JPS61170629A - Pressure gage - Google Patents

Abstract

PURPOSE:To miniaturize a device and to increase a detecting sensibility and detecting accuracy by providing an auxiliary spring cyclically at the tip of a piece of supporting spring which is along the diameter direction of a detecting coil and by fitting a core via a fitting member to the tip thereof. CONSTITUTION:The pressure member 13 having an elastic film 31 is arranged inside the case 11 of a pressure gage 10. A core 21 is integrally fitted via a fitting member 45 to the pressure member 13. The fitting member 45 is supported by the auxiliary spring 35 cyclically fitted to the tip of a sheet of supporting spring 32 one end of which is fixed to the case 11. With this constitution the movement of the core 21 becomes linearly. When the fluid bodies 43, 44 of high pressure and low pressure are respectively fed to each pressure chambers 14, 15, the pressure member 13 and core 21 are moved in the axial direction A of detecting coils 19A, 19B by the pressure difference. The signal (b) proportional to the pressure difference in the fluid bodies 43, 44 is thus outputted from the coils 19A, 19B.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field) The present invention relates to a pressure gauge that detects the pressure difference of gas or the like between mutually separated areas, such as the inside and outside of an air-conditioned room.

(Prior Art) This type of pressure gauge is required to accurately detect a pressure difference of, for example, about 1 H.0. Therefore, a precise pressure gauge as shown in FIG. 6 is used.

In FIG. 6, a case 11 is divided into upper and lower parts by a partition wall 12, and a pressure receiving chamber member 13 provided with an elastic membrane is disposed in a space below the partition wall 12. By means of this pressure receiving chamber material 13, two pressure receiving areas 3i14.15 are formed in the case 11, one on the high pressure side and one on the low pressure side. Reference numerals 16 and 17 indicate fluid supply ports to the pressure receiving chambers 14 and 15. Above partition wall 1
A bobbin 20 on which a pair of detection coils 19A and 19B are wound is fixed to the pressure receiving chamber member 131Cs.
A core 21 made of a magnetic material attached with b is placed in the hollow part of the detection coil 19A, 19B.
It is movably inserted into the axial dowel of 19B.

The core 21 has coil springs 22 .
It is supported by the case 11 via 22. Further, lead wires 23 are drawn out from the detection coils 19A and 19B, and their tips are connected to external terminals 24 provided outside the case 11 111aK.

In the above configuration, when the pressure receiving chamber material 13 moves up and down due to the pressure difference between both pressure receiving chambers 14 and 15, the core 21 moves up and down integrally with this pressure receiving chamber material 13, and the detection coils 19A, 19B Change the instance. Accordingly, from the detection coils 19A and 19B, the core 2
A signal proportional to the amount of movement of 1 and proportional to the pressure difference mentioned above is output, and pressure is detected by this signal.

However, in the above configuration, since the core 21 is supported at both ends by the coil springs 22 that extend axially, the case 11 becomes larger in the vertical direction, and
Since the core 21 tends to vibrate in the radial direction B, the detection accuracy decreases.

(Objective of the Invention) The present invention has been made in order to eliminate the drawbacks of the conventional pressure gauges described above, and provides a pressure gauge that has high pressure difference detection accuracy and sensitivity and can be miniaturized. The purpose is to

(Structure of the Invention) In order to achieve the above object, the present invention is a pressure receiving chamber material equipped with an elastic membrane, the inside of the case is divided into two pressure receiving chambers, and one pressure receiving chamber is provided with a pressure receiving chamber material in a direction parallel to the pressure receiving chamber material. one support spring made of a leaf spring, one end of which is fixed to the case, and a fixed end of an auxiliary spring arranged in a folded manner with respect to the support spring are connected to the other end of the support spring, The free end of the auxiliary spring is attached to the core mounting member provided on the pressure receiving chamber material, and the support spring and the auxiliary spring cancel out the inclination angle when a load is applied to the free end of the auxiliary spring. The pressure needle of the present invention is characterized in that it is set to be zero. The pressure needle of the present invention is arranged in one partitioned pressure receiving chamber in a direction parallel to the pressure receiving chamber material, and has one end fixed to the other end of a support spring. By attaching the core to a folded auxiliary spring, it was possible to downsize the pressure gauge.

