JP2006126214A - Differential pressure/pressure transmitter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a differential pressure/pressure transmitter which can take have a large excluding volume, and prevent a sensor breakage due to excessive pressure. <P>SOLUTION: This device comprises a high-pressure (HP) side preliminary load diaphragm 32 arranged in a sidewall face of a body 21; a HP side process diaphragm 34 covering the HP-side preliminary load diaphragm; a HP-side conduction hole 39 is arranged on the outside position at the outer periphery edge part of the HP-side pre-load diaphragm; a low-pressure (LP)-side pre-load diaphragm 36 arranged on a body sidewall face; a LP-side process diaphragm 38 covering the LP-side pre-load diaphragm; a LP-side communication hole 42 is arranged at the outer position of the outer periphery edge part of the LP-side pre-load diaphragm; the HP-side sensor conduction hole 40 which communicates with the HP-side conduction hole; a HP-side excessive pressure conduction hole 41 which communicates with the HP-side conduction hole and pushes from the backside the LP-side preliminary load diaphragm; the LP-side sensor conduction hole 43 which communicates with the LP-side conduction hole; the LP-side excessive pressure conduction hole 44, which communicates with the LP-side conduction hole and pushes from the backside the HP-side pre-load diaphragm. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a differential pressure / pressure transmitter, and more particularly, to a pressure gauge used for industrial measurement, and has a structure that prevents pressure from being transmitted to a sensor even when an excessive pressure is applied to the pressure sensor, thereby preventing damage to the sensor. It relates to a pressure / pressure transmitter.

  Conventionally, “f (φ)” indicating the characteristic of the displacement volume “ΔV” with respect to the pressure “P” of the diaphragm is used as a characteristic index of the diaphragm employed in the differential pressure / pressure transmitter. As this characteristic, a linear relationship having a gradient as uniform as possible in the measurement pressure range is required.

  A differential pressure gauge that employs a center diaphragm with such ideal characteristics makes it possible to obtain an output proportional to the process pressure of the signal from the sensor, and the signal conversion in the amplification section and the correction calculation in the CPU are high order. Even if the higher order terms in the equation are omitted, the measurement error can be minimized.

  In addition, the conventional three-diaphragm system, that is, differential pressure / pressure transmission consisting of a total of three high / low pressure seal diaphragms in contact with the process side of the body and one center diaphragm inside the body. The vessel has a structure in which the center diaphragm moves to both sides by the process pressure.

  As a result, it was necessary to obtain a uniform linear characteristic “f (φ)” in a wide range moving to both sides. In order to obtain these characteristics, a solution for increasing the outer diameter of the center diaphragm or reducing the plate thickness of the center diaphragm is effective.

  However, since the generated stress increases when the plate thickness is reduced, the problem is solved mainly in the direction of increasing the outer diameter of the center diaphragm.

  In the differential pressure / pressure transmitter having such a three-diaphragm system, when an excessive pressure is applied to the high-pressure side and low-pressure side seal diaphragm portions, the applied side seal diaphragm adheres to the body. To do.

  As a result, there is no movement of the pressure transmission oil enclosed in the body, so that there is no pressure transmission to the sensor portion, and no excessive pressure is transmitted to the sensor portion.

  As shown in FIGS. 7 and 8, the configuration of the differential pressure / pressure transmitter 110 includes a pressure detection unit 111 that converts a pressure from a high pressure and a low pressure difference from a process into an electric signal, and the pressure. An amplifying unit 112 including an electric circuit for amplifying the signal generated by the detecting unit 111 is included.

  The pressure detection unit 111 includes a high pressure side flange 113 that forms a high pressure introduction unit that introduces a high pressure from the process, and a low pressure side flange 114 that forms a low pressure introduction unit that introduces a low pressure from the process, The high pressure side flange 113 and the low pressure side flange 114 are configured by a pressure receiving portion 115 that detects high pressure and low pressure by a diaphragm, and the high pressure side flange 113 and the low pressure side flange 114 are structured to be locked by a nut 116 and a bolt 117. is there.

