JP6566339B1 - Differential pressure monitoring device - Google Patents

Abstract

In a differential pressure gauge, there is provided a differential pressure monitoring device capable of promptly issuing an alarm when a differential pressure exceeds a predetermined value without consuming electric power in a normal time. A differential pressure detection unit that detects a differential pressure that is a difference between two pressures, a pointer unit that changes a rotational position according to a detection amount of the differential pressure detection unit, and is electrically connected to a voltage input unit and a pointer A main body, a scale plate indicating a differential pressure value, and a detection needle section and a detection needle hole which are provided on the scale plate and are electrically connected to the voltage output section, respectively. When abutting, an electrical closed circuit is configured, and the voltage output unit outputs a warning. [Selection] Figure 1

Description

  The present invention relates to a technique for monitoring a differential pressure, and more particularly, to a technique for issuing an alarm when a differential pressure exceeds a predetermined value.

  Conventionally, differential pressure gauges for measuring a pressure difference between two points have been used in various places. In the compressed air circuit, the air filter is often used to check the clogged state.

  When clogging occurs in the air filter, the pressure difference between the upstream side and the downstream side becomes larger than usual. The administrator checks the pressure difference with a differential pressure gauge. Depending on the degree of pressure difference, the clogging state is judged, and if necessary, the filter element and the like are replaced.

  Some devices operate for a long time. At that time, the administrator periodically checks and monitors the value of the differential pressure gauge. When the value of the differential pressure gauge becomes larger than usual due to clogging, etc., it may be necessary to respond quickly depending on the device, but for that purpose, frequent monitoring is required and the workload of the administrator is reduced. It was supposed to increase.

Therefore, it is conceivable to automatically monitor the differential pressure by contact output.
The differential pressure measurement method can be broadly divided into two types: a mechanical type that operates the pointer using a gear or a link mechanism to change the state of the Bourdon tube or diaphragm due to pressure, and a pressure sensor and electronic circuit. Some digital displays display numerical values.
Generally, the instrument part itself is smaller in the digital type than in the mechanical type.
Further, regardless of which method is used, automatic alarm issuance is performed by opening and closing the contact when the differential pressure exceeds a predetermined threshold.

Many digital differential pressure gauges with pressure sensors require a DC power supply, so they must be used after being converted from an AC power supply that can be easily obtained in the factory to a DC voltage, and for such alarm contacts Since the output is also for DC voltage, re-conversion to AC voltage is required in some cases.
Therefore, in order to reduce the size of the device, which is an advantage of the digital system, in the end, there are many cases where the size is hindered by the size of the power supply device.
The differential pressure is also displayed numerically, and the display is often small and difficult to understand when visually inspecting.

  On the other hand, since the mechanical differential pressure gauge has various mechanisms for operating the pointer inside, it tends to be larger than the digital type, but it is easy to check visually today. But it is used a lot.

  Conventionally, various technical proposals have been made for alarms in mechanical indicators. For example, in Patent Document 1, in a mechanical indicator (speedometer), a detection member having a contact portion protruding to the side of a pointer shaft capable of rotating at an angle and a detection member in an alarm area are provided, and the detection member is intermittently connected. In particular, a technique capable of issuing an alarm by contacting and energizing a detection member has been proposed and is a known technique.

In the technical proposal according to Patent Document 1, if the detected member and the detection member come into contact with each other due to the angular rotation of the needle shaft, that is, if the protruding portion presses the detection portion that is the electrode portion and is energized, an alarm is issued. The
Therefore, it is not necessary to select the type of power source, and it is not necessary to obtain a dedicated power source, and it is possible to issue an alarm only with or without energization.

  However, the technical proposal according to Patent Document 1 still has problems in the following points.

  First, in addition to the mechanism of the instrument itself, at least a member to be detected and a detection member must be prepared.

Secondly, it is not considered that the pointer swings violently.
In a differential pressure gauge, the situation where the pointer swings violently is caused by overshoot or undershoot of pressure change that occurs when a nearby valve is opened or closed when the pneumatic circuit is used or stopped. Some are generated, and some are generated especially when other fluids such as drain (condensate) are mixed into the pipe.
Under such circumstances, there is a possibility that the detected member or the detecting member may break down when the pointer is vigorously shaken.

Japanese Utility Model Publication No. 62-140455

  An object of the present invention is to provide a differential pressure gauge that has few structural members for alarming and that can operate normally even when the pointer vibrates violently.

