JPH05196529A - Differential pressure transmitter - Google Patents

Abstract

PURPOSE:To reduce the size and weight of a differential pressure transmitter and, at the same time, to considerably reduce the manufacturing cost of the transmitter by fetching the pressure in each process pipeline by using one piece of pressure receiving flange. CONSTITUTION:The high and low pressure sides of process pressures are received by using one piece of flange 15 and, at the same time, the received pressures are transmitted to each surface of a sensor 5 by leading the pressures into a block main body 1 from the end of each pressure leading passage 13 and 14 formed in the main body 1 through a circular liquid separating diaphragm 28 and ring-like liquid separating diaphragm 29.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a differential pressure transmitter used in various plants.

[0002]

2. Description of the Related Art As one of differential pressure transmitters used in various plants, the one shown in FIG. 3 is conventionally known.

The differential pressure transmitter shown in this figure comprises a block portion 101 formed in the shape of a thick plate, and pressure receiving flange portions 102 provided on both sides of the block portion 101, and each pressure receiving flange portion 102 has a pressure receiving flange portion 102. The pressure difference between the connected process pipes 103a and 103b is detected and transmitted to the outside.

The block portion 101 connects the block main body 105 formed in the shape of a thick plate, the diaphragm diaphragm 107 provided so as to cover the concave portions 106 formed on both surfaces of the block main body 105, and the concave portions 106, respectively. In order to allow the pressure medium passage 108 formed in the block body 105 to be provided at a substantially central portion thereof, the differential pressure detecting element 109, the pressure medium passage 108, and the block body 105 to penetrate through the block. Body 10
The signal line 111 that is inserted into the signal line hole 110 formed in 5 and guides the output of the differential pressure detection element 109 to the outside, and the signal line 111 while closing the signal line hole 110 of the block body 105. Hermetic seal 112 leading to the outside, and inside the pressure medium passage 108 and the signal line hole 11 sealed by each partition diaphragm 107.
And a pressure medium 113 such as silicone oil filled in 0.

Further, each pressure receiving flange portion 102 is provided with a thick plate-shaped flange main body 115 provided so as to cover each surface of the block main body 105, and a peripheral groove formed on the partition diaphragm 107 side of the flange main body 115. 11
6 is provided with a packing 117 fitted therein, and a bolt-nut mechanism 118 for tightly adhering each of these flange bodies 115 to both surfaces of the block body 105. The pressure of the process pipes 103a and 103b is controlled by the flange body 115. Through the passage hole 119 formed in the upper portion, it is guided to the concave portion 120 formed in the flange main body 115 on the diaphragm diaphragm side.

Then, each process pipe 103a, 103
If each partition diaphragm 107 is distorted by the pressure from b, the pressure applied to each surface of the differential pressure detection element 109 will differ accordingly, and this will be detected by the differential pressure detection element 109, and this detection result will be a signal. It is output to the outside via the line 111.

In addition to such a differential pressure transmitter, various structures are known, but in principle they are based on the same measurement principle.

[0008]

However, in the above-mentioned conventional differential pressure transmitter, the pressure receiving flange portion 102 is used.
There are two requirements, one for high pressure and one for low pressure.

In the case of the differential pressure transmitter, since the process pressure is often high, it is necessary to increase the pressure resistance of the pressure receiving flange portion 102, and to increase the thickness accordingly, which is expensive. There was a problem that it would end up.

Further, if the pressure receiving flange portion 102 is attached with a high degree of accuracy, it may not be possible to connect it to the process pipe when the three-way valve is attached.

In view of the above circumstances, the present invention can take in the pressure of each process pipe with one pressure receiving flange,
Thus, it is an object of the present invention to provide a differential pressure transmitter that can achieve a reduction in size and weight of the transmitter and can significantly reduce the manufacturing cost.

[0012]

In order to achieve the above object, a differential pressure transmitter according to the present invention is provided at a position that divides a pressure medium passage formed in a block body into two, and each surface thereof is divided. A plate-shaped differential pressure detection element in contact with each of the pressure medium passages, a circular diaphragm that closes one end of the pressure medium passage, and a second differential pressure detection element that closes the other end of the pressure medium passage. A ring-shaped diaphragm that is provided so as to surround the outer side of the circular diaphragm, a thick plate-shaped flange that is provided so as to cover the circular diaphragm and the ring-shaped diaphragm, and this flange Of the one surface, the process pressure passage communicating from the portion corresponding to the circular diaphragm to the other surface, and the ring-shaped diaphragm diaphragm of the one surface of the flange. And process pressure passage communicating from the portion corresponding to the ram to the other surface, is characterized in that said flange and a fastening mechanism to come into close contact with the surface of the 隔液 diaphragm side of the block body.

