JP2531829Y2 - Electro-pneumatic converter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application field] The present invention is directed to detecting a pilot pressure acting on a diaphragm connected to a main valve for shutting off a communication between an input port and an output port with a detected pressure on an output port side. The present invention relates to an electropneumatic converter provided with a pilot pressure control circuit for performing electrical control based on a comparison between pressure and a set pressure.

[Prior Art] An electropneumatic converter of this type is disclosed in Japanese Utility Model Laid-Open No. 61-125715. This conventional device includes a nozzle flapper mechanism that changes a nozzle back pressure by a displacement of a nozzle flapper formed of a piezoelectric element, a diaphragm that is displaced in accordance with the nozzle back pressure, and a main valve that shuts off communication between input and output by displacement of the diaphragm. And a control circuit for controlling the displacement of the nozzle flapper based on a comparison between the output pressure and the set pressure. With this configuration, the set pressure is stably supplied to the output side.

[Problem to be Solved by the Invention] In such an electropneumatic converter, the output pressure can be adjusted by changing the set pressure input to the control circuit. The control circuit of the electropneumatic converter is connected to the control circuit by electric wires, and an input operation is performed by an external operation unit. If such an external operation method is used, it is not necessary for the operator to go to the installation location of the electropneumatic converter body.

However, such a wired method requires cumbersome connection work, and the installability of the electropneumatic converter body may be influenced by the connection work of the electric wire and the wiring structure.

An object of the present invention is to provide an electro-pneumatic converter capable of solving the problems inherent in such a wired system.

[Means for Solving the Problems] For this purpose, in the present invention, a receiving circuit that receives a modulated optical signal and converts the modulated optical signal into an electric signal,
A conversion output circuit that demodulates the electric signal converted by the reception circuit and outputs the demodulated electric signal to a pilot pressure control circuit; and a wireless type that emits a modulation optical signal to the reception circuit and modulates the modulation optical signal. An electro-pneumatic converter was constituted by the transmitting means.

[Operation] The modulated light emitted from the transmitting means is output as desired modulated light by the modulation operation in the transmitting means. By projecting this modulated light on the receiving circuit of the electropneumatic converter body, the receiving circuit converts the modulated light into an electric signal. The converted electric signal is demodulated by the modulation output circuit and output to the pilot pressure control circuit. The set pressure is input and set to the pilot pressure control circuit by the input of the demodulated electric signal. The pilot pressure control circuit controls the operation of a drive mechanism for pilot pressure control based on a comparison between the set pressure and the detected pressure, and the drive mechanism operates to adjust the detected pressure to the set pressure.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

Reference numeral 1 denotes a valve housing in which a main valve 2 is housed so as to be slidable up and down. The main valve 2 opens and closes an internal passage connecting the input port 1a and the output port 1b formed in the valve housing 1. A support cap 3 is fixedly joined to an upper end of the valve housing 1, and a diaphragm assembly 4 is accommodated in a space between the valve housing 1 and the support cap 3 so as to be slidable up and down. A diaphragm 5 is provided between the small-diameter flange portion 4a at the top of the diaphragm assembly 4 and the inner peripheral surface of the valve housing 1, and a diaphragm 6 is also provided between the large-diameter flange portion 4b and the inner peripheral surface of the support cap 3. provided, the space portion is divided into an exhaust chamber S ₁ and the pilot chamber S ₂ leading to an exhaust port 1c by both diaphragms 5,6.

The support cap 3 is pilot port 3a is provided, communicating with the pilot port 3a is communicated with the pressure fluid source 7 for supplying pressure fluid to the input port 1a, the pilot chamber S ₂ through the orifice 8 Have been.
Further, a pressure sensor 9 is built in the support cap 3 so that the pressure on the output port 1b side is detected.

Pilot chamber nozzle 10 on the upper surface of the support cap 3 S ₂
The flapper is composed of a piezoelectric bimorph supported by a flapper drive mechanism 11 for pilot pressure control in the extension direction of the injection port 10a of the nozzle 10.
12 is arranged to be orthogonal to the nozzle 10. Pressure in the pilot chamber S ₂ is controlled by the opening and closing of the flapper 12 with respect to the injection port 10a. Input port 1a and the output port 1b to the main valve 2 when pressure rises in the pilot chamber S ₂ is moved downward
DOO are communicated, the main valve 2 with decreasing pressure in the pilot chamber S ₂ is to shut off the input port 1a and the output port 1b rise. Moreover, the diaphragm assembly 4 when the pressure in the pilot chamber S ₂ is lowered is moved upward, the pressure fluid of the output port 1b side is discharged from the exhaust port 1c.

