JPH036435A - Differential-pressure and pressure transmitter - Google Patents

Abstract

PURPOSE:To enable simplification of an entire construction, to make it small in size and to reduce the cost by providing a transmitter housing in such a manner that the main body of the housing is joined into the fore end side of a cylindrical joining part of a body of a detecting element. CONSTITUTION:A transmitter housing 10 joined to a body of a detecting element having a pressure-receiving part through the intermediary of a cylindrical joining part 5 is used. In this housing 10, an amplifier chamber 22 provided inside with an amplifier unit 21 receiving a detection signal from the body 4 side and executing an arithmetic processing thereof and a terminal chamber 26 provided inside with a terminal plate unit 25 having a terminal 23a connecting the unit 21 to an external power source etc. are formed in a state of lamination from the body 4 side. When a meter is used as an option, a meter chamber 28 is laminated on the cover body 12 side of the terminal chamber 26 so that it is visible from outside. Accordingly, all of necessary members of an electric system are incorporated in one housing 10, and thus a pressure-resistant explosion-proof structure thereof can be secured simply.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a field installation type differential pressure or pressure indicating transmitter (hereinafter simply referred to as a differential pressure/pressure transmitter) that requires a flameproof and explosion-proof structure, and particularly relates to This invention relates to improvements in differential pressure/pressure transmitters that aim to reduce the size, weight, and cost of the entire transmitter.

[Conventional technology]

This type of field-installed differential pressure/pressure transmitter is installed at the measurement site to measure the pressure, differential pressure, or liquid level of various process fluids and transmit the measurement signal to the controller side. Yes, for example Utility Model No. 81-1122
Various configurations have been known in the past, including the one disclosed in Japanese Patent No. 48.

Conventionally, this type of differential pressure/pressure transmitter generally includes a pressure receiving part, a detecting part body having a means for sensing the received pressure signal and sending out a detection signal, and a cylindrical connecting part extending from the detecting part body. An amplifier unit connected to the tip side of the sensor and connected to the detection signal sending means, and an indicator (hereinafter referred to as a meter) that is selectively connected to the amplifier unit side and used as an option to confirm measured values at the installation site. ), etc., and a terminal board that is integrally connected to the side of the transmitter case via a connecting part and is connected to an external power source. It is equipped with a transmitter casing consisting of a terminal box,
The amplifier unit, meter, and terminal board, which are internally housed components, are housed in a required position and installed inside the device while being appropriately electrically connected through lead wires, connectors, and the like.

For safety reasons, such field-installed differential pressure/pressure transmitters used in oil refineries, etc. are required to have a pressure-resistant and explosion-proof structure on the outside. The transmitter casing has a structure that ensures a sealed structure in each part of the transmitter casing and ensures a pressure-resistant and explosion-proof structure.

[Problem to be solved by the invention]

By the way, according to the conventional differential pressure/pressure transmitter as described above, there is a detection part body including a pressure receiving part, a transmitter case constituting a transmitter casing connected to this, and a terminal connected to this. Since it is constructed by combining three components with the box, the overall size of this instrument becomes large and the structure becomes complicated. In particular, when this transmitter is made to have a flameproof structure, it is necessary to make the transmitter case and the terminal box, which make up the above-mentioned transmitter casing, a flameproof and explosion-proof structure, which tends to increase the size of the entire instrument. In addition, the structure is complicated, which poses a problem in terms of cost.

In particular, for this type of differential pressure/pressure transmitter, it is desirable to satisfy the explosion-proof structure that complies with the pressure-resistant explosion-proof guidelines, and to make the entire instrument smaller, lighter, more compact, and lower in cost. Therefore, it is desirable to consider some measures that can satisfy these demands.

[Means to solve the problem]

In order to meet the above-mentioned demands, the differential pressure/pressure transmitter according to the present invention includes a substantially bottomed cylinder that is connected and fixed to the tip of a cylindrical connecting part extending from a detecting part body having a pressure receiving part. The transmitter housing consists of a shaped housing body and a lid that closes the open end of the housing, and an amplifier unit is installed inside the transmitter housing to receive the detection signal from the detection body side and process it. amplifier room,
A terminal chamber in which a terminal board unit having terminals for connecting the amplifier unit, an external power source, and a remote control section is installed is formed in a stacked state from the detection body side, and facing this terminal chamber, the housing body is A cable entry port from the outside that is selectively connected to each of the terminals is formed on the side, and when a meter is used as an option, the meter is stacked in the terminal chamber within the transmitter housing described above. It forms a room and is configured to be visible from the outside.