[0013]

In the above structure, one flange receives the high pressure side and the low pressure side of the process pressure, and
The pressure medium passages formed in the block body are guided through the circular diaphragm and the ring-shaped diaphragm to the inside of the block body to be transmitted to each surface of the differential pressure detecting element.

[0014]

1 is a sectional view showing an embodiment of a differential pressure transmitter according to the present invention.

In the differential pressure transmitter shown in this drawing, first, a circular recess 2 and a ring-shaped recess 3 are provided on the plane of the main body block 1. Then, each of these recesses 2 and 3 is covered with one diaphragm 4, and the vicinity of the outer periphery of the circular recess 2 is
The high pressure side diaphragm chamber 25 and the low pressure side diaphragm chamber 26 are formed by welding the vicinity of the outer periphery of the ring-shaped recess 3 to each other.

The diaphragm 4 of the body block 1
A sensor support 6 having the sensor 5 mounted thereon is welded to the surface opposite to the side. At this time, the sensor 5 is airtightly adhered to the back side (low pressure side) of the sensor 5 through the glass tube 7 in the recess provided in the sensor support 6 having a substantially cylindrical shape. The high pressure side measurement chamber is formed by the space 8 between the support base 6.

Further, the sensor support base 6 is formed with a low-pressure side pressure passage 9 which communicates with the cylindrical side surface from the center of the sensor bonding portion, and a lead 10 for outputting the output of the sensor 5 is attached by a hermetic seal. The tip of the lead 10 is connected to the sensor 5 by wire bonding.

A cylindrical cylinder 11 is externally inserted into the sensor support base 6 and welded to the end portion of the sensor support base 6, and welded to the main body block 1 at the butting portion with the main body block 1. The clearance between the sensor support base 6 and the cylinder 11 formed by this is used as the passage 12 on the low pressure side.

Further, the high pressure side diaphragm chamber 25 and the high pressure side measurement chamber 8 are communicated with each other in the main body block 1 to form a high pressure side pressure guiding path 13 and the low pressure side diaphragm chamber 2
A low-pressure side pressure guiding passage 14 that connects 6 and the passage 12 is formed.

The thick plate-shaped flange 15 also has a circular recess 16 and a ring-shaped recess 1 as in the main body block 1.
7 and are provided. Then, a groove 18 for an O-ring is provided on the plane between these recesses 16 and 17, and the O-ring 1
Wear 9. Further, an O-ring groove 20 is provided near the outer periphery of the ring-shaped recess 17, and an O-ring 21 is attached.

Further, a high-pressure side process pipe connection port 22 and a low-pressure side process pipe connection port 23 are provided on the surface of the flange 15 opposite to the recesses 16 and 17, and each of the pressure guide paths 3 is provided.
0, 31 to the process pipe connection port 22 on the high pressure side,
Low-pressure process pipe connection port 23 and circular recess 16
And the ring-shaped recess 17 communicate with each other.

Further, the recessed portion of the flange 15 and the diaphragm portion of the main body block 1 are aligned and tightened with the bolt 24 so that the flange 15 and the main body block 1 are brought into close contact with each other.

After this, the high pressure side diaphragm chamber 25, the high pressure side measurement chamber 8, the high pressure side pressure guiding passage 13, the low pressure side diaphragm chamber 26, and the low pressure side passages 14, 12, 9 are filled with silicone oil 27. To do.

With this structure, the high-pressure side pressure applied to the high-pressure side process pipe connection port 22 is transmitted to the silicon oil 27 in the high-pressure side diaphragm chamber 25 through the circular portion of the diaphragm 4, and the pressure is transmitted. The surface (high pressure side) of the sensor 5 is reached through the path 13 and the pressure measuring chamber 8.

On the other hand, the low-pressure side pressure applied to the low-pressure side process pipe connection port 23 is transmitted to the silicon oil 27 in the low-pressure side diaphragm chamber 26 via the ring-shaped portion on the outside of the diaphragm 4, and the pressure guiding path. It reaches the back surface (low pressure side) of the sensor 5 through 14, 12, and 9.

As a result, a differential pressure is generated in the sensor 5, and a signal (differential pressure detection signal) corresponding to this differential pressure is output to the outside of the sensor body via the lead 10.

As described above, in this embodiment, the pressure on the high-pressure side and the pressure on the low-pressure side can be guided to the sensor 5 serving as the differential pressure detecting portion by the single flange 15, whereby the flange 2 It can be made smaller and lighter than the conventional differential pressure transmitter required, and the manufacturing cost can be considerably reduced.

Further, since the diaphragm 4 on the high-pressure side and the diaphragm diaphragm 29 on the low-pressure side are constituted by one diaphragm 4, the material cost can be reduced.