  As shown in FIG. 8, the pressure receiving portion 115 includes a body 121 having an upper middle position formed in a narrow neck shape, a sensor portion 123 locked by a ring 122 at the upper central position of the body 121, and a lower portion of the body 121. It has a high-pressure side diaphragm portion 124 and a low-pressure side diaphragm portion 125 that are disposed so as to face each other and face outward.

  Further, inside the body 121, a high pressure side oil transmission hole 126 for transmitting oil from the high pressure side diaphragm portion 124 to the sensor portion 123 and a low pressure side oil for transmitting oil from the low pressure side diaphragm portion 125 to the sensor portion 123. And a transmission hole 127. Hereinafter, details of each component will be described.

  The sensor unit 123 is electrically connected by wire bonding to the terminal 128, a differential pressure sensor 129 for detecting a differential pressure by applying a pressure on the high pressure side from the top and a pressure on the low pressure side from the bottom, and the differential pressure sensor 129. It consists of a pair of connected hermetic terminals 130a and 130b. The pair of hermetic terminals 130a and 130b communicate with the amplifying unit 112 shown in FIG.

  Between the high pressure side diaphragm portion 124 and the body 121, there is a space in which the high pressure side oil 133 is enclosed, and this space and the high pressure side conduction hole 139 communicating with the space between the center diaphragm C and the body 121. Connect.

  Further, the high pressure side conduction hole 139 is connected to the high pressure side oil conduction hole 126. These spaces are filled with high-pressure oil 133 for transmission.

  Similarly, there is a space in which the low pressure side oil 137 is sealed between the low pressure side diaphragm portion 125 and the body 121, and the low pressure side conduction that communicates with this space and the space between the center diaphragm C and the body 121. The low-pressure side conduction hole 142 is connected to the low-pressure side oil conduction hole 127. These spaces are filled with low-pressure oil 137 for transmission.

  In the differential pressure / pressure transmitter 110 having such a structure, particularly in the pressure receiving unit 115, for example, when the high pressure side process diaphragm 134 receives pressure from the high pressure side process, the pressure is applied to the high pressure side oil 133. The transmitted pressure of the high-pressure side oil 133 passes through the high-pressure side conduction hole 139 and is supplied to the differential pressure sensor 129 and the center diaphragm C of the sensor unit 123 through the high-pressure side sensor conduction hole 126.

  At the same time, when the low pressure side process diaphragm 125 receives pressure from the low pressure side process, the pressure is transmitted to the low pressure side oil 137, and the transmitted pressure passes through the low pressure side conduction hole 142, and the low pressure side sensor conduction hole 127. Is supplied to the differential pressure sensor 129 and the center diaphragm C of the sensor unit 123.

  In this way, the pressures from the high pressure side and the low pressure side are transmitted by the oils 133 and 137, and the difference is detected by the differential pressure sensor 129.

  Here, a pressure difference occurs between the high pressure side and the low pressure side. For example, when the pressure balance between the high pressure side and the low pressure side is lost and the pressure on the high pressure side becomes excessive, the high pressure side diaphragm 124 moves to the body 121 side. At this time, the center diaphragm C also bends corresponding to the volume of the oil that has moved.

  Further, the low pressure side oil is also moved by the deflection of the center diaphragm C, and the low pressure side diaphragm 125 is pushed out.

  However, when the three-diaphragm center diaphragm described in the prior art is employed, the stress generated in the center diaphragm is increased, and there is a problem that a material having a high strength must be employed.

  Also, in order to form a diaphragm, the material itself needs to be ductile. However, if the stress generated by the center diaphragm used in the differential pressure / pressure transmitter increases, a strong material with no ductility is essential. It becomes.

  In view of the above, in the center diaphragm of the prior art, since a strong material is hard and does not extend, it becomes difficult to mold as a center diaphragm, and these conflicting problems cannot be solved.

  Therefore, the waveform shape of the center diaphragm is improved, and it is resolved to have a shape that increases a large excluded volume even with a small stress, that is, a volume that is larger than the moving volume of the center diaphragm in the initial state and the pressure applied state. Has a problem that must be done.

