JPH0592675U - Differential pressure / pressure transmitter - Google Patents

Abstract

(57) [Abstract] [Purpose] To shorten the sealing and sealing work time by the ball and screw plug in the sealing and sealing part of the sealing liquid for pressure transmission to the sealing space in the detection unit body. [Structure] Both ends of a main body 20 are partitioned by barrier diaphragms 3 and 4, and a sealed space 30 formed in the body is filled with a pressure transmitting sealed liquid 17. Introductory hole 2 that communicates the enclosed space in the main body with the outside
A groove 33 is formed at the tip of at least one of the threads 32a, 31a of the female screw portion 32 of the screw hole 21a on the first side and the male screw portion 31 of the pressing and fixing screw plug 23 of the ball 22. Then, the cross-sectional area of the clearance passage 34 that communicates the enclosed space with the outside is increased.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a differential pressure / pressure transmitter for continuously measuring the pressure difference between two points of various process fluids, and particularly for detecting the pressure acting on the barrier diaphragm enclosed in the detector body. The present invention relates to a structure for sealing and sealing a sealed liquid for pressure transmission.

[0002]

[Prior Art]

 For example, when measuring the flow rate of a fluid in a pipe, an orifice plate is provided in the pipe as a fluid resistance, and the pressure difference on the downstream side is calculated and measured based on a predetermined arithmetic expression. .. The detection unit in the differential pressure transmitter used for this type of differential pressure measurement has a configuration as schematically shown in FIG.

To briefly explain this, reference numerals 1 and 2 in the drawing denote a pair of left and right detection unit bodies that form a main body of the detection unit. The back plate surfaces 1a and 2a are formed on the outer surfaces of the left and right detection unit bodies. The high-pressure side and low-pressure side barrier diaphragms 3 and 4 each having a substantially corrugated disk shape are mounted on the. The back plate surfaces 1a and 2a are each formed in a circular shape having a corrugated cross section that is substantially the same as the barrier diaphragms 3 and 4, and the pressure measuring chambers 5 and 6 are formed between the back plate surfaces 1a and 2a and the barrier diaphragms 3 and 4, respectively. Are formed. Further, as described above, the high pressure PH on the upstream side of the pipe orifice and the low pressure PL on the downstream side are applied to the outer side surfaces of the barrier diaphragms 3 and 4, respectively.

A body inner chamber is formed between the detection unit bodies 1 and 2, and the body inner chamber is partitioned by a corrugated disc-shaped center diaphragm 7 into a pair of left and right chambers 7a and 7b. One chamber 7a is communicated with the pressure measuring chamber 5 on the high pressure side through through holes 8a, 9a for circulating the pressure medium and the enclosed circuit 10, and the other chamber 7b is communicated with the pressure measuring chamber on the low pressure side. 6 through the through holes 8b and 9b, and similarly to the enclosed circuit 11.

On the other hand, a header 12 including an inner cylinder 12a and an outer cylinder 12b, which are made of stainless steel or the like, is provided at the upper ends (lower ends in the figure) of the outer peripheral portions of the detection unit bodies 1 and 2. The sensor unit 13 is disposed inside the sensor unit 13. The sensor unit 13 includes a conventionally known semiconductor pressure-sensitive sensor 14 that partitions the enclosed circuits 10 and 11, and a protector 15 that protects the pressure-sensitive sensor 14 and seals the open ends of the inner cylinder 12a and the outer cylinder 12b. It consists of and.

