JPH0348128A - Differential pressure/pressure transmitter - Google Patents

Abstract

PURPOSE:To properly and certainly perform connection by welding a cylindrical connection part to the bottom lid part of a transmitter housing having an amplifying unit provided therein an connecting a led-out lead to a printed circuit board at a right angle by solder. CONSTITUTION:Signal leads are led out of the cylindrical connection part 5 provided to a pressure receiving part having a means sending a pressure sensitive signal to a detection part body 4 provided therein in a protruding state. The leading end of the connection part 5 is fitted in and welded to the opening of the bottom lid part of a transmitter housing 10 and an amplifying unit 21 is provided in the transmitter housing 10 by printed circuit boards 21a, 21b having circuits performing the operational processing of detection signals and the surfaces of the printed circuit boards are directly soldered to the leads at a right angle. At this time, slit grooves are provided so that connection holes 9 in which the leads led out from the leading end of the connection part 5 are inserted are positioned on the separate divided pieces of the printed circuit boards. By this constitution, a differential pressure/pressure transmitter reduced in the number of components or the number working processes and connected properly and certainly is obtained.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to, for example, 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 The present invention relates to an improvement of a differential pressure/pressure transmitter by improving the structure of a connecting part with a detection part in this transmitter.

[Conventional technology]

This type of field-installed differential 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. can be.

For example, various configurations have been known in the past, such as those disclosed in Japanese Utility Model Application Publication No. 81-112248.

Conventionally, this type of differential pressure/pressure transmitter generally has a detection part body having a pressure receiving part, etc., and a cylindrical connecting part extending from the detection part body side, which is connected to the tip side and connected to a detection signal sending means. A transmitter case that is equipped with an amplifier unit that is connected to the amplifier unit and an indicator (hereinafter referred to as a meter) that is selectively connected to the amplifier unit and used as an option to confirm the measured value at the installation site; It is equipped with a transmitter casing, etc., consisting of a terminal box that is integrally connected to the side of the transmitter case via a connecting part and has a terminal board connected to the external power supply side, and its internal functional parts. Certain pressure-sensitive sensors, amplifier units, meters, terminal boards, and the like are housed and housed in desired positions with appropriate electrical connections via leads, connectors, and the like. For safety reasons, this type of differential pressure transmitter used in oil refineries, etc. is required to have a pressure-resistant and explosion-proof structure on the outside. This ensures a sealed structure in each part of the container casing, ensuring a pressure-proof structure.

[Problem to be solved by the invention]

By the way, - in the conventional differential pressure/pressure transmitter as mentioned above, the connecting part between the transmitting part case and the cylindrical connecting part on the detecting part body side, which constitute the two transmitter casings, has a structure that complies with the flameproof and explosion-proof guidelines. It is necessary to do so. In other words, conventionally, the cylindrical connection part on the detection part body side mentioned above is made of stainless steel, etc., while the transmitter case is made of aluminum die-casting, which is not suitable for welding and is not suitable for flameproof and explosion-proof construction. The connecting portion must be configured with a gap and depth that match the guideline. Therefore, in the transmitter case described above, the cylindrical connecting portion extending from the detector body side must fit into the through hole into which the connecting portion is fitted. In order to secure the length of the included part, conventionally, an inner boss part was generally provided that protruded into the transmitter case, and the cylindrical connecting part was fitted and fixed inside this part with the above-mentioned explosion-proof gap and depth. structure was adopted.

However, with such a conventional structure, the shape of the transmitter case becomes complicated, and the work of fitting and fixing the cylindrical connecting part into the transmitter case and further wiring and connecting it to the amplifier unit on the transmitter side is cumbersome and cumbersome. This is complicated, and it is necessary to take some measures to solve these problems.

In particular, in the conventional structure described above, a flexible material such as a flexible printed circuit board or a lead wire is used as a means for guiding the detection signal from the pressure-sensitive sensor through the cylindrical connecting part. The configuration is such that it can be connected to the printed circuit board, etc. that makes up the amplifier unit, where the installation position is limited due to internal space, etc.
The number of component parts increased, the number of man-hours per assembly increased, and handling was inconvenient. Furthermore, in such a wiring structure, it is necessary to perform botting or the like in order to maintain insulation between the leads from the sensor, which is problematic in terms of the number of man-hours required. Also, if the impedance of the sensor's eye is small, this will not be such a problem, but if the insulation deteriorates, it will be mixed into the output as sensor noise, and the input from the sensor to the amplifier circuit on the X board etc. It is necessary to pay sufficient attention to ensuring insulation up to the parts and to avoid noise, and it is desired to eliminate such problems.