The differential pressure / pressure transmitter according to the present invention that achieves the above object is as follows.
(1) In a differential pressure / pressure transmitter having a sensor that detects the difference between the pressure of the high-pressure side oil and the pressure of the low-pressure side oil, the high pressure that is arranged facing the back and facing outward from the body A high-pressure side diaphragm portion and a low-pressure side diaphragm portion, wherein the high-pressure side diaphragm portion includes a high-pressure side wetted portion having a wetted surface in which a side wall surface of the body is formed in a first concave curved surface shape, and the first concave portion. A high pressure side preloading diaphragm disposed in contact with the curved surface and covering the high pressure side preloading diaphragm, and a space between the high pressure side preloading diaphragm is filled with the high pressure side oil, A high pressure side process diaphragm that transmits high pressure to the high pressure side oil; and a high pressure side wetted part that communicates with the high pressure side wetted part at an outer position of an outer peripheral end of the high pressure side preload diaphragm. A low pressure side liquid contact portion having a wetted surface in which a side wall surface of the body is formed in a second concave curved surface shape, and a high pressure side conductive hole filled with side oil. A low-pressure side pre-loading diaphragm disposed in contact with the concave curved surface 2 and the low-pressure side pre-loading diaphragm, and a space between the low-pressure side pre-loading diaphragm is filled with the low-pressure side oil, A low-pressure side process diaphragm that transmits low pressure from the process to the low-pressure side oil, and is formed in communication with the low-pressure side wetted part at an outer peripheral end portion of the low-pressure side preloading diaphragm, A low-pressure side conduction hole filled with oil, communicated with the high-pressure side conduction hole, and communicated with the high-pressure side oil through the high-pressure side conduction hole. A high pressure side overpressure conduction hole arranged to push the pre-loading diaphragm from behind, a low pressure side sensor conduction hole communicating with the low pressure side conduction hole and transmitting the low pressure side oil to the sensor unit, and the low pressure side conduction A differential pressure / pressure transmitter comprising: a low pressure side overpressure conduction hole which communicates with the hole and is arranged to push the high pressure side preloading diaphragm from behind.
(2) The high pressure side overpressure conduction hole is arranged so as to push a substantially center position of the low pressure side preloading diaphragm from behind, and the low pressure side overpressure conduction hole is located behind the substantially center position of the high pressure side preloading diaphragm. The differential pressure / pressure transmitter according to (1), wherein the differential pressure / pressure transmitter is arranged so as to be pushed from the side.
(3) The high-pressure process diaphragm that transmits high pressure from the process to the high-pressure side oil, and the high-pressure side liquid-contact surface that has the low-pressure side overpressure conduction hole on the front side and the high-pressure side oil The high pressure side pre-loading diaphragm, the low pressure side process diaphragm that transmits low pressure from the process to the low pressure side oil, the low pressure side that has the high pressure side overpressure conduction hole on the back side and the back side is in contact with the low pressure side oil A low pressure side pre-loading diaphragm disposed so as to be bonded to the liquid contact surface, and a sensor unit for detecting a difference between the pressure of the high pressure side oil and the pressure of the low pressure side oil, and the high pressure side diaphragm portion includes: And a high-pressure side wetted part in which the side wall surface of the body is formed in a first concave curved surface shape, and the high-pressure side preloading diaphragm is in contact with the first concave curved surface. The low pressure side diaphragm portion includes a low pressure side liquid contact portion in which a side wall surface of the body is formed in a second concave curved surface shape, and the low pressure side preload diaphragm is formed along the second concave curved surface. A differential pressure / pressure transmitter characterized by being placed in contact.