[Effect]

According to the present invention, the housing body constituting the transmitter housing is connected to the tip side of the cylindrical connecting part of the detection body, and the amplifier unit, the terminal plate unit, and the By selectively installing meters in a stacked manner and closing the open end of the housing body with a lid, it has a flameproof and explosion-proof structure, and the overall configuration is simplified, making it smaller and lower in cost. It becomes possible to obtain a differential pressure/pressure transmitter that can measure the

〔Example〕

Hereinafter, the present invention will be explained in detail using embodiments shown in the drawings.

1 to 3 show an embodiment of the differential pressure fist pressure transmitter according to the present invention, and in these figures, the differential pressure/pressure transmitter (in this embodiment, the differential pressure transmitter is indicated as a whole by the symbol l) is shown. exemplifying a pressure transmitter) has a pair of barrier diaphragms 2a as pressure receiving parts.

? b and these barrier diaphragms 2a.

A detection unit body 4 which includes a built-in pressure sensor 3 and the like that detects the differential pressure between two fluid pressures sensed by the sensor 2b, and a tip end of a cylindrical connecting unit 5 that protrudes from the detection unit body 4. The transmitter housing 10 includes a housing body 11 having a substantially bottomed cylindrical shape connected to and fixed to the transmitter housing 10 and a lid body 12 closing the open end of the housing body 11. As is well known, the above-mentioned detection body 4 is integrally assembled by fastening a plurality of divided bodies with port nuts, and two types of fluid pressures to be measured are introduced into the body. A pair of pressure chambers 6 and 7 introduced from ports 6a and 7a, and a pressure transmitting medium sealed between these pressure chambers 6 and 7, which face each other via barrier diaphragms 2a and 2b and reach the pressure sensor 3. Pressure measurement chambers 8a, 8b
These pressure measuring chambers 8a and 8b are defined by a center diaphragm 2C.

Further, the cylindrical connecting portion 5 is made up of a metal cylinder 5a and an inner cylinder 5b, and the inner cylinder 5b has a plurality of wires for guiding the detection signal from the pressure sensor 3 to the outside. A signal extraction lead 9 is sealed with a hermetic seal or the like and protrudes from the tip of the connecting portion 5.

Here, the configuration of the detection section and its operation in this type of detection section body 4 are conventionally well known, and detailed explanation thereof will be omitted.

Now, according to the present invention, the transmitter housing 10 connected to the tip of the cylindrical connecting part 5 of the detection part body 4 described above has a structure that complies with the pressure-resistant explosion-proof guidelines by the housing main body 11 and the lid body 12. At the same time, an amplifier unit 21 consisting of a plurality of printed circuit boards 21a and 21b and an electric component 21c mounted thereon is housed inside, which receives detection signals from the detection unit body 4 side and processes the signals. A terminal block 23 having a plurality of terminals 23a for connecting the amplifier room 22 to be installed, its amplifier unit) 21, an external power source, and a remote control unit (not shown), and a terminal board 24 on which a plurality of electrical components 24a are mounted. A terminal room 26 in which a terminal board unit 25 is installed, and a meter room 2 in which a meter 27 that is selectively used as an option is installed.
8 are formed in a stacked state from the detection unit body 4 side. And the terminal chamber 2
On the side of the housing main body 11 facing the terminal 6, there is provided an external cable (
A transparent plate 3o that forms a lead-in port 29 (not shown) and allows the meter 27 to be viewed from outside the housing 10 is placed inside an opening 30a opened in the lid 12 constituting the housing 10. We are trying to provide it in a manner that satisfies the explosion-proof guidelines. In addition, in this embodiment, the above-mentioned transparent plate 30 is attached to the set ring 30 inside the lid body 12.
b shows that the meter 27 is assembled in a fixed manner, and the meter 27 is fixed to a hexagonal stud 31 erected from the terminal board unit 25 side with screws I.