Furthermore, in this type of differential pressure/pressure transmitter, the entire instrument can be made smaller, lighter and more compact, and the cost can be lowered, and the ease of assembly and wiring work can be improved. etc., and these points must also be taken into consideration.

[Means to solve the problem]

In order to meet the above-mentioned demands, a differential pressure/pressure transmitter according to the present invention is provided with a means for sensing the pressure received at the pressure receiving part and transmitting a detection signal, and a signal transmission lead from this means. A detecting unit body having a cylindrical connecting part protruding from the pressure receiving part, an opening into which the tip of the cylindrical connecting part is fitted is formed on the bottom M side, and the detection signal is received on the bottom cover side. The transmitter housing includes an amplifier unit made of a printed circuit board having a signal processing circuit that performs arithmetic processing. It is made of a weldable material, and the tip of the cylindrical coupling part is fitted into the opening and fixed by welding, and serves as an amplifier unit 71 for the plurality of leads led out from the tip of the cylindrical coupling part facing inside the housing. A printed circuit board is arranged so that the board surface is perpendicular to the leads, and wire connections are made by direct soldering. Further, according to the present invention, in the differential pressure/pressure transmitter having the above-described configuration, a plurality of leads facing inside the housing and led out from the tip of the cylindrical connecting part are inserted and a plurality of leads are connected by soldering. For a printed circuit board on which several connection holes are drilled, the part with each connection hole is a separate piece.
A plurality of slits are formed so as to be located at the center.

[Effect]

According to the present invention, the tip of the cylindrical connecting end on the detection unit body side is fitted into the opening of the bottom cover portion of the transmitter housing, and these are fixed by welding, and the tip of the cylindrical connecting end on the side of the detector body is fitted into the opening of the bottom cover portion of the transmitter housing, and these are fixed by welding. By placing the printed circuit board constituting the amplifier unit with the board surface orthogonal to the protruding signal transmission lead from the detection section, and directly connecting the node to the circuit on the board surface by soldering, Wire connection can be made between the detection unit and the transmitter side.

〔Example〕

FIGS. 1 to 4 show an embodiment of the differential pressure/pressure transmitter according to the present invention, and in these figures, the differential pressure/pressure transmitter is designated as a whole by the symbol l (the differential pressure transmitter is exemplified). is the first
As is clear from the figures, a pair of barrier diaphragms 2a serve as pressure receiving parts.

2b and a detection unit body 4 having a built-in pressure sensor 3 etc. that detects the differential pressure between the two fluid pressures sensed by these barrier diaphragms, and a cylinder protruding 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 tip of the connecting portion 5, and a lid body 12 for closing the open end of the housing body 11.

As is well known, the detection unit body 4 is integrally assembled by fastening a plurality of divided bodies with a port nut, and two types of fluid pressures to be measured are inserted into the body through an inlet 6a, an inlet 6a, Pressure chamber 6.7 introduced from 7a
A pair of side pressure chambers aa and ab are formed in which a pressure transmission medium is sealed between the pressure chambers and the pressure sensor 3, facing each other via the barrier diaphragms 2a and 2b, and these side pressure chambers are connected to the center diaphragm 2C. It is defined by

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 signal extraction leads for guiding the detection signal from the pressure sensor 3 to the outside. 9 protrudes from the tip of the connecting portion 5 while being sealed with a hermetic seal or the like. Here, the configuration of the detection section in the detection section body 4 and its functions and effects are conventionally well known, and detailed explanation thereof will be omitted.

In addition, in this embodiment, the transmitter housing 10 connected to the tip of the cylindrical connecting part 5 on the detection part side has a structure that complies with the pressure-resistant explosion-proof guidelines by the housing body 11 and the lid body 12, and A plurality of printed circuit boards 21a, 21 each have a signal processing circuit therein that receives a detection signal from the detection body 4 side and performs arithmetic processing on the signal.
an amplifier chamber 22 in which an amplifier unit 21 consisting of an electric component 21c mounted therein is housed, and a plurality of terminals 23a for connecting the amplifier 21) to an external power source and a remote control section (not shown); A printed circuit board (terminal board) on which a terminal block 23 and a plurality of electrical components 24a are mounted.
A terminal chamber 26 in which a terminal board unit 24 and a terminal 25 are installed.
, and a meter 2 which is optionally used selectively.
A meter chamber 28 in which the sensor 7 is installed is formed in a stacked state from the detection unit body 4 side. Furthermore, the terminal chamber 26
On the side of the housing main body 11 facing the.