  In order to solve the above-described problems, a differential pressure monitoring apparatus according to the present invention has a differential pressure detection unit that detects a differential pressure that is a difference between two pressures, and a rotational position according to a detection amount of the differential pressure detection unit. A pointer portion and a pointer main body that change and conduct with the voltage input portion, a scale plate that indicates the value of the differential pressure, a detection needle portion and a detection needle hole that are provided on the scale plate and are electrically connected to the voltage output portion, respectively. When the detection needle part and the pointer main body come into contact with each other, an electrical closing circuit is configured, and the voltage output unit outputs an alarm.

  Preferably, the pointer body adopts a configuration in which it is an elastic body coated or painted with a conductor.

  Preferably, the detection needle portion has a rod shape and an elastic body coated or painted with a conductor.

  Preferably, a plurality of the detection needle holes are provided, the detection needle portion is inserted into at least one detection needle hole, and the detection needle portion is detachable.

  Preferably, the scale plate is a substrate on which an electric circuit pattern connecting the detection needle hole and the voltage output unit is generated, and the detection needle hole is a through hole formed of a conductor. Adopt the configuration.

  According to the differential pressure monitoring apparatus according to the present invention, it is possible to provide an apparatus that has very few alarm components in addition to a normal differential pressure gauge, and that has a very low possibility of failure even if the pointer shakes violently. .

1 is an overall view of an embodiment in which a differential pressure monitoring device according to the present invention is used for an air filter. It is side surface partial sectional drawing of the Example which used the differential pressure monitoring apparatus which concerns on this invention for the air filter. It is a schematic diagram which shows the electric circuit of the differential pressure monitoring apparatus which concerns on this invention. It is a surface view of the scale plate of the differential pressure monitoring apparatus according to the present invention. It is a rear view of the scale plate of the differential pressure monitoring apparatus according to the present invention. It is a sectional side view of the scale plate of the differential pressure monitoring apparatus according to the present invention.

The differential pressure monitoring apparatus 1 according to the present invention includes a differential pressure detection unit 130 that detects a differential pressure that is a difference between two pressures, a rotational position that changes according to a detection amount of the differential pressure detection unit 130, and a voltage. Pointer portion 200 and pointer main body 210 that are electrically connected to the input portion 500, a scale plate 300 that indicates the value of the differential pressure, a detection needle portion 400 that is provided on the scale plate 300 and that is electrically connected to the voltage output portion 600, and a detection needle hole, respectively. 320, and when the detection needle unit 400 and the pointer main body 210 come into contact with each other, an electrical closed circuit is configured, and the voltage output unit 600 outputs an alarm.
Hereinafter, an embodiment of a differential pressure monitoring apparatus 1 according to the present invention will be described with reference to the drawings.

  Note that the differential pressure monitoring device 1 according to the present invention is not limited to the embodiments described below, but within the scope of the technical idea of the present invention, that is, the shape, dimensions, etc. that can exhibit the same operational effects. It can be changed within the range.

The present invention will be described with reference to FIGS. 1 to 4 and 6.
FIG. 1 is an overall view of an embodiment in which a differential pressure monitoring device 1 according to the present invention is used for an air filter 700. FIG. 2 is a partial cross-sectional side view of an embodiment in which the differential pressure monitoring device 1 according to the present invention is used for an air filter 700. FIG. 3 is a schematic diagram showing an electric circuit of the differential pressure monitoring apparatus 1 according to the present invention. FIG. 4 is a surface view of the scale plate 300 showing an embodiment of the differential pressure monitoring apparatus 1 according to the present invention. FIG. 5 is a back view of the scale plate 300 showing an embodiment of the differential pressure monitoring apparatus 1 according to the present invention. FIG. 6 is a sectional side view of the scale plate 300 showing an embodiment of the differential pressure monitoring apparatus 1 according to the present invention.

The differential pressure monitoring device 1 is a device that issues an alarm when a pressure difference between two locations exceeds a predetermined value, and includes a differential pressure gauge unit 100, a voltage input unit 500, and a voltage output unit 600. ing.
The differential pressure gauge unit 100 includes a differential pressure detection unit 130, a pointer unit 200, a scale plate 300, and a detection needle unit 400 as a rough configuration. Except for the detection needle part, the overall shape is the same as that of a normal analog differential pressure gauge that does not use electricity.
In view of the above, when the differential pressure monitoring device 1 according to the present invention excludes a normal analog differential pressure gauge that does not use electricity and one aspect, a detection needle unit 400, a voltage input unit 500, and a voltage output Only the part 600 has a difference in component configuration.

