JPH03225242A - Pressure detecting device - Google Patents

Abstract

PURPOSE:To linearize a pressure-displacement curve at the time of starting pressurization by making the tilt of the swirly wave pattern of a diaphragm in a radial direction recessed on the outside. CONSTITUTION:A pressure detecting chamber 3 sectioned by the diaphragm D is formed in a casing 1. Fluid (a) whose pressure should be detected is introduced in one sectioned chamber 3a and a sensor 4 which consecutively detects the deflection of the diaphragm D is provided in the other sectioned chamber 3b. In the diaphragm D, the swirly wave pattern P is formed on the periphery of a central circle 10 by swirling from an optional point on the periphery. In a disk spring constituted by inclining toward the central circle 10, the tilt in the radial direction of the wave pattern P is made recessed on the outside. By applying pressing force, for example, compressed air, etc., to the surface of the diaphragm D, the deflection is transmitted to all the areas through the wave pattern P and deviation is not caused in generated stress, then the diaphragm equally bends in a peripheral direction without the inclination of a center axis.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a pressure detection device that continuously (analog-wise) detects pressure fluctuations in a pressure-detected fluid using a diaphragm.

[Conventional technology and its LIP! I) This type of pressure detection device will be described with reference to FIGS. 1 and 2. A pressure detection chamber 3 partitioned by a diaphragm D is formed in a casing 1, and one side of the pressure detection chamber 3 is 3
Generally, a pressure detection fluid a is introduced into the diaphragm 3b, and a sensor 4 for continuously detecting the deflection of the diaphragm D is provided at the other 3b.

In this pressure detection device, in order to improve detection accuracy, it is important that the deflection characteristics of the diaphragm D be proportional to pressure changes.

By the way, in Utility Model Application No. 1-18718 and Utility Model Application No. 118719, the inventors of the present invention, as shown in FIG. 7 and FIG. We have proposed a pressure detector equipped with a diaphragm D having a wave-shaped cross section exhibiting spiral ripples P starting from at least two points. This one! ! In the proposed diaphragm D, since the ripples P have a spiral shape, the rigidity of the periphery is uniform, and when the diaphragm D is deflected, there is no unevenness of stress and the diaphragm D is deflected uniformly in the circumferential direction. It was satisfying.

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

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

[Means to solve the problem]

In order to solve the above problems, the present invention provides a pressure sensor having a diaphragm having the above-mentioned spiral ripples and whose ripples are inclined toward a central circle, in the radial direction of the spiral ripples of the diaphragm. The slope was made concave outward.

The degree of inclination of the spiral ripples, that is, the ratio of the inclination height h to the radial length l in FIG. 4 (h/7) is preferably 115 or less, preferably 1/6 or less. This is because, with the current technology, during press molding, the molding pressure differs greatly between the outward and inward slopes, making it impossible to manufacture them.

Concentric circular ripples are formed adjacent to the center circle of the material plate, outer circular ripples are formed concentrically with the concentric circular ripples at a predetermined interval, and the spiral ripples are formed between the dual-purpose ripples. It can also be assumed that

[Effect]

In a pressure detection device configured in this way, when a pressing force, such as compressed air pressure, is applied to the surface of the diaphragm, the deflection due to the pressing pressure is transmitted to the entire area via spiral ripples, and the stress generated is biased. The center axis flexes evenly in the circumferential direction without tilting.

In addition, if concentric circular ripples and outer circular ripples are provided, when the ripples are press-formed, the raised distortion that occurs in the center will be absorbed and dispersed in the concentric circular ripples, and the melted distortion that occurs on the outer periphery will be absorbed and dispersed in the outer circular ripples. absorbed and dispersed. This absorption and dispersion becomes even more effective if the beginning and end of the spiral ripple merge into the dual-use ripple.

〔Example〕

As shown in FIGS. 1 and 2, the casing 1 consists of three members 1a, 1b, and 1c, and a pressure detection chamber 3 is formed between the members 1a and 1b. The diaphragm D is interposed through the backing 2,
Due to this diaphragm D, the pressure detection chamber 3 is divided into two chambers 3a and 3.
It is divided into b. A pressure-detected fluid a is introduced into one detection chamber 3a from a pressure introduction port 5, and a diaphragm D is bent based on this pressure change. has been made into

Another member 1C of the casing 1 is fixed to the member 1b with screws 7, and a sensor 4 is configured within this member 1C. The sensor 4 includes a differential transformer 4a, a lever 4b for moving its iron core, an operating ram 4C, etc.A zero-actuation ram 4C passes through a member 1b, and its upper end can come into contact with and separate from a diaphragm D, and its lower end It is in contact with the lever 4b.

