JPH0716114U - Transmitter case structure - Google Patents

Abstract

(57) [Abstract] [Purpose] The cylindrical connection part of the terminal box is connected to the through hole of the transmitter case with a structure that has excellent vibration resistance without causing rattling. [Structure] A cylindrical connecting portion 17 of a terminal box 18 is fitted into a through hole 16 formed in a side wall of a transmitter case 15. At this time, the outer cylindrical portion 3 forming the through holes of these cases
The tip end of 2 and the base end of the cylindrical connecting portion of the terminal box are fitted to each other by abutting the tapered surfaces provided on the two. And
The set screw 30 is provided so as to be inclined from the inside of the case with respect to the axis of the fitting portion, and both members are fastened and coupled together to be integrated.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to, for example, a field-installed pressure or differential pressure indicating transmitter (hereinafter simply referred to as a differential pressure / pressure transmitter), and particularly to a case where a terminal box is integrally connected to the side wall of the main body of the transmitter. Regarding the structure.

[0002]

[Prior art]

 This type of field-installed differential pressure / pressure transmitter is installed at the measurement site, etc. in order to measure the pressure, differential pressure, liquid level, etc. of various process fluids and transmit the measurement signal to the controller side. There are various known structures, such as Japanese Utility Model Laid-Open No. 61-112248.

That is, as a conventional differential pressure / pressure transmitter of this type, generally, there is provided a pressure sensing portion and a sensing portion body having pressure sensitive sensor means for sensing the pressure sensing signal and sending a sensing signal, and the sensing portion body. And a transmitting unit case which is internally installed to accommodate an amplifier unit or the like connected to the extended end of the cylindrical connecting unit and connected to the detection signal transmitting means. The transmitter casing includes a terminal box that is integrally connected through a connecting portion and that houses a terminal plate connected to the external power source side inside thereof.

Then, the amplifier unit, the meter, and the terminal plate, which are the parts internally housed in such a transmitter casing, are housed at desired positions in a state where they are appropriately electrically connected by lead wires and connectors. The structure that it was installed internally was adopted.

Further, in such a field-installed differential pressure / pressure transmitter used in, for example, an oil refining factory, it is required to have a pressure-proof explosion-proof structure on the outside thereof for safety reasons. For this reason, the structure is such that the sealing structure at each part of the transmitter casing is secured and the flameproof structure is secured.

[0006]

[Problems to be solved by the device]

 By the way, in the conventional differential pressure / pressure transmitter as described above, the terminal box is not attached to the cylindrical portion having the lead connecting through hole formed in the side wall portion of the transmitter case that constitutes the transmitter casing. There is a problem from a practical point of view when the projecting cylindrical connection part is fitted and continuously connected.

That is, the transmitter case and the terminal box are integrally connected to each other with a reliable sealing property and vibration resistance, and the structure of the connecting part is simple, and the workability and the assembly workability are improved. It is also required to minimize the space and the like.

However, in the above-described conventional general connecting portion, the cylindrical connecting portion on the terminal box side is connected to the cylindrical portion protruding on the side portion of the transmitting portion case via a sealing material such as an O-ring. The structure was such that they were fitted and inserted while being screwed together, and a lock nut was screwed into the threaded portion at the outer end of the connecting portion to integrally connect them.

In addition, in such a structure, screwing or the like is required in the continuous portion, and not only is assembly and screwing troublesome and complicated, but operation such as screwing a lock nut is also necessary. There were problems in terms of structure, workability, assembly, and cost. Furthermore, in such a conventional structure, it is necessary to screw the lock nut onto the threaded portion of the cylindrical connecting portion on the outer end side of the cylindrical portion, and from the viewpoint of workability, the lock nut and It was necessary to provide some space with the terminal box.

