JP6322147B2 - Electro-pneumatic positioner - Google Patents

Description

  The present invention relates to an electropneumatic positioner with a built-in pressure sensor.

  Conventionally, an electropneumatic positioner is provided for the control valve, and the valve opening of the control valve is adjusted by the electropneumatic positioner. This electro-pneumatic positioner calculates the deviation between the valve opening setting value sent from the host device and the actual opening value fed back from the control valve, and generates an electrical signal corresponding to this deviation as a control output. And a pilot that amplifies the nozzle back pressure converted by the electropneumatic converter and outputs it as an output air pressure to the control valve actuator. It has a relay.

  Such an electro-pneumatic positioner has a built-in pressure sensor and uses the built-in pressure sensor to observe the pressure of the internal air so that the observed value can be used for various diagnoses and controls. (For example, refer to Patent Document 1).

  When a pressure sensor is used, it is necessary to connect the pressure sensor to an air circuit through which an air pressure signal to the control valve flows. Therefore, a device is required for the structure of the air circuit and the shape of the printed wiring board on which the pressure sensor is mounted. In addition, the electropneumatic positioner is always required to have an explosion-proof structure and downsizing (for example, see Patent Document 2).

  FIG. 2 shows an example of a connection structure of a pressure sensor to a conventional air circuit. In the figure, 1 is the main board on which the main electrical components of the electropneumatic positioner (CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), etc.) are mounted, 2 is the control valve An air circuit forming member 3 is formed with grooves 2-1 and 2-2 serving as air circuits through which air pressure signals flow. Reference numeral 3 denotes a main body case (housing), and the main body case 3 includes a body 3-1 and a lid 3-2. It consists of.

  On the main board 1, pressure sensors S1 and S2 are mounted on one side 1a, and main electrical components 4 such as a CPU are mounted on the other side 1b. The main board 1 is joined to the air circuit forming member 2 so that the pressure sensors S1 and S2 are positioned in a sealed state in the grooves 2-1 and 2-2. O-rings 5-1 and 5-2 are mounted between the main board 1 and the grooves 2-1 and 2-2.

  FIG. 3 shows another example of a structure for connecting a pressure sensor to a conventional air circuit. 2, the same reference numerals as those in FIG. 2 denote the same or equivalent components as those described with reference to FIG. 2, and the description thereof will be omitted. In this connection structure, a pressure sensor dedicated board 6 on which pressure sensors S1 and S2 are mounted is provided separately from the main board 1, and the main board 1 and the pressure sensor dedicated board 6 are connected by a cable 7. .

  That is, in this connection structure, the pressure sensors S1 and S2 are mounted on the one surface 6a side of the pressure sensor dedicated substrate 6, and the pressure sensors S1 and S2 are sealed in the grooves 2-1 and 2-2. Thus, the pressure sensor dedicated substrate 6 is joined to the air circuit forming member 2, the other surface 6 b of the pressure sensor dedicated substrate 6 and the one surface 1 a of the main substrate 1 are opposed to each other, and a power supply or The communication signal cable 7 is used for connection. The main substrate 1 is isolated from the pressure sensor dedicated substrate 6 by fixing one surface 1a to a holding portion 3-3 provided in the main body case 3.

JP 2009-257513 A JP-A-11-190673

  However, according to the connection structure of the pressure sensor to the conventional air circuit, the pressure sensor S1 and S2 are mounted on the main board 1 in the connection structure shown in FIG. There are restrictions on the mounting positions of the pressure sensors S1 and S2, and an air circuit must be formed for the pressure sensors S1 and S2 mounted at the restricted positions, which complicates the structure of the air circuit. Further, when the main board 1 is replaced, it is necessary to attach and detach the air circuit. If the connection with the air circuit is incomplete, there is a possibility that air leakage may occur.

  In addition, the connection structure shown in FIG. 3 requires a cable 7 that connects between the main board 1 and the pressure sensor board 6, and the assemblability is poor. In addition, there is a possibility that the cable 7 is sandwiched and cut during assembly. Consideration is also required to meet the intrinsically safe requirements.

  The present invention has been made in order to solve such problems, and the object of the present invention is that the structure of the air circuit is not complicated, and it is not necessary to attach and detach the air circuit when replacing the main board. Another object is to provide an electropneumatic positioner that is easy to assemble and easily meets the requirements of intrinsically safe explosion protection.

