JPH062190U - Differential pressure measuring device - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a differential pressure measuring device with improved performance characteristics, assembling property, and workability. [Structure] A center diaphragm that divides the pressure measuring chamber into two pressure chambers, a corrugated separator diaphragm that is provided on each side of the housing and forms a separator chamber with the housing, and a diaphragm diaphragm that faces the separator diaphragm. And a back plate that is provided on the side surface of the housing and has a corrugated shape,
In a differential pressure measuring device provided in a housing and having a communication hole for communicating a pressure chamber and a liquid separating chamber, a first pressure chamber is provided with one end opened to the pressure chamber side and the other end bored close to the back plate.
And at least one second hole smaller than the first hole and having one end open to the back plate and the other end communicating with the other end of the first hole formed by electric discharge machining from the back plate side to the pressure chamber side. And a communication hole including a hole.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a differential pressure measuring device having improved performance characteristics, assembling property, and workability.

[0002]

[Prior art]

FIG. 4 is an explanatory view of the configuration of a conventional example which has been generally used conventionally, and is shown, for example, in FIG. 1 of JP-A-59-56137. In the figure, a flange 2 and a flange 3 are fitted and assembled on both sides of a housing 1 and are fixed by welding or the like. Both flanges 2 and 3 are provided with a high-pressure fluid inlet port 5 of a pressure P _H to be measured and a pressure P _{An L} low-pressure fluid inlet 4 is provided. A pressure measuring chamber 6 is formed in the housing 1, and a center diaphragm 7 and a silicon diaphragm 8 are provided in the pressure measuring chamber 6.

The center diaphragm 7 and the silicon diaphragm 8 are separately fixed to the wall of the pressure measurement chamber 6, and the pressure measurement chamber 6 and the pressure chamber 61 and the pressure chamber 62 are separated by the center diaphragm 7 and the silicon diaphragm 8. It's been 2 minutes. Back plates 6A and 6B are formed on the wall of the pressure measuring chamber 6 facing the center diaphragm 7. The center diaphragm 7 has a peripheral edge portion welded to the housing 1. The silicon diaphragm 8 is entirely formed of a single crystal silicon substrate.

Impurities such as boron are selectively diffused on one surface of the silicon substrate to form four strain gauges 80, and the other surface is machined and etched to form a diaphragm having an overall concave shape. . The four strain gages 80 are designed so that when the silicon diaphragm 8 bends due to the differential pressure ΔP, two are pulled and two are compressed, and these are connected to the Wheatstone bridge circuit, The resistance change is detected as a change in the differential pressure ΔP. Reference numeral 81 is a lead whose one end is attached to the strain gauge 80. Reference numeral 82 is a hermetic terminal to which the other end of the lead 81 is connected.

The support 9 has a hermetic terminal, and the silicon diaphragm 8 is adhesively fixed to the end surface of the support 9 on the pressure measurement chamber 6 side by a method such as low-melting glass connection. Pressure introducing chambers 10, 11 are formed between the housing 1 and the flanges 2 and 3. The pressure introducing chambers 10 and 11 are provided with corrugated diaphragm diaphragms 12 and 13, and the walls 10A and 11A of the housing 1 facing the diaphragm diaphragms 12 and 13 have shapes similar to those of the diaphragm diaphragms 12 and 13. A back plate is formed.

The space formed by the diaphragms 12 and 13 and the back plates 10A and 11A and the pressure measurement chamber 6 are in communication with each other through communication holes 14 and 15. As shown in FIGS. 5 and 6, reference numerals 21 and 22 are collars that are provided in the communication holes 14 and 15 and have small holes 23 and 24. Then, between the diaphragms 12 and 13, a filling liquid 101 such as silicone oil is provided. 102 is filled, and the filled liquid reaches the upper and lower surfaces of the silicon diaphragm 8 through the communication holes 16 and 17. The filled liquids 101 and 102 are divided into two by the center diaphragm 7 and the silicon diaphragm 8. However, the amount is considered to be almost even.

In the above structure, when pressure is applied from the high pressure side, the pressure acting on the diaphragm diaphragm 13 is transmitted to the silicon diaphragm 8 by the enclosed liquid 102. On the other hand, when pressure acts from the low pressure side, the pressure acting on the diaphragm diaphragm 12 is transmitted to the silicon diaphragm 8 by the enclosed liquid 101. As a result, the silicon diaphragm 8 is distorted according to the pressure difference between the high pressure side and the low pressure side, and the strain amount is electrically taken out by the strain gauge 80, and the differential pressure is measured.