For this reason, as shown in FIG. 3, in the above-mentioned connecting portion, the set screw 2 is screwed inside the transmitting case 1, so that the through hole 3 formed in the side wall of the transmitting case 1 is inserted. A structure is also considered in which the cylindrical connecting portion 5 on the side of the terminal box 4 that is fitted inside is fixed. In the figure, 6 is an O-ring which is a sealing material, 7 is a chamfered portion of the inner edge of the outer cylindrical portion 3A forming the through hole 3, and 8 is a chamfered portion 7 on the terminal box 4 side so as to engage with the chamfered portion 7. It is a tapered surface portion formed at the base end of the cylindrical connecting portion 5.

That is, the tip of the cylindrical connecting portion 5 of the terminal box 4 described above is fitted into the through hole 3 of the transmitting portion case 1 with the O-ring 6 interposed, and in this state, the set screw 2 is inserted. Is screwed into the cylindrical connecting portion 5 via the screw hole 2a formed in the inner cylindrical portion 3B in the through hole 3 portion of the transmitting portion case 1 in the centripetal direction, and the cylindrical connecting portion 5 is attached to the case 1 It was fixed from the inside.

However, in such a conventional structure, the cylindrical connecting portion 5 of the terminal box 4 is inserted into the through hole 3 of the transmitting portion case 1 to a predetermined position, and the pressing state is maintained by a jig or the like. However, the set screw 2 is screwed and fixed, but since the cylindrical connecting portion 5 is only fixed in the through hole 3 and there is no force to pull in in the axial direction, the chamfered portion 7 and the tapered surface portion 8 are The contact was likely to be incomplete, rattling was likely to occur even in the fixed state, and there was a problem in terms of vibration resistance of the terminal box 4.

In particular, there is a clearance of about 0.1 mm between the above-mentioned through hole 3 and the cylindrical connecting portion 5 that is fitted and inserted into the through hole 3, which allows the terminal box 4 to be connected to the transmitter case 1. The assembly was incomplete, and rattling was likely to occur. Further, such a problem is insufficient even if the contact of the tapered surface portion 8 with the chamfered portion 7 is ensured by dimensional accuracy or pressing with a jig or the like, and such a problem can be solved. It is hoped that some measures will be taken.

Further, as shown in FIG. 4, in the outer cylindrical portion 3 A of the through hole 3 in the transmitting portion case 1, the set screw 9 with a hexagonal hole is provided with the set screw 2 in the circumferential direction, for example, 90. There is also known one that is screwed into a position (illustration is omitted) that is deviated from the position for temporary fixing.

That is, in such a configuration, with the cylindrical connecting portion 5 of the terminal box 4 fitted in the through hole 3 of the transmitting portion case 1, the set screw 9 for temporary fixing is screwed in to fix them. This prevents the movement in the axial direction and eliminates the need for the above-mentioned jigs, etc., but even with this, rattling can not be avoided in the connected state, as described above. However, the problem of vibration resistance is unavoidable, and such points must be taken into consideration.

The present invention has been made in view of the above circumstances, and has a simple structure when the cylindrical connecting portion of the terminal box is fitted and screwed in the through hole of the transmitter case, and the structure is simple. The purpose is to obtain a transmitter case structure that has excellent workability and assemblability, and can be constructed without rattling the connecting part, and can improve vibration resistance.

[0017]

[Means for Solving the Problems]

 In order to meet the above-mentioned demands, the case structure of the transmitter according to the present invention is such that when the protrusion of the terminal box is connected to the through hole provided in the side wall of the transmitter main body, the protrusion is abutted against the through hole. In addition, the fastening member is inclined and provided with respect to the axis of the fitting portion.

[0018]

[Action]

 According to the present invention, the projecting portion of the terminal box is fitted into the through hole of the side wall of the transmitter to be in contact with the through hole, and the fastening member is inclined with respect to the axis of the fitting portion. With this fastening member, the transmitter main body and the projecting portion of the terminal box are fastened, and thereby the projecting portion of the terminal box can be connected and fixed while being pulled into the through hole of the transmitter body.