A pilot pressure control circuit 13 is accommodated in a storage case 21 on the support cap 3, and a flapper drive mechanism 11 for applying a voltage to a flapper 12 composed of a piezoelectric bimorph.
Are controlled by the pilot pressure control circuit 13. The pilot pressure control circuit 13 performs feedback control of the flapper driving mechanism 11 based on a comparison between the pressure detected by the pressure sensor 9 and a preset pressure, and
Performs voltage application so as to maintain the feedback control to the pressure set pressure in the pilot chamber S _2.

A receiving circuit 14, a pulse demodulating circuit 19, and a driving circuit 20 are provided on the side of a storage case 21 constituting such an electropneumatic converter body.
The drive circuit 20 is electrically connected to the pilot pressure control circuit 13. The light receiving element 14a constituting the receiving circuit 14 receives the light emitted from the light emitting element 17a of the transmitter 15 separate from the electropneumatic converter main body. The transmitter 15 includes a pulse modulation circuit 16 and an oscillation circuit connected to the pulse modulation circuit 16.
17 and operation keys 18 for performing pulse modulation and transmission. The operation key 18 is used to input a set pressure value, and the pulse modulation circuit is operated according to the input operation of the set pressure value.
16 outputs a pulse modulation signal according to the set pressure value, and the light emitting element 17a of the transmission circuit 17 emits infrared modulation light according to the pulse modulation signal.

The receiving circuit 14 that has received the infrared modulated light projected from the light emitting element 17a outputs the converted electric signal to the pulse demodulation circuit 19, and the pulse demodulation circuit 19 demodulates the converted electric signal and outputs it to the drive circuit 20. This allows the pilot pressure control circuit 13
Is input and set, and the set pressure to be compared with the detected pressure is changed. Since the change of the set pressure is performed by wireless remote control of the transmitter 15 completely separated from the electropneumatic converter main body, the worker goes to the installation location of the electropneumatic converter main body and the pilot pressure control circuit 13
It is not necessary to change the set pressure in. Moreover, since it is not necessary to connect the electropneumatic converter main body and the transmitter 15 with electric wires, it is not necessary to perform a troublesome work of connection. or,
Since there is no connecting wire, the installation of the electropneumatic converter main body is not affected by the wiring work and the wiring structure.
Furthermore, the range of action of the worker is widened by the portability of the transmitter 15, and the workability of changing the set pressure is very good. Therefore, with the configuration as in the present embodiment, particularly when the electro-pneumatic converter body is installed in a place where people cannot enter or in an isolated place such as a clean room, it is compared with the conventional wired type. It is very effective.

The present invention is, of course, not limited to the above-described embodiment. For example, a configuration in which the receiving circuit is separated from the electropneumatic changer main body is also possible, and this separation structure can perform transmission and reception while avoiding obstacles. Is obtained.

Alternatively, the transmitter may be provided with a channel switching mechanism so that a plurality of electropneumatic converter bodies are adjusted in pressure by one transmitter. Further, it is also possible to directly transmit and receive between the pilot pressure control circuit and the transmitter in the above embodiment.

[Effects of the Invention] As described in detail above, the present invention receives a modulated optical signal, converts the modulated optical signal into an electric signal, and demodulates the electric signal converted by the receiving circuit to generate a pilot signal. A conversion output circuit for outputting to the pressure control circuit;
Since the electro-pneumatic converter is configured by projecting the modulated optical signal to the receiving circuit and wireless transmitting means for performing the modulation operation of the modulated optical signal, the work of installing the electro-pneumatic converter body and setting the pressure is performed. It is very effective compared to the wired system, and is very effective especially when installing the electro-pneumatic converter body in a place where people can not enter or in an isolated place such as a clean room. It works.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing one embodiment of the present invention,
FIG. 2 is a block circuit diagram. Flapper drive mechanism as drive mechanism for pilot pressure control
11, a pilot pressure control circuit 13, a reception circuit 14, a pulse demodulation circuit 19 and a drive circuit 20, which constitute a conversion output circuit, a transmitter
15.

Continuation of the front page (56) References JP-A-60-181802 (JP, A) JP-A-61-10717 (JP, A) JP-A-63-101710 (JP, A) , U) Japanese Utility Model Showa 63-17301 (JP, U) Japanese Utility Model Showa 56-106203 (JP, U)

Claims (1)

(57) [Scope of request for utility model registration] A pilot pressure acting on a diaphragm (5, 6) connected to a main valve (2) for interrupting communication between an input port (1a) and an output port (1b) is applied to an output port (1).
b) In the electropneumatic converter equipped with a pilot pressure control circuit (13) for electrically controlling based on the comparison between the detected pressure on the side and the set pressure, while receiving the modulated optical signal,
Receiver circuit (14) that converts this modulated optical signal into an electric signal
And a conversion output circuit (19, 20) for demodulating the electric signal converted by the receiving circuit (14) and outputting the demodulated electric signal to the pilot pressure control circuit (13); and projecting the modulated optical signal to the receiving circuit (14). An electro-pneumatic converter characterized by comprising a wireless transmission means (15) for performing a modulation operation of the modulated optical signal.