JPS61227866A - Ultrasonic liquid atomizer - Google Patents

Abstract

PURPOSE:To prevent the cavitation due to vibration and the corrosion by liq. and to obtain the titled ultrasonic liq. atomizer having excellent durability by forming the front part of the front phone of the ultrasonic liq. atomizer with a ceramic material. CONSTITUTION:A piezoelectric vibrator is clamped by the front phone and the rear block in an ultrasonic liq. atomizer. A high-strength, high-elasticity and high-toughness ceramic material such as hot-pressed silicon carbide and hot-pressed zirconia having >=30kg/mm<2> tensile strength, >=10ton/mm<2> Young's modulus and >=4MN/m<3/2> fracture toughness is used in the atomization part 8 at the leading end of the front phone 1. Consequently, cavitation at the atomization part and corrosion accelerated by the cavitation can be controlled and a durable ultrasonic liq. atomizer can be obtained.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to an ultrasonic liquid atomizer with excellent durability.

(Prior art) As shown in Fig. 4, a conventional ultrasonic liquid atomizer is one in which a piezoelectric vibrator is sandwiched between metal blocks at the front and back and fixed with bolts, and has an atomizing surface at the tip. There is. In Fig. 4, 1 is a metal front horn, 2 is a rear block, and 3 is a metal front horn.
4 is a piezoelectric vibrator, 4 is an electrode plate, 5 is a screw K for fixing the piezoelectric vibrator 3 to the front horn, 6 is a flange that supports the atomizer, and 7 is a screw for the front horn and rear block. A liquid introduction path 8 passing through the central axis is an atomizing section. In the ultrasonic liquid atomizer having the configuration shown in FIG. 4, the electrode plate 4 becomes a node of vibration and the vibration speed becomes zero, and the atomization part 8 becomes a vibration antinode and the vibration speed becomes maximum. . The diameter of the front horn tip is smaller than the other parts,
As this effect.

The vibration speed of the atomizer increases.

(Problem to be solved by the invention) In the above case, the aluminum alloys and titanium alloys conventionally used for the horn cannot withstand the high vibration speed and acceleration that occur on the atomization surface, and are susceptible to cavitation and corrosion. . Furthermore, when water or the like is used as the liquid to be converted into a, corrosion becomes a particular problem.

In view of the above points, it is an object of the present invention to provide an ultrasonic liquid atomizer that prevents both cavitation caused by vibration and corrosion caused by liquid, and has a long life and is stable.

(Means for Solving the Problems) The present invention provides an ultrasonic liquid atomizer having a structure in which a piezoelectric vibrator is sandwiched between a front horn and a rear block, in which the front portion of the front horn is made of a ceramic material. Relating to a sonic liquid atomizer.

and are fastened together by a mechanical method such as screwing. Preferably, the front portion of the front horn using ceramic includes an atomizing section or an atomizing section and a vibration amplifying section.

The ceramic used in the present invention has a tensile strength of 3 at room temperature.
0 kg/mm" or more and Young's modulus 0 tOn/m
It is preferable to have high strength and high elasticity of 4 MN/m 2 or more, and even more preferable if it has high fracture toughness of 4 MN/m 2 or more. something like this) 7'
Vs silicon carbide, hot pressed zirconia, etc.

There are no particular limitations on how to attach the front horn to the ultrasonic liquid atomizer using a known method.

(Example) Examples will be described below.

Embodiment 1 FIGS. 1 and 2 are a half-sectional front view and a perspective view of an ultrasonic liquid atomizer according to an embodiment of the present invention.

In the figure, 1 has a tensile strength of 30 kg/
Circle 2. Young's modulus 4Qtor+7 mark 2 and fracture toughness 4MN
The front horn is made of a hot-pressed silicon carbide ceramic material with a diameter of 1.5 mm and is screwed to an aluminum front block 10.A PzT piezoelectric vibrator 3 sandwiching a copper electrode plate 4,
3 was sandwiched between a front horn 1 and a rear block 2 made of aluminum, and a steel bolt 5 was fixed to the front block 10 by screwing to obtain an ultrasonic liquid atomizer. Note that 7 is a liquid introduction passage passing through the central axis of the front horn 1 and the bolt 5, and 6 is a flange that supports the atomizer.

Example 2 In place of the hot-pressed silicon carbide in the atomization part 8 in Example 1, a tensile strength of 50 kg/mm2 was used. Young's modulus 30t
An ultrasonic liquid atomizer was created using a hot-pressed tetragonal zirconia ceramic material with on/nun2 and fracture toughness of 8 MN/m2.

Comparative Example An ultrasonic liquid atomizer having the same construction as in Example 1 was obtained, except that the front horn 1 shown in FIG. 4 was entirely made of aluminum. Said Example 1. The driving power of the ultrasonic liquid atomizers of Example 2 and Comparative Example was 10 W.

A life test was conducted under conditions of spraying water at a frequency of 50 KHz at a rate of 50 m/min. As shown in Table 1, the results show that the ultrasonic liquid atomizer of the example is more than 20 times that of the comparative example.

Table 1 Example 3 Figure 3 shows an example of the structure of an ultrasonic liquid atomizer in which the vibration amplifying part 9 and the atomizing part 8, each having an exponential curve on the outer periphery, and the atomizing part 8 are made of hot-pressed silicon carbide ceramic material. , the ceramic material is screwed to the front block 11 of an aluminum cylinder. The structure of other parts is the same as in the first embodiment.

(Effects of the Invention) According to the present invention, an ultrasonic liquid atomizer with a long life can be obtained because cavitation in the atomization section and the progress of corrosion due to cavitation are suppressed.

[Brief explanation of drawings]

1 and 2 are a sectional view and a perspective view of an ultrasonic liquid atomizer according to an embodiment of the present invention, and FIG. 3 is a sectional view of an ultrasonic liquid atomizer according to another embodiment of the present invention. . FIG. 4 is a sectional view of a conventional ultrasonic liquid atomizer. Explanation of symbols 1...Front horn 2...Rear block 3.
... Piezoelectric vibrator 4 ... Electrode plate 5 ... Bolt 6 ... Flange 7 ... Liquid introduction path
8...Atomization section 9...Vibration amplification section 10.
11...Front block 6-

Claims (1)

[Claims] 1. An ultrasonic liquid atomizer having a structure in which a piezoelectric vibrator is held between a front horn and a rear block, in which the front part of the front horn is made of a ceramic material.