JPS6237241B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to pressure generators that generate pneumatic output signals in response to electrical input signals.

(Prior Art) FIG. 3 is a diagram illustrating the configuration of a conventional example that has been commonly used.

In the figure, 1a is an input electric signal, 2a is a current-displacement converter, and 3a is a balance lever whose midway is supported by a fulcrum 0 and to which displacement from the current-displacement converter 2a is applied at one end. A nozzle 4a is disposed opposite the other end of the lever 3a and constitutes a nozzle-flapper mechanism with the lever 3a. 41a is a supply air source. 5a is an air amplifier that amplifies the back pressure Pn of the nozzle 4a. 6a is a feedback bellow disposed opposite the lever 3a. A part of the output of the air amplifier 5a is introduced into a feedback bellow 6a and outputted as an output air pressure 7a. 8a is a zero adjustment spring mechanism.

In the above configuration, when the input electric signal 1a is input, a displacement corresponding to the magnitude thereof is applied to one end of the lever 3a by the current-displacement converter 2a. In response to this displacement, the other end of the lever 3a and the nozzle 4a
The gap G changes. This change in gap G causes the back pressure Pn of the nozzle 4a to change, and this back pressure
Pn is amplified by the air amplifier 5a and outputted as an output air pressure 7a, and a portion is fed back to the feedback bellow 6a. Thus, in the balance lever 3a, the balance lever is maintained in equilibrium in a state where the force due to the current-displacement converter 2a and the force based on the feedback bellow 6a are balanced. As described above, input electric signal 1
An output air pressure 7a corresponding to a is output.

(Problems to be Solved by the Invention) However, such a conventional device requires a supply air pressure source 41a. Further, the nozzle 4a normally consumes air.

Furthermore, since a nozzle flapper mechanism is used, nonlinearity errors near zero pressure become large due to its characteristics.

Further, the nozzle-flutter mechanism generally has a high gain. That is, the nozzle back pressure Pn is equal to the supply air pressure 4
The nozzle gap G from 1a to almost 0 atm usually has a stroke of only 0.1 to 0.2 mm. Therefore, if an attempt is made to obtain a device with a resolution of 0.01%, the displacement of the flapper will be on the order of 0.02 μm. Such a device cannot be used because vibrations, subtle changes in ambient temperature, etc., minute hysteresis, etc. greatly affect the characteristics as errors. In order to set the loop gain of the entire device to an appropriate value,
Attempting to lower the gain has the disadvantage that the non-linear error near zero pressure becomes worse and the output pressure no longer approaches zero pressure. Therefore, it is easy to oscillate, the device lacks stability, and offset is likely to occur. Additionally, the flapper is susceptible to vibrations in the direction of movement and output tends to fluctuate.

In addition, in practical use, for example, 100mmH ₂ O
There is often a need to use pressures close to zero, such as .

An object of the present invention is to provide a pressure generator that is free from offset, highly earthquake resistant, highly accurate, and does not require a supply air source.

(Means for solving the problem) In order to achieve this object, the present invention includes a fluid pressure converter that converts an output fluid pressure signal into an electric signal in response to an output fluid pressure signal, and an electric signal from the fluid pressure converter. a differential amplifier section that differentially amplifies and input electrical signals; a servo motor section that is driven by the output of the differential amplifier section; and a servo motor section that generates and outputs a fluid output signal in conjunction with the servo motor section. This constitutes a pressure generator comprising a compressor and a compressor whose portion is returned to the fluid converting section.

(Function) In the above configuration, the output signal converted into an electrical signal by the fluid pressure conversion section is compared with the input electrical signal in the differential amplifier section. If there is a deviation from the input electrical signal, the amount of deviation is amplified by the differential amplifier section. The DC servo motor rotates clockwise or counterclockwise depending on the polarity of the electrical signal amplified by the differential amplifier section.
As the servo motor rotates, the compressor operates,
At the same time, a part of the fluid is returned to the fluid converter.

Then, the above operation is repeated continuously,
A fluid output signal corresponding to the input electrical signal is obtained.

Hereinafter, it will be explained in detail based on Examples.

(Embodiment) Fig. 1 is an explanatory diagram of the configuration of an embodiment of the present invention, and Fig. 2
The figure is a block diagram of FIG.

