JPH045532A - Differential pressure and pressure transmitter - Google Patents

Abstract

PURPOSE:To realize explosion-proof structure and to miniaturize this transmitter by coupling the housing main body of the transmitter with the tip side of the cylindrical coupling part of a detection part body, incorporating an amplifier unit, a terminal plate unit, etc., in a housing main unit, and closing the opening end of the housing main body with a lid body. CONSTITUTION:The differential pressure and pressure transmitter 1 has the explosion-proof structure by coupling the housing main body 11 (bottom lid member 41) constituting a transmitter housing 10 with the tip side of the cylindrical coupling part 5 of the detection body 4, incorporating the amplifier unit 21, terminal plate unit 25, and further selectively a meter 27 in the housing main body 11 in a laminating state from the side of the detection part body 4, and closing the opening end of the housing main body 11 with the lid body 12; and the whole constitution is simplified and the size and cost are reduced.

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 Utsukai 61-1122
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 gauging 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, the detection part body including the pressure receiving part, the transmitting part case constituting the transmitter gauging connected to this, and the 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 detecting part body comprising a pressure receiving part and a means for sensing the received pressure and sending out a detection signal, and a detecting part body comprising a means for sensing the received pressure and sending out a detection signal, A housing body having a substantially bottomed cylindrical shape and having a partition wall that is connected to and fixed to the distal end of a cylindrical connecting part and that divides an internal space into two chambers approximately at the center in the axial direction thereof, and closing the open end thereof. It is equipped with a transmitter housing consisting of a lid body, and a chamber formed on the detector body side within the transmitter housing contains an amplifier unit that receives a detection signal from the detector body side and processes the signal. The other chamber is formed as a terminal chamber in which a terminal board unit having terminals for connecting the amplifier unit, an external power source, and a remote control unit is installed. A cable entry port from outside the housing is formed on the side of the housing to be selectively connected to each terminal.

[Effect]

According to the present invention, the housing body constituting the transmitter housing is connected to the tip end side of the cylindrical connecting part of the detection body, and the amplifier unit is inserted from the detection body side within the housing body and from the other end side. By incorporating and arranging the terminal board unit, etc., 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 pressure/pressure transmitter.

〔Example〕

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

1 to 4 show an embodiment of the differential pressure/pressure transmitter according to the present invention. As is clear from FIG. 1 etc.,
A detection unit body 4 has a pair of barrier diaphragms 2a and 2b as a pressure receiving unit and incorporates a pressure sensor 3 and the like for detecting the differential pressure between two fluid pressures sensed by these barrier diaphragms 2a and 2b. and a housing body 11 having a substantially bottomed cylindrical shape and connected to and fixed to the tip of the cylindrical connecting part 5 protruding from the detection part body 4.
and a transmitter housing 10 consisting of a lid 12 that closes the open end of the transmitter housing 10. As is well known, the detection unit body 4 described above is integrally assembled by fastening a plurality of divided bodies with bolt donuts, and two types of fluid pressures to be measured are inserted into the body through an inlet. A pair of pressure chambers 6, 7 introduced from 6a, 7a, and a pressure transmitting medium sealed between these pressure chambers 6, 7 facing each other via barrier diaphragms 2a, 2b and up to the pressure sensitive sensor 3. Pressure measuring chambers 8a and 8b are formed, and 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 distal end of the cylindrical connecting part 5 of the detecting part body 4 described above is provided with a partition wall 13 that divides the internal space into two chambers approximately at the center in the axial direction. The housing main body 11 has a substantially bottomed cylindrical shape with a cylindrical member 40 and a cup-shaped bottom lid member 41, which will be described later, and a lid 12 that closes the open end of the housing main body 11 ensures a structure that complies with the pressure-resistant and explosion-proof guidelines. , a plurality of printed circuit boards 21a and 21b for receiving and arithmetic processing the detection signal from the detection body 4 side, and electrical components mounted thereon are placed in a chamber formed inside the detection body 4 side. 21c, and the other chamber has a terminal block 23 having a terminal 23a for connecting the amplifier unit 21 to an external power source and a remote control unit (not shown), Formed as a terminal chamber 26 in which a terminal board unit 25 is formed by a terminal board 24 on which an electrical component 24a is mounted,
A lead-in port 29 for a cable (not shown) from outside the housing IO to be selectively connected to each terminal 23a is formed on the side of the cylindrical member 40 constituting the housing body 11 facing the terminal chamber 26. It is characterized by the fact that it is

Therefore, in this embodiment, a meter chamber 28 is formed on the open end side of the housing body 11 in which a meter 27 that is selectively used as an option is installed.
A transparent plate 30 that allows the components 7 to be viewed from the outside is provided inside an opening 30a opened in the lid 12 constituting the housing 10 in a state that satisfies the pressure-resistant and explosion-proof guidelines.

