JP2005227137A - Differential pressure transmitter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a differential pressure transmitter which will not reduce the resistance to pressure for differential pressure even when thermal strain on a block section is not permitted to be transmitted to a detection element, by increasing the thickness of adhesive which fixes the detection element and the block section. <P>SOLUTION: The flexible detection element, having a sealed structure in between its one surface and the other surface, is mounted on the block section, and the detection element is deformed by the difference between the pressure applied to the one surface and that applied to the other surface. The deformation is converted into an electrical signal to be transmitted, and the detection element is attached to the block section via an O-ring and the adhesive. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a differential pressure transmitter configured to detect a differential pressure of a measurement object applied to both surfaces of a flexible detection element and to extract a detection signal.

In general, when a flow rate measurement of liquid, gas, vapor or the like, a liquid level measurement, or a pressure measurement is performed in a factory or a plant, a differential pressure transmitter or a pressure transmitter is used as the sensor.

FIG. 6 is a diagram showing a configuration example of the differential pressure transmitter. In FIG. 6, the differential pressure transmitter includes a main body 20 and a detector 30. In the main body 20, the first pipe 40A of the conduit 40 is connected to the flange 20A, and the second pipe 40B is connected to the flange 20B. The conduit 40 is provided with an orifice plate 41 between the pipe 40A and the pipe 40B.

  The fluid 50 to be measured is guided from the piping 40A of the conduit 40 to the flange 20A, and through the orifice plate 41, from the piping 40B to the flange 20B. The fluid 50 guided to the flange 20A and the flange 20B is guided to the conduits 24A and 24B filled with the silicon oil 23 through the seal diaphragm 21, respectively, and the detection element provided in the high pressure vessel 32 of the detection unit 30. The pressure of the fluid 50 is respectively applied to both surfaces of 31.

At this time, the pressure applied to the seal diaphragm 21 is lower on the pipe 40B side than the pipe 40A side due to the orifice plate 41, and a difference is generated in the pressure applied to the detection element 31, so this differential pressure is detected. Then, it is output to an external display unit or the like (not shown) by the Herme terminal 33.

  FIG. 7 is a diagram illustrating an internal configuration example of the detector 30. In FIG. 7, the detector 30 includes a block 5 having a hole 5A into which the silicon oil 23 from the conduit 24B in FIG. 6 is introduced, the pressure of the silicon oil 23 from the conduit 24B in FIG. 6, and the silicon from the conduit 24A. A detection element 4 that receives the pressure of the oil 23, and a lead pin 6 and a wire bond 6A that electrically extract the result of the detection element 4 receiving the pressure are provided.

The detection element 4 is fixed on the block part 5 by applying the adhesive 11 on the block part 5 or on the detection element 4, bringing them into contact with each other, and curing the adhesive 11 by raising the temperature.

  The material of the adhesive 11 for fixing the detection element 4 to the block portion 5 uses epoxy or low melting point glass in consideration of pressure resistance.

In Patent Document 1, an insulating film is formed on one surface of a strain-generating portion of a diaphragm formed of a metal plate, a strain gauge film and a wiring film are provided on the insulating film, and each surface on the front and back of the diaphragm is provided. An example of a differential pressure sensor configured to guide the fluid pressure to the wiring film and to extract the pressure detection signal generated in the wiring film with a wiring drawn through a hermetic seal structure formed in the non-strained portion of the diaphragm Is described.

JP-A-5-18840

  In general, the detection element 4 uses a silicon chip or the like. The block 5 is made of a metal such as kovar for the purpose of maintaining strength. Here, when the metallic block portion 5 expands due to heat, the bonded portion to which the detection element 4 is fixed is also distorted, and accurate detection by the detection element 4 becomes impossible.

In order not to transmit the strain due to the expansion of the block portion 5 to the detection element 4, it is necessary to increase the thickness of the adhesive 11. However, it is not easy to apply a thick adhesive, and it is difficult to control the height after bonding, and since a differential pressure is applied to the detection unit 4, a lateral pressure is applied to the bonding unit. There is a problem that the breakdown voltage is lowered.

The present invention has been made in order to solve the above-described problems. The thickness of the adhesive for fixing the detection element and the block portion is increased so that the thermal strain of the block portion is not transmitted to the detection element. Another object of the present invention is to provide a differential pressure transmitter that does not lower the pressure resistance against the differential pressure.

  In order to achieve such a problem, the invention according to claim 1 has a flexible detection element, and the detection element is attached to the block portion in a seal structure, and one side and the other side In the differential pressure transmitter for converting the deformation based on the pressure difference into an electric signal and transmitting the electric signal, the detection element is attached to the block portion via an O-ring and an adhesive.