Then, one support spring is bent through the pressure receiving chamber material due to the pressure difference in the pressure receiving blank, and the pressure difference is detected by the amount of movement of the core at that time. This cancels out each other's circular motions and turns the core movement into a linear motion, improving pressure detection accuracy and sensitivity.

(Example) Examples of the present invention will be described below based on the drawings and each.

In FIG. 1, inside the case 11 of the pressure gauge 10.

A pressure receiving chamber material 13 having an elastic membrane (diaphragm) 31 on the entire outer periphery is disposed, and the peripheral edge of the elastic membrane 31 is inserted and solidified between the joints of the case 11 which has been split into two parts. Inside 11 are a pressure receiving chamber 14 on the high pressure side and a pressure receiving chamber 1 on the low pressure side.
It is divided into 5 sections.

In the pressure receiving chamber 14 on the high pressure side, a core 21 made of a magnetic material such as ferrite is attached to the tip of a mounting member 45 provided at the center of gravity of the pressure receiving chamber material 13, and this core 21 is attached to the outer wall 11a of the case 11. Attached detection coil 19
A, 19B is inserted so as to be movable in the axial direction A. In addition, in the pressure receiving chamber 14 on the high pressure side, a detection
One support spring 32 made of a leaf spring is arranged along the radial direction BK of 9A and 19B, and one end of the support spring 32 is fixed to the case 11 with a bolt 33. This support spring 32
An auxiliary spring 35 made of a leaf spring is fixed to the other end through a spacer 34 in a folded shape, and at the tip of the auxiliary spring 35,
A mounting member 45 for the core 21 is attached. As shown in FIG. 2, the support spring 32 has nine through holes 3.
6, the mounting member 45 is inserted so as to be axially movable and not in contact with the surface of the through hole 36.

Further, as shown in FIG. 2, the support spring 32 is composed of a support part 32a fixed to the case 11, and a tip member 32b fixed to the tip thereof and having approximately the same length as the auxiliary spring 35. and the rigidity of the tip member 32 is higher than that of the support portion 32m.
b, and the rigidity of the auxiliary spring 35 are reduced, and the support portion 32a, the tip member 32b, and the auxiliary spring 35 are
When the pressure-receiving chamber member 13 is configured to satisfy the formula, and pressure is applied to the pressure-receiving chamber member 13, the support portion 32a of the support spring 32 bends and the tip member 32b
By bending the auxiliary spring 35 away from each other, the axis of the core 21 and the axes of the detection coils 19A and 19B become substantially parallel to each other.

l!・HL-tl・δ1 Length and plate thickness of δ1 support part 32A,
Inclination angle, tip deflection l!・h-・1m・δ3-Tip member 32b and auxiliary spring 3
5 length, plate thickness, inclination angle, amount of deflection at the tip (see Figure 3) E-Longitudinal elastic modulus f depending on the material of each leaf spring! - Flexible lid b of support spring 32 and auxiliary spring 35 Width 11 of leaf spring = l volume + l!・・・・・・・・・ Formula 0 Formula % As a means of satisfying the condition of formula D for the support spring 32 and the auxiliary spring 35, it is unnecessary to limit it to the above rigidity difference, and each spring It is also possible to use any means such as length.

In the above detection, the coils 19A and 19B are wound around a bobbin 20, and this bobbin 20 includes a bobbin body 20a made of synthetic resin as an insulator, and a gold MM? The lower part of the bobbin case 20b is screwed into the mounting hole (screw hole) 37 of the outer wall 11a of the case 11, and a rubber seal ring 38 is attached to the outer periphery of the central part. is fixed to the outer wall 11& by a fastening member 39 such as a nut. Thereby, the bobbin 20 is detachably and airtightly attached to the outer wall 11& of the case 11.

