JPH04101082A - Piezoelectric plate for gas pump - Google Patents

Abstract

PURPOSE:To stabilize the vibration of a piezoelectric plate so as to improve the accuracy of a gas pump by supporting the outer peripheral parts of the vibrating part of a metal plate with piezoelectric elements stuck thereto, and providing vibration nodes between the vibrating part and the outer peripheral parts. CONSTITUTION:This piezoelectric plate 1 is formed by sticking piezoelectric elements 3, 3 to the top and back faces of a disc like metal plate 2, and provided with a through hole 4. The metal plate 2 is so formed that vibration nodes are generated between a vibrating part 12b and outer peripheral parts 2a clamped by a holder 13 by previously increasing the thickness of the outer peripheral parts 2a. The connections between the outer peripheral parts 2a and the vibrating part 2b thereby become the vibration nodes when the piezoelectric plate 1 is vibrated by the piezoelectric elements 3, 3. Accordingly, even if slight play is generated to the clamping accuracy of the outer peripheral parts 2a, only the vibrating part 2b can be vibrated without being influenced by this play.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a piezo plate used as a drive section of a gas pump.

[Conventional technology]

FIG. 7 shows an example of a conventional piezo plate 91, in which a disk-shaped electrode 9 is inserted from the front and back surfaces of a thin metal plate 92
The piezoelectric plate 91 has a piezoelectric element 93, 93 attached thereto, and a through hole 94 is provided at an appropriate position in the piezo plate 91. FIG. 8 shows an example of a gas pump 11 using the piezo plate 91, in which the piezo plate 91 is attached to the pump body 12 by holding the outer circumferential portion 91a in a ring shape with a holder 13 having a cylindrical shape. The inside of this outer circumferential portion 91a serves as a vibrating portion 91b. The pump main body 12 is provided with a jet hole 12 a facing the through hole 94 , and the pump chamber 14 formed by the holder 3 is depressurized and exhausted by the vibration of the vibrating portion 91 b of the piezo plate 91 . Gas flowing in a fixed direction is discharged from the jet hole 12a.

[Problem to be solved by the invention]

However, the piezo plate 9 of the conventional configuration described above
In No. 1, it is extremely difficult to clamp the outer circumferential portion 91a with the holder 13 with uniform pressure, and for example, a portion of the outer circumferential portion 91a is lifted, causing a plurality of resonance frequencies in the piezo plate 91, and vibrations occur. This causes the problem that the discharge amount from the jet hole 12a fluctuates and the accuracy of the gas pump 11 decreases, and it is an issue to solve this problem. It had become.

[Means to solve the problem]

As a specific means for solving the above problems, the present invention provides a piezo plate for a gas pump that supports the outer peripheral part of a vibrating part of a metal plate to which a piezoelectric element is attached. By providing a piezo plate for a gas pump characterized in that a vibration node is provided between the piezo plate, the vibration of the piezo plate can be stabilized, and the above-described conventional problems can be solved. It is.