In order to achieve such an object, the present invention provides an electropneumatic positioner that converts an electrical signal into a pneumatic signal to adjust the opening of a control valve, and a main board on which an electrical component including a central processing unit is mounted. The pressure sensor dedicated board on which the pressure sensor is mounted on one side of the main board and the groove part serving as an air circuit through which the air pressure signal to the control valve flows are formed, and the pressure sensor is disposed in the groove part. An air circuit forming member to which a pressure sensor dedicated substrate is joined so as to be positioned in a sealed state, the pressure sensor dedicated substrate includes a wireless transmission unit that wirelessly transmits an output of the pressure sensor, and the main substrate is It is characterized by comprising a wireless receiver for receiving the output of the pressure sensor from the wireless transmitter of the pressure sensor dedicated board.

  In the present invention, the pressure sensor is mounted on the pressure sensor dedicated board, and the output of the pressure sensor on the pressure sensor dedicated board is sent to the main board by wireless transmission. In this configuration, since the position of the pressure sensor on the pressure sensor dedicated substrate is not restricted, the air circuit in the air circuit forming member is not complicated. Further, since the main substrate can be replaced while the pressure sensor dedicated substrate is left as it is, the attachment / detachment with the air circuit is also unnecessary. In addition, since the pressure sensor dedicated board and the main board are connected wirelessly, the assemblability is good and the possibility of connection mistakes due to attachment / detachment can be reduced. In addition, since there is no cable between the pressure sensor dedicated board and the main board, the intrinsically safe explosion-proof requirement can be easily satisfied by covering the pressure sensor dedicated board with a filler.

  According to the present invention, the pressure sensor is mounted on the pressure sensor dedicated substrate, the wireless sensor is provided on the pressure sensor dedicated substrate, and the pressure sensor from the wireless transmitter of the pressure dedicated substrate is provided on the main substrate. Since the wireless receiver that receives the output of the air circuit is provided, the structure of the air circuit is not complicated, and it is not necessary to attach or detach the air circuit when replacing the main circuit board. It is possible to make it easier to satisfy the requirements.

It is a figure which shows the structure (connection structure of the pressure sensor to an air circuit) of the principal part of one Embodiment of the electropneumatic positioner which concerns on this invention. It is a figure which shows an example of the connection structure of the pressure sensor to the conventional air circuit. It is a figure which shows the other example of the connection structure of the pressure sensor to the conventional air circuit.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a view showing the structure of a main part of one embodiment of an electropneumatic positioner according to the present invention (connection structure of a pressure sensor to an air circuit).

  In FIG. 1, 11 is a main board on which main electric components of the electropneumatic positioner are mounted, and 12 is an air circuit formation in which grooves 12-1 and 12-2 are formed as air circuits through which air pressure signals to the control valve flow. A member, 13 is a main body case (housing), 16 is a pressure sensor dedicated board on which pressure sensors S1 and S2 are mounted, and the main body case 13 includes a body 13-1, a lid 13-2, and a holding portion 13-3. Consists of. The main body case 13 and the air circuit forming member 12 are made of metal.

  Pressure sensor S1 and S2 are mounted on pressure sensor board 16 on one surface 16a side, and pressure sensors S1 and S2 are positioned in a sealed state in grooves 12-1 and 12-2. The pressure sensor dedicated board 16 is joined to the air circuit forming member 12. O-rings 15-1 and 15-2 are mounted between the pressure sensor dedicated substrate 16 and the grooves 12-1 and 12-2.

The main substrate 11 is fixed to a holding portion 13-3 provided in the main body case 13 with one surface 11a as a lower surface. The holding member 13-3 is widely formed in the case 13 so as to receive the entire one surface 11 a of the main substrate 11. Thereby, the main board | substrate 11 is isolated from the pressure sensor exclusive use board | substrate 16 on both sides of the holding member 13-3. On the other surface 11 b side of the main substrate 11, main electrical components 14 such as a CPU (Central Processing Unit) are mounted.

  Further, the pressure sensor dedicated board 16 is provided with a wireless transmitter 17 for wirelessly transmitting the outputs of the pressure sensors S1 and S2 and a battery 18 for supplying power to the wireless transmitter 17 on the other surface 16b side. In addition, the main board 11 is provided with a wireless receiver 19 that receives the outputs of the pressure sensors S1 and S2 wirelessly transmitted from the wireless transmitter 17 of the pressure sensor dedicated board 16 on the other surface 11b side. In the present embodiment, wireless communication between the wireless transmission unit 17 and the wireless reception unit 19 is performed by short-range wireless communication such as Bluetooth (registered trademark).