The bobbin main body 20m has a closed-bottomed cylindrical shape, and is fixed to the bobbin case 20b with an adhesive. With this, in addition to the use of the seal ring 38, the bobbin 20 airtightly intersects between the pressure receiving chamber 14 on the cylinder pressure side and the outside.

The bobbin body 20a includes a detection coil 19A.

Lead wires 23 connected to 19B are attached throughout the page, and these lead wires 23 are connected to a transmitting circuit 40 and an amplifying circuit 41, respectively. Furthermore, a controlled object 42 such as a passage opening/closing valve of an air conditioner is connected to this amplifier circuit 41. In the above configuration, the pressure receiving chamber 14
is supplied with an island-pressure fluid 43, such as indoor air, and the pressure-receiving chamber 15 is supplied with a low-pressure fluid 44, such as atmospheric air.

Due to the pressure difference between the above two receiving pressures m14 and 15, the pressure receiving chamber material 1
3 is the axial direction A (vertical direction) of the detection coils 19A and 19B.
When the core 21 is moved integrally with this pressure receiving chamber material 13,
moves in the same direction in the axial direction, and the inductance of one of the sensing coils 19A and 19B increases while the other decreases. In this way, from the detection coils 19A and 19B, the core 21
A signal proportional to the amount of movement of the clamp and proportional to the pressure difference above is output, and pressure is detected by this signal.

Note that a differential transformer type may be used as the detection coils 19A and 19B instead of the differential inductance type described above.

In order to efficiently generate the above inductance, a high frequency current a is applied from the transmitting circuit 41 to the detection coils 19A and 19B.
is applied. Furthermore, since the pressure detection signals from the detection coils 19A and 19B are weak, they are amplified by the amplifier circuit 42 and then input to the controlled object 43. In response to the pressure detection signal, the controlled object 43 controls the opening and closing of the passage of the nine-word device, for example, so that the pressure in the room becomes constant.

The support spring 32 that supports the mounting member 45 attached to the pressure receiving chamber material 13 has one end fixed to the case 11, and the trajectory when the pressure receiving chamber material 13 moves becomes an arc. However, the support spring 32 is composed of a support portion 32a and a tip member 32b, and has an auxiliary spring 35 at the tip of the tip member 32b.
In addition, since the rigidity of the tip member 32b and the auxiliary spring 35 is smaller than the rigidity of the support spring 32, the auxiliary spring 35 also curves as the support member 32 curves, as shown by the @ line in FIG. The support part 32m, the tip member 32b, and the auxiliary spring 35
act to cancel out the circular motion of each other. Therefore, the movement of the A 21 and the pressure receiving chamber material 13 is a linear movement, there is no inclination of the core 21 with respect to the axial direction AK, and the amount of movement of the core 21 can be made accurately proportional to the pressure difference. Accuracy can be improved ◎ The support spring 32 is composed of a single leaf spring and can be easily elastically deformed, so it is possible to detect small pressure differences.
Detection sensitivity can also be improved. When detecting a pressure as low as 1■HxO, it is necessary to make the support spring 32 thin, but since it is a single piece, it is easy to assemble and it is possible to obtain a highly accurate pressure gauge. .

Furthermore, the above radial direction BK? Since the nine support springs 32 are employed, the coil springs 22, 22 at both ends of the core 21 in the example shown in FIG. 6 are omitted, so that the axial dimension of the pressure gauge 10 is shortened and the pressure gauge 10 is made smaller.

In addition, in this embodiment, the bobbin 20 around which the detection coils 19A and 19B are wound is not attached to the inside of the case 11, but is detachably attached to the outer wall 11aK by the fastening member 37. By doing so, the pressure gauge can be easily disassembled and assembled by attaching and detaching the seven bobbins 20.