In the figure, 1 is an input electrical signal, and 2 is a pneumatic converter that converts the output pneumatic signal 3 into an electrical signal. a differential inductance circuit 23 that converts into an electrical signal via a spring 22;
The system includes a preamplifier 24 for amplifying the output of the system, and a phase lead compensation circuit 25 (not shown) for improving system characteristics. Reference numeral 4 denotes a differential amplifier section that differentially amplifies the input electric signal 1 and the electric signal from the pneumatic conversion section 2. 5 is a servo motor section driven by the output of the differential amplifier section, and 6 is a compressor that generates an output air pressure signal 3 in conjunction with the servo motor section. 7 is an output tank, 8 is a pipe connecting the compressor 6, the bellows 21, and the output tank 7, and 81 is a throttle provided in the pipe 8 near the output tank 7.

In the above configuration, the output pneumatic signal 3 converted into an electrical signal by the pneumatic conversion section 2 is compared with the input electrical signal 1 in the differential amplifier section 4. If there is a positive or negative deviation with respect to the input electrical signal 1, the amount of deviation is amplified by the differential amplifier section 4. The DC servo motor 5 rotates clockwise or counterclockwise depending on the polarity of the electrical signal amplified by the differential amplifier section 4. As the servo motor 5 rotates, the compressor 6 operates and provides an output air pressure signal 3 to the output tank 7 and applied to the bellows 21.

In the above, each component is configured to reduce deviation. That is, for example, if the output air pressure signal 3 is lower than the input electric signal 1, the servo motor 5 rotates in a direction such that the compressor 6 supplies air pressure to the output side. If the output air pressure signal 3 is high, the opposite operation is performed. Then,
The above-described operation is continuously repeated, and an output pneumatic signal 3 corresponding to the input electrical signal 1 is obtained.

In the above-mentioned embodiment, it has been explained that the pneumatic converter 2 is composed of the bellows 21, the spring 22, the differential inductance circuit 23, the preamplifier circuit 24, and the phase lead compensation circuit 25, but this is not limited to this. Any device that converts air pressure into an electrical signal will suffice. Of course, a phase lag circuit may be selected as the phase lead compensation circuit 25 depending on the system conditions.

Further, it goes without saying that the output tank 7 and the throttle 81 may be omitted depending on the load condition.

Further, in the above-described embodiments, the case where the output is pneumatic pressure in response to the input electric signal has been described, but the output is not limited to this, and for example, oil pressure or the like may be used, in short, any fluid pressure may be used.

(Effects of the Invention) As described above, the present invention includes a fluid pressure converter that converts an output fluid pressure signal into an electrical signal, and a difference between the electrical signal from the fluid pressure converter and the input electrical signal. a differential amplifier section that dynamically amplifies; a servo motor section that is driven by the output of the differential amplifier section; and a servo motor section that generates and outputs a fluid output signal in conjunction with the servo motor section, and also partially converts the fluid output signal. The pressure generator is equipped with a compressor that returns to the pump.

That is, in the present invention, the differential amplifier section,
The servo motor section and air compressor constituted a forward circuit, and the pneumatic converter section constituted a feedback circuit.

As a result, since a servo motor section having integral characteristics is used, offset can be eliminated. Furthermore, since an electrical signal is used to match the output signal to the input signal, higher resolution can be obtained than when using an air signal.

Furthermore, since the air compressor is used as a direct control element, there is no need for an air pressure supply source, and the device can be operated with just a power supply.Moreover, the gain of the compressor can be selected arbitrarily, so the system Stabilization is achieved and a product with great practical effects can be obtained.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the configuration of one embodiment of the present invention, and FIG.
The figure is a block diagram of FIG. 1, and FIG. 3 is an explanatory diagram of the configuration of a conventional example that has been generally used. DESCRIPTION OF SYMBOLS 1... Input electrical signal, 2... Pneumatic conversion section, 3... Output pneumatic signal, 4... Differential amplifier, 5... Servo motor section, 6... Compressor.

Claims (1)

[Claims] 1: a fluid pressure converter that converts an output fluid pressure signal into an electrical signal; a differential amplifier that differentially amplifies the electrical signal from the fluid pressure converter and the input electrical signal; A pressure generator comprising: a servo motor section driven by the output of an amplifier section; and a compressor that generates and outputs a fluid output signal in conjunction with the servo motor section, and also returns a portion of the fluid output signal to the fluid converting section. vessel.