(1) A high pressure side process diaphragm that transmits high pressure from the process to the high pressure side transmission oil, and a high pressure side wetted liquid that has a surface bonded to the high pressure side transmission oil and has a low pressure side overpressure liquid passage on the back side. A high pressure side diaphragm portion comprising a high pressure side pre-loading diaphragm disposed so as to be joined to the surface, a low pressure side process diaphragm for transmitting low pressure from the process to the low pressure side transmission oil, and the low pressure side transmission oil A low-pressure side diaphragm portion comprising a low-pressure side pre-loading diaphragm disposed so as to join the surface to the low-pressure side wetted surface having the high-pressure side overpressure liquid passage, and the high-pressure side diaphragm portion A differential pressure sensor for detecting a pressure difference between the high pressure side transmission oil from the low pressure side diaphragm and the low pressure side transmission oil from the low pressure side diaphragm The high-pressure side and / or the low-pressure side pre-loading diaphragm includes a center flat portion formed in a disk shape and having a flat central position, and an outer side of the center flat portion. A wave portion formed in a wave shape so as to protrude to the surface side in contact with the high-pressure side and the low-pressure side liquid contact surface, and an outer flat portion formed in a flat manner from the outside of the wave portion to the outer peripheral end portion A differential pressure / pressure transmitter characterized by comprising:
(2) The differential pressure / pressure transmitter according to (1), wherein at least one wave-shaped wave forming the wave portion is provided.
(3) The differential pressure / pressure transmitter according to (1), wherein there are at least two wave-shaped waves forming the wave part.
(4) A high-pressure side process diaphragm that transmits high pressure from the process to the high-pressure side transmission oil, and a high-pressure side wetted liquid that has a surface joined to the high-pressure side transmission oil and has a low-pressure side overpressure liquid passage on the back side. A high pressure side diaphragm portion comprising a high pressure side pre-loading diaphragm disposed so as to be joined to the surface, a low pressure side process diaphragm for transmitting low pressure from the process to the low pressure side transmission oil, and the low pressure side transmission oil A low-pressure side diaphragm portion comprising a low-pressure side pre-loading diaphragm disposed so as to join the surface to the low-pressure side wetted surface having the high-pressure side overpressure liquid passage, and the high-pressure side diaphragm portion A differential pressure sensor for detecting a pressure difference between the high pressure side transmission oil from the low pressure side diaphragm and the low pressure side transmission oil from the low pressure side diaphragm The high-pressure side and / or the low-pressure side pre-loading diaphragm includes a center flat portion formed in a disk shape and having a flat central position, and an outer side of the center flat portion. A wave portion formed in a wave shape in which the height of a wave peak protruding on the surface side in contact with the high pressure side and the low pressure side wetted surface is higher than the height of the wave protruding on the opposite surface, A differential pressure / pressure transmitter comprising an outer flat portion formed flat at a position from the outside to the outer peripheral end portion.
(5) The differential pressure / pressure transmitter according to (4), wherein there is at least one wave-shaped wave forming the wave part.
(6) The differential pressure / pressure transmitter according to (4), wherein there are at least two wave-shaped waves forming the wave part.
(7) A high-pressure side process diaphragm that transmits high pressure from the process to the high-pressure side transmission oil, and a high-pressure side wetted liquid that has a surface joined to the high-pressure side transmission oil and has a low-pressure side overpressure liquid passage on the back side. A high pressure side diaphragm portion comprising a high pressure side pre-loading diaphragm disposed so as to be joined to the surface, a low pressure side process diaphragm for transmitting low pressure from the process to the low pressure side transmission oil, and the low pressure side transmission oil A low-pressure side diaphragm portion comprising a low-pressure side pre-loading diaphragm disposed so as to join the surface to the low-pressure side wetted surface having the high-pressure side overpressure liquid passage, and the high-pressure side diaphragm portion A differential pressure sensor for detecting a pressure difference between the high pressure side transmission oil from the low pressure side diaphragm and the low pressure side transmission oil from the low pressure side diaphragm The high-pressure side and / or the low-pressure side pre-loading diaphragm includes a center flat portion formed in a disk shape and having a flat central position, and an outer side of the center flat portion. A wave portion formed into a wave shape having a larger outside diameter than the inside diameter of a wave peak protruding on the surface side in contact with the high pressure side and the low pressure side wetted surface; A differential pressure / pressure transmitter comprising an outer flat portion formed flat at a position from the outside to the outer peripheral end portion.
(8) The differential pressure / pressure transmitter according to (7), wherein at least one wave-shaped wave forming the wave portion is provided.
(9) The differential pressure / pressure transmitter according to (7), wherein there are at least two wave-shaped waves forming the wave part.
(10) The differential pressure / pressure transmitter according to (7), wherein the outer flat portion has an inner dimension in the center direction that is at least five times the diaphragm plate thickness.