A transparent plate 30 is provided in the housing lid 12 to form a lead-in port 29 for external cables 29a, 29a selectively connected to each terminal 23a, and to make the meter 27 visible from outside the housing 10. opening 30
A is provided on the inside in a condition that satisfies pressure-resistant and explosion-proof conditions. In addition, 29b is a cable protection tube which is provided by internally disposing the cables 29a and 29a and being screwed into the lead-in port 29.

Further, the housing body 11 constituting the transmitter housing 10 described above is constituted by a cylindrical member 40 having a cable lead-in port 29 and a cup-shaped bottom cover member 41 connected to close one end opening of the cylindrical member 40. , an amplifier unit) 21 and a terminal board unit 25 are installed on this bottom cover member 41 side.
etc. are stacked and fixed, and the cylindrical member 40 is rotatably fitted to the bottom cover member 41, so that they are integrally connected with a gap and a depth that conform to the flameproof explosion-proof guidelines,
Furthermore, when using the meter 27 that displays the output signal from the amplifier unit 21 via the terminal board unit 25 as an option, this is connected to the housing body 1.
In this embodiment, the transparent plate 30 is selectively installed inside and fixed to the bottom lid member 41 side constituting the lid body 1.
2 shows a case in which the meter 27 is fixed with a set ring 30b inside, and the meter 27 is screwed and fixed to a hexagonal stud 31 that stands up from the terminal board unit 25 side that is fixed to the bottom cover member 41 side. There is. Furthermore, 31a in the figure is a fixing base to which a bolt 31b passing through the hexagonal stud 31 is screwed.

Here, such a transmitter housing IO and the structure for introducing the transmitter components into its interior will be described in detail using FIGS. 1 to 4. First, a cylindrical member 40 constituting the housing main body 11 is formed by casting, for example, an aluminum alloy or by casting, and a tab-shaped bottom cover member 41, which is assembled with the cylindrical member 40 with a screw 11, is attached to the cylindrical member. 40 cannot be joined by welding, but the cylindrical connecting part 5 on the detecting section side is made of a material that can be joined by welding, such as stainless steel, by drawing or the like. Note that 40a 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 circumferential wall of the bottom cover member 41 which is screwed thereto, and these are screwed together. This allows the gap and depth to meet the flameproof and explosion-proof guidelines for this part. Further, 42 is a push screw for connecting and fixing both members at a desired rotational position at a required location when the threaded portions 40a and 41a are screwed together.

Now, according to the present invention, as described above, the signal transmission lead 9 from the means for sensing the received pressure and transmitting the detection signal
,9. The detection part body 4 has a cylindrical connecting part 5 projecting thereon, and an opening 11141b into which the tip of the cylindrical connecting part 5 is fitted is formed on the bottom cover member 41 side. The housing 10 is equipped with a transmitter I/Using 10 which includes an amplifier unit 21 made up of printed circuit boards 21a and 21b having a signal processing circuit for receiving detection signals and performing arithmetic processing on the member 41 side. At least the part where the opening 41b is formed is made of a material that can be welded to the detection part body 4 side as the bottom cover member 41, and the tip of the cylindrical connecting part 5 is fitted into the opening 41b and fixed by welding, and the housing A plurality of leads 9.9. led out from the tip of the cylindrical connecting portion 5 facing inside the bottom lid member 41.
Against...

The printed circuit board 21a, which becomes the amplifier unit 21, is disposed so that its surface is perpendicular to the leads 9, and is directly connected by soldering.

According to this configuration, the tip of the cylindrical connecting end 5 on the detection unit body 4 side can be fitted into the opening 41b of the bottom cover portion of the transmitter housing 10 and fixed by welding. This not only makes it possible to obtain a connection part structure without any problems in terms of pressure resistance and explosion-proofness, but also allows the signal transmission leads 9, 9 . ..., a printed circuit board 21a constituting the amplifier unit 21 with the board surfaces orthogonal to each other.
, connect the leads 9 to the lead connection holes 60 , 60 , ...
゜9, . . . are inserted and mounted, and the leads 9, 91, . Wiring connection can be made to the housing 10 side. Further, in such a structure, each lead 9, 9 . . . . The insulation between them is reliable, and the problem of increasing the number of parts such as potting and the number of man-hours required in the conventional method can be eliminated. Furthermore, the printed circuit board 21a etc. can be arranged side by side on the bottom cover inside the housing 10. It can be stored and arranged compactly, and has the effect of downsizing the entire transmitter.