  The space between the holding member 13-3 and the air circuit forming member 12 in the case body 13 is filled with the filler 20. In other words, in the space between the holding member 13-3 and the air circuit forming member 12 in the case body 13, the pressure sensor dedicated substrate 16 is entirely covered with the filler 20.

  In this connection structure, since the pressure sensor dedicated substrate 16 is provided as a dedicated substrate for the pressure sensors S1 and S2, the mounting positions of the pressure sensors S1 and S2 are not restricted. For this reason, the air circuit in the air circuit forming member 12 is not complicated. Further, since only the main substrate 11 can be exchanged while leaving the pressure sensor dedicated substrate 16 as it is, it is not necessary to attach or detach the air circuit. For this reason, the problem that the connection with the air circuit becomes incomplete and air leakage occurs does not occur.

  Further, in this connection structure, since the pressure sensor dedicated board 16 and the main board 11 are connected wirelessly, the assembling property is good and the possibility of connection mistakes due to attachment / detachment can be reduced. Further, a free layout is possible, and a reduction in size and weight can be achieved.

  In this connection structure, since there is no cable between the pressure sensor dedicated board 16 and the main board 11, the entire pressure sensor dedicated board 16 can be covered with the filler 20, which is intrinsically safe. Explosion-proof requirements can be easily met.

  In the above-described embodiment, the air circuit forming member 12 is provided as a member independent of the main body case 13, but the air circuit forming member 12 may be a part of the main body case 13. That is, the air circuit forming member 12 may be integrated with the main body case 13.

  In the above-described embodiment, the holding portion 13-3 is provided in the main body case 13, but the holding member 13-3 may be omitted. That is, the main substrate 11 may be fixed using the filler 20 as an adhesive.

  Further, the holding member 13-3 may not be a holding member that receives the entire surface of the main board 11, but may be a holding member that receives the peripheral edge of the main board 11 similar to the holding member 3-3 illustrated in FIG. 3. The main body case 13 and the air circuit forming member 12 may be made of resin.

  In the above-described embodiment, the battery 18 is provided on the pressure sensor dedicated board 16, but power may be supplied in a non-contact manner from the main board 11 side.

[Extension of the embodiment]
The present invention has been described above with reference to the embodiment. However, the present invention is not limited to the above embodiment. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the technical idea of the present invention.

  DESCRIPTION OF SYMBOLS 11 ... Main board | substrate, 12 ... Air circuit formation member, 12-1, 12-2 ... Groove part, 13 ... Main body case, 13-1 ... Body, 13-2 ... Lid body, 13-3 ... Holding part, 14 ... Electricity Components, 15-1, 15-2 ... O-ring, 16 ... Board for pressure sensor, 17 ... Wireless transmission part, 18 ... Battery, 19 ... Wireless reception part, 20 ... Filler, S1, S2 ... Pressure sensor.

Claims (4)

In an electropneumatic positioner that converts the electrical signal into a pneumatic signal to adjust the opening of the control valve,
A main board on which electrical components including a central processing unit are mounted;
A pressure sensor dedicated board which is provided separately from the main board and has a pressure sensor mounted on one surface thereof;
An air circuit forming member in which a groove serving as an air circuit through which an air pressure signal to the control valve flows is formed, and the pressure sensor dedicated substrate is bonded so that the pressure sensor is sealed in the groove. With
The pressure sensor dedicated substrate is
A wireless transmission unit for wirelessly transmitting the output of the pressure sensor;
The main board is
An electro-pneumatic positioner comprising: a wireless receiver that receives an output of the pressure sensor from a wireless transmitter of the pressure sensor dedicated board. In the electropneumatic positioner according to claim 1,
The electro-pneumatic positioner, wherein the pressure sensor substrate is covered with a filler. In the electropneumatic positioner according to claim 1 or 2,
The air circuit forming member is:
The electro-pneumatic positioner, which is a part of a main body case that houses a main part of the electro-pneumatic positioner including the main board and the pressure sensor dedicated board. In the electropneumatic positioner according to any one of claims 1 to 3,
The electro-pneumatic positioner, wherein the pressure sensor dedicated board includes a battery that supplies power to the wireless transmission unit.

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