JPH03225239A - Pressure detecting device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a pressure detection device that detects pressure fluctuations in a pressure-detected fluid using a diaphragm to detect fluctuations in a required amount.

[Conventional technology and its problems]

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 3 of the pressure detection chamber 3 is formed in a casing 1.
Generally, the pressure detection fluid a is introduced into the diaphragm 3b, and a switch 4 which is activated by a required amount of 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 diaphragm D has a sharp rise characteristic.

By the way, the present inventors, in Utility Application No. 1-18718 and Utility Application No. 1-18719,
A pressure detector has been proposed which is equipped with a diaphragm D having a corrugated cross section around a circular center circle 10 of a material plate and exhibiting spiral ripples P starting from at least two points equidistant in the circumferential direction. In this proposed diaphragm D, since the ripples P have a spiral shape, the rigidity of the surrounding area is made uniform, and when deflection is applied, the diaphragm D is deflected uniformly in the circumferential direction without unevenness of stress. It was somewhat satisfying.

However, users have requested a device that can obtain a large displacement with a very small pressure, that is, a device with a large slope of the pressure-displacement curve.

In order to meet this demand, the inventors of the present invention considered that the way to increase the slope of the pressure-displacement curve is to reduce the overall rigidity of the diaphragm D. For this reason, first,
- It was found that the longer the total length of the spiral ripples P of the muscle, the lower the stiffness.

Further, the reason why the spiral ripples P are started from at least two points equally spaced around the central circle 10 is to prevent the central axis of the diaphragm D from tilting when patterning. However, it has been found that even if the spiral ripple P is a single line, if the number of circumferences increases, the central axis will not tilt (it will tilt only to a negligible extent).

The present invention takes the above points into consideration, and an object of the present invention is to increase the gradient of the pressure-displacement curve of the diaphragm of the spiral ripples.

[Means to solve the problem]

In order to solve the above problem, in the present invention, based on the above knowledge, in the above-mentioned pressure detection device, the number of revolutions of the spiral ripples of the diaphragm is set to three or more times.

A single spiral ripple may be used, or in the case of multiple ripples, the starting points of each ripple are equally spaced around the central circle.

Concentric circular ripples are formed adjacent to 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 the two circular ripples. It can also be assumed that

If the number of turns of the spiral ripple is three or more, the inclination of the central axis will be eliminated when the diaphragm is deflected, and preferably it is five or more.

[Effect]

In a pressure detection device configured in this manner, when a pressing force, such as compressed air pressure, is applied to the surface of the diaphragm, the deflection due to the pressing force is transmitted to the entire area via spiral ripples, and the generated stress is not biased. , the central axis flexes evenly in the circumferential direction without tilting.

During this deflection, the total length of the spiral ripples becomes longer, so
Compared to the conventional one, the stiffness is lower, that is, the degree of deflection is greater, and therefore the slope of the pressure-displacement curve is larger.

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 wrinkle-shaped distortion that occurs on the outer periphery will be absorbed and dispersed on the outer periphery. It is absorbed and dispersed into circular ripples. This absorption and dispersion becomes more effective if the beginning and end of the spiral ripples are merged into both circular ripples.

〔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. diaphragm D is interposed via banking 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 IC of the casing 1 is fixed to a member 1b with screws 7, and a switch 4 is configured within this member 1c. The switch 4 has a contact 4a and a lever 4b.
, actuating ram 40, etc.

The actuating ram 4c passes through the member 1b so that its upper end can move toward and away from the diaphragm D, and its lower end is in contact with the lever 4b. The lever 4b is swingably supported by a support rod 4d, and an operating pressure regulator 8 having a member 1c threaded through it is in contact with the lower surface of the lever 4b via a spring 9. By adjusting the screwing amount of this adjuster 8, the lever 4b
And the position of the actuating ram 4c is determined, and by this adjustment, at the time of the rise characteristic in the deflection of the diaphragm D, which will be described later,
Diaphragm D pushes actuating ram 4c to actuate (turn on or off) contact 4a.