In this case, the high pressure side enclosing circuit 10 communicates with the inside of the inner cylinder 12 a to apply the high pressure PH to the surface side of the pressure sensitive sensor 14. Further, the low-pressure side enclosed circuit 11 communicates with a passage formed in the protective body 15 or the like through a space passage 16 between the inner cylinder 12a and the outer cylinder 12b, so that the low-pressure PL is applied to the inner surface of the pressure-sensitive sensor 14. I'm giving. Silicon oil is provided in the conduction path between the pressure measuring chambers 5 and 6 and the high pressure side and low pressure side of the pressure sensitive sensor 14 through the through holes 8a, 9a; 8b and 9b and the enclosed circuits 10 and 11. Filled liquid 17 such as is filled as a pressure transmission medium. Reference numeral 18 in the drawing denotes a throttle member provided in the high pressure side and low pressure side pressure fluid passages and passages. In addition, reference numerals 19A and 19B in the figure are cover members that are assembled on the outside of the detection unit bodies 1 and 2 and that form a high pressure chamber and a low pressure chamber for introducing a process-side measurement fluid to act on the barrier diaphragms 3 and 4. Is.

In the differential pressure transmitter having such a configuration, when high pressure PH and low pressure PL are applied to the barrier diaphragms 3 and 4 from the process side, the differential pressure (PH-PL) at this time is detected by the semiconductor. Since it is added to the pressure sensor 14, the sensor 14 is deformed according to the differential pressure, and the amount of deformation is electrically extracted, amplified by an amplifier (not shown), and then displayed on a meter or the like or transmitted remotely. It was something.

By the way, in the differential pressure / pressure transmitter as described above, the sealed space for sealing the sealed liquid 17 is provided inside the main body body 20 constituted by the detection unit bodies 1 and 2. , 6, through holes 8a, 9a; 8b, 9b, and the enclosing circuits 10, 11, and the operation of enclosing the encapsulating liquid 17 in these spaces is carried out at the time of assembling this detecting portion. ..

That is, in order to fill the enclosed liquid 17 in the internal space of the main body 20, first, the above-described components are assembled, and the main body 20 thus obtained is placed in the vertical relationship as shown in FIG. With such a posture as described above, the enclosed space in the body is evacuated, and then the filling liquid 17 is filled and filled from the introduction holes 21 and 21 into the filled space opened on the upper end side of the main body 20.

The introduction holes 21 and 21 are hermetically sealed by the sealing balls 22 and 22 and the screw plugs 23 and 23 for fixing the balls 22 and 22 by applying a pressing force to secure the sealing property. It is designed to be sealed. In FIG. 4, 21a and 21a are screw holes formed in a part of the introduction hole 21 into which the screw plug 23 is screwed, and 24 is used to further hermetically seal the open ends of the introduction holes 21 and 21. It is a potting material.

[0011]

[Problems to be solved by the device]

 However, in the differential pressure / pressure transmitter as described above, the sealing of the introduction holes 21 and 21 of the filled liquid 17 into the filled space inside the main body 20 by the detection body 1 and 2 is performed by the ball 22 and this ball. When the screw plug 23 for pressing and fixing 22 is used, the following problems occur.

That is, conventionally, after filling the filled liquid 17, the filling pipes and the jigs for joints are removed from the introduction holes 21 and 21. At this time, the filled liquid 17 fills the upper end surface of the main body 20. It is in the state of being Then, in this state, in order to seal the introduction hole 21, the ball 22 and the screw plug 23 for pushing the ball 22 are assembled. At this time, the ball 22 and the screw plug 23 are in the introduction hole 21. The filled liquid 17 overflows to the outside as much as it enters.

When the ball 22 of the introduction hole 21 and the screw plug 23 are enclosed, first, the ball 22 is put into the introduction hole 21, and the screw plug 23 is screwed into the screw hole 21 a to seal the ball 22 in the sealing step. When the male screw portion of the screw plug 23 meshes with the female screw portion of the screw hole 21a when it is pressed against the portion 21b for sealing, the enclosed liquid 17 gradually propagates through the gap formed in the meshing portion of the screw portions. It overflows to the outside and the screw plug 23 is screwed in, so that it flows out to the outside.

However, in the gap formed between the screw plug 23 and the screw hole 21a, as the screw plug 23 is screwed in, the outflow passage due to the screw engagement portion becomes longer, and the enclosed liquid 17 is hard to escape. It was.

