JPS5943328A - Differential pressure transmitter - Google Patents

Abstract

PURPOSE:To provide an easy to work construction of the titled device by arranging a pressure receiving diaphragm provided at both ends of a casing, an elastic member and semiconductor pressure sensitive element so that pressure receiving surfaces of each of them become parallel to one another while the centers thereof are on the same axis. CONSTITUTION:A high pressure side pressure coming at a high pressure side inflow part 21a is transferred to a pressure transmission medium 32A through a pressure receiving diaphragm 23 to be applied to an intermediate diaphragm 29 while to a high pressure side communication hole 35 through a high pressure side communication hole 34 formed in or about a high pressure side block 26. The high pressure side communication hole 35 communicates with one pressure receiving surface of a semiconductor pressure sensitive element 33 and a high pressure side pressure treansmission medium sealing port to transmit pressure to the pressure sensitive element 33. When a pressure transmission medium is sealed in, it is moved to the pressure sensitive element 33 and other parts from the communication hole 35.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention detects differential pressure (14) and corresponds to a difference of 1F (7/7)? It is related to a differential pressure transmitter that outputs a 11° air signal, especially -t.
Regarding the 41q construction.

[Technical Prospects and Problems of the Invention] An example of a conventional differential pressure transmitter is shown in Figure 1. In Fig. 1, the fluid to be measured on the high-pressure side flows into the flange (11 and low) f, 11 (If 4 measurements υ
l (Inlet where the body flows (2a)) Fully healed flange (2)
) are high pressure (illll die "r flam (3)
and the casing (
51, (6) and (7). In addition, diamond counters (3A) and (4A-) are formed on the surfaces of the casings (5), (6), and (7) facing the pressure receiving diaphragms, +3) and (4), respectively. Casings (5), (6), (1) and flanges (+), (
2+ and a U seal member (8) for liquid-tight sealing. An intermediate diaphragm (9) is interposed between the casings (5) and (6).

The first pressure chamber (1) is formed by this intermediate diaphragm (9) and the high pressure 4111j pressure receiving tire phragm (3).
), a pressure transmission medium (12A) is contained in the second pressure chamber (11) formed by the intermediate diaphragm (9) and the low pressure side pressure receiving diaphragm (4).
B) are filled respectively. Further, a semiconductor pressure-sensitive element (1:13) is provided in the casing (7), and this semiconductor pressure-sensitive element (+31 is a communication hole (1, 4), 41
．． Pressure transmission medium (12A) via 51.

(12B) detects the differential pressure between the pressures transmitted to the two pressure receiving surfaces, converts it into a pressure signal corresponding to this differential pressure, and outputs it to the outside via the lead wire LIi3).

In this structure, M of the intermediate diaphragm (9) is generally
Since the rigidity is designed to be sufficiently larger than the rigidity of the pressure-receiving diaphragms (3) and (4), the influence on the differential pressure transmitted to the semiconductor pressure-sensitive element 03) is extremely small.

Further, the intermediate diaphragm (9) i"l is provided for the purpose of protecting the pressure sensitive element from excessive differential pressure. For example, when a larger pressure is applied from the high pressure side than the low pressure side, the intermediate diaphragm (9) When L moves to the right, the high-pressure side pressure receiving diaphragm (3) moves out of its deflected volume to the right in the figure.When even greater pressure is applied to the high-pressure side,
The intermediate diaphragm (9) further moves to the right in the figure,
The high pressure side pressure receiving tire anorum (3) is connected to the diaphragm part (3).
Take a seat in A). After seating, even if even greater pressure is applied to the high pressure side pressure receiving diaphragm (3), the pressure transmission medium (
Since the pressure applied to in) is maintained at one level of the pressure at the time of seating, there is no risk that the semiconductor pressure sensitive element tl:3) will be damaged due to an excessive pressure difference. The sensitive element is similarly protected even when a pressure that is excessive compared to the high pressure 1111 is applied from the low pressure side.

However, the differential pressure transmitter with this structure has the following drawbacks.

1.11 Pressure sensing element 03) is connected to pressure receiving diaphragm (3+
, < 41, the temperature of the fluid in contact with the liquid, that is, the temperature of the pressure transmission medium inside the pressure receiving diaphragm, and the temperature of the pressure sensitive element (near the temperature of 1 ni) may differ. The method commonly used in this method, which detects the temperature near the L[-element and compensates for temperature errors, causes errors.This is due to expansion due to temperature of the pressure transmission medium,
This is because the error based on the circular occurrence caused by contraction takes on different values at different temperatures.

C2] Since the pressure transmission medium must be sealed in a sufficiently deaerated state in a vacuum, high C: l+llI,
Is it safe to install a publication entrance for each of the low pressure 11111?
- The opening must be provided, making the structure of the casing complicated.

[Purpose of the invention]

The present invention has a structure in which the temperature of the pressure transmission medium in the casing and the temperature of the pressure sensing element are always almost the same even if the temperature of the fluid in contact with the liquid or the ambient temperature changes, and the structure is easy to process. The purpose is to provide a differential pressure transmitter with a structure.