The invention of claim 2 is characterized in that a first backup ring having the same diameter as the inner diameter of the O-ring is provided inside the O-ring.

The invention of claim 3 is characterized in that a second backup ring having the same diameter as the outer diameter of the O-ring is provided outside the O-ring.

According to a fourth aspect of the present invention, a first backup ring having a diameter substantially equal to the inner diameter of the O-ring is provided inside the O-ring, and a first backup ring having a diameter substantially equal to the outer diameter of the O-ring is provided outside the O-ring. 2 backup rings are provided.

According to a fifth aspect of the present invention, in any one of the second to fourth aspects, the diameter of the O-ring is higher than the height of the backup ring.

The invention of claim 6 has a detecting element having flexibility, the detecting element is attached to the block portion with a seal structure between one surface and the other surface, and is attached to the one surface and the other surface. In the differential pressure transmitter that deforms the detection element due to a difference in pressure, and converts the deformation into an electric signal and transmits the electric signal, an O-ring, and a groove that is formed in the block portion and accommodates the O-ring, The detection element is attached to the block portion through an adhesive filled between the O-ring and the detection element.

The invention of claim 7 is characterized in that the groove is shallower than the diameter of the O-ring.

The invention of claim 8 is the invention according to any one of claims 1 to 7, wherein the O-ring is made of the same material as the adhesive.

The invention of claim 9 is the invention according to any one of claims 1 to 8, wherein the O-ring and the adhesive are made of a rubber-based material.

  According to a tenth aspect of the present invention, in any one of the first to ninth aspects, the detection element is made of a silicon chip or silicon and a support glass.

According to the present invention, an O-ring is adopted as a bonding portion between the detection element and the block portion, and the detection element is attached to the block portion via the O-ring and the adhesive. For this reason, the bonding height between the detection element and the block part is ensured, and it becomes easy to apply the adhesive with a substantially constant adhesive thickness. Does not affect the bonded portion to which the detection element is fixed, and enables accurate detection by the detection element.

In addition, since a backup ring having the same diameter as the inner diameter of the O-ring is provided inside the O-ring, even if a differential pressure is applied to the detection unit and a lateral pressure is applied to the bonding portion, the lateral pressure is bonded. Only the backup ring and block mounted on the O-ring and the gap between the backup ring and the detection element are applied to the O-ring, and the breakdown voltage is improved.

In addition, since a backup ring having the same diameter as the outer diameter of the O-ring is provided on the outside of the O-ring, even if a differential pressure is applied to the detection portion and a lateral pressure is applied to the bonding portion, the lateral pressure is This applies only to the backup ring and block mounted on the O-ring, not to the entire bonded portion, and to the gap between the backup ring and the detection element, thereby improving the pressure resistance.

In addition, a backup ring having the same diameter as the outer diameter of the O-ring is provided outside the O-ring, and a backup ring having the same diameter as the inner diameter of the O-ring is provided inside the O-ring. Even if lateral pressure is applied to the bonded portion, the lateral pressure is applied not only to the entire bonded portion, but only to the backup ring and the block portion attached to the O-ring and the gap between the backup ring and the detection element. That is, the breakdown voltage is further improved.

In addition, because the O-ring and adhesive used rubber-based materials, even if the block part expands due to heat, the distortion is elastically absorbed by the adhesive part where the detection element is fixed, and the detection element is accurate. Detection is possible.

Further, a groove for accommodating the O-ring was provided on the detection element mounting surface of the block part, and the detection element was attached to the block part via the O-ring and an adhesive. For this reason, the bonding height between the detection element and the block portion is ensured, and the lateral pressure is applied only to the height of the groove provided in the block portion and the gap portion between the detection elements, thereby improving the pressure resistance.

  Hereinafter, the structure of the differential pressure transmitter according to the present invention will be described. FIG. 1 is a block diagram of an embodiment of the present invention. In FIG. 1, the same reference numerals are assigned to the same parts as those in the previous figure. In FIG. 1, the detection unit includes a detection element 4, a block unit 5, a lead pin 6, a wire bond 6 </ b> A, and an adhesive ring 10. In FIG. 1, the detection element 4 is fixed to the block portion 5 via an adhesive ring 10.

  Next, the configuration of the adhesive ring 10 will be described. FIG. 2 is a plan view of the adhesive ring 10 and includes an O-ring 1, backup rings 2 </ b> A and 2 </ b> B, and an adhesive 3. The O-ring 1 is made of, for example, fluorosilicone rubber, and the adhesive 3 is also made of the same material as that of the O-ring 1.

