JPS60166061A - Spraying device - Google Patents

Abstract

PURPOSE:To guarantee the high dependability of the titled device with a simple constitution, and to manufacture the device with a simple assembling process by fixing or supporting mechanically the outer circumference of a vibrating body consisting of an electrical vibrator and a nozzle plate with a fixing means. CONSTITUTION:A body 16 having a pressurized chamber 15 to be filled with a liquid, a plate-shaped electrical vibrator 22 having an opening 19, and a nozzle plate 18 having a nozzle 17 are provided. Then the nozzle plate 18 and the vibrator 22 are attached to each other so that the nozzle 17 may face the pressurized chamber 15 to constitute a vibrating body, and a fixing means 23 is provided for fixing the vibrating body to the body 16 so that the nozzle 17 may face the pressurized chamber 15. The outer circumference of the vibrating body is mechanically fixed or supported by the fixing means 23. Consequently, the high dependability can be guaranteed with a simple constitution, and the device can be manufactured with a simple assembling process. In addition, since the variance of the positions where the vibrating body is fixed can be remarkably reduced, the variance of the performance in spraying is reduced. Moreover, a stable performance in spraying can be exhibited.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a spraying device for spraying and atomizing various liquids such as liquid fuels such as kerosene and light oil, water, chemicals, and recording inks. relates to a so-called piezoelectric spraying device in which a liquid in a pressurized chamber is vibrated by an electric vibrator such as a piezoelectric vibrator and is sprayed from a nozzle to atomize the liquid.

Conventional configurations and their problems Conventionally, spraying devices of this type have been mainly used in ink jetting devices of inkjet recording apparatuses, and various configurations have been proposed. However, in both of these methods, the ink chamber (ink chamber) filled with ink is deformed by the strain of the piezoelectric vibrator, and the pressure rises due to the volume change in the liquid chamber caused by this. The idea was to eject ink (liquid) from a nozzle installed on the other wall.

For this reason, a liquid containing a large amount of dissolved air has the disadvantage that bubbles may be generated due to cavitation and cannot be injected stably. In order to solve this drawback, a configuration as shown in FIG. 1 has been proposed. In FIG. 1, a spray device 1 includes an annular piezoelectric ceramic 2 and a nozzle 3.
The nozzle plate 4 and the piezoelectric ceramic 2 are bonded to each other by a contact layer 7, and the nozzle plate 4 and the body 6 are connected to each other by a contact layer 7. It is assembled by bonding with layer 8.The pressure chamber is connected to a tank 10 with a five-piece vibrator 9, and liquid is supplied to it. is installed as shown in the figure.

Electrodes (not shown) are provided on the bonding surface of the piezoelectric ceramic 2 and on the surface opposite thereto, and lead wires 12a
is marked with "Half H". An alternating current voltage shown in FIG. 2 is supplied between lead wires 12a and 12b. The piezoelectric ceramic 2 undergoes expansion and contraction strain in the radial direction (in the vertical direction in the figure) as indicated by the arrows in FIG. 1, depending on the polarity of this alternating voltage.

Since the piezoelectric ceramic 2 and the nozzle plate 4 are bonded to each other as described in M7J, this expansion/contraction strain is converted into a deflection of the nozzle plate 4 as shown by the broken line in the figure.

Therefore, the liquid in the pressurizing chamber 5 is greatly vibrated by the nozzle plate 4 around the vicinity of the nozzle 3, and as a result, droplets 13 are ejected from the nozzle 3 as shown in the figure.

At this time, since only the vicinity of the nozzle 3 is extremely vibrated, the liquid in the pressurizing chamber 5 is injected from the nozzle without generating cavitation bubbles. . Therefore, even a liquid containing melt air can be sprayed with sufficient stability.

In addition, in the case of a liquid containing a large amount of dissolved air, some cavitation bubbles will occur, but even in this case, by providing an exhaust port above the pressurizing chamber 5 (at the top of the figure), stable air bubbles can be generated. There are several ways to maintain the spray operation.

A volume of liquid corresponding to the injected liquid is naturally sucked up from the vibrator 9 and supplied to the pressurizing chamber 5. This is because the nozzle 3 has a small hole of 30 fi m to 1100 fi, and thus the surface tension of the liquid acts to prevent air from flowing into the pressurizing chamber 5 from the nozzle 3. As described above, the pump had a self-priming pump, and had a very compact and simple structure.

However, this conventional spraying device (d:) had the following drawbacks.

As described above, the flexural vibrating body composed of the piezoelectric ceramic 2 and the nozzle plate 4 generates vibrations as shown in FIG. That is, the piezoelectric ceramic 2 and the four nozzle plates shown in FIG. In the portion (r=r) bonded with the adhesive layer 8, the value is δ-0.