[0008]

[Problems to be solved by the device]

However, in such a device, when the overpressure is applied, the diaphragm 12 or 13 of the diaphragm contacts the back plate 10A or 11A to prevent the overpressure from being applied to the sensor portion. In the case of the high withstand pressure type differential pressure measuring device, a pressure of 100 Kgf / cm ² or more is applied to the thin diaphragms 12 and 13.

Therefore, as shown in FIG. 5, the communication holes 14 and 15 are usually 1 mm or less in diameter (the hole diameter is reduced to a small value so that the diaphragms 12 and 13 are not broken). If it is too large, the responsiveness will deteriorate, so it cannot be made too small.) The hole diameter of the portion opening to the pressure measuring chamber 6 is 2 to 3 mm for ease of processing (if the hole diameter is too large, the filled liquid 101, 102 , And the temperature characteristics deteriorate. It is common to increase the number.). Although the collars 21 and 22 are used in FIG. 6 because of the ease of processing, in such a case, the collars 21 and 22 are provided only on a flat portion such as a diaphragm of diaphragm.

In the case of a high withstand pressure type differential pressure measuring device, it is necessary to reduce the hole diameter and increase the number of holes. However, it is desirable that the flat portion is as narrow as possible in order not to reduce the characteristics of the diaphragm and the like, and the number of holes cannot be increased. The present invention solves this problem. An object of the present invention is to provide a differential pressure measuring device having improved performance characteristics, assemblability, and workability.

[0011]

[Means for Solving the Problems]

 To achieve this object, the present invention provides a pressure measuring chamber provided inside a housing, a center die diaphragm provided so as to divide the pressure measuring chamber into two pressure chambers, and A corrugated diaphragm diaphragm which is provided on each side of the housing and constitutes a liquid chamber with the housing; and a corrugated back plate which is provided on a side surface of the housing facing the diaphragm diaphragm. In the differential pressure measuring device, which is provided in the housing and includes a communication hole that communicates the pressure chamber and the partition chamber,

A first hole having one end opened to the pressure chamber side and the other end drilled to the vicinity of the back plate, and one end formed on the back plate from the back plate side to the pressure chamber side by electric discharge machining And a communication hole having the other end communicating with the other end of the first hole and having at least one second hole smaller than the first hole. The pressure measuring device is configured.

[0013]

[Action]

 In the above structure, when pressure is applied from the high pressure side, the pressure applied to the diaphragm is transmitted to the silicon diaphragm by the enclosed liquid. On the other hand, when pressure acts from the low pressure side, the pressure acting on the diaphragm is transmitted to the silicon diaphragm by the sealing liquid.

As a result, the silicon diaphragm is distorted according to the pressure difference between the high pressure side and the low pressure side, and the strain amount is electrically taken out by the strain gauge, and the differential pressure is measured. Thus, when the overpressure is applied, the diaphragm diaphragm contacts the back plate to prevent the overpressure from being applied to the sensor portion. Hereinafter, detailed description will be given based on examples.

[0015]

【Example】

 FIG. 1 is an explanatory view of a main configuration of an embodiment of the present invention, FIG. 2 is a detailed explanatory view of FIG. 1, and FIG. 3 is a side view of FIG. In the figure, the same symbols as those in FIG. 4 represent the same functions. Only parts different from FIG. 4 will be described below.

From the back plates 10A, 11A side, the first holes 33, 34 are opened at one end on the pressure chambers 61, 62 side and the other ends are bored to near the back plates 10A, 11A. At least one smaller than the first hole 33,34 is formed on the pressure chamber 61,62 side by electric discharge machining and has one end opened to the back plates 10A, 11A and the other end communicating with the other ends of the first holes 33,34. It is a communication hole including one or more second holes 35 and 36.

In the above structure, when pressure acts from the high pressure side, the pressure acting on the diaphragm diaphragm 13 is transmitted to the silicon diaphragm 8 by the enclosed liquid 102. On the other hand, when pressure acts from the low pressure side, the pressure acting on the diaphragm diaphragm 12 is transmitted to the silicon diaphragm 8 by the enclosed liquid 101.

Then, the silicon diaphragm 8 is distorted according to the pressure difference between the high pressure side and the low pressure side, and the strain amount is electrically taken out by the strain gauge 80, and the differential pressure is measured. . Thus, when the overpressure is applied, the diaphragm diaphragm 12 or 13 contacts the back plate 10A or 11A to prevent the overpressure from being applied to the sensor portion.

