JPH0628211Y2 - Ultrasonic atomizer - Google Patents

Description

[Detailed Description of the Invention] (Industrial field of application) The present invention is used for atomizing and scattering scattered water, such as in air conditioners and air conditioners. The present invention relates to an ultrasonic atomizer that sucks and atomizes a liquid such as water by directly utilizing water, and particularly relates to a sealing structure that prevents the liquid from entering the piezoelectric element portion.

(Prior Art) FIG. 4 is a sectional view showing a structure of a conventional ultrasonic atomizer. In FIG. 4, reference numeral 1 is a shaft having a through hole 2 provided in the axial direction, and an amplitude increasing horn portion 4 for an atomizing function is provided on the shaft 1. In some cases, the lower portion of the shaft 1 may be provided with an amplitude-increasing horn portion having a pump function and a disc-shaped portion at the lower end. Reference numerals 6 and 7 denote disc-shaped piezoelectric elements having a hole for inserting the shaft 1 in the center, 8 denotes electrodes provided between the piezoelectric elements 6 and 7,
Reference numerals 9 and 10 denote electrodes provided on the upper and lower surfaces of the piezoelectric elements 6 and 7, respectively. The piezoelectric elements 6 and 7 together with the electrodes 8 to 10 are screw grooves 11 and 12 formed on the outer periphery of the intermediate portion of the shaft 1. The upper and lower tightening nuts 13 and 14 screwed onto the washer 1
It is fixed by tightening via 5, 16. The electrode 8 is electrically insulated from the shaft 1, and the electrodes 9 and 10 are electrically connected via the washers 15 and 16, the nuts 13 and 14, and the shaft 1.

A curve Z1 in FIG. 5 is a diagram showing the relationship between the vibration frequency of this ultrasonic atomizer and the two-terminal impedance Z of the vibrator with respect to longitudinal vibration. The ultrasonic atomizer is determined by the length of the shaft 1 and the like. Has an inherent fundamental resonance frequency o. Therefore, by applying a high frequency voltage of the fundamental resonance frequency o between the electrode 8 between the piezoelectric elements 6 and 7 and the electrodes 9 and 10 having the same potential as the shaft 1, as shown in FIG. , Ultrasonic vibration is generated in the piezoelectric elements 6 and 7 in the upside-down direction, whereby the liquid 3 such as water is passed through the through hole 2 from the lower end of the through hole 2.
It is sucked in, atomized at the upper end of the through hole 2 and diffused into the atmosphere.

In such an ultrasonic atomizer, when water acts on the piezoelectric elements 6 and 7, the electrodes 8 to 10 and the like, compositional changes and corrosion of these elements may occur, resulting in deterioration of characteristics and failure. Further, since a short circuit may occur, a sealing structure that prevents water or the like from entering the piezoelectric element portion is adopted. Reference numerals 17 and 18 denote rubber covers for sealing the covers, and each of the covers 17 and 18 includes a tubular portion a through which the shaft 1 is inserted, and a flange portion b that overlaps the both covers 17 and 18. Both covers 17 and 18 are provided with the tightening nuts 13 and
14, the washer 15 and 16 and the piezoelectric elements 6 and 7 are surrounded by inserting the shaft 1 into the tubular portion a and overlapping the flange portions b with the rings 19 and 20 and the bolts 21 and the nut 22. It can be attached by tightening b. Electrodes 8, 10
The lead wire 23 connected to is clamped between the collars b and b and drawn out to the outside.

(Problems to be Solved by the Invention) According to the conventional sealing structure shown in FIG. 4, since the tubular portion a of the covers 17 and 18 is brought into contact with the shaft 1 only by the elasticity of the covers 17 and 18, the tubular portion is formed. When the liquid 3 easily infiltrates from between the a and the shaft 1 and the liquid 3 has conductivity like water, the piezoelectric elements 6 and 7 are short-circuited through the liquid 3 and the vibration stops and the liquid absorbing action is achieved. There was a problem that was stopped.

Further, in order to solve this problem, if the tubular portion a is tightened with a ring or the like and brought into close contact, the mechanical impedance characteristic with respect to the vibration frequency of this atomizer changes as shown by Z2 in FIG. There has been a problem that the target Q is remarkably lowered, the efficiency is lowered and the liquid absorbing ability is impaired.

The present invention has been made in view of the above problems, and an object thereof is to provide an ultrasonic atomizer having a sealing structure that can obtain a sufficient sealing effect and does not impair the liquid absorbing ability.

