JP2524237B2 - Pressure detector - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a pressure detection device that continuously (analogously) detects pressure fluctuations of a fluid to be pressure-detected by a diaphragm.

[Conventional technology and its problems]

This type of pressure detecting device will be described with reference to FIGS. 1 and 2. In the casing 1, a pressure detecting chamber 3 defined by a diaphragm D is formed, and one of the pressure detecting chambers 3 is formed.
A sensor 4 for introducing the pressure detection fluid a into 3a and continuously detecting the deflection of the diaphragm D in the other 3b.
It is generally provided with.

In this pressure detecting device, in order to improve the detection accuracy, it is an important factor that the bending characteristic of the diaphragm D is proportional to the pressure change.

By the way, the inventors of the present invention have found that Japanese Patent Application No. 1-171818 (Japanese Patent Application Laid-Open No. 2-290523) and Japanese Patent Application No. Hei 1-18719 (Japanese Patent Application Laid-Open No. 2-290523).
No. 522), as shown in FIG. 7 and FIG. 8, a diaphragm D having a corrugated cross-section having spiral corrugations P starting from at least two points in the circumferential uniform quantile is provided around the center circle 10 of the material plate. The equipped pressure detector was proposed. In the proposed diaphragm D, since the ripples P have a spiral shape, the rigidity of the surroundings is made uniform, and during the bending action, there is no bias of stress and the bending is uniform in the circumferential direction. That is, the above-mentioned bending characteristics were satisfied to some extent.

However, as shown in FIG. 5, the pressure-displacement curve (∘: during pressurization, ●: during depressurization, see comparative example (broken line)).
Lacks linearity and is not particularly smooth at the start of pressurization. Some pressure detectors of this type require linearity at the start of pressurization.

Therefore, it is an object of the present invention to provide a pressure detector having a linear pressure-displacement curve at the start of pressurization.

[Means for solving the problem]

In order to solve the above problems, in the present invention, in a pressure detector having a diaphragm having the above-mentioned spiral ripple, the ripple being inclined toward a central circle, in the radial direction of the spiral ripple of the diaphragm. The cross section of the inclined portion is concave when viewed from the projecting side of the central circle.

The inclination of the spiral ripple, that is, the ratio (h / l) between the inclination height h and the radial length l in FIG. 4 is preferably 1/5 or less. It is preferably 1/6 or less. If it is 1/5 or more, it is impossible to manufacture by press molding with the current technology because the molding pressure is largely different between the outward slope and the inward slope.

Concentric circular ripples are formed adjacently around the center circle of the material plate, and outer circular ripples are formed concentrically with the concentric circular ripples at a predetermined interval, and the spiral ripples are formed between both circular ripples. It can also be done.

[Action]

In the pressure detecting device configured as described above, when a pressing force, such as compressed air pressure, is applied to the surface of the diaphragm, the bending caused by the pressing force is transmitted to the entire area through the spiral ripples, and the generated stress is uniform. , The center axis bends uniformly in the circumferential direction without tilting.

In addition, if concentric circular ripples and outer circular ripples are provided, the ridge-like distortion that occurs in the center during ripple press molding will be absorbed and dispersed into the concentric circular ripples, and the wrinkle-like distortion that occurs on the outer periphery will become the outer circular ripples. Absorbed and dispersed. This absorption / dispersion becomes more effective if the beginning and end of the spiral ripple are merged into both circular ripples.

〔Example〕

As shown in FIGS. 1 and 2, the casing 1 is composed of three members 1a, 1b and 1c, and the pressure detection chamber 3 is provided between the members 1a and 1b.
Are formed. Diaphragm D between both members 1a, 1b
Is interposed via the packing 2, and the diaphragm D divides the pressure detection chamber 3 into two chambers 3a and 3b. The pressure detection fluid a is introduced into the one detection chamber 3a from the pressure introduction port 5, and the diaphragm D bends due to the pressure change. The entire circumference of the joint surface between the two members 1a and 1b has a sealing 6
It is sealed by.

Another member 1c of the casing 1 is fixed to the member 1b by a screw 7, and the sensor 4 is formed in the member 1c. The sensor 4 includes a differential transformer 4a, an iron core moving lever 4b, an operating ram 4c, and the like. Actuating ram 4c is a member
It penetrates 1b, the upper end thereof can be brought into contact with and separated from the diaphragm D, and the lower end is brought into contact with the lever 4b. Lever 4b
Is oscillatably supported by a supporting rod 4d, and an operating pressure adjuster 8 having a member 1c threaded thereon is in contact with the lower surface thereof via a spring 9. By adjusting the screwing amount of the adjuster 8, the positions of the lever 4b and the operating ram 4c are determined, and by this adjustment, when the diaphragm D, which will be described later, is bent, the bent state is linear. The diaphragm D pushes the operating ram 4c to move the iron core of the differential transformer 4a. At this time, the detected value is compensated by considering the elastic force of the spring 9.

 Next, the diaphragm D will be described.