  The differential pressure detection unit 130 includes a high-pressure side input unit 110 and a low-pressure side input unit 120, and is a part that detects and measures the pressure of the high-pressure side input unit 110 with reference to the low-pressure side input unit 120. The amount of pressure to be measured varies depending on the type of the differential pressure detector 130, but in the present embodiment, it can be measured up to 0.2 Mpa (megapascal). The high-pressure side input unit 110 and the low-pressure side input unit 120 are connected like a branch pipe from an inlet 710 of an air filter 700 described later. The differential pressure detection unit 130 converts the measurement amount into a rotation angle and transmits it to the pointer unit 200. This mechanism is the same as a normal analog differential pressure gauge.

If the pointer portion 200 is of a Bourdon tube type, the pointer portion 200 is angularly rotated from the high pressure side input portion 110 by a differential pressure amount via a Bourdon tube (not shown), a link mechanism (not shown), a gear (not shown), or the like. This is a part indicating the amount of differential pressure. The pointer main body 210 is an elongated meter needle protruding from the end of the rotating shaft, and the tip is thin so that the differential pressure can be easily read.
The entire pointer portion 200 is a conductor that conducts electricity. In the vicinity of the rotating shaft portion end of the pointer portion 200, there are the above-described gears and the like, which are fixed to the differential pressure detecting portion 130 through them. The pointer part 200 and the pointer main body 210 are electrically connected. An electric wire 820 is connected to the end of the pointer part 200 (FIG. 6). One end of the electric wire is connected to the voltage input unit 500. In principle, the voltage input unit 500 is supplied from an external power source. However, the type of power supply may be any appropriate one.
The pointer main body 210 is preferably made of a material that is unlikely to corrode or the like in order to flow electricity smoothly when it comes into contact with the detection needle portion 400.

Also, during abnormal operation due to a sudden increase in the differential pressure, the opening or closing of a valve in the compression / pneumatic circuit, the mixing of other fluids such as drainage, etc., the pointer main body 210 may hit the detection needle section 400 at high speed, Even after 210 abuts on the detection needle portion 400, the pointer main body 210 may continue to push the detection needle portion 400 with a rotational force corresponding to the differential pressure value. Therefore, it is preferable that the pointer main body 210 and / or the detection needle portion 400 is an elastic body that is coated or painted with a conductor.
With such a configuration, the pointer main body 210 and / or the detection needle portion 400 does not fail due to self-confidence or deformation of the detection needle portion 400 even under a situation where the pointer main body 210 shakes violently.
Most elastic bodies are non-conductive resins. However, if they are coated or painted with a conductor, they can be made into an elastic conductor relatively easily.
Examples of such treatment include metal powder coating and coating treatment with a metal thin film.

  The scale plate 300 is a dial for reading the value of the differential pressure. The scale plate 300 itself is electrically non-conductive. In the present embodiment, a scale 310 having an upper limit of 0.2 Mpa is entered (FIG. 4). In the center of the scale plate 300, a needle shaft hole 330 is provided. In FIG. 4, a plurality of detection needle holes 320 are provided in the upper right portion of the scale plate 300 on the paper surface. In this embodiment, three detection needle holes 320 are provided, but the number may be larger or one. The position of the detection needle hole 320 is provided at a position where a warning should be given when the differential pressure is measured and monitored. If the value to be alarmed differs depending on the situation, season, etc., a plurality of detection needle holes 320 are provided accordingly. The size of the detection needle hole 320 is appropriate so that the detection needle portion 400 can be properly inserted and the detection needle portion 400 does not tilt even when the pointer main body 210 comes into contact.

FIG. 5 is a view showing the back surface of the scale plate 300. A plurality of detection needle holes 320 are provided. Further, a pattern 810 that is an electric conduction path 800 is formed. One of the patterns 810 is connected to the detection needle hole 320, and the other is collected in one place and connected to the electric wire 820. That is, it can be said that the scale plate 300 is a kind of electronic substrate.
The detection needle hole 320 is a conductive through hole. The detection needle part 400 is a rod-like elastic pin, and the detection needle part 400 and the detection needle hole 320 are electrically connected by being inserted into the detection needle hole 320. Therefore, by inserting the detection needle portion 400 into the detection needle hole 320, the detection needle portion 400 and the voltage output portion 600 are connected via the detection needle hole 320, the pattern 810, and the electric wire 820. Such an aspect contributes to the reduction of the number of electric wires 820 and the reduction of man-hours.
In view of the above, the electric conduction path 800 may be a pattern 810 or an electric wire 820, and may be appropriately selected from them.