The lever 4b is swingably supported by a support rod 4d, and has an operating pressure regulator 8 having a member 1C screwed through its lower surface.
are in contact with each other via a spring 9. By adjusting the screwing amount of this adjuster 8, the lever 4b and the actuating ram 4 can be adjusted.
The position of C is determined, and by this adjustment, when the diaphragm D is bent, which will be described later, the diaphragm D pushes the operating ram 4C and moves the iron core of the differential transformer 4a, with the bending state being linear. do. At this time, the elastic force of the spring 9 is taken into consideration and compensated for in the result value.

Next, the diaphragm D will be explained.

This diaphragm D has a spiral ripple P formed around 12 times from one point around the central circle 10, and is a stainless steel whistle with a thickness of 0.015 mm.
A hoop of 341 IIφ was pressed and had a finished outer diameter of 25.4 mmφ.

This is shown in Figures 3 and 4, in which the pitch of the spiral ripple P is d = 0.598, the center circle is 10.
diameter S = S, O dragon, outermost diameter of ripple P = 20.21, curvature of valley and peak r = Q, 3ms, height of ripple P [=
0.08 dragon, height difference between the outer periphery and the center T = 1.2 ■ -1 Curvature R of the ripple P portion = 100 m, the center of the curvature R is set to the outside (the slope of the ripple P is concave to the outside) (in addition, Waves are omitted in Figures 3 and 4).

On the other hand, as a comparative example, the spiral ripples P shown in FIGS. We also manufactured one in which the slope of P was outwardly convex. At this time, d
, S, r, t, T, R, etc. were all the same.

The diaphragm D of the example and comparative example manufactured in this way was set in the casing 1 as shown in Figs. In Figure 0 shown in FIG. 5, the solid line represents the example, and the broken line represents the comparative example.

From this result, in the example, at the start of pressurization (0 to 700 sn
It can be seen that Ag) exhibits a nearly linear pressure-displacement.

In the above embodiment, as shown in FIG.
A concentric circular ripple P is formed adjacent to the concentric circular ripple P1, and an outer circular ripple P2 is formed concentrically with the concentric circular ripple P1 at a predetermined interval, and a spiral ripple P is formed between the sun-shaped ripples P+ and Pg. , was manufactured with the same circumference as in the previous example, and similar effects were obtained. In this case, the inner circular ripple P can also be omitted.

Furthermore, in the case shown in FIG. 7, the same effect was obtained when each spiral ripple P had an outward concave inclination in the radial direction. In this case, the outer circular ripple P2 may be formed, and each spiral ripple P may be added to the outer circular ripple P2.

〔Effect of the invention〕

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

[Brief explanation of drawings]

1 and 2 are a cutaway front view and a cutaway side view of an embodiment of the pressure detection 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 the other side of diaphragm D, FIG. 7 is a schematic front view of a conventional example of diaphragm D, and FIG. 8 is a schematic front view of the other side of diaphragm D. FIG. 7 is a schematic cross-sectional view of FIG. 7; D...Diaphragm, P, P+, Pg, Ps...Ripple, R...
-Diaphragm curvature 5, r...Trough and peak curvature, 1...Casing, 3. 3a, 3b...Pressure detection chamber, 4...Sensor 10...Central circular shape.

Claims (1)

[Scope of Claims] (1) A pressure detection chamber 3 partitioned by a diaphragm D is formed in the casing 1, and a pressure-detected fluid a is introduced into one side 3a of the pressure detection chamber 3 and the other 3b. In a pressure detection device provided with a sensor 4 that continuously detects the deflection of the diaphragm D, the diaphragm D is
Around the center circle 10 of the material plate, from any point around it,
A wave cross section exhibiting a spiral ripple P, and the spiral ripple P
2. A pressure detection device characterized in that, in a disc spring inclined toward the circular shape 10, the spiral ripple P has an outward concave inclination in the radial direction. (2) The pressure detection device according to claim (1), wherein the ratio h/l of the inclination height h to the radial length of the spiral ripple P is 1/5 or less. (3) Concentric circular ripples P_1 are formed adjacently around the center circle 10 of the material plate, and this concentric circular ripple P_
According to claim (1) or (2), an outer circular ripple P_2 is formed concentrically with the outer circular ripple P_2 at a predetermined interval from the outer circular ripple P_2, and the spiral ripple P_3 is formed between both the circular ripples P_1 and P_2. pressure detection device. (4) The starting and ending ends of the spiral ripples are connected to the center circular ripple P
The pressure detection device according to claim (3), characterized in that the pressure detection device merges with the outer circular ripple P_1 or the outer circular ripple P_2.