In particular, as the screw plug 23 used in the sealing seal portion that seals the introduction hole 21 of the filling liquid 17 into the filling space, a general type of screw plug 23 that has been conventionally generally manufactured by cutting, grinding or forging. Screws are used. According to such an ordinary screw, when the male screw portion is screwed into the female screw portion of the screw hole 21a formed on the opening side of the introduction hole 21, there is almost no gap between both members. , Or only a very small gap exists between the screw parts, and if it is attempted to remove the residual enclosed liquid 17 through the gap generated in the meshing part of such screw parts, the threads of both screw parts are The clearance passage formed between the groove and the valley is too small, and it is difficult to swiftly overflow the enclosed liquid 17 and remove it. As a result, the work time for sealing in such a sealing seal portion is increased. There was a problem that it became long.

[0016] Therefore, when the conventional filling liquid 17 is filled, it takes a final working time to seal the ball 22 and the screw plug 23 by screwing, which causes a problem in workability. However, it is desired to take some measures that can solve such problems.

[0017]

[Means for Solving the Problems]

 In order to meet such a demand, the differential pressure / pressure transmitter according to the present invention presses a sealing ball provided in a communication path between the space filled with the pressure transmitting filled liquid formed in the body of the detection unit and the outside. The groove portion is formed at the tip of at least one thread of the male screw portion of the screw plug to be fixed and the female screw portion of the screw hole.

[0018]

[Action]

 According to the present invention, when a sealing ball is inserted into the introduction hole and a screw plug is screwed into the screw hole at the time of sealing and sealing the sealed liquid in the sealed space in the main body body, these male screw parts are Since the groove is formed at the top of the tip of the thread of the female thread, the gap space when the screw plug is screwed into the screw hole is widened compared to the conventional method, and it is guided to the outside through the gap space. It is possible to shorten the time required for the filled liquid to be overflowed when it is spilled out, so that the ball and screw plugs can be sealed and sealed in a short time.

[0019]

【Example】

 1 and 2 show an embodiment of a differential pressure / pressure transmitter according to the present invention. In these drawings, the schematic configuration of the entire detection unit is as illustrated in FIG. Corresponding parts are designated by the same reference numerals, and detailed description thereof will be omitted.

Now, according to the present invention, in the detection part of the differential pressure / pressure transmitter, it becomes a communication path between the sealed space 30 of the pressure transmitting sealed liquid 17 formed in the main body 20 of the detection part and the outside. At least one of the thread ridges 31a, 32a of the male screw portion 31 of the screw plug 23 and the female screw portion 32 of the screw hole 21a for pressing and fixing the sealing ball 22 provided in the introduction hole 21 for sealing this portion It is characterized in that the groove portion 33 is formed at the same time when the thread forming is performed.

Here, in the present embodiment, the male screw portion 31 of the screw plug 23 and the female screw portion 32 of the screw hole 21a are formed by a rolling screw, and at the time of this rolling, the diameter before rolling is determined. By setting the relationship between the concave and convex portions and shortening the rolling time, it is possible to form a concave groove due to the depression at the tip apex of the threads 31a, 32a. It's good.

According to such a configuration, when the sealing liquid 17 is sealed and sealed in the sealing space 30 in the main body 20, the sealing ball 22 is inserted into the introduction hole 21 and the screw hole 21a. When the screw plug 23 is screwed in, the groove 33 is formed by rolling at the tip apex of the screw threads 31a, 32a of the male screw portion 31 and the female screw portion 32. The gap space 34 having a spiral shape when the screw 23 is screwed in can be widened as compared with the conventional one, and the time for leading out the enclosed liquid 17 that is led to the outside through the gap space 34 and overflows can be shortened. As a result, the sealing by the ball 22 and the screw plug 23 can be performed quickly, easily, and reliably in a short time.