Moreover, since the bobbin 20 airtightly blocks the pressure receiving chamber 14 on the high pressure side from the outside, the fluid 3 in the pressure receiving chamber 14
8 is a gap 26 between the detection coils 19A, 19B and the core 21
Since the fluid 38 does not pass through the fluid 38 and simply enters and stays in the gap 26, the total amount of the fluid 38 that comes into contact with the sensing coils 19A, 19B is extremely small. Therefore, even if the high-pressure fluid 38 is a corrosive gas such as exhaust gas, there is no risk that this gas will corrode the sensing coils 19A, 19B, and the reliability of the pressure gauge 10 is improved.

If the tip member 32b and the auxiliary spring 35 are made separate from each other and fixed to each other with the spacer 34 interposed as in the above embodiment, it is possible to arrange the tip member 32b and the auxiliary spring 35 in parallel. Although suitable, it is also possible to form the one tip member 32b and the auxiliary spring 35 by bending one leaf spring into a U-shape as shown in FIG. As shown in FIG. 5, the support spring 32 can also be placed on the pressure receiving chamber member 13 side.

The support spring 32 is composed of a support part 32a and a tip member 32b, as shown in FIG. 1
This is to enable the size and weight of the auxiliary spring 3 and the auxiliary spring 35 to be reduced. Therefore, the support spring 32 can be constructed entirely of an integral leaf spring, and the support spring 13 and the auxiliary spring 35 can also be constructed of an integral leaf spring. The tip member 32b can also be made of a material other than a leaf spring.

(Effects of the Invention) As explained above, according to the present invention, since the core is supported by a single support along the radial direction of the detection coil, it is possible to downsize the pressure gauge in the axial direction of the detection coil. Additionally, the support springs can be set accurately and easily. An auxiliary spring is provided in a folded manner at the tip of the support spring, and a core is attached to the tip of the spring via a mounting member, so that the movement of the core is a linear motion. Since the song is easy, detection sensitivity can be increased.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a pressure gauge showing an embodiment of the present invention;
Figure 2 is an enlarged front view with a part of the support spring in section;
The figure is a front view of the support spring in a concave state, Figure 4 is a perspective view of another example of the support spring part, Figure 5 is a front view of still another example of the support spring part, and Figure 6 is a conventional example. i of the pressure gauge? 1=Front view. 11... Case, 13... Pressure receiving chamber material, 14.15.
...Received pressure %, 19A, 19B...Detection coil, 21.
... Core, 32 ... Support spring, 35 ... Auxiliary spring,
A... Axial rotation, B... Radial direction @ Fig. 1 1: Ap) detection A~ Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6

Claims (3)

[Claims] (1) The interior of the case is divided into two pressure receiving chambers by a pressure receiving member equipped with an elastic membrane, and a core attached to the center of gravity of the pressure receiving member via a mounting member is placed inside a sensing coil supported by the case. In a pressure gauge that is movably inserted in the axial direction of the detection coil and outputs a pressure detection signal proportional to the amount of movement of the core from the detection coil, the pressure gauge is inserted in the pressure receiving chamber having the detection coil in the radial direction of the detection coil. One end of this support spring is fixed to the case, and the fixed end of an auxiliary spring arranged in a folded manner with respect to the support spring is fixed to the support spring. The mounting member is attached to the free end of the auxiliary spring, and the supporting spring and the auxiliary spring can mutually cancel out the inclination angle when the pressure receiving member is bent due to a load. A pressure gauge characterized by being set. (2) Claim 1, wherein the support spring is composed of a support portion fixed to the case and a tip member fixed to the tip thereof, and the tip member and the auxiliary spring have approximately the same length. pressure gauge. (3) The pressure gauge according to claim 2, wherein the tip member and the auxiliary spring are provided separately, and their ends are fixed to each other via a spacer.