Here, the above-described transmitter housing 10 and the structure for assembling the transmitter components therein are illustrated in FIGS. 1 to 8.
To explain in detail using FIGS. (a) and (b), first, in this embodiment, the housing body 11 constituting the transmitter housing 10 is made of aluminum alloy casting or glue casting to have a substantially cylindrical shape. The formed cylindrical member 40 and the cylindrical member 40, which is assembled and fixed by screwing so as to close the opening on one end side (on the back side of the transmitter), are made of different materials that cannot be joined by welding, for example. A bottom cover member 41 (FIGS. 4(a) and 4(b) formed of stainless steel into a substantially cup shape by drawing or the like
) is shown. In addition, 4 in the figure
0a and 41a are an inner circumferential threaded portion formed in the opening on one end side of the cylindrical member 40 and an outer circumferential threaded portion formed in the peripheral wall portion of the bottom cover member 41 which is screwed thereto, and these are screwed together. As a result, the structure is such that the gap and depth at this joint part meet the flameproof and explosion-proof guidelines1. Further, in the figure, 41b is an opening into which the cylindrical connecting portion 5 is fitted and welded, and 42 is an opening for these threaded portions 40&
, 41a is a push screw for connecting and fixing both members at a required point when screwing them together, and such a push screw 42
According to the above, a cylindrical member 40 whose directionality is specified like the cable entry port 29 in the housing body 11 is
It can be connected to the bottom cover member 41 at a required rotational position, which has a great practical advantage. By adopting such a configuration, the entire housing body 11 can be manufactured more easily than in the case where the entire housing body 11 is integrally formed by casting from an aluminum alloy, as has been the case in the past. Detector body 4
There are also advantages such as an excellent joint structure with the cylindrical connecting portion 5 on the side. That is, when the entire housing body 11 is configured as a gui-cast product made of aluminum alloy as described above, the connecting portion connecting with the cylindrical connecting portion 5 on the detection body 4 side made of stainless steel or the like is It was not possible to use simple welding methods, and a joint structure with a gap and depth that complied with the flameproof and explosion-proof guidelines had to be adopted. In order to adopt a joint structure that complies with such flameproof and explosion-proof guidelines, a boss part capable of holding the cylindrical joint part 5 over a predetermined length must be formed on the outside or inside of the bottom of the housing body 11. As a result, the joint structure becomes complicated, and the overall size and weight of the instrument are unavoidably increased.

On the other hand, in the configuration according to the present invention, the cylindrical connecting portion 5 and the cup-shaped bottom cover member 41 can be joined by welding,
Since it is not necessary to consider the pressure-resistant and explosion-proof guidelines for this joint, the structure can be simplified and the number of parts, processing, assembly man-hours, etc. can be reduced, and the thickness of the bottom cover member 41 can be adjusted to allow for the joint strength. This has the advantage of being able to be made as thin as possible within limits and reducing weight.

Further, the nozzing body 11 configured as described above
In the bottom cover member 41, the amplifier unit) 21 is installed.
An amplifier chamber 22 is formed for accommodating and arranging the.

In this embodiment, a shield plate 43 that is fitted and fixed into the opening of the bottom cover member 41 is used as a countermeasure against external noise for various electrical components arranged in the amplifier chamber 22. I am using it. This shield plate 43 is the fifth
As shown in FIGS. (a) and (b), the entire body has a substantially disk shape, and the bottom cover member 41 is provided outwardly at a part of its peripheral edge.
It constitutes a locking piece 43a (see FIG. 6, etc.) that is locked when it is fitted into the side, and the other part is bent and formed as an arcuate wall portion 43b, and is easy to assemble with the bottom cover member 41. The structure is such that alignment can be performed appropriately and reliably.

As is clear from FIG. 1, 43c in FIG. 5(a) is a hole for a communication terminal 44 for electrically connecting both surfaces of the shield plate 43, and 43d is a hole for the terminal unit 25.
The fixing hole of the terminal block spacer 45 for assembling etc.
Furthermore, 43e is a large diameter opening opened in the center of this shield plate 43, and this opening 43e is covered with a thin metal plate 46 having the shielding function. this is,
This bottom cover member 41 allows the amplifier chamber and the terminal chamber 26 to communicate with each other so that no pressure buildup occurs between the two chambers, and also ensures a shielding function.

Also, as is clear from Figures 1 and 7, 47 is
In the amplifier chamber 22, a plurality of printed circuit boards 21a, 2
This is a holder for holding 1b in a stacked state at a predetermined interval.