FIG. 2A shows a backup ring 2 </ b> A provided on the outer peripheral side of the O-ring 1. FIG. 2B shows a backup ring 2 </ b> B provided on the inner peripheral side of the O-ring 1. In FIG. 2C, a backup ring 2A is provided on the outer peripheral side of the O-ring 1, and a backup ring 2B is provided on the inner peripheral side.

  3 is a cross-sectional view taken along the line AA in FIG. 2C. Backup rings 2A and 2B are attached to the inner and outer peripheral sides of the O-ring 1, and the height of the backup rings 2A and 2B is the O-ring 1. The upper and lower surfaces are filled with the adhesive 3. For example, the height of the O-ring is 100 μm, the height of the backup ring is about 50 μm, and an adhesive is previously applied thereon to about 300 μm.

Next, a state in which the adhesive ring 10 is attached between the detection element 4 and the block portion 5 will be described. FIG. 4 is an explanatory view of the attachment state of the detection element 4 and the block portion 5 according to the present invention. The detection element 4 is fixed to the block portion 5 while maintaining the height corresponding to the diameter of the O-ring 1.

  Next, another configuration of the differential pressure transmitter according to the present invention will be described. FIG. 5 is a block diagram of another embodiment of the present invention. In FIG. 5, the detection unit includes an O-ring 1, an adhesive 3, a detection element 4, and a block unit 7, and the others are the same as in FIG. 1. That is, instead of the adhesive ring 10 in FIG. 1, a groove 7 </ b> A in which the O-ring 1 is accommodated is provided in a portion where the detection element 4 of the block portion 7 is fixed, and the adhesive filled between the O-ring 1 and the detection element 4 is provided. The detection element 4 is attached and fixed to the block portion 7 via the agent 3. The height of the groove 7 </ b> A is configured to be lower than the diameter of the O-ring 1.

In addition, when it is difficult to manufacture the adhesive ring 10 alone, the adhesive 3 is attached on the block portion 5, the O-ring 1 is attached, and the backup ring is attached to the outer periphery, the inner periphery, or both, Further, the sensor element 4 may be stacked in order such that an adhesive is attached and the detection element 4 is attached from the adhesive.

It is a block diagram of one Example of this invention. 1 is a configuration diagram of an adhesive ring 10. FIG. FIG. 3 is a cross-sectional view of FIG. It is attachment state explanatory drawing of the detection element 4 and the block part 5 by this invention. It is a block diagram of the other Example of this invention. It is a block diagram of a differential pressure transmitter. It is a conventional block diagram of the detector 30 of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 O ring 2A, 2B Backup ring 3 Adhesive 4 Detection element 5 Block part 6 Lead pin 6A Wire bond 7 Block part 7A Groove 10 Adhesive ring

Claims (10)

It has a detection element with flexibility, this detection element is attached to the block part with a seal structure, and deformation based on the difference in pressure applied to one surface and the other surface of the detection element is converted into an electric signal. In the differential pressure transmitter that transmits
A differential pressure transmitter, wherein the detection element is attached to the block portion via an O-ring and an adhesive. The differential pressure transmitter according to claim 1, wherein a first backup ring having a diameter substantially the same as the inner diameter of the O-ring is provided inside the O-ring. The differential pressure transmitter according to claim 1, wherein a second backup ring having a diameter substantially the same as the outer diameter of the O-ring is provided outside the O-ring. A first backup ring having the same diameter as the inner diameter of the O-ring is provided inside the O-ring, and a second backup ring having the same diameter as the outer diameter of the O-ring is provided outside the O-ring. The differential pressure transmitter according to claim 1. 5. The differential pressure transmitter according to claim 2, wherein a diameter of the O-ring is higher than a height of the backup ring. It has a detection element having flexibility, and this detection element is attached to the block portion with a seal structure between one surface and the other surface, and the difference in pressure applied to each of the one surface and the other surface In the differential pressure transmitter that deforms the detection element, converts the deformation into an electric signal, and transmits it.
The detection element is attached to the block part via an O-ring, a groove formed in the block part and accommodating the O-ring, and an adhesive filled between the O-ring and the detection element. Characteristic differential pressure transmitter. The differential pressure transmitter according to claim 6, wherein the groove has a depth smaller than a diameter of the O-ring. The differential pressure transmitter according to claim 1, wherein the O-ring is made of the same material as the adhesive. 9. The differential pressure transmitter according to claim 1, wherein the O-ring and the adhesive are made of a rubber material. The differential pressure transmitter according to claim 1, wherein the detection element is made of a silicon chip or silicon and support glass.

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