JPH0578680B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD This invention relates to a fluid drive device for conveying fluid such as gas or liquid. BACKGROUND ART Conventional fluid drive devices that transport gas or liquid using a reciprocating drive source require a suction valve 2 and a discharge valve 3, as shown in FIG. 6, resulting in a complicated structure. , it is difficult to provide cheap products. In addition, since it is based on a reciprocating drive source, the flow rate fluctuates greatly due to the suction stroke and discharge stroke, and in order to keep the flow constant, a smoothing device 6 such as a large-capacity storage tank is required. Flow control becomes difficult. Further, in a conventional device as shown in FIG. 7 which uses a rotating body such as an impeller as a driving source, it is easy to obtain a constant flow rate, but it is expensive because it uses an electric motor 8 and an impeller 7. Further, since the rotor of the electric motor 8 and the impeller 7 have rotational inertia, this type of fluid drive device also has poor responsiveness when changing the flow rate, making it difficult to control the flow rate. In addition, with the advancement of electronic technology, highly accurate control is possible using advanced control devices and special electric motors, but they are also more expensive, and conventional pumps and blowers have fixed structures. It is difficult to integrate into mechanical equipment. Problems to be Solved by the Invention As mentioned above, the conventional technology has problems such as complicated and expensive structure, large flow rate fluctuations, poor controllability, and fixed shape that makes installation difficult. There's a problem. The present invention has been made in view of the above problems, and
The object of the present invention is to provide a fluid drive device with a simple configuration using a diaphragm as a drive source, stable flow rate, and good controllability at a low cost. Means for Solving the Problems In order to solve the above problems, the present invention provides a diaphragm inside a hollow container to form a space with a volume V, and faces the space with a volume V and communicates with the outside. drive tubes having a cross-sectional area A and a length L are connected to each other, and a frequency adjustment function is provided to match the drive power frequency of the diaphragm to a frequency determined by the dimensional conditions of the space V and the drive tubes A and L. A type of Helmholtz resonance system is constructed by providing a driving power supply device having the following characteristics. Effects With the above configuration, the present invention generates a piston motion of the same fluid as the driven fluid inside the drive tube by vibrating the diaphragm in the hollow container at the resonance frequency of the system, so that the drive tube axis is aligned at the tip of the drive tube. It generates a fluid flow in the same direction, and although it uses a reciprocating diaphragm as the drive source, it does not require suction or discharge valves and has a constant flow rate from the tip of the drive pipe, with good controllability. Fluid flow can be obtained. Embodiment FIG. 1 is a cross-sectional view showing an embodiment of the present invention.
A drive pipe 12 having a cross-sectional area A and a length L is connected to the housing 10 and communicates with the outside. A diaphragm 13 is attached to the casing 10 via a spring 14 inside the casing 10.
The chamber is airtightly divided into two chambers by a spring 14, and a space 11 with a large volume V is formed on the drive tube side with the diaphragm as a boundary. The drive tube 12 and the space 11 form a Helmholtz resonator. Vibration plate 13
A coil 15 is fixed to and faces the permanent magnet 16 concentrically. A power supply device 17 has a frequency adjustment function and supplies power to the coil 15 with a voltage at a predetermined frequency. As mentioned above, the drive tube 13 (cross-sectional area: A, length:
L) forms a Helmholtz resonator with the space 11 (volume: V), and resonates at a frequency of ₀ Hz expressed by the following equation.