  As described above, since the differential pressure / pressure transmitter according to the present invention has a high-pressure side and a low-pressure side pre-loading diaphragm formed in a wave shape, a large displacement volume can be obtained even at a low pressure. The diaphragm itself can be designed to be small, and there is no need to use a high-strength material, so that the manufacturing process can be simplified and the manufacturing cost can be reduced.

  Next, an embodiment of a differential pressure / pressure transmitter according to the present invention will be described with reference to the drawings.

  As shown in FIGS. 1 and 2, the differential pressure / pressure transmitter of the present invention includes a pre-loading diaphragm that detects an excessive pressure when an excessive pressure is applied to the high-pressure side and low-pressure side diaphragm portions. A pressure detection unit 11 having a structure for converting a pressure from a pressure difference between a high pressure and a low pressure from a process into an electric signal, and an amplification unit 12 including an electric circuit for amplifying a signal generated by the pressure detection unit 11 Become.

  The pressure detection unit 11 includes a high pressure side flange 13 that forms a high pressure introduction unit that introduces a high pressure, a low pressure side flange 14 that forms a low pressure introduction unit that introduces a low pressure, and the high pressure side flange 13, It comprises a pressure receiving portion 15 that detects a high pressure and a low pressure from the low pressure side flange 14 with a diaphragm, and the high pressure side flange 13 and the low pressure side flange 14 are engaged with a nut 16 and a bolt 17.

  As shown in FIG. 2, the pressure receiving portion 15 includes a body 21 and a sensor portion 23 that is locked by a terminal 28 at an upper center position of the body 21.

  The body 21 has a high pressure side diaphragm portion 24 and a low pressure side diaphragm portion 25 which are disposed in a lower position facing each other and facing outward, and inside the body 21, the high pressure side diaphragm portion 24. From the high pressure side oil transmission hole 26 for transmitting the oil from the low pressure side diaphragm part 25 to the sensor part 23, and the low pressure side oil transmission hole part 27 for transmitting the oil from the low pressure side diaphragm part 25 to the sensor part 23. . Hereinafter, details of each component will be described.

  The sensor unit 23 has a differential pressure sensor attached to a terminal 28. The differential pressure sensor detects a differential pressure by applying a pressure on the high pressure side from the top and a pressure on the low pressure side from the bottom.

  The differential pressure sensor has a pair of hermetic terminals electrically connected by wire bonding, and the pair of hermetic terminals is connected to the amplifying unit 12 shown in FIG.

  The high pressure side diaphragm portion 24 is arranged in a state where the high pressure side liquid contact portion 31 having a liquid contact surface 51 having a concave curved surface on the side wall surface of the body 21 and the high pressure side preloading is arranged in contact with the concave curved surface. Diaphragm 32 and high-pressure side conduction hole 39 that has a predetermined space with high-pressure side preloading diaphragm 32 and covers high-pressure side preloading diaphragm 32 and transmits high-pressure side oil 33 to the outside of the outer peripheral end. And a high-pressure side process diaphragm 34 having a planar shape disposed so as to face the outside so as to shield the concave-shaped high-pressure side wetted part 31 from the outside, a high-pressure side preloading diaphragm 32 and a high-pressure side process. It consists of high pressure side oil 33 for transmission filled in the space between the diaphragm 34.

  The low pressure side diaphragm portion 25 is formed on the opposite side of the high pressure side diaphragm portion 24, and has a low pressure side liquid contact portion 35 having a liquid contact surface 52 in which the side wall surface of the body 21 is formed in a concave curved surface shape, and along the concave curved surface. The low-pressure side preloading diaphragm 36 arranged in contact with the low-pressure side preloading diaphragm 36 has a predetermined space and covers the low-pressure side preloading diaphragm 36, and is disposed outside the outer peripheral end portion. A low-pressure side conduction hole 42 that is an inlet of a hole (low-pressure side conduction hole) for transmitting the low-pressure side oil 37 is provided, and the concave-shaped low-pressure side liquid contact part 35 is arranged to face the outside so as to be shielded from the outside. And a low pressure side process diaphragm 38 having a planar shape, and a low pressure side oil 37 for transmission filled in a space between the low pressure side preloading diaphragm 36 and the low pressure side process diaphragm 38. .