[Summary of the invention]

The present invention includes pressure receiving diaphragms provided on both sides of the casing with their peripheral edges sealed, and a space inside the casing closed by these pressure receiving diaphragms as a first pressure chamber and a space inside the casing. an elastic member disposed within the casing so as to be isolated to a second pressure chamber; a pressure transmission medium encapsulated in each of the first and second pressure chambers; The first pressure chamber has the other pressure-receiving element, and the differential pressure between the target 1111 constant fluid applied with the opening force 11 to both the pressure-receiving diaphragms is detected. A pressure differential characterized in that the pressure receiving surfaces of the tire flamm, the eye fl NL elastic member, and the semiconductor pressure sensitive element are arranged so that they are parallel to each other and their centers are on the same axis. Transmitter 4-Realized and achieved the intended purpose 1-1.

[Practice of the invention +4'j+] Hereinafter, I will explain the non-inventive Song Ping (one example is the same song 4').
Akira-1-ru.

FIG. 2(a), (+)) shows a differential ratio transmitter according to an embodiment of the present invention (7). Figure 2 ta+f+:;l: Cross-sectional view, 2nd
Figure (1)) is a main part view as viewed from arrow A in Figure 2 (a) ('').

In the figure, t2+), l rib is flange, (21a) is high F:
T, E side inflow 1-1, (Z2a) is low FE 1111 inlet, to: 3), +,,! 4) A pressure-receiving diaphragm, with tires r7, A11 and (23
A) There is (24A). t2ii) is the '1-zinc, ()ti) is the high pressure side hook with the diaphragm seating surface (23A), (27) is the diaphragm seating surface (24A).
The low-pressure side block [1 piece, marked (,) is the flange I), which seals between the tg:4+ and the no-r-jinog (25), (,!!11 is the elastic f() 1 (In the mid-evening Ianorum consisting of the example Q Ding Tai j'Fram,
r-)ru. (γ)) (·, j, the first pressure chamber formed on the quotient 1L side, GE &; I, low) 1 - formed on the decoy /C the second pressure chamber, - so It respectively pressure transmission medium (, 32A).

(32B) is enclosed. The key is the semiconductor pressure-sensitive element,
gu3i), (shield) is the crystal pressure side connection [dehole, qllij ~t
'i! O&J, low pressure side communication hole, U()) is a pressure sensitive element,
;) This is a hole for passing the output wire to the outside, and also serves as a communication hole on the low pressure side.

(4i) and (41') are the sealing bodies provided in the holes for sealing the pressure transmission medium; (42) and (42') are the sealing bodies (41);
, (4) It is a sealing body valve that serves to hold down the white.

However, in this structure, the semiconductor pressure sensitive element C(3) is
The pressure receiving part of the pressure receiving diaphragm (2 views C24) of the casing 05) and the intermediate diaphragm C! Arranged so that the center of the pressure receiving part J) is on the axis connecting the centers of each pressure receiving part.

Moreover, the pressure receiving parts are arranged parallel to each other. In addition, the hole for enclosing the pressure transmission medium and the lead wire outlet are arranged in the same direction so that these holes can be machined from the same direction.

Further, the directions of the holes and the pressure receiving direction of the receiving diaphragm 12a are arranged at right angles to each other.

Next, the operation of the differential pressure transmitter according to one embodiment of the present invention will be explained.

High pressure 1jllll entered from the high If side inlet (21a)
)E force is transmitted to the pressure transmission medium (32A) via the pressure receiving diaphragm U3) and applied to the intermediate diaphragm, and also to the high pressure side communication hole C (41) formed in and around the high pressure side block (26). The high pressure side communication hole (9) communicates with one pressure receiving part of the semiconductor pressure sensitive element (3) and the 4% H-side pressure transmission medium enclosure (1). This communication hole C3 is used to transmit pressure to the pressure sensitive element C■ and to enclose a pressure transmission medium.
The pressure transmission medium moves from 5) to the pressure sensitive element (c) and other parts.

On the other hand, the low pressure side F)- which entered from the low pressure side inlet (22a)
The force 01 is transmitted to the pressure transmission medium (32B) via the pressure receiving diaphragm C2, and is applied to the intermediate diaphragm (21) between the low pressure side communication holes and (32B), and is applied to the intermediate diaphragm (21) between the low pressure side communication holes (21 and L-do through hole (4t, Il
The pressure is transmitted to the other pressure receiving part of the pressure sensitive element. Also, the low pressure side communication hole C (l is connected to the low pressure side pressure transmission medium inlet instead of the low pressure side communication hole (31i).

In this way, the tile pressure applied to the semiconductor pressure sensitive element (3, a is one of the receivers 1): the high pressure side receiver 11 - the diaphragm C13 is applied, and the other pressure receiver is low = 11
The 1F force applied to the pressure receiving diaphragm (111) is softened, the differential pressure between these two pressures is detected, and an electric signal corresponding to the difference)E is sent to the outside through lead #M (4:C). .