[0019]

【Example】

 FIG. 1 and FIG. 2 show one embodiment of the case structure of a transmitter according to the present invention. In these drawings, first, a schematic structure of a differential pressure / pressure transmitter indicated by reference numeral 1 is shown as a whole. A brief description will be given with reference to FIG.

That is, as is well known, the transmitter 10 has a pressure receiving portion for high and low pressure process fluid pressures and senses a differential pressure between the two fluid pressures sensed by these. A detection body from which a pressure sensor or the like is incorporated (both not shown) is connected to the extended end of a cylindrical connecting portion, and a detection signal from the pressure sensor is transmitted through the flexible printed wiring board 11b. As a result, a housing body 13 having a substantially cylindrical shape with a bottom and a bottom-side housing body 13 in which an amplifier chamber 12 in which an amplifier unit 11 is formed by a printed wiring board 11a and the like serving as an amplifier portion for performing the arithmetic processing is formed is formed. A transmitter case 15 including a lid 14 for closing the open end, and a connection opening formed in a part of a side wall of the housing body 13 in the transmitter case 15 which is the transmitter body. The terminal box 18 is provided with a cylindrical connecting portion 17 as a protruding portion which is fitted and fixed in the through hole 16.

Here, reference numeral 19 in the drawing denotes a terminal plate which is incorporated in the terminal box 18 and is connected to a connection lead 20 for connecting with the amplifier chamber 12, and a terminal plate in which the terminal plate 19 is provided. Although not shown, the opening of the box 18 is closed by a lid. Further, in the figure, 24 is a transparent plate provided on a part of the lid 14 in the transmitter case 15, 25 is a meter which is arranged to be visually recognizable from the outside by the transparent plate 24, and these are compliant with the pressure and explosion proof guidelines. It has a well-known structure.

Further, reference numeral 26 is a connecting cylinder body which is fixed to the base end portion of the housing body 13 by screwing and is connected to the detecting body side, and the cylinder body 26 is also provided with a known structure. The schematic configuration of the above-described oscillator 10 is well known in the art, and a detailed description thereof will be omitted.

According to the present invention, in the oscillator 10 as described above, the projecting portion of the terminal box 18 is provided in the through hole 16 provided in a part of the side wall of the housing body 13 which is the transmitter body. When the cylindrical connecting portions 17 are connected and integrally connected, as apparent from FIGS. 1 and 2, the cylindrical connecting portions 17 are fitted into the through holes 16 so as to be brought into contact with each other, and It is characterized in that the set screw 30 as a fastening member is provided so as to be inclined with respect to the axis line of the fitting portion.

Here, in the drawing, 31 and 32 are an inner cylindrical portion protruding from the side wall portion of the housing body 13 to form the through hole 16, and 33 and 34 are inner cylindrical portions 31 and the cylindrical portion. These are a screw insertion hole and a screw hole that are formed so as to be inclined with respect to the tip end of the connecting portion 17 and into which the locking screw 30 is screwed from the inside of the housing body 13. Further, in the figure, reference numeral 35 denotes an inner wall portion of the through hole 16, which is an O-ring as a sealing material interposed between the inner wall portion of the through hole 16 and the cylindrical connecting portion 17, 36 denotes a chamfered portion of the inner peripheral edge of the outer cylindrical portion 32, and 37 denotes It is a taper surface portion formed at the base end portion of the cylindrical connecting portion 17 that is fitted in contact with the chamfered portion 36.

According to such a configuration, the set screw that is obliquely screwed from the inside of the transmitter case 15 (housing body 13) despite having a simple configuration excellent in workability and assembling property. When the housing main body 13 and the cylindrical connecting portion 17 of the terminal box 18 are integrally connected by means of 30, the cylindrical connecting portion 17 of the terminal box 18 is pulled into the through hole 16 of the housing main body 13 so as to connect the both. It can be connected and fixed.