In particular, according to 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 in the past, but also the detection part body (4 side It is also excellent in terms of the structure of the abutment part with the cylindrical connecting part 5. That is, when the entire housing body 11 is constructed as a Gui-cast product made of aluminum alloy as in the past, it is made of 7 stainless steel or the like. Simple welding means cannot be used for the connection between the cylindrical connection part 5 on the detection part body 4 side, and a connection structure with a gap and odor line length of ≠ 5 that meets the pressure-resistant and explosion-proof guidelines is required. In addition, in order to adopt a joint structure that complies with such flameproof and explosion-proof guidelines, the boss portion that can hold the cylindrical connecting portion 5 over a predetermined length should be placed on the outside of the bottom of the housing body 11 or on the outside of the bottom of the housing body 11. As a result, the joining structure became complicated, making it unavoidable to increase the size and weight of the instrument as a whole. However, by welding the joint, the flameproof and explosion-proof guidelines were considered. This makes it possible to simplify the structure, reduce the number of parts and the number of assembly steps per process, and reduce the thickness of the bottom cover member 41 by reducing the thickness of the bottom cover member 41.
It has the advantage that it can be made as thin as possible within an allowable range, and weight can also be reduced.

Here, the above-mentioned leads 9, 9. 5(a),
(b) Or if the configuration shown in FIG. 6 is adopted, the lead 9.9. . . and the connection holes 60 , 60 , . This has the advantage that proper and reliable wire connections can be made while ensuring insulation. That is, FIG. 5(a)
, (b), at the connection part of the printed circuit board 21a,
A plurality of slit grooves 82, 62, consisting of circular holes and radial grooves, such that the portions having the connecting holes 60, 60, . . . are located on separate divided pieces 61, 61, . ...
・We are trying to form a In such a configuration, while ensuring the insulation of each part, the leads 9, 9 . ... can be appropriately and reliably absorbed by the elastic deformation of each divided piece 61, and also prevents excessive stress from being applied. It has the advantage of being extremely easy to perform. Further, in FIG. 6, there are divided pieces 81, 61, .・
In addition to this, there are various other possible variations in the shape of the slit grooves, etc. These slit grooves can be formed by punching the printed circuit board 21a by pressing, etc. Although it can be easily obtained by doing this, it goes without saying that it may also be formed by machining.

Further, in the embodiment described above, an amplifier chamber 22 for accommodating and arranging the amplifier unit 21 is formed in the bottom cover member 41 of the housing body 11, and this amplifier chamber 2
A shield plate 43 is fitted and fixed in the opening of the bottom cover member 41 as a countermeasure against noise from the outside for various electrical components arranged inside the bottom cover member 41, and a large diameter opening 43e in the center thereof is fixed. The platform is made of metal foil 46 which has a shielding function. In addition, 44 is a communication terminal 3C for communicating and electrically connecting both sides of this shield plate 43, and 45 is a terminal block spacer provided on this shield plate 43 for assembling the terminal unit 25 etc. . Furthermore, 47 is a plurality of printed circuit boards 21a and 21b inside the amplifier chamber 22.
This is a holder that holds the sheets stacked at predetermined intervals.

Further, 50 is a terminal chamber 2 that is continuous with the amplifier chamber 22 described above.
6, a protective cover having a cable guide function is placed over the mounting surface of the terminal block 23 of the printed circuit board 24 of the terminal board unit 25 so as to cover the external noise blocking component 24a and the circuit surface.

At the side edge of the protective cover 50, in a portion close to the cable lead-in mirror 29, there is a guide surface that guides the cable 29a toward the terminal block 23, for example, an inclined guide surface that is bent toward the lead-in port 29. 50a is formed. Furthermore, 52 and 53 are connectors for electrically connecting the board 24 and the meter 27.

According to the above configuration, the cylindrical connecting portion 5 of the detection body 4
The bottom cover member 41 of the housing body 11 constituting the transmitter housing 10 is connected to the tip side, and the amplifier 2212)21.
The terminal board unit 25 and optionally internal functional parts such as the meter 27 are assembled and arranged in a stacked state, and
By rotatably fitting the cylindrical member 40 into the bottom cover member 41 with a gap and depth that meet the pressure-resistant and explosion-proof guidelines, the housing main body 11 can be easily assembled, and its open end can be attached to the cover body 12. This makes it possible to obtain a differential pressure/pressure transmitter that has a pressure-resistant explosion-proof structure, simplifies the overall configuration, and can be made smaller and lower in cost.