  The high-pressure side oil transmission hole 26 communicates with the high-pressure side conduction hole 39, which is in communication with the high-pressure side wetted part 31, at the outer position of the outer peripheral end of the high-pressure side preloading diaphragm 32. The high-pressure side sensor conduction hole 40 for transmitting the high-pressure side oil 33 to the sensor unit 23 and the high-pressure side conduction hole 39 are also communicated with each other so as to push the substantially center position of the low-pressure side preloading diaphragm 36 from behind. And the high pressure side overpressure conduction hole 41.

  The low-pressure side oil transmission hole 27 communicates with the low-pressure side conduction hole 42 that communicates with the low-pressure side liquid contact part 35 at the outer position of the outer peripheral end of the low-pressure side preloading diaphragm 36, and the low-pressure side conduction hole 42. The low pressure side sensor conduction hole 43 for transmitting the low pressure side oil 37 to the sensor unit 23 and the low pressure side conduction hole 42 are also arranged so as to push the substantially center position of the high pressure side preloading diaphragm 32 from behind. And the low pressure side overpressure conduction hole 44.

  The structures of the high pressure side preloading diaphragm 32 and the low pressure side preloading diaphragm 36 are shown in detail in FIG.

  The high-pressure side preloading diaphragm 32 and the low-pressure side preloading diaphragm 36 have the same structure, and a center flat portion 53 having a flat central position formed in a disk shape and a high-pressure side wetted liquid outside the center flat portion 53. The corrugated wave part is formed so that a wave-shaped peak is projected on the surface side of the part 31 and the low-pressure side liquid-contacting part 35 in contact with the liquid contact surfaces 51 and 52 and the opposite surface is flush with the center flat part 53. 54, and an outer flat portion 55 in which a position from the outer end portion of the wave portion 54 to the outer peripheral end portions of the pre-loading diaphragms 32 and 36 is formed flat. The number of wave portions 54 is two in the embodiment, but may be one or two or more.

  The high-pressure side pre-loading diaphragm 32 and the low-pressure side pre-loading diaphragm 36 having such a structure have a structure in which a wave crest protrudes from the surface in close contact with the liquid contact surfaces 51 and 52 and the opposite surface does not protrude. For the plus pressure (+ P) from the high pressure side and low pressure side overpressure conduction holes 41, 44, the peak of the protruding wave portion 54 extends to increase the surface area of the diaphragm itself. Since the area to be pressed is wide, it is possible to obtain a large displacement volume (moving volume in the initial state and in the pressure application state) with a low pressure as compared with a normal diaphragm.

  Further, for the negative side pressure (-P), a large excluded volume cannot be obtained as compared with a normal diaphragm, but this is not a problem because it is not used in the pre-weighted diaphragms 32 and 36.

  As shown in FIG. 6, if the relationship between the pressure (P) and the excluded volume (V) is expressed by “f (φ)”, the pre-weighted diaphragms 32 and 36 of the present invention are employed. When the pressure is applied (+ P), the peak portion of the wave portion 54 extends, so that “f (φ)” is compared with the graph “f (φ)” of the normal three-diaphragm method described in the prior art. Thus, it can be easily understood that the excluded volume (+ V) increases with a steep slope.

  Next, another embodiment of the high pressure side and low pressure side preloading diaphragms 32 and 36 will be described with reference to the drawings.

An example of the high-pressure side and low-pressure side preloading diaphragms 32 and 36 is shown in FIG.
In this example, the high-pressure side and low-pressure side pre-loading diaphragms 32 and 36 include a center flat portion 53A having a flat center position formed in a disk shape, and liquid contact surfaces 51 and 52 outside the center flat portion 53A. The wave portion 54A is formed in a wave shape in which the height hA of the wave peak projecting on the surface side in contact with the surface is higher than the height hB of the wave projecting on the opposite surface, and from the outside of the wave portion 54A to the outer peripheral edge. The outer flat portion 55A is formed with a flat position. The number of the wave portions 54A is two in the embodiment, but may be one or two or more.