[C] Here, C is the sound velocity of the fluid, π is pi, and α is the correction coefficient. Next, the operation of this device will be explained. When the power supply device 17 supplies power to the coil 15 with a sinusoidal voltage with a frequency of ₀ determined by equation (1), the diaphragm 13 supported by the spring 14 and the coil 15 _move in the left and right direction in FIG. It vibrates at a frequency of and radiates pressure waves into the space 11. As mentioned above, the resonance frequency between the space 11 and the drive tube 12
Since the Helmholtz resonance system of f ₀ is constructed,
The fluid in the drive tube 12 vibrates as a columnar fluid 23 with an amplitude ab as if it were a rigid body, as shown by the dotted line in the figure. The vibrational movement of the columnar fluid 23 constitutes a second driving source. Resonance frequency with drive tube 18mm in diameter and 160mm in length
In the 135Hz example, ab was approximately 10mm. When the columnar fluid 23 moves to the right in the figure, from a to b, the drive tube 1
The fluid in part 2 ab is driven to the right. When the columnar fluid 23 reaches the position of the maximum amplitude b on the right side, the movement changes from b to a to the left. Columnar fluid 23
As it moves to the left, negative pressure is generated at the inlet of the drive tube 12, but the fluid driven rightward continues to flow rightward along the axis of the drive tube 12 due to inertia. As a result, the negative pressure generated at the end of the drive tube 12 has the following effects:
Fluid from the surrounding area flows in. As the columnar fluid 23 moves to the left, the surrounding fluid also continues to flow in. When the columnar fluid 23 reaches the position a of maximum amplitude on the left side, it changes its direction of motion to the right again. At this time, the fluid flowing in from the surroundings is driven to the right without flowing into the columnar fluid 23 portion, and flows as shown by curve A in the figure, and then becomes a flow B.
This situation can be observed using a stroboscope and smoke. At the stage where the fluid that has flowed into the drive tube AB section is driven to the right and becomes the flow B, it is assumed that part of the fluid near the periphery of the drive tube 12 flows to the right due to the viscous force of the flow B. It will be done. The flow state of this wake and the flow state immediately before the output of the drive tube 12 are difficult to observe and have not been fully elucidated. Thereafter, by repeating the same process, a continuous flow is formed in the right direction around the axis of the drive tube 12. When the flow velocity is measured at a position 5 cm downstream (to the right) of outlet b on the axis of the drive tube 12, the average flow velocity is
The flow velocity fluctuation is +0.08m/sec compared to 3.4m/sec,
It was confirmed that a rightward flow with a constant velocity and little pulsation was formed. This fluid drive device can form a flow within a few cycles after starting operation, and can obtain a highly responsive flow. In addition, while the reciprocating diaphragm 13 is used as the first drive source and the second drive source formed as the reciprocating movement of the columnar fluid 23 inside the drive tube 12 is used as the direct drive source, a smooth vibration absorber that absorbs pulsation is used. It is possible to obtain a flow at a stable flow rate without using any equipment or the like. Moreover, changing and controlling the flow rate and flow rate can be easily achieved by changing and controlling the voltage or frequency applied to the coil 15. Next, other embodiments of the present invention will be described. In FIG. 2, the wall portion of the space 11 in front of the coil 15 is made into a truncated conical wall 18. A diaphragm 13 is provided parallel to the bottom surface of the wall 18, and the drive tube is perpendicular to the top surface. 12 are connected. Other configurations and operations are the same as the embodiment shown in FIG. However, by forming the wall 18 into a truncated cone shape, the effect of improving work efficiency can be obtained. Figure 3 shows the spring 1 of the embodiment shown in Figure 1.
4. The drive source composed of the diaphragm 13, the coil 15, and the permanent magnet 16 is configured by bonding the piezoelectric element 22 to the diaphragm 21 as the drive source, allowing for a simpler structure. Other functions and effects are the same as those of the embodiment shown in FIG. In addition, the vibration system spring 14, diaphragm 13, and coil 1 of the drive source shown in the embodiments of FIGS.
5, or the combination of the piezoelectric element 22 and the diaphragm 21, the natural frequency of the vibration system is set to the resonance frequency of the Helmholtz resonator, which is composed of the space 11 and the drive tube 12, at ₀ Hz. By making them equal, a fluid drive device with a large capacity can be provided. FIG. 4a shows an embodiment in which a taper 19 is provided at the end of the drive tube 12, and FIG. However, with the configurations shown in FIGS. 4a and 4b, work efficiency can be improved. FIG. 5 is a diagram showing an embodiment in which a drive tube 23 having a rectangular cross section is installed, and a fluid flow having a rectangular cross section can be obtained. Other configurations, functions and effects are the same as those of the embodiment shown in FIG. Effects of the Invention The present invention uses a reciprocating drive source while
Generates a stable flow rate and flow rate with few pulsating components without the need for suction or discharge valves, and without using a flow smoothing device.The flow rate and flow rate can be changed or controlled by changing the power supply voltage or power frequency. It is possible to provide a fluid drive device that only needs to be controlled and has good responsiveness. Furthermore, according to the present invention, the fluid is driven without passing through the inside of the drive device, so it can be used as a fluid drive means in special devices such as etching devices without changing the temperature or cleanliness of the fluid. It is. In addition, as can be seen from the above explanation, the device is basically composed of a hollow container, branch pipes communicating with it, and vibrating branches, so it can be made into any shape according to the purpose of use, so it is different from the conventional blower. It is possible to provide a fluid drive device that is easier to use, has a simpler structure, and is less expensive than a pump.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a fluid drive device according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of a fluid drive device according to a second embodiment, and FIG. 3 is a cross-sectional view of a fluid drive device according to a third embodiment. FIGS. 4a and 4b are detailed cross-sectional views showing the ends of the drive tube of the device, FIG. 5 is a front view showing an embodiment in which the drive tube has a rectangular cross-sectional shape, and FIG. The figure is a cross-sectional view showing a conventional example using reciprocating motion as a driving source, and FIG. 7 is a cross-sectional view showing a conventional example using rotary motion as a driving source. 10... Housing, 11... Space, 12... Drive tube, 13... Vibration plate, 14... Spring, 15
... Coil, 16 ... Permanent magnet, 17 ... Power supply device, 21 ... Vibration plate, 22 ... Piezoelectric element.

Claims (1)

[Scope of Claims] 1. A diaphragm is airtightly provided inside a hollow container to form a space with a volume V, and a drive pipe having a cross-sectional area A and a length L is connected to the space facing the volume V and communicating with the outside. and the drive power frequency of the diaphragm,
A fluid drive device characterized by comprising a drive power supply device having a frequency adjustment function to match a frequency determined by the dimensional conditions of the space V and the drive tubes A and L. 2. The fluid drive device according to claim 1, wherein the natural frequency of the diaphragm is made to match the frequency determined by the dimensional conditions of the spatial volume V and the cross-sectional area A and length L of the drive tube. 3 The shape of the hollow container is made into a truncated cone shape, and
2. The fluid drive device according to claim 1, further comprising: a drive tube connected to the top of the truncated conical hollow container, and a diaphragm arranged parallel to the bottom of the truncated conical hollow container.