This diaphragm D is formed by forming a spiral ripple P over 12 laps from one point around the center circle 10 and is finished by pressing a stainless foil of 0.015 mm thickness and a hoop of 34 mmφ. The outer diameter was 25.4 mmφ.

This is shown in FIGS. 3 and 4, in which the pitch d of the spiral ripple P is 0.598 mm and the diameter S of the central circle 10 is S =
5.0 mm, outermost diameter of ripple P = 20.2 mm, curvature of valley and peak r = 0.3 mm, height of ripple P t = 0.08 mm, height difference T between outer circumference and center T = 1.2 mm, ripple P part R = 100 mm, and the center of the curvature R is set to the protruding side of the central circle 10 (the ripple of the ripple P is concave outward) (waves are omitted in FIGS. 3 and 4).

On the other hand, as a comparative example, the spiral ripple P shown in FIG. 7 and FIG. 8 is formed from the trisection of the central circle 10, the number of turns is one extra, and the center of the curvature R is inside ( A product in which the inclination of the ripples P was convex outward was also manufactured. At this time, d,
S, r, t, T, R, etc. were all the same.

The diaphragm D of the example and the comparative example thus manufactured is set in the casing 1 as shown in FIGS. 1 and 2, and the pressure-displacement result when the pressure detection fluid a is introduced into the detection chamber 3a is shown. It is shown in FIG. In the figure, the solid line indicates the example and the broken line indicates the comparative example.

From this result, in the example, at the start of pressurization (0 to 700 mmA
It can be seen that g) shows almost linear pressure-displacement.

In the above embodiment, as shown in FIG.
A concentric circular ripple P ₁ is formed adjacently around 10 and an outer circular ripple P ₂ is formed concentrically with the concentric circular ripple P ₁ and at a predetermined interval, and between the circular ripples P ₁ and P _2. When the spiral ripple P ₃ was formed around the same circumference as in the above embodiment, the same effect was obtained. In this case, the inner circular ripple P ₁ can be omitted.

In addition, in FIG. 7, the same effect was obtained when the spiral ripples P each have an outwardly concave inclination.
In this structure, the outer circular ripple P ₂ may be formed and the spiral ripple P ₂ may be merged with the ripple R ₂ .

〔The invention's effect〕

Since the present invention is configured as described above, the pressure-displacement curve at the start of pressurization can be linear.

Further, by forming inner and outer circular ripples and joining both ends of the spiral ripple to the both circular ripples, when the ripples are press-molded, wrinkle distortion is less likely to occur and the flexing action is smoothed.

[Brief description of drawings]

1 and 2 are a cut-away front view and a cut-away side view of an embodiment of the pressure detecting device according to the present invention, FIG. 3 is a schematic front view of an example of the diaphragm of FIG. 1, and FIG. 3 is a schematic sectional view, FIG. 5 is a pressure-displacement measurement diagram, FIG. 6 is a schematic front view of another example of the diaphragm D, FIG. 7 is a schematic front view of a conventional example of the diaphragm D, and FIG. It is a schematic sectional drawing of FIG. D: Diaphragm, P, P ₁ , P ₂ , P ₃ ... Ripples, R ...
Diaphragm curvature, r ... Valley and peak curvature, 1 ... Casing, 3, 3a, 3b ... Pressure detection chamber, 4 ... Sensor, 10 ... Central circle.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Teruo Watanabe 2-3-1 Iwata-cho, Higashi-Osaka City, Osaka Prefecture Tatsuta Electric Wire Co., Ltd. (72) Inventor Kihachi Onishi 2-3-3 Iwata-cho, Higashi-Osaka City, Osaka Prefecture No. 1 in Tatsuta Electric Wire Co., Ltd. (56) Reference JP-A-60-227141 (JP, A) JP-B 47-15275 (JP, B1)

Claims (2)

(57) [Claims] 1. A pressure detection chamber 3 defined by a diaphragm D is formed in a casing 1, and one of the pressure detection chambers 3 is formed.
A sensor 4 for introducing the pressure detection fluid a into 3a and continuously detecting the deflection of the diaphragm D in the other 3b.
In the pressure detecting device provided with, the diaphragm D has a corrugated cross section around the center circle 10 of the material plate and exhibits a spiral ripple P from any point around the circle, and the spiral ripple P is inclined to the central circle 10. The pressure detecting device is characterized in that the disc spring has a cross section of the inclined portion in the radial direction of the spiral ripple P as viewed from the projecting side of the central circle 10. 2. A concentric circular ripple P ₁ is formed adjacently around the center circle 10 of the material plate, and an outer circular ripple P ₂ is formed concentrically with the concentric circular ripple P ₁ and at a predetermined interval. ,
The spiral ripple P ₃ is formed between both circular ripples P ₁ and P _2, and the start and end of the spiral ripple P ₃ are merged with the central circular ripple P ₁ and the outer circular ripple P _2. Claim (1)
The pressure detection device described.