Further, by forming a circular diaphragm diaphragm 28 and a ring-shaped diaphragm diaphragm 29 with one diaphragm 4, the diaphragm diaphragms 28, 29 on the high-pressure side and the low-pressure side are formed as described below. The stiffness ratio can be set freely.

That is, the error e of the differential pressure transmitter due to the thermal expansion and compressibility of the silicone oil 27 is as shown in the following equation: the amount V (CC) of the silicone oil 27 on one side and the stiffness S of the diaphragms 28, 29. (Pa / cc)

E = k (SH.multidot.VH-SL.VL) (1) where k: coefficient determined by temperature and pressure SH: high pressure side stiffness VH: high pressure side silicone oil amount SL: low pressure side stiffness VL : Silicon oil amount on the low pressure side Therefore, when the diameter of the high pressure side diaphragm and the diameter of the low pressure side diaphragm are the same as in the conventional differential pressure transmitter, the high pressure side stiffness SH and the low pressure side stiffness SL are set. Therefore, the high-pressure side silicone oil amount VH and the low-pressure side silicone oil amount VL must be the same value.

On the other hand, in the above-mentioned embodiment,
As shown in FIG. 2, the diameter a of the circular diaphragm diaphragm 28,
The ratio between the inner diameter b of the ring-shaped diaphragm 29 and the outer diameter c of the diaphragm 29 can be freely set, whereby the stiffness of the circular diaphragm 28 and the ring-shaped diaphragm 29 can be set. It is possible to freely set the ratio with the stiffness of.

Therefore, according to the amount VH of the high-pressure side silicone oil 27 and the amount VL of the low-pressure side silicone oil 27 in the detecting portion, the diameter a of the circular diaphragm 28 is determined so as to satisfy the equation (1). By determining the inner diameter b of the ring-shaped diaphragm 29 and the outer diameter c of the ring-shaped diaphragm 29, the high-pressure side stiffness SH and the low-pressure side stiffness SL can be set. As a result, the temperature error and the static pressure error can be reduced. Moreover, since the differential pressure can be detected by the single flange 15, it is possible to save the trouble of adjusting the position of the connection port when assembling the flange.

In the above-described embodiment, the circular diaphragm diaphragm 28 is on the high pressure side and the ring-shaped diaphragm diaphragm 29 is on the low pressure side. Diaphragm diaphragm 2
Even if 9 is set to the high pressure side, the pressure of each process pipe can be taken in by one flange 15 as in the above-described embodiment, whereby the transmitter can be reduced in size and weight and the manufacturing cost can be reduced. It can be significantly reduced.

Further, in the above-mentioned embodiment, the pressure from the pipes is introduced into the high pressure side and the low pressure side of the differential pressure transmitter, but the low pressure side (or the high pressure side).
When is set to atmospheric pressure (or vacuum pressure) and the measured pressure is guided to the high pressure side (or low pressure side), it can be used as a pressure transmitter or an absolute pressure transmitter.

[0036]

As described above, according to the present invention, 1
The pressure of each process pipe can be taken in by one pressure receiving flange, whereby the size and weight of the transmitter can be reduced, and the manufacturing cost can be considerably reduced.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a differential pressure transmitter according to the present invention.

2 is a plan view of the diaphragm diaphragm shown in FIG. 1. FIG.

FIG. 3 is a sectional view showing an example of a conventionally known differential pressure transmitter.

[Explanation of symbols]

 1 Block Main Body 13, 14 Pressure Passage Path (Pressure Medium Passage) 5 Sensor (Differential Pressure Detection Element) 28 Separation Diaphragm (Circular Separation Diaphragm) 29 Separation Diaphragm (Ring-shaped Separation Diaphragm) 15 Flange 30 Pressure Transmission Path ( Process pressure passage) 31 Pressure guide passage (process pressure passage) 24 Bolt (fastening mechanism)

Claims (1)

[Claims] 1. A plate-shaped differential pressure detecting element, which is provided at a position that divides a pressure medium passage formed in a block body into two, and each surface of which is in contact with each of the pressure medium passages, and the pressure medium passage. A circular diaphragm that closes one of the ends, and a ring-shaped diaphragm that is provided so as to close the other end of the pressure medium passage and that surrounds the outside of the circular diaphragm. A thick plate-shaped flange provided so as to cover the circular diaphragm and the ring-shaped diaphragm, and a process pressure that communicates from one portion of the flange corresponding to the circular diaphragm to the other surface A passage, a process pressure passage communicating from a portion of one surface of the flange corresponding to the ring-shaped diaphragm diaphragm to the other surface, and A differential pressure transmitter, comprising: a fastening mechanism for bringing the lunge into close contact with the surface of the block body on the diaphragm side.