Further, if such a configuration is adopted, even if the screw plug 23 is not formed of a corrosion-resistant material, the opening end portion of the introduction hole 21 is covered with a potting material rather than the screw plug 23 for sealing and sealing work. By doing so, a reliable sealing and sealing state can be surely obtained. In particular, such a potting material is difficult to adhere when the enclosed liquid 17 is attached to the peripheral wall of the introduction hole 21, and a reliable sealed state cannot be obtained. However, according to the present invention, the sealing liquid 17 can be removed. Since it can be properly performed, the above-mentioned potting material can be used for sealing, and this has an advantage that restrictions on the material of the screw plug 23 can be eliminated.

It should be noted that the present invention is not limited to the structure of the embodiment described above, and the shape and structure of each part of the sealing seal part, including the structure of the detection part of the differential pressure / pressure converter, can be appropriately modified or changed. Needless to say. For example, in the above-described embodiment, the case where the groove portion 33 by rolling is formed in the screw threads 31a and 32a of the male screw portion 31 of the screw plug 23 and the female screw portion 32 of the screw hole 21a has been described. Is not limited to this, and it will be easily understood that the clearance passage 34 can be increased as compared with the related art by forming only one of the threads.

[0025]

As described above, according to the differential pressure / pressure transmitter according to the present invention, the differential pressure / pressure transmitter is provided in the communication passage between the sealed space of the pressure transmitting sealed liquid formed in the body of the detection unit and the outside. Since a groove is formed at the tip of at least one of the male screw part of the screw plug that presses and fixes the sealing ball and the female screw part of the screw hole, it is possible to seal the inside of the introduction hole despite the simple structure. When inserting a ball and screwing a screw plug into the screw hole to seal the sealed seal of the filled liquid, a clearance space created by the groove formed at the tip apex of the male and female screw threads. Can be expanded compared to the conventional method, and the time required to discharge the filled liquid that is guided to the outside through the gap space and overflows can be shortened, which allows the screw plug to be screwed in quickly, resulting in a ballMoreover, there are various practically excellent effects that the sealing by the screw plug can be surely performed in a short time.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view of a main part of a sealed seal portion for filled liquid showing an embodiment of a differential pressure / pressure transmitter according to the present invention.

FIG. 2 is a schematic cross-sectional view for explaining an outline of a sealing seal portion in the differential pressure / pressure transmitter according to the present invention.

FIG. 3 is an enlarged view of a main part showing another embodiment of the differential pressure / pressure transmitter according to the present invention.

FIG. 4 is a schematic cross-sectional view for explaining a structure of a detection unit in a preferred differential pressure / pressure transmitter to which the present invention is applied.

[Explanation of symbols]

 1 Detection Body 2 Detection Body 3 Barrier Diaphragm 4 Barrier Diaphragm 5 Pressure Measuring Chamber 6 Pressure Measuring Chamber 7 Center Diaphragm 7a One Room 7b Other Room 8a Through Hole 8b Through Hole 9a Through Hole 9b Through Hole 10 Enclosed Circuit 11 Enclosed Circuit 14 Pressure sensor 17 Enclosed liquid for pressure transmission 20 Body of detection unit 21 Introduction hole (communication passage) 21a Screw hole 22 Sealing ball 23 Screw plug 30 Enclosed space 31 Male screw part 31a Screw thread 32 Female screw part 32a Screw thread 33 By rolling Groove 34 Gap passage

Claims (1)

[Scope of utility model registration request] 1. A differential pressure / pressure transmitter comprising barrier diaphragms on both ends of a main body body, and a filled space for filling pressure is filled in a sealed space formed in the body between these barrier diaphragms. At least one screw thread tip in the male screw portion of the screw plug and the female screw portion of the screw hole for pressing and fixing the sealing ball provided in the communication passage between the enclosed space of the enclosed liquid formed in the main body and the outside A differential pressure / pressure transmitter characterized in that a groove is formed in the.