Note that in this embodiment, the above-described transparent plate 30 is attached to the lid body 12.
The meter 27 is fixed by a set ring 30b inside the terminal board unit 25, while the meter 27 is screwed and fixed to a hexagonal stud 31 erected from the terminal board unit 25 side.

Here, the above-described transmitter housing 10 and the structure for assembling the transmitter components therein will be described in detail using FIGS. 1, 3, and 4. First, in this embodiment,
The housing main body 11 constituting the transmitter housing 10 is formed into a substantially cylindrical shape by casting or die-casting of aluminum alloy, and has a partition wall 13 that divides the internal space into two chambers at the center. The cylindrical member 40 and the cylindrical member 40, which is assembled and fixed by fitting so as to close the opening on one end side (back side of the transmitter), are made of different materials that cannot be joined by welding, such as stainless steel. A case is shown in which the bottom cover member 41 is formed of steel into a substantially cup shape by drawing or the like. The bottom cover member 41 is fitted from the open end of the cylindrical member 40 on the detection unit body 4 side in a substantially fitted state, and is pushed in so that the opening edge 41a thereof is in contact with the partition wall 13. This bottom cover member 41 is assembled by locking a set screw 42 screwed from the side of the cylindrical member 40 into a stepped portion 41c of a recess 41b formed in a part of its outer circumference. It is constructed so that it can perform the functions of preventing removal and preventing rotation with respect to the cylindrical member 40 without rattling. Note that when the above-mentioned depressions 41b are provided at multiple locations in the circumferential direction on the outer circumference of the bottom cover member 41, the cylindrical member 4 of the bottom cover member 41
0 can be arbitrarily selected in the circumferential direction, and the direction determined by the gel pull outlet 29, the meter 27, etc. can be selected as appropriate, and the advantages are obvious.

Further, the fitting portion of the bottom cover member 41 into the cylindrical member 40 is such that the gap and depth of the joint portion meet the pressure-resistant and explosion-proof guidelines. Here, in the figure, 43 is an O-ring, 44 is a holder for stacking and holding a plurality of printed wiring circuit boards 21a and 21b in the amplifier chamber 22, and 45 is a penetrating partition wall 13 of the cylindrical member 40. This is a long-path terminal for electrically connecting the amplifier chamber 22 and the terminal chamber 26.

Further, the bottom of the bottom cover member 41 is provided with an opening 41d into which the cylindrical connecting portion 5 on the detection body 4 side is fitted and welded.

By adopting such a configuration, manufacturing is not only easier than in the case where the entire housing body 11 is integrally formed by casting from an aluminum alloy as has been common 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 die-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 formed of stainless steel or the like is It was not possible to use simple welding methods, and it was necessary to adopt a joint structure with a gap and depth that complied with the flameproof and explosion-proof guidelines. 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. Furthermore, according to the present invention, the detection body 4 of the cylindrical member 40 described above
The amplifier chamber 22, which is formed independently of the terminal chamber 26 by the partition wall 13 and the bottom cover member 41 on the side, can have a reliable flameproof and explosion-proof structure. It is possible to ensure that electrical components are protected from external noise, and its advantages are easily understood.

Reference numeral 50 denotes a guide plate which serves as a guide surface 50a, which is placed over the terminal board unit 26 and whose portion facing the cable lead-in port 29 is bent so as to be inclined. As described above, the terminal plate 24
The structure is such that the electrical components 24a and the like at the top will not come into contact with the tip of the cable drawn in from the lead-in port 29 and be damaged. Note that it is functionally advantageous if this guide plate 50 has a shielding function to protect the electrical components 24a and the like on the terminal board 24 from electrical noise. Furthermore, 52 and 53 in FIG. 1 are connectors for electrically connecting the terminal plate 25 and the meter 27.

According to the differential pressure/pressure transmitter 1 of 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 body 4. and this housing body 1
1, an amplifier unit 21, a terminal board unit 25, and optionally a meter 27 are assembled and arranged in a stacked state from the detection body 4 side, and the open end of the housing body 11 is closed with a lid body 12. As a result, it has a pressure-resistant and explosion-proof structure, and the overall structure is simplified, resulting in advantages such as being smaller and lower in cost.