Now, when a higher pressure is applied to the high-pressure side than the low-pressure side, the differential pressure is applied to the pressure sensing element α), and the intermediate diaphragm 09) moves to the right in the figure, and the pressure receiving diaphragm ) moves to the right. Move to. When further excessive pressure is applied from the high pressure side, the intermediate diaphragm wing moves further to the right, and the pressure receiving diaphragm m3) seats on the diaphragm seating surface (23A,). After seating, even if an even more excessive pressure is applied to the high-pressure side pressure receiving diaphragm (23), the pressure applied to the pressure transmission medium (32A) is maintained at the pressure at the time of seating, and the excessive pressure of pressure-sensitive element C+: <) is maintained. to prevent damage caused by

Note that the intermediate diaphragm 4 is not necessarily limited to a diaphragm, and may be any elastic member (such as a bellows) that can move when pressure is applied. In addition, in the embodiments shown in FIGS. 2(a) and 2(b), the semiconductor pressure-sensitive element (mold) is located on the right side of the intermediate diaphragm in 1).
The effect is the same even if placed on the left side.

〔Effect of the invention〕

According to the present invention, the following effects can be achieved:
.

(''[Semiconductor pressure-sensitive element (:i) is placed in the center of the gauging by placing it at the center of the gauging 1-■-
It is possible to add the element receiving part from the pressure-receiving tire flange 18 to the LF side, and to make the center of the intermediate tire anorum and the center of the area near the pressure-sensitive element the same as that of the pressure-receiving tire flange. By placing it on the 1tQl+ line 1-, the mouth core processing became Shuhoku, and 11. A total of q for each side of
By placing the parts parallel to each other, processing of the re-sink becomes extremely easy.

[2] Since the distance between the pressure-sensitive element and the pressure-receiving tire flat surface is close, the temperature of most of the torque transmission medium in the casing and the temperature of the pressure-sensitive element are approximately 7"C, Sufficient compensation can also be achieved by detecting the warm temperature near the pressure-sensitive element and extracting all the f7iA J-side errors.

C3) Processing is easy because the IJ-do dregs outlet and the pressure transmission medium sealing port can be formed in the same direction, and can be installed in a direction perpendicular to the pressure receiving direction.

(4) Target of the sealing part of the intermediate diaphragm to the casing 1. All communication formed in the casing by means of a diameter smaller than the diameter of the sealing part of the XS 40 tire phragm to the /7--sink. The direction of application of the hole can be the same as the pressure receiving direction of the pressure receiving diaphragm and the machining direction of the lead wire extraction and pressure transmission medium sealing openings, making drilling easy.

[5] The casing body can be made smaller, lighter and vertical.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing a conventional example of a differential pressure transmitter, and Figure 2 (a
)l(1)) shows a differential pressure transmitter according to an embodiment of the present invention, FIG. 2(a) is a sectional view, and FIG. 2(1)) is a cross-sectional view.
It is a main part view as seen from arrow A in a). 21, 22...Flange 21a...High pressure side inflow 22a...Low pressure 11111 inlet 23, 24...Pressure receiving diaphragm 23A, 24A...Diaphragm seat surface 25...
Casing 26...High pressure side block 27...Low pressure side block 28...Seal portion 29...Intermediate diaphragm 30...1st pressure chamber 31...Second pressure chamber 32A, 32B...Pressure Transmission medium 33... Semiconductor pressure sensitive element: 34, 35... High) E side communication hole 36.37, 38.39... Low pressure side communication hole 40...
Lead through hole and low pressure side communication hole 41.41'...Sealing body 42.42'...Sealing body valve 43...Lead - Misaki Kamitsuyo Patent attorney I - Seven - Younger brother 1 figure 7m

Claims (3)

[Claims] (1) Pressure-receiving diaphragms provided at both ends of the casing with their peripheral edges sealed, and the inside of the casing closed by these pressure-receiving diaphragms? between P and i
an elastic member disposed within the casing so as to be separated into a c force chamber and a second If force chamber; a pressure transmission medium enclosed in the first and second pressure chambers, respectively; The pressure receiving surface of the pressure receiving surface communicates with the first pressure chamber and the other pressure receiving surface communicates with the second pressure chamber, respectively, and a semiconductor element that detects the differential pressure in the compartment, converts it into an electrical signal, and outputs it, In the differential pressure transmitter that detects the differential pressure between the fluid to be measured applied to both pressure receiving diaphragms, 111
% that the pressure receiving diaphragms, the elastic member, and the jailU semiconductor sensing element are arranged so that the respective pressures +f+i are parallel to each other and their centers are on the same axis.
Differential pressure transmitter. (2) A patent claim characterized in that the pressure transmission medium sealing port and the output signal lead outlet of the semiconductor pressure sensitive element are arranged in the same direction and in a direction perpendicular to the pressure receiving direction of the pressure receiving diaphragm. Differential pressure transmitter according to range 1. (3) The elastic member is a diaphragm, and the diameter of the sealing portion of the diaphragm to the casing is smaller than the diameter of the sealing portion of the three-diaphragm to the casing. The differential pressure transmitter according to any one of Item 2.