Reference numeral 50 denotes a guide plate which is placed over the terminal board unit 26 and serves as a guide surface 50a whose portion facing the cable lead-in port 29 is bent so as to be inclined;
As is clear from FIG. 1 and FIGS. 8(a) and (b), the electrical components 24a, etc. on the terminal board 24 mentioned above come into contact with the tip of the cable drawn in from the lead-in port 29, and are damaged. The structure is designed so that it will not happen.

Note that the electrical components 2 on the terminal board 24 are attached to this guide plate 50.
It is functionally advantageous to have a shielding function to protect 4a etc. from electrical noise. Furthermore, 52.5 in Figure 1
3 is a connector for electrically connecting the terminal board 25 and the meter 27.

According to the differential pressure/pressure transmitter 1 according to the present invention having the above configuration, the housing main body 11 (bottom cover member 41) constituting the transmitter housing 10 is connected to the tip side of the cylindrical connecting portion 5 of the detection unit body 4. and this housing body 11
The amplifier unit 21, the terminal board unit 25, and optionally the meter 27 are assembled and arranged in a stacked manner from the detection part body 4 side, and the open end of the housing body 11 is closed with the lid body 12. It has a pressure-resistant and explosion-proof structure, and has various excellent effects such as a simplified overall configuration, miniaturization, and cost reduction.

Here, in the embodiment described above, the meter 27 is connected to the amplifier unit 21 or the terminal board unit 2 in the transmitter housing 10.
Although the case in which the meter 27 is stacked on the housing main body 11 and fixed as an example is illustrated, the present invention is not limited to this, and as shown in FIG.
The meter 27 may be rotatably supported by the terminal block 6, and when the lid body 12 is opened, the meter 27 may be rotated to open the inside and the terminal board unit 25 etc. may be easily inspected. It's good.

Note that 61 in the figure is a lead wire having a connector 62 connected to the terminal board unit 25 side.

Further, in the embodiment described above, the transmitter housing l
The housing main body 11 constituting the O is composed of a cylindrical member 40 and a bottom cover member 41, which are connected by screws with a gap and depth that satisfy the flameproof explosion-proof guidelines. The invention is not limited to this, but the first θ
Of course, it is also possible to adopt the structure of the connecting portion as explained below in FIGS. (a) and (b). Here, in Figure 1O (a
) and (b), the bottom cover member 41 made of stainless steel and formed into a cup shape is used, and the connecting portion 70 thereof is formed of a plurality of annular protrusions and an annular groove. There is. The bottom cover member 41 having such a joint portion 70 is formed by inserting it into a mold and joining it almost integrally when the cylindrical member 40 is formed of aluminum alloy or the like by gui-casting. do. In this way, it is possible to obtain the joint portion 70 that has a gap and a depth that meet the pressure-resistant and explosion-proof guidelines. Note that in order to prevent the two members from rotating relative to each other in the joint portion 70, it is preferable to form an uneven portion in a portion in the circumferential direction as a rotation stopper.

A modification example of such a configuration is shown in FIG. 11(a).
, (b) and (c), the bottom cover member 41 may be divided into a plurality of parts and these parts may be joined and fixed by welding or the like as appropriate, or as shown in FIG. Only the portion connected to the shaped connecting portion 5 may be integrally formed on the cylindrical member 40 side via the above-mentioned connecting portion 70 as a sleeve. Moreover, as the above-mentioned coupling part 70, FIGS. 13(a) and 13(b),
Various modifications as shown in (c) are possible.

It should be noted that the present invention is not limited to the structure of the embodiment described above, and the shape, structure, etc. of each part of the transmitter may be modified or changed as appropriate, and various modifications may be considered. For example, in the above-mentioned embodiment, the case where the meter 27 is used as an option is illustrated, but the present invention is not limited to this, and the effects of the present invention can be obtained even when the meter 27 is not provided. Needless to say.

〔Effect of the invention〕

As explained above, according to the differential pressure/pressure transmitter according to the present invention, a transmitter housing is connected to a detecting part body having a pressure receiving part via a cylindrical connecting part. , an amplifier room that houses an amplifier unit that receives and arithmetic-processes detection signals from the detection body side, and a terminal that houses a terminal board unit that has terminals that connect the amplifier unit to an external power source and a remote control unit. The chambers are formed in a stacked state from the detection part body side, and
When using a meter as an option, the meter chamber is stacked on the lid side of the terminal chamber so that it can be seen from the outside, so despite the simple and inexpensive configuration, - All the necessary electrical components are built into the instrument9, making it relatively easy to ensure its flameproof and explosion-proof structure, and it also has various advantages such as making the entire instrument smaller, more compact, and lower cost. effective.

