JPS6318072B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an active damper using a piezoelectric element.The present invention relates to an active damper using a piezoelectric element.The present invention relates to an active damper that uses a piezoelectric element. The purpose of this invention is to provide a damper that can absorb and remove

Conventionally, a regulator 11 as shown in FIG. 4 has been used to deal with high frequency pressure fluctuations within a pipe. In the regulator, the pressure regulating spring 12
This has been countered by increasing the spring constant of the diaphragm 13 and increasing the natural frequency by increasing the rigidity of the diaphragm 13, but since the diaphragm is generally made of rubber, the strength of the spring is naturally limited. Furthermore, metallizing the diaphragm to increase rigidity also leads to higher costs. Since the spring constant of the spring and the rigidity of the diaphragm are thus limited, it has been impossible to follow high frequency pressure waves within the pipe, and it has been impossible to smooth the pressure inside the pipe.

In the present invention, the size and frequency of a pressure wave are detected by a piezoelectric element, and an appropriate calculation is performed to operate an actuator, which is another piezoelectric element, to arbitrarily control subsequent pressure waves. Yes, the damper effect can be maintained up to high frequencies,
It has the advantage that feedback control can be performed using electric and electronic circuits.

Next, the present invention will be specifically explained based on the drawings.

FIG. 1 shows a side view of the active damper of the present invention, in which a piezoelectric pressure sensor 2 is mounted on the wall of a highly rigid conduit 1, and an actuator 3 consisting of a piezoelectric diaphragm is located upstream of the pressure sensor. A calculation control circuit 4 is arranged between the pressure sensor 2 and the actuator 3. When the pressure wave traveling in the pipe line 1 reaches the sensor 2, it generates a pressure wave electrical signal as shown in FIG. 2, and enters the control circuit 4a from the input circuit 5. The control circuit 4a includes a function circuit 6, such as a delay circuit, and an amplifier circuit 7, and operates the actuator 3, which is a piezoelectric diaphragm, so as to smooth pressure fluctuations after detection.

When a pressure wave with a frequency F advances in the pipe 1, the pressure and frequency are detected by the sensor 2, and the pressure and frequency are detected by the input circuit 5, the function circuit 6, and the amplifier circuit 7. Waves are generated in the lateral direction of the pressure waves with a phase shift, and the actuator 3 is vibrated as if expanding the diameter of the pipe inner wall in accordance with the arrival and cycle of the pressure waves.This absorbs the energy of the pressure waves, and after detection. This is to smooth the pressure inside the pipe.

Fig. 3 is a side view of the case where it is used as a pressure damper, in which fluid is sent from a pressure generating device 8 such as a pump to a pressure tank 9 via a pipe 1, and a combustion device and other end devices handling various fluids are connected. When sending to a utilization system 10 such as the
is installed, detects the pressure waves advancing in the pressure tank 9, performs appropriate calculations using the calculation control circuit 4, transmits the calculation results to the actuator 3 as an electric signal, and adds new pressure to the fluid. This is to control the pressure waves inside the pipe after detection.

As described above, the present invention detects pressure waves of fluid flowing in a pipe with a sensor, performs appropriate calculations, and transmits the calculation results to an actuator using a piezoelectric diaphragm installed upstream of the sensor. By applying a lateral wave motion that expands the diameter of the tube wall each time a pressure wave arrives, it is possible to absorb the pressure wave in the tube after detection and smooth the pressure in the tube. Since the pressure sensor and actuator use piezoelectric elements, the damper effect can be sustained up to high frequencies, and they can be manufactured at low cost. Furthermore, there are advantages such as ease of feedback and control by using electric and electronic circuits.

[Brief explanation of the drawing]

FIG. 1 is a side view of the active damper of the present invention.
FIG. 2 is a block diagram of the control system, FIG. 3 is a side view of the device used, and FIG. 4 is a sectional view of a conventionally used regulator. DESCRIPTION OF SYMBOLS 1... Pipe line, 2... Pressure sensor, 3... Actuator, 4... Arithmetic control circuit, 5... Pressure signal input circuit,
6...Function circuit, 7...Amplification circuit.

Claims (1)

[Claims] 1. An actuator made of a piezoelectric diaphragm is attached to the inner wall of the conduit, and a pressure sensor for detecting the magnitude and frequency of pressure waves is installed downstream of the actuator and spaced apart from the actuator. a pressure signal input circuit that is installed with an opening and inputs a pressure signal detected by the pressure sensor;
An arithmetic control circuit is provided, which includes a function circuit that performs an arithmetic operation using an input signal from the pressure signal input circuit and generates an output signal that has the same frequency and a different phase as the input signal, and an amplifier circuit that amplifies the output signal. , an active device using a piezoelectric element, characterized in that the actuator is configured to vibrate so as to expand the diameter of the inner wall of the pipe at the same period as the arriving pressure wave after the detected pressure wave by the output of the arithmetic control circuit. damper. 2. An active damper using a piezoelectric element according to claim 1, wherein the pressure sensor is a piezoelectric element.