As is well known, the relationship between the amplitude δ and the stress σ is a contradictory one-force relationship, and the smaller the amplitude rlJδ, the larger the stress σ becomes. Therefore, it was inevitable that very strong stress would be concentrated on the adhesive layer 8, which is the fixing part of the vibrating body.

Therefore, it is important to stabilize the adhesive force and increase the reliability of the adhesive layer 8, which requires a very troublesome bonding process and requires an expensive adhesive plate.

Still, it is very difficult to bond the adhesive layer 8 as shown in the figure fbl, and for example, the fixed position (r2') tends to fluctuate as shown in the figure Jcl, and it is troublesome to manage all of this. In addition, there was a drawback that the spray performance varied, making it difficult to obtain any results.

Also, since it is necessary to form the adhesive layer 7 and the adhesive layer 8, the entire assembly process is a one-step process! It would be a shame if it was something complicated and complex.

OBJECTS OF THE INVENTION The present invention provides a spraying device that completely eliminates the major drawbacks of the prior art.

The first object is to provide a spraying device that can guarantee extremely high reliability with a simple flat configuration and that can simplify the assembly process.

Furthermore, the second objective is to provide a complete spraying device that can guarantee stable spraying operation with small variations in characteristics despite a simple assembly process.

Structure of the Invention In order to achieve the above object, the present invention has the structure described below.

That is, a plate-shaped vibrating body consisting of a plate-shaped electric vibrator having an opening and a nozzle plate is attached to a body having a pressurized chamber filled with liquid, and the vibrating body is vibrated in the pressurized chamber. In addition, the outer periphery of the vibrating body is mechanically fixed or supported by the mounting means to the body, and the outer periphery of the vibrating body where the stress concentration is greatest can be fixed with high precision despite the simple manufacturing process. Moreover, it can be fixed with high reliability.

Description of examples An embodiment of the present invention will be described below with reference to the drawings.

FIG. 4 is a sectional view of a spray device showing an embodiment of the present invention.

In FIG. 4, the spray device 14 has a body 16 having a cylindrical pressurizing chamber 15 with a diameter of 5 to 20 mm and a depth of 0.5 to 5 fi, a nozzle 17 with a diameter of 30 pm to 100 m,
It has a metal nozzle plate 18 with a thickness of 30/' m -100 fi m, a circular opening 19, a diameter of 5 to 20 m, a thickness of 0.5 to 2 m, and electrodes 20.21' i7 on both mJ. It is composed of a piezoelectric ceramic 22 and a fixing member (attachment means) 23.

The piezoelectric ceramic 22 connects the nozzle plate 1 with its electrode 21.
8 and is soldered to form an adhesive layer (solder layer) 24. Therefore, this piezoelectric ceramic 22 and the nozzle plate 18 form one disc-shaped vibrating body. This vibrating body is fixed by being sandwiched between the outer periphery 25 of the pressurizing chamber 15 and the fixing portion 26 of the fixing member 23, and is firmly tightened and fixed by screws 28, 29.

Therefore, the vibrating body is mechanically fixed and attached to the body 16 by the fixing member (attachment means) 23. FIG. 5 is a diagram modeling this state,
A vibrating body 30 consisting of a nozzle plate 18 and a piezoelectric ceramic 22
is fixed by the outer walls 31 and 32 to meet the peripheral fixation condition. Of course, this vibrating body 3
The fixed condition of 0 may be a condition called so-called peripheral support.

In FIG. 4, the spray device 14 having such a configuration is connected to a tank 34 by a pipe 33, and
5 is connected to a suction port 37 of a fan 36, and constitutes a liquid supply system to the pressurizing chamber 15.

That is, since negative pressure is generated at the suction port 37 by the operation of the fan 36, the liquid level A in the pipe 33 (same height as the liquid level B in the tank 34) is sucked up, and the liquid level in the pipe 35 is lowered. The balance becomes C, resulting in the state shown in the figure.

In this state, when an alternating current voltage as shown in FIG. 2 is supplied between the electrodes 20 and 21 of the piezoelectric ceramic 22, flexural vibration as shown by the broken line in the figure occurs due to the radial expansion and contraction strain of the piezoelectric ceramic 22. Droplets 38 are ejected from the nozzle 17.

At this time, the vibrating body consisting of the nozzle plate 18 and the piezoelectric ceramic 22 moves around the outer periphery of the pressurizing chamber 15 as described above.
5 and the fixing part 26 of the fixing member (attachment means) 23, there is no problem that the dispersion of the fixing position increases and the dispersion of the spray performance increases as in the conventional case. In addition, the entire outer periphery of the vibrating body, where the stress concentration is greatest, is mechanically fixed without relying on adhesive, so it is possible to guarantee extremely high reliability, and moreover, it is possible to achieve stable spray operation. can be done. Furthermore, the assembly process of the spray device 14 includes the nozzle plate 1
8 and the piezoelectric ceramic 22, no other bonding work is required, and the assembly can be easily assembled using screws 29 and 30, thereby significantly simplifying the assembly process.