  In this way, the shape of the pre-loaded diaphragms 32 and 36 has wave peaks protruding on both sides, but the wave height hA on the wetted surfaces 51 and 52 is higher than the height hB on the opposite side. Depending on the shape, the crest portion of the wave portion 54A extends with respect to the plus side pressure (+ P) from the high pressure side and low pressure side overpressure conduction holes 41, 44, and the surface area of the diaphragm expands. As compared with, a large excluded volume (moving volume in the initial state and in the pressure application state) can be obtained with a low pressure.

  Moreover, compared with a normal diaphragm, a large excluded volume cannot be obtained with respect to the negative side pressure (-P), but this is not a problem because it is an area not used in a pre-weighted diaphragm.

  Next, still another embodiment of the high pressure side and low pressure side preloading diaphragms 32 and 36 will be described with reference to the drawings.

The high pressure side and low pressure side preloading diaphragms 32, 36 are shown in FIG.
The high-pressure side and low-pressure side pre-loading diaphragms 32 and 36 in this example include a center flat portion 53B formed in a disk shape with a flat central position, and a high pressure side and low pressure side wetted fluid outside the center flat portion 53B. A wave portion 54B formed in a wave shape in which the outside diameter R2 is larger than the inside diameter R1 of the wave crest projecting to the surface side in contact with the surfaces 51 and 52, and the outer periphery end from the outside of the wave portion 54B The outer flat portion 55B is formed so that the position reaching the portion is flat.

  As described above, since the outer diameter (radius) R2 is larger than the inner diameter (radius) R1 of the waveform of the wave portion 54B, plus from the high-pressure side and low-pressure side overpressure conduction holes 41 and 44 is achieved. The pressure (+ P) of the inner surface R1 has a better contact with the surface of the wave having a small inner diameter R1, and the extension of the peak portion of the demultiplexing becomes smoother. (Φ) ”is further improved.

  Further, by making the width of the outer flat portion 55B at least five times the plate thickness t of the pre-loading diaphragms 32, 36, the pressure abutting against the inner mountain (radius R1) is received, and the received pressure has a width. By receiving the outer flat portion 55B, it is possible to flexibly expand and deform, and the inclination of the characteristic “f (φ)” of the excluded volume is further improved.

  In this way, the high pressure side and low pressure side pre-heavy weight diaphragms 32 and 36 are corrugated, and the corrugated crests can be received well with positive pressure by changing the diameter in the height direction and width direction. Even if the oil transmission pressure is low, the displacement volume of the high-pressure side and low-pressure side preloading diaphragms 32 and 36 can be increased.

  Therefore, a smaller pre-loading diaphragm can be designed at the design stage, and therefore a more compact pressure receiving portion can be designed. Further, when such a pre-loaded diaphragm is used, it is not necessary to use a special high-strength material for the diaphragm material.

1 is a plan view of a differential pressure / pressure transmitter according to the present invention. It is sectional drawing which showed the pressure receiving part in FIG. It is sectional drawing which showed the structure of the pre-loading diaphragm. It is sectional drawing which showed the structure of the pre-loading diaphragm of another Example. It is sectional drawing which showed the structure of the pre-loading diaphragm of another Example. It is a graph of the characteristic “f (φ)” showing the relationship between the pressure of the pre-weighted diaphragm and the excluded volume. It is a top view of the differential pressure transmitter in a prior art. It is sectional drawing of the pressure receiving part shown in FIG. 7 in a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Pressure detection part 12 Amplifier 13 High pressure side flange 14 Low pressure side flange 15 Pressure receiving part 16 Nut 17 Bolt 21 Body 22 Terminal 23 Sensor part 24 High pressure side diaphragm part 25 Low pressure side diaphragm part 26 High pressure side oil conduction hole 27 Low pressure side oil conduction hole 31 High pressure side wetted part 32 High pressure side preloaded diaphragm 33 High pressure side oil 34 High pressure side process diaphragm 35 Low pressure side wetted part 36 Low pressure side preloaded diaphragm 37 Low pressure side oil 38 Low pressure side process diaphragm 39 High pressure side conduction hole 40 High pressure side Sensor conduction hole 41 High pressure side overpressure conduction hole 42 Low pressure side conduction hole 43 Low pressure side sensor conduction hole 44 Low pressure side overpressure conduction hole 51, 52 Wetted surface 53, 53A, 53B Center flat part 54, 54A, 54B Wave part 55 , 55A, 55B outer flat