【Example】

Next, the present invention will be explained in detail based on an embodiment shown in the drawings. In order to facilitate understanding, parts that are the same as those in the conventional example will be described with the same reference numerals, and descriptions of some overlapping parts will be omitted. 1 is a piezo plate according to the present invention, and this piezo plate 1 is formed by pasting piezoelectric elements 3.3 on the front and back surfaces of a disk-shaped metal plate 2, and has through holes 4. The metal plate 2 is similar to the conventional example in that it is provided with a It is formed in such a way that there are knots. FIG. 2 shows a gas pump 11 formed using the piezo plate 1 described above.Similar to the conventional example, the piezo plate 1 is sandwiched between a pump body 12 and a holder 13; Sometimes, it is clamped by a pre-formed thick outer peripheral part 2a. In addition, what is indicated by the reference numeral 15 in the figure is a packing made of silicone rubber, for example, and this packing 15 is attached to the pump chamber 14 formed by the pump body 12 and the holder 13.
This increases the confidentiality of information. FIG. 3 shows the function and effect of the piezo plate 1 configured as described above. By forming the thick outer peripheral part 2a and the thinner vibrating part 2b in the piezo plate 1, the piezoelectric elements 3.3 When piezo plate 1 is vibrated by Only the vibrating part 2b vibrates without being influenced by this, and therefore, there is no generation of multiple resonance frequencies, and very stable vibration is obtained, which has the effect of stabilizing the discharge amount from the jet hole 12a. (See FIG. 2) This increases the accuracy of the gas pump 11. What is shown in FIG. 4 is a second embodiment of the present invention, and in the previous embodiment, the thicknesses of the outer circumferential portion 2a of the metal plate 2 and the vibrating portion 2b are changed from both sides of the metal plate 2. On the other hand, as in this embodiment, the process was carried out from one side of the metal plate 21. Moreover, what is shown in FIG. 5 is also a second embodiment of the present invention, and in both of the previous embodiments, vibration nodes are reduced by providing a difference in plate thickness between the outer peripheral portion 2a121a and the vibrating portions 2b and 21b. However, in this embodiment, the metal plate 22 has a uniform thickness, and a ring-shaped groove 22 ON 22 c is formed from the front and back surfaces between the outer peripheral part 22a and the vibrating part 22b. By doing so, the above-mentioned vibration nodes are generated. FIG. 6 also shows a fourth embodiment of the present invention, and while in the previous embodiment the grooves 22CN22C were formed from the front and back surfaces of the metal plate 22, the grooves 22c were formed from the - side surface. This is what I did. In short, in any embodiment, the outer peripheral portion 21 a% 22a
The gist is to form a vibration node between the vibrating parts 21b and 22b, and the method does not matter, and the effect is not different from that of the first embodiment described above, so these individual details will not be discussed. Explanation will be omitted. It should be noted that the present invention is not limited to the above-mentioned embodiments, and can be implemented, for example, in a bellows-type device as shown in FIG. 7 or a pan-shave-type device as shown in FIG.

【Effect of the invention】

As explained above, according to the present invention, by providing a piezo plate with vibration nodes between the vibrating part and the outer circumferential part,
The vibrating part vibrates around this vibration node as a boundary, and is not affected by the condition of the outer circumferential part, such as uneven clamping force, floating, etc., and the discharge amount of the gas pump is made uniform. This has an extremely excellent effect of improving the precision of this type of gas pump used for purposes such as measurement.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing a first embodiment of a piezo plate for a gas pump according to the present invention, FIG. 2 is a cross-sectional view showing a state in which the piezo plate of the same embodiment is attached to a gas pump, and FIG. FIG. 4 is a cross-sectional view showing the main part of the second embodiment of the present invention, FIG. 5 is a cross-sectional view showing the third embodiment of the present invention, and FIG. FIG. 7 is a sectional view showing a fourth embodiment of the invention; FIG. 7 is a sectional view showing an example in which the invention is implemented in a bellows type; FIG. FIG. 9 is a sectional view showing a conventional piezo plate for a gas pump, and FIG. 10 is a sectional view showing a state in which the conventional piezo plate is attached to a gas pump. i ----------Piezo plate 2.21.22-----Metal plate 2 a N 2
1 a 12-2 a-----One outer peripheral part 2 b1
21 b, 22 b --- Vibrating part 22 c
------One groove 3---One piezoelectric element 4---One through hole 11---One gas bomb 12--------- -Pump body 12a------Jet hole 13------
---Holder 14---------Pump chamber 15------Packing Figure 1 Figure 2

Claims (3)

[Claims] (1) In a piezo plate for a gas pump that supports the outer periphery of a vibrating part of a metal plate to which a piezoelectric element is attached, a vibration node is provided between the vibrating part and the outer periphery. A piezo plate for gas pumps featuring: (2) The piezo plate for a gas pump according to claim (1), wherein the vibration nodes are formed by increasing the thickness of the outer circumferential portion than the thickness of the vibrating portion. (3) The vibration node is formed by a ring-shaped groove formed from at least one surface between the outer circumferential portion and the vibrating portion.
) Piezo plate for gas pumps described in section 2.