Further, according to the present invention, the housing body constituting the transmitter housing is composed of a cylindrical member and a bottom cover member that is connected to the opening at one end of the cylindrical member and is made of a material different from that of the cylindrical member. By integrally connecting these cylindrical members and the bottom cover member through a joint having a gap and a depth that conforms to the flameproof explosion-proof guidelines, the transmitter casing is constructed in one piece. It has the advantage that it can be easily molded, satisfies the required pressure-resistant and explosion-proof structure, and can reduce costs.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view showing an embodiment of the differential pressure/pressure transmitter according to the present invention, FIGS. 2 and 3 are side and front views thereof, and FIGS. 4(a) and (b) are 5(a) and 5(b) show an enlarged front view and side sectional view of the bottom cover member that constitutes a part of the housing body, and the amplifier chamber is assembled into the opening of the bottom cover member. Figure 6 is an enlarged view of the main parts to explain the assembly of the shield plate member to the bottom cover member, and Figure 7 is a diagram showing the inside of the amplifier chamber. 8(a) and 8(b) are schematic sectional views showing the state in which the terminal board unit is installed in the terminal chamber, and FIG. FIGS. 11A and 11B are side sectional views showing another embodiment of the invention; FIGS. Figure (a
), (b), (C), Figures 12 and 13 (a)
,(b). (c) is an enlarged sectional view of a main part for explaining the modification. DESCRIPTION OF SYMBOLS 1... Differential pressure/pressure transmitter, 2a, 2b... Barrier diaphragm, 3... Pressure sensitive sensor, 4... Detector body, 5... Cylindrical connection part, 10... Transmitter housing, 11... Housing body, 12...
... Lid body, 21 ... Amplifier unit, 21a, 2
1b...Printed circuit board, 22...Amplifier room, 23...Terminal block, 23a...Terminal, 24...
...Terminal board, 25...Terminal board unit, 26...
・Terminal room, 27...meter, 28...meter room, 30...transparent plate, 40...cylindrical member, 41
...Bottom cover member, 70...Joining part.

Claims (3)

[Claims] (1) A detection unit body comprising a pressure receiving unit and a means for sensing the pressure received and sending a detection signal, and a detection unit body that is connected and fixed to the tip of a cylindrical connection unit extending from the detection unit body. The transmitter housing includes a housing body having a substantially bottomed cylindrical shape and a lid body that closes the open end of the housing body, and a detection signal from the detection body side is received within the transmitter housing. An amplifier room that houses an amplifier unit that performs calculation processing, and a terminal room that houses a terminal board unit that has terminals that connect the amplifier unit, an external power source, and a remote control unit are formed in a stacked manner from the detection unit body side. At the same time, a differential pressure/pressure transmitter characterized in that a lead-in port for an external cable selectively connected to each of the terminals is formed on a side of the housing body facing the terminal chamber. (2) A detection unit body comprising a pressure receiving unit and a means for sensing the pressure received and transmitting a detection signal, and a detection unit body that is connected and fixed to the tip of a cylindrical connection unit extending from the detection unit body. The transmitter housing includes a housing body having a substantially bottomed cylindrical shape and a lid body that closes the open end of the housing body, and a detection signal from the detection body side is received within the transmitter housing. an amplifier room that houses an amplifier unit that performs arithmetic processing; a terminal room that houses a terminal board unit that has terminals that connect the amplifier unit to an external power source and a remote control unit; A meter chamber containing an indicator that displays the output signal from the sensor is formed in a laminated state from the detection body side, and a transparent plate that allows the indicator to be viewed from the outside of the housing is provided as a part of the housing. A differential pressure/pressure transmitter characterized by the following: (3) Consisting of a housing body that has a substantially bottomed cylindrical shape and is connected to and fixed to the tip of a cylindrical connecting part that extends from the detection part body that is equipped with a pressure receiving part, and a lid that closes the open end of the housing body. The transmitter housing includes a housing main body that includes a cylindrical member and a bottom cover member that is connected to an opening at one end of the cylindrical member and is made of a material different from that of the cylindrical member. Also, a differential pressure/pressure transmitter characterized in that the cylindrical member and the bottom cover member are integrally connected via a connecting portion having a gap and a depth that conforms to the pressure-resistant and explosion-proof guidelines.