(Means for Solving the Problems) In order to achieve the above object, the present invention has a shaft having a liquid suction through hole formed in the axial direction, and a plurality of piezoelectric elements are provided in the middle of the shaft. Protecting the piezoelectric element part in an ultrasonic atomizer having a structure in which the piezoelectric element is clamped and fixed by upper and lower washer nuts that are attached and screwed into screw grooves provided on the outer circumference of the shaft. Between the lower surface of the inner peripheral portion of the upper split case and the upper surface of the upper washer, and between the upper surface of the inner peripheral portion of the lower split case and the lower surface of the lower washer,
By interposing an O-ring made of a material having elasticity between the mating surfaces of the upper and lower split cases, and connecting the upper and lower split cases to each other with a fixture,
It is characterized in that the respective O-rings are compressed between the respective parts to realize a sealing structure.

(Operation) The elasticity that is used between the washer and the split case and between the mating surfaces of the split cases by using the tightening force when the upper and lower split cases are aligned and joined together with the fixtures such as screws and nuts. The compression of the O-ring completely prevents the ingress of liquids such as water from these parts.

(Embodiment) FIG. 1 is a semi-longitudinal sectional view showing an embodiment of an ultrasonic atomizer according to the present invention, and the same reference numerals as those in FIG. 4 indicate the same parts.
Reference numerals 24 and 25 denote upper and lower split cases that protect the piezoelectric elements 6 and 7, and these are made of metal or hard molding resin.
Each of the divided cases 24 and 25 has a circular shape, has openings c and d larger than the tightening nuts 13 and 14 in the center, and has grooves e on the lower and upper surfaces of the inner peripheral portion near the openings c and d, respectively. , F are provided. In addition, each divided case 24, 2
The outer peripheral portion of 5 has collars g and h, and grooves i and j are provided on the mating surfaces of the collars g and h. These division cases 24,
The reference numeral 25 denotes O-rings 26 and 27 made of an elastic material such as rubber between the upper and lower washers 15 and 16 and the grooves e and f of the upper and lower divided cases 24 and 25, and the collars g and h. An O-ring 28 made of the same material as described above is also sandwiched between the grooves i and j, and the collars g and h are fastened and coupled by a plurality of screws 29 (or bolts) and a nut 30. As a result, the O-rings 26 to 28 are compressed and sandwiched between the respective parts. Lead wire 23 connected to electrodes 8 and 9
Is drawn out through the hole 31 provided in the upper split case 15, and the hole 31 and the lead wire 23 are sealed by a sealing material 32 such as silicon rubber.

As shown in FIG. 6, the amplitude is small in the middle part of the shaft 1 and becomes larger toward the ends, but according to the structure of FIG.
Washer 15 in the small amplitude area near the middle of
Since the split cases 24 and 25 are fixed to 16 and the split cases 24 and 25 are fixed via the O-rings 26 and 27 made of a material having elasticity, sealing against longitudinal vibration of the shaft 1 is achieved. The amount of vibration damping by the member becomes extremely small.
It has been confirmed by experiments that this vibration damping amount is small enough to be ignored.

Further, since the O-rings 26 to 28 are sandwiched between the respective parts in a compressed state, infiltration of liquid is completely prevented. In order to test the effect of preventing the infiltration of this liquid, put the atomizer in a closed container, and immerse the atomizer in the water in the closed container. In the conventional structure shown in FIG. 4, when the atmospheric pressure in the closed container reached about 400 Torr, water intruded into the covers 17 and 18, which were normal pressure, but
According to the structure of the present invention, it was confirmed that water does not enter the split cases 24 and 25, which are at normal pressure, until 10 minutes have passed at 38 Torr, and the sealing effect is remarkably improved.

2 (A) and 2 (B) are respectively a semi-longitudinal sectional view and an assembly work state view showing another embodiment of the present invention, in which a pressing ring 33 for the lead wire 23 is provided on the upper split case 24. The ring 33 is tightened and fixed together with the upper and lower split cases 24 and 25 by screws 29 and nuts 30. As shown in FIG. 2 (B), the upper surface of the collar g of the upper split case 24 and the ring 33 are fixed. A groove k into which the lead wire 23 is fitted is provided on the lower surface of the lead wire 23. To fix the lead wire 23, the seal material 32 is applied to the groove k in advance, and the lead wire 23 is passed through the hole 31 of the upper split case 24. Is fitted in the groove k, and the ring 33 is inserted as shown by the arrow Y in FIG. 2 (B).
The ring 33 is fixed to the upper split case 24 with the screw 29 and the nut 30 while sandwiching the upper surface of the lead wire 23 with the groove.