In particular, in such a configuration, the terminal box 18 that is fitted into the through hole 16 with respect to the chamfered portion 36 formed at the inner peripheral edge of the tip end portion of the outer tubular portion 32 in the through hole 16 on the oscillator case 15 side. With the taper surface portion 37 formed at the base end portion of the cylindrical connecting portion 17 of the above abutting, the set screw 30 is obliquely screwed from the inside of the case 15, whereby the chamfered portion 35 and the taper surface portion are formed. 37 and 37 can be fixed to each other so that a so-called wedge effect is produced.

In other words, by screwing the set screw 30 in this way, it is possible to exert an action force so that the cylindrical connecting portion 17 is pulled into the oscillation portion case 15 side within the through hole 16, and thus the conventional connection is achieved. Both parts can be connected and integrated in a desired state without using a special jig or temporary fixing means.

According to the present invention as described above, the oscillator case 15 (housing body 13) and the terminal box 18 are simply slid in the case 15 from a diagonal direction by screwing the set screw 30. It can be connected together without rattling, which can improve vibration resistance, and the transmitter case 15 and the terminal box 18 can be integrated with a minimum required space. it can. Therefore, in such a configuration, there is an advantage that a connecting work in a narrow space is not necessary, and moreover, it is possible to easily and surely connect and integrate.

In addition, with such a configuration, it is possible to suppress the vibration of the terminal box 18 in spite of excellent workability and assembling of each part, which allows the transmitter case 15 side to be suppressed. There is also an advantage that the acceleration magnification can be reduced, and fatigue breakdown in various electric components and the meter 25, etc. incorporated in the case 15 can be prevented.

The present invention is not limited to the structure of the above-described embodiment, and the shape, structure, etc. of each part of the differential pressure or pressure transmitter 1 can be freely modified and changed, and various uses thereof can be made. A modified example of is possible.

[0031]

[Effect of device]

 As described above, according to the case structure of the oscillator according to the present invention, when the projecting portion of the terminal box is connected to the through hole provided in the side wall of the transmitter body, the projecting portion is abutted and fitted into the through hole. In addition, since the fastening member is provided so as to be inclined with respect to the axis line of the fitting portion, the following various practical advantages are achieved in spite of the simple structure with excellent workability and assembly. Produce an effect.

That is, when the transmitter body and the projecting portion of the terminal box are fastened by the fastening member, the projecting portion of the terminal box can be connected and fixed in a state of being pulled into the through hole of the transmitter body. As a result, both can be connected together without rattling, and vibration resistance can be improved, and the transmitter body and terminal box can be integrated with the minimum required space.

According to such a configuration of the present invention, by suppressing the vibration of the terminal box, the acceleration multiplication factor on the transmitter body side can be reduced, and various electric components and There is also an advantage that fatigue failure of meters and the like can be prevented.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a transmitter housing showing an embodiment of a case structure of a transmitter according to the present invention.

FIG. 2 is a schematic cross-sectional view showing the configuration of main parts in FIG.

FIG. 3 is a schematic cross-sectional view for explaining a conventional example.

FIG. 4 is a schematic cross-sectional view for explaining another conventional example.

[Explanation of symbols]

 10 Differential pressure / pressure transmitter (transmitter) 12 Amplifier chamber 13 Housing body 14 Lid body 15 Oscillator case (transmitter body) 16 Through hole 17 Cylindrical connection part (protruding part) 18 Terminal box 30 Set screw (fastening member) ) 31 inner tubular portion 32 outer tubular portion 33 screw insertion hole 34 screw hole 35 O-ring (sealing material) 36 chamfered portion 37 taper surface portion

Claims (1)

[Scope of utility model registration request] 1. A case structure of a transmitter in which a terminal box is connected to a side wall of a transmitter body, wherein a projecting portion of the terminal box is abutted and fitted into a through hole provided in the transmitter, and an axis line of the fitting portion is fitted. The case structure of the transmitter is characterized in that the fastening member is inclined and provided.