating element54is comprised of a piston rod541, a one-way exhaust valve542, a tenon543and a latch portion544, and the piston rod541is installed at the top of the outer cup body525and slidably disposed on an inner wall of the outer cup body522, and the one-way exhaust valve542is installed on a side of the piston rod541, and the tenon543is disposed on a side of the outer cup body522, and the latch portion544is formed on a side of the piston rod541and corresponding to the tenon543of the outer cup body522to latch the piston rod541to the outer cup body522.

When the piston rod541is pressed, the volume of the carrying cavity52is decreased, and the piston rod541is moved downwardly to the top of the inner cup body521, so that some air is discharged from the one-way exhaust valve241. When the piston rod541is pulled upwardly to the tenon543, the volume of the carrying cavity52is increased. Since the one-way exhaust valve542can prevent external air from entering into the carrying cavity52, therefore the pressure of air in the carrying cavity52is smaller than the atmospheric pressure to produce a negative pressure state to facilitate an exchange of the nebulized liquid and external air by the nebulizing plate for a nebulization.

In summation of the description above, the nebulizer with a negative pressure structure installed in the nebulizer in accordance with the present invention can be used for expanding the volume of the carrying cavity or removing air from the carrying cavity to reduce the air pressure of the carrying cavity, so that the carrying cavity is situated in a negative pressure state to improve the effect of nebulizing a liquid of a low surface tension or a high viscosity.