Here, in the embodiment described above, the meter 27 is connected to the amplifier unit 21 and the terminal board unit 2 in the transmitter housing 10.
5 is laminated and integrally assembled and fixed, but it goes without saying that the present invention is not limited to this.

Furthermore, in the embodiment described above, the transmitter housing 1
The housing body 11 constituting the 0 is composed of a cylindrical member 40 and a bottom cover member 41, which are connected by fitting together with a gap and depth that can satisfy the flameproof explosion-proof guidelines. It goes without saying that the invention is not limited to this, and that a connection structure such as a screw connection may be employed.

In the above-described embodiment, the set screw 42 is inserted into the recess 41b formed on the outer periphery of the bottom cover member 41 and is locked to the stepped portion 41c. For example, as shown in FIG. 5, a cover is formed by screwing a set screw 42 through the bottom cover member 41, and fixing the tip of the screw to the inside of the bottom cover member 41 with adhesive. 60, and may be configured to ensure a gap and length that conforms to the flameproof and explosion-proof guidelines for this part. In addition, in order to securely fix the bottom cover member 41 to the cylindrical member 40, a nut 61 is welded to the recess 41b on the side of the bottom cover member 41 as a fixing member by screwing the setscrew 42. It is also possible to provide it in a fixed manner.

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, there is provided a detection part body comprising a pressure receiving part and a means for sensing the pressure received and transmitting a detection signal, and an extension extending from the detection part body. A housing body having a substantially bottomed cylindrical shape and having a partition wall that divides an internal space into two chambers approximately at the center in the axial direction, and which is fixed by connecting the distal ends of the provided cylindrical connecting portions, and closing the open end thereof. A chamber formed on the detector body side in the transmitter housing is provided with an amplifier unit that receives a detection signal from the detector body side and processes the signal. The other chamber is formed as a terminal chamber in which a terminal board unit having terminals for connecting the amplifier unit, an external power source, and a remote control unit is installed. Since the cable inlet from the outside of the housing is formed on the side of the main body to selectively connect to each terminal, all necessary electrical system components can be integrated into one housing despite the simple structure. It has a variety of excellent effects, such as being able to ensure a pressure-resistant and explosion-proof structure relatively easily, making the entire instrument smaller and more compact, and lowering costs.

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 an 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 can be easily molded, and the presence of the partition wall ensures a reliable partition between the amplifier room and the terminal room, eliminating the need for measures against noise silt, etc., and satisfying the required flameproof and explosion-proof structure.
It also has the advantage of reducing costs.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view showing one embodiment of the differential pressure-pressure transmitter according to the present invention, FIG. 2 is an enlarged view of the main part thereof, and FIGS. 5 and 6 are schematic sectional views showing other embodiments of the present invention. DESCRIPTION OF SYMBOLS 1...Differential pressure/pressure transmitter, 2a, 2b...-barrier diaphragm, 3...Pressure sensitive sensor, 4...-Detection body, 5--Cylindrical connection part, 10-... Transmitter housing, 11... Housing body, 12...
... Lid body, 13 ... - Partition wall, 21 ... Amplifier unit, 21a, 21b ... - Printed circuit board, 22
...Amplifier room, 23...Terminal block, 23a...
・Terminal, 24...Terminal board, 25...One terminal board unit, 26...Terminal chamber, 27...Meter, 28
...Meter room, 29...Cable entry port, 3
0-... Transparent plate, 40... Cylindrical member, 41...
・-Bottom cover member, 41a...Opening edge, 41b-...
Hollow, 41c...step, 42...set screw,
45...--Communication terminal.

Claims (1)

[Claims] 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 connected to and fixed to the tip of a cylindrical connection unit extending from the detection unit body, and its axis line. The transmitter housing includes a housing body having a substantially bottomed cylindrical shape having a partition wall that divides the internal space into two chambers at approximately the center of the direction, and a transmitter housing consisting of a lid body that closes the open end of the housing body. The chamber formed on the detection unit body side is an amplifier chamber in which an amplifier unit that receives a detection signal from the detection unit body side and processes it is installed, and the other chamber is connected to the amplifier unit and the outside. A housing formed as a terminal chamber in which a terminal board unit having terminals for connecting to a power source and a remote control unit is installed therein, and selectively connected to each of the terminals on a side of the housing body facing the terminal chamber. A differential pressure/pressure transmitter characterized by forming a cable entry port from the outside.