As a result, one end of the back plate 10A, 11A is formed from the side of the back plate 10A, 11A to the side of the pressure chamber 61, 62 by the discharge machining, and the other end is opened by the other end of the first hole 33, 34. Since at least one second hole 35, 36 smaller than the communicating first holes 33, 34 is formed, the second plates 35A, 36A can be formed in any desired position such as a corrugated slope of the back plates 10A, 11A. The required number of holes 35 and 36 can be provided. That is, the second holes 35 and 36 are not restricted in processing and can be provided at arbitrary positions such as the corrugated slopes of the back plates 10A and 11A, so that the characteristics of the device are not impaired. It is not necessary to provide a separate component such as a collar, and a differential pressure measuring device with excellent assembly and workability can be obtained.

[0020]

[Effect of device]

 As described above, the present invention provides a pressure measurement chamber provided inside a housing, a center diaphragm provided so as to divide the pressure measurement chamber into two pressure chambers, and the housing. A corrugated diaphragm diaphragm provided on each side surface and forming a partition chamber with the housing, a corrugated back plate provided on the side surface of the housing facing the diaphragm diaphragm, and a corrugated back plate on the housing. A differential pressure measuring device provided with a communication hole provided to communicate the pressure chamber and the liquid separating chamber,

A first hole having one end opened to the pressure chamber side and the other end bored to near the back plate, and one end formed on the back plate from the back plate side to the pressure chamber side by electric discharge machining And a communication hole having the other end communicating with the other end of the first hole and having at least one second hole smaller than the first hole. A pressure measuring device was constructed.

As a result, one end of the back plate, which is formed by electrical discharge machining from the back plate side to the pressure chamber side, opens to the back plate and the other end communicates with the other end of the first hole. At least one smaller than the first hole. Since the second holes are formed, it is possible to provide the required number of the second holes at any position such as the corrugated slope of the back plate. That is, there is no processing restriction in providing the second hole, and the second hole can be provided at an arbitrary position such as the corrugated slope of the back plate, so that the characteristics of the device are not impaired and a component such as a collar is also provided separately. There is no need to obtain a differential pressure measuring device with excellent assemblability and workability.

Therefore, according to the present invention, it is possible to realize a differential pressure measuring device having improved performance characteristics, assembling property, and workability.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a main part configuration of an embodiment of the present invention.

FIG. 2 is a detailed view of a main part of FIG.

FIG. 3 is a side view of FIG.

FIG. 4 is an explanatory diagram of a configuration of a conventional example that is generally used in the past.

5 is a detailed view of a main part of FIG.

FIG. 6 is a side view of FIG.

[Explanation of symbols]

 1 ... Housing 2 ... Flange 3 ... Flange 4 ... Inlet port 5 ... Inlet port 6 ... Pressure measuring chamber 6A ... Back plate 6B ... Back plate 7 ... Center diaphragm 8 ... Silicon diaphragm 9 ... Support 10 ... Pressure introduction Chamber 11 ... Pressure introducing chamber 10A ... Back plate 11A ... Back plate 12 ... Separation diaphragm 13 ... Separation diaphragm 14 ... Communication hole 15 ... Communication hole 16 ... Communication hole 17 ... Communication hole 31 ... Communication hole 32 ... Communication hole 33 ... First hole 34 ... First hole 35 ... Second hole 36 ... Second hole 80 ... Strain gauge 81 ... Sensor chamber 82 ... Sensor chamber 101 ... Filled liquid 102 ... Filled liquid

Claims (1)

[Scope of utility model registration request] 1. A pressure measuring chamber provided inside a housing, a center diaphragm provided so as to divide the pressure measuring chamber into two pressure chambers, and both side faces of the housing. A corrugated diaphragm diaphragm which forms a partition chamber with the housing, a back plate which is corrugated and is provided on a side surface of the housing facing the partition diaphragm, and a corrugated back plate, which is provided in the housing and separates from the pressure chamber. A differential pressure measuring device comprising: a communication hole that communicates with a liquid chamber, wherein a first hole having one end opened to the pressure chamber side and the other end bored to near the back plate, and from the back plate side At least one smaller than the first hole is formed on the pressure chamber side by electric discharge machining and has one end opened to the back plate and the other end communicating with the other end of the first hole. Differential pressure measuring device, characterized by comprising a communication hole and a second hole.