Next, the diaphragm D will be explained.

This diaphragm D is formed by forming spiral ripples P around 12 times from one point around the central circle 10, and is made of stainless steel foil with a thickness of 0.015 μl;
A hoop with a diameter of 34 cranes is pressed and the finished outer diameter is 2.
The diameter was 5.4 mm.

This is shown in Figure 3 and Part 4, in which the pitch d of the spiral ripple P = 0.5981 m, the center circle 1
0 diameter S=5. Omm, outermost diameter of ripple P -20,2+n
, curvature r of valleys and peaks r ” 0.3 Dragon, height of ripple P [= 0.08 Emperor Crow, height difference between outer periphery and center T = 1.2
mm, and the curvature R of the ripple P portion was set to 100 mm (in addition,
Waves are omitted in Figures 3 and 4).

On the other hand, as a comparative example, a spiral ripple P shown in FIG. 7 was formed from three equal parts of the central circle 10, and the number of revolutions was more than one. 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. It is shown in FIG. In the figure, solid lines indicate examples and chain lines indicate comparative examples.

From this result, it can be seen that the slope of the example is steeper (larger) than that of the comparative example. That is,
In the example, a larger displacement can be obtained with a lower pressure than in the comparative example. Note that no inclination of the central axis occurred on both sides.

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 both circular ripples P, , P,
A similar effect was obtained when a spiral ripple P was formed in the same circumference as in the above embodiment. 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 was made to rotate three times or more.

In this one, the outer circular ripple P2 is formed, and the ripple P! It is also possible to have a configuration in which the spiral ripples P are merged into each other.

Incidentally, the degree of inclination of the spiral ripples P and Pt, that is, the ratio of the inclination height h to the radial length l in FIG. 4 (h#)
is preferably 115 or less, preferably 1/6 or less. If it exceeds 115, the molding pressure will be significantly different between the outward slope and the inward slope during press molding, making production impossible.

〔Effect of the invention〕

Since the present invention is configured as described above, it is possible to obtain a large displacement (deflection) with a small pressure compared to the conventional one.

Further, if the spiral ripples of the diaphragm D are made into one strip, it is easier to manufacture than if a plurality of strips are formed.

[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 the diaphragm D, and FIG. 7 is a schematic front view of a conventional example of the diaphragm D. D...Diaphragm, P, P+, Pt, Px...Ripple, R...
...Diaphragm curvature, r...Trough and peak curvature, 1...Casing, 3. 3a, 3b...Pressure detection chamber, 4...Switch, 10...Central circle.

Claims (5)

[Claims] (1) A pressure detection chamber 3 partitioned by a diaphragm D is formed in the casing 1, and the pressure-detected fluid a is introduced into one 3a of the pressure detection chamber 3, and the required amount of the diaphragm D is introduced into the other 3b. In a pressure detection device equipped with a sensor 4 that is activated by the deflection of the diaphragm D, the diaphragm D is
A pressure detection device characterized by having a wave-shaped cross section exhibiting spiral ripples P from arbitrary points around a center circle 10 of a material plate, and the spiral ripples P are formed around at least three circumferences. (2) The pressure detection device according to claim (1), wherein the spiral ripple P is formed as a single line. (3) The pressure detection device according to claim 1, wherein the spiral ripples P are formed in a plurality of stripes, and the starting point of each spiral ripple P is equally spaced around the central circle 10. (4) Concentric circular ripples P_1 are formed adjacently around the center circle 10 of the material plate, and this concentric circular ripple P_
1, and an outer circular ripple P_2 is formed concentrically with the circular ripple P_2 at a predetermined interval, and the spiral ripple P_3 is formed between both the circular ripples P_1 and P_2. The pressure detection device according to item 1. (5) The starting and ending ends of the spiral ripples are connected to the center circular ripple P
_1 or outer circular ripple P_2. The pressure detection device according to claim (4).