Note 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 l can be modified as appropriate.

It is free to change, and various modifications may be considered.

[Effects of the Invention] As explained above, according to the differential pressure-pressure transmitter according to the present invention, the cylindrical connecting portion having the signal transmission lead from the means for sensing the pressure receiving pressure and transmitting the detection signal is connected to the pressure receiving portion. A signal processing device that includes a detection unit body protruding from the bottom cover, and an opening into which the tip of the cylindrical connection part is fitted is formed on the bottom cover side, and receives the detection signal on the bottom cover side and performs arithmetic processing. It comprises a transmitter housing in which an amplifier unit made of a printed circuit board having a circuit is installed, and at least a bottom cover portion of the housing in which an opening is formed is made of a material that can be welded to the detection body side. The tip of the cylindrical connection part is fitted into the opening and fixed by welding, and the printed circuit board that will become the amplifier unit is connected to the multiple leads led out from the tip of the cylindrical connection part facing inside the housing, with the board surface facing the leads. Because the wires are arranged perpendicular to the wires and connected by direct soldering, despite the simple and inexpensive configuration, #
The structure of the connection between the detector and the transmitter, which requires a pressure-proof structure, can be simplified, the number of component parts and the number of work steps can be reduced, and an appropriate and reliable connection structure can be achieved. Further, according to the present invention, a plurality of connection holes are formed facing into the housing mentioned above, into which a plurality of leads led out from the tip of the cylindrical connection part are inserted and connected by soldering. Since multiple slits are formed on the printed circuit board so that the parts with each connection hole are located on separate pieces, connection to the leads can be made extremely easily and appropriately, and some processing errors can be avoided by separating the parts. The flexibility of the piece allows it to be absorbed, eliminating problems such as excessive stress being applied to the leads and damage to insulation.

[Brief explanation of drawings]

FIG. 1 is a side sectional view showing an embodiment of the differential pressure/pressure transmitter according to the present invention, FIG. 2 is a side view thereof, and FIGS. 3(a) and (b).
) is a schematic plan view and side sectional view of the bottom cover member constituting the housing body, FIG. 4 is a plan view of the inside of the amplifier chamber, and FIG.
Figures (a) and (b) are a plan view of the main parts and a side sectional view showing an example of the connection part of the lead to the printed circuit board that characterizes the present invention, and Fig. 6 is a schematic plan view showing a modification thereof. It is. 1... Differential pressure/pressure transmitter, 4... Detector body 5... Cylindrical connection part, 9-... Lead, 10...
... Transmitter housing 11 ... Housing body, 12 ... Lid body, 21 ... Amplifier unit. 21a, 21b...Print 71.22...Amplifier chamber, 40...Cylindrical member, 41...Bottom M member, 40a, 41a...Threaded portion, 42...・Push screw. 60... Connection hole, 61... Divided piece, 62...
・Slit groove.

Claims (2)

[Claims] (1) A detection part in which a means for sensing the pressure received at the pressure receiving part and sending out a detection signal is installed therein, and a cylindrical connecting part having a lead for transmitting a signal from this means protrudes from the pressure receiving part. A body, a printed circuit board in which an opening into which the tip of the cylindrical connecting part from the detection body side is fitted is formed on the bottom cover side, and a signal processing circuit for receiving the detection signal and performing arithmetic processing thereof is formed. The transmitter housing includes an amplifier unit disposed inside the bottom cover, and at least a bottom cover portion of the transmitter housing in which the opening is formed is made of a material that can be welded to the detection unit body side. The tip of the cylindrical connecting portion is fitted into the opening and fixed by welding, and the printed circuit board constituting the amplifier unit is attached to a plurality of leads led out from the tip of the cylindrical connecting portion facing into the housing. A differential pressure/pressure transmitter characterized by being arranged so that the board surface is perpendicular to the leads and connected by direct soldering. (2) In claim 1, a plurality of connection holes are formed into which a plurality of leads led out from the tip of the cylindrical connection portion facing into the transmitter housing on the detection body side are inserted and connected by soldering. 1. A differential pressure/pressure transmitter, characterized in that a plurality of slits are formed in a printed circuit board provided so that portions having respective connection holes are located on separate divided pieces.