Since the fixing member (attachment means) 23 and the body 16 are in contact with the electrodes 20, 21, respectively, in the embodiment of FIG. 4, at least one of them must be an insulator. By making the structure shown in ibl, the body 16 and the fixing member (attachment means)
23 can both be made of a conductive material such as metal.

FIGS. 6(a) and fbl are partial cross-sectional views showing other embodiments of the spray device, and the same reference numerals as in FIG. 4 indicate corresponding structures.

FIG. 6 +Ll indicates the fixing part 2 of the fixing member (attachment means) 23.
G is made of an insulating material, and with this structure, both the fixing member 23 and the body 16 can be made of a metal material.

1, the same figure fl)l is the electrode 20 of the piezoelectric ceramic 22.
As shown in the figure, the outer circumference of the body 16 and the fixing member 2 are made smaller than the outer circumference of the piezoelectric ceramic 22 so as not to contact the fixing part 26.
3 can be made of a metal material.

FIG. 7 shows another embodiment of the present invention, and the same reference numerals as in FIG. 4 indicate corresponding structures.

In the figure, a fixing member 23 (attachment means) is made of ceramic and is configured to wrap around a vibrating body made up of a piezoelectric ceramic 22 and a nozzle plate 18 as shown in the figure. In this case, the structure is such that the vibrating body is fixed to the fixing member 23 by the body 16 having the pressurizing chamber 15, but the vibrating body is connected to the outer periphery 25 of the pressurizing chamber 15 and It has a configuration in which it is mechanically fixed by the fixing part 26 of A variety of other embodiments for securing the device may be used.

Effects of the Invention As described above, according to the present invention, the outer periphery of the vibrating body consisting of the electric vibrator and the nozzle plate is attached to the machine α.
Since the spray device is fixed or supported on the j, it is possible to guarantee high reliability with an extremely simple configuration, and it can be manufactured with a simple assembly process. Since the variation in the position of fixing the body can be significantly reduced, it is possible to exhibit stable spray performance with little wobbling.Therefore, its value in industrial production is extremely large. It is something.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a conventional spraying device, Figure 2 is a drive voltage waveform diagram of the piezoelectric ceramic of the same device, Figure 3 + al is a distribution diagram of the amplitude S of the vibrating body of the same device, and fbl is the same device. +01 is a partially enlarged cross-sectional view of the same device for explaining the drawbacks of the same device, FIG. 4 is a cross-sectional view of a spraying device showing an embodiment of the present invention, and FIG. Modeled partial cross-sectional view, FIG. 6+al, (bl is a partial enlarged cross-sectional view showing another embodiment of the vibrating body fixing part of the same device, and FIG. 7 is a spray device showing still another embodiment of the present invention. It is a sectional view of 15... pressurization chamber, 16... body, 17...
・Nozzle, 1B... Nozzle plate, 19... Opening, 22
・Electrical vibrator, 23 ・Cat mounting means. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
Figure 3 (!l, Stomach Figure 5 6rA 16?5

Claims (1)

[Scope of Claims] (1) A body having a pressurized chamber filled with liquid, a plate-shaped electric vibrator having an opening, and a nozzle plate having a nozzle, the nozzle facing the opening. The nozzle plate and the electric vibrator are attached to each other to form a whole vibrating body, and a mounting means is provided for attaching the vibrating body to the ifft debody so that the nozzle faces the pressurizing chamber, A spray device in which the outer periphery of the vibrating body described in 11J is mechanically defined or supported by a mounting means. (21 electric pendulum and 10 nozzle plate are disk-shaped,
2. The spray device according to claim 1, comprising a disc-shaped vibrating body with a nozzle located in the center, and an outer periphery of the disc-shaped vibrating body being fixed or supported by mounting means. (3) The ring-shaped piezoelectric vibrator and the circular nozzle plate have approximately the same outer diameter, and are bonded to each other to form a disc-shaped vibrating body, and the disc-shaped vibrating body is mounted by mounting means provided with a circular fixing part. The spray device according to claim 2, wherein the outer periphery of the spray device is fixed to the body. (4) The vibrating body is attached to the body so as to face the pressurizing chamber described in 11a, and the outer circumferential shape of the vibrating body and the outer circumferential shape of the pressurizing chamber are made to substantially match, and the outer circumferential shape of the pressurizing chamber is The mounting means is configured to have a fixing part that follows the shape, and the fixing part and the outer periphery of the pressurizing chamber are (+t).
The spray device according to claim 1, wherein the outer periphery of the vibrating body J is fixed.