According to the structure of FIG. 2, the lead wire 23 can be fixed over a wide area, so that the lead wire 23 can be fixed for some reason.
Even if a pulling force is applied to the lead wire 23, the lead wire 23 does not separate from the upper split case 24 and does not come off, and there is no possibility that the lead wire 23 will be separated from the electrodes 8 and 9.

FIG. 3 further shows another embodiment of the present invention, in which a groove m is provided on the upper surface of the washer 15 for tightening the piezoelectric elements 6 and 7 over the entire circumference, and an O-ring 26 is fitted into the groove m to divide the upper part. The structure is such that the O-ring 26 is sandwiched between the groove e of the case 24, and when the divided cases 24 and 25 are combined, the upper O-ring 26 can be assembled with the groove m fitted therein. Therefore, it is easy to combine the upper and lower split cases 24 and 25, and the O-ring 26 is accurately set and fixed. Since it is also possible to combine the upper and lower split cases 24 and 25 in an inverted state, this groove m may be provided only on the lower washer 16 as shown by the chain double-dashed line. 16 may be provided.

Although two piezoelectric elements are provided in the above embodiment, four or more piezoelectric elements may be provided. The present invention can be applied not only to the case where the liquid to be sucked up and atomized is water, but also to the case of other liquids. It can also be used in the heated state of.

(Effect of the Invention) According to the present invention, an O-ring made of an elastic material such as rubber is interposed in a compressed state between the upper and lower washers for fastening the piezoelectric element and the upper and lower split cases, and the upper and lower split cases are provided. Since the space is also sealed by the O-ring, the sealing effect on the piezoelectric element portion is dramatically improved as compared with the conventional structure. Therefore, there is no possibility that the piezoelectric element short-circuits due to the intrusion of liquid such as water to stop the vibration.

Further, in the present invention, since the split case is fixed to the washer in the middle portion of the shaft, that is, the portion where the amplitude is small, and further, the split case is fixed through the O-ring made of the elastic material, The sealing member does not adversely affect the longitudinal vibration and the amplitude is hardly attenuated.

[Brief description of drawings]

FIG. 1 is a semi-longitudinal sectional view showing an embodiment of the ultrasonic atomizer according to the present invention, FIG. 2 (A) is a semi-longitudinal sectional view showing another embodiment of the present invention, and FIG. FIG. 3 is a side view showing an assembling work state, FIG. 3 is a semi-longitudinal sectional view showing another embodiment of the present invention, FIG. 4 is a semi-longitudinal sectional view showing a conventional ultrasonic atomizer, and FIG. FIG. 6 is a relationship diagram between the vibration frequency of the atomizer and the two-terminal impedance of the vibrator, and FIG. 6 is a relationship diagram between the position of the axis of the ultrasonic atomizer and the amplitude. 1: Shaft, 2: Through hole, 6, 7: Piezoelectric element, 8-10: Electrode, 11, 12: Thread groove, 13, 14: Tightening nut,
15, 16: Washer, 23: Lead wire, 24: Upper split case, 25: Lower split case, 26-28: O-ring,
29: Screw, 30: Nut, 31: Hole, 32: Sealing material, 33: Holding ring, c, d: Opening part, e, f,
i, j, k ,: Groove, g, h: Tsuba

Claims (1)

[Scope of utility model registration request] 1. A shaft having a liquid suction through hole formed in the axial direction thereof, wherein a plurality of piezoelectric elements are attached to an intermediate portion of the shaft.
In order to protect the piezoelectric element part in an ultrasonic atomizer having a structure in which the piezoelectric element is clamped and fixed through upper and lower washers by upper and lower tightening nuts screwed into a thread groove provided on the outer circumference of the shaft. Elasticity is provided between the lower surface of the inner case of the split case and the upper surface of the upper washer, between the upper surface of the inner case of the lower case and the lower surface of the lower washer, and between the mating surfaces of the upper and lower split cases. By interposing an O-ring made of a material having the above, and connecting the upper and lower divided cases to each other with a fixture, the O-rings are compressed between the respective parts to realize a sealing structure. An ultrasonic atomizer.