Claims (3)

In the differential pressure / pressure transmitter including a sensor unit that detects the difference between the pressure of the high-pressure side oil and the pressure of the low-pressure side oil,
A high-pressure side diaphragm portion and a low-pressure side diaphragm portion that are arranged facing the back to the body and facing outward,
The high-pressure side diaphragm portion is
A high-pressure side wetted part having a wetted surface in which the side wall surface of the body is formed in a first concave curved surface shape;
A high-pressure pre-loading diaphragm disposed in contact with the first concave curved surface;
A high-pressure side process diaphragm that covers the high-pressure side pre-loading diaphragm, a space between the high-pressure side pre-loading diaphragm is filled with the high-pressure side oil, and transmits high pressure from a process to the high-pressure side oil;
A high-pressure side conduction hole that is formed in communication with the high-pressure side wetted part at an outer position of an outer peripheral end of the high-pressure side preloading diaphragm, and is filled with the high-pressure side oil;
The low-pressure side diaphragm portion is
A low-pressure side wetted part having a wetted surface in which the side wall surface of the body is formed in a second concave curved surface shape;
A low pressure side pre-loading diaphragm disposed in contact with the second concave curved surface;
A low pressure side process diaphragm that covers the low pressure side preloading diaphragm, a space between the low pressure side preloading diaphragm is filled with the low pressure side oil, and transmits a low pressure from the process to the low pressure side oil;
A low-pressure side conductive hole formed in communication with the low-pressure side wetted part at an outer position of an outer peripheral end of the low-pressure side pre-loading diaphragm, and filled with the low-pressure side oil;
A high pressure side sensor conduction hole communicating with the high pressure side conduction hole and transmitting the high pressure side oil to the sensor unit;
A high pressure side overpressure conduction hole arranged to communicate with the high pressure side conduction hole and push the low pressure side preloading diaphragm from behind;
A low-pressure side sensor conduction hole communicating with the low-pressure side conduction hole and transmitting the low-pressure side oil to the sensor unit;
A differential pressure / pressure transmitter, comprising: a low pressure side overpressure conduction hole arranged to communicate with the low pressure side conduction hole and to push the high pressure side preloading diaphragm from behind. The high-pressure side overpressure conduction hole is arranged so as to push a substantially central position of the low-pressure side preloading diaphragm from behind,
2. The differential pressure / pressure transmitter according to claim 1, wherein the low pressure side overpressure conduction hole is disposed so as to push a substantially central position of the high pressure side preloading diaphragm from behind. A high-pressure process diaphragm that transmits high pressure from the process to the high-pressure oil;
A high pressure side pre-loading diaphragm arranged so that the surface side is in contact with the high pressure side oil and the back side is joined to the high pressure side wetted surface having a low pressure side overpressure conduction hole;
A low-pressure process diaphragm that transmits low pressure from the process to the low-pressure oil;
A low pressure side pre-loading diaphragm arranged so that the surface side is in contact with the low pressure side oil and the back side is joined to the low pressure side wetted surface having a high pressure side overpressure conduction hole;
A sensor unit for detecting a difference between the pressure of the high-pressure side oil and the pressure of the low-pressure side oil;
The high pressure side diaphragm portion includes a high pressure side liquid contact portion in which the side wall surface of the body is formed in a first concave curved surface shape,
The high-pressure side pre-loading diaphragm is arranged in contact with the first concave curved surface,
The low pressure side diaphragm portion includes a low pressure side liquid contact portion in which a side wall surface of the body is formed in a second concave curved surface shape,
The differential pressure / pressure transmitter, wherein the low-pressure side preloading diaphragm is disposed in contact with the second concave curved surface.

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