The detection needle part 400 is one of the important elements in the present invention. The detection needle part 400 is arranged at a position indicated by the pointer main body 210 when the differential pressure to be alarmed on the scale plate 300 is reached. The detection needle hole 320 is provided at that position, and the detection needle portion 400 is inserted therein. In that case, a part of detection needle part 400 is fixed so that it may protrude on the surface of the scale plate 300 (FIG. 6). The protruding length is a length that can contact the pointer main body 210 when the pointer main body 210 rotates according to the differential pressure. The detection needle part 400 is an electrical conductor. One of the detection needles 400 is connected to the electric wire 820 and is electrically connected to the voltage output unit 600 (FIG. 6). The portion of the detection needle portion 400 that protrudes from the surface is preferably made of a material that is unlikely to corrode or the like so that electricity flows smoothly when it contacts the pointer main body 210.
It is also conceivable that the pointer main body 210 hits the detection needle portion 400 at a high speed. Therefore, as described in the preceding paragraph, the detection needle unit 400 is preferably an elastic body that is coated or painted with a conductor in order to reduce impact.

  The differential pressure gauge unit 100 has a case 140 as an external appearance and a glass plate 150 that protects the scale plate 300 as in the case of a normal analog differential pressure gauge. In addition, a plurality of electric wires 820 that are electrically connected to the voltage input unit 500 and the voltage output unit 600 are provided from the case 140.

The voltage output unit 600 is a part that issues an alarm when it is determined that the differential pressure value should be alarmed, that is, when the pointer main body 210 and the detection needle unit 400 come into contact with each other.
The alarm receiving side turns on a relay or a semi-conductor such as a photocoupler, a transistor, or an FET by the voltage. The alarm is used for some circuit control, or a sounding means such as a buzzer or a light emitting means such as an LED is operated, and is finally delivered to the operator's perception.

Next, the operation of the embodiment according to FIG. 1 will be described.
An example of an air filter 700 is shown in FIG. 1 as a part for detecting pressure. The air filter 700 removes gaseous and liquid impurities by the filter 730. Fluid is introduced from the inlet 710 of the air filter 700, impurities are removed by the filter 730 in the air filter 700, and the fluid is discharged from the outlet 720.
In this embodiment, two air filters 700 are connected in series.

Two air filters 700 are connected in series. The outlet 720 of the upstream air filter 700 and the inlet 710 of the downstream air filter 700 are connected. A high pressure side input unit 110 of the differential pressure gauge unit 100 is connected to the inlet 710 of the upstream air filter 700, and a low pressure side input unit 120 is connected to the inlet 710 of the downstream air filter 700. Therefore, the differential pressure measured by the differential pressure gauge unit 100 is a pressure difference between the inlet 710 and the outlet 720 of the upstream air filter 700. If the filter 730 in the air filter 700 is clogged, the pressure difference between the inlet 710 and the outlet 720 of the air filter 700 increases. In many cases, the air filter 700 on the upstream side has a large filter diameter for the purpose of treating foreign particles having a large particle size and having a higher appearance frequency. Therefore, the differential pressure increases from the upstream air filter 700.
The high pressure side input unit 110 and the low pressure side input unit 120 are connected to the differential pressure detection unit 130, and the differential pressure detection unit 130 is connected to the pointer main body 210. The value of the differential pressure can be read from the position of the needle by the rotation of the pointer main body 210 and the scale 310 of the scale plate 300. The movement up to this point is the same as the use contents of a normal analog differential pressure gauge.

  The scale plate 300 is provided with a detection needle hole 320. The position of the detection needle hole 320 is provided at a position indicating the minimum value to be alarmed in the air filter 700 to be used. This is because when the pointer main body 210 indicates this value, the pointer main body 210 and the detection needle hole 320 come into contact with each other. A voltage output unit 600 is connected to one of the detection needle holes 320 via a pattern 810 and an electric wire 820. Similarly, the voltage from the voltage input unit 500 is applied to one of the pointer unit 200 and the pointer main body 210 via the electric wire 820.

Here, the electrical configuration will be described with reference to the schematic diagram of FIG. The drawing shows a state in which the pointer main body 210 and the detection needle portion 400 are in contact with each other to form an electrical circuit. A voltage from the voltage input unit 500 is supplied to the electric conduction path 800 connected to the pointer unit 200. This voltage is always applied to the pointer main body 210 via the pointer portion 200.
Next, the electric conduction path 800 connected to the detection needle unit 400 is connected to the voltage output unit 600. When no voltage is applied to the detection needle unit 400, the voltage output unit 600 naturally does not generate an alarm. In other words, as shown in FIG. 3, when the pointer main body 210 and the detection needle unit 400 come into contact with each other and the voltage from the pointer main body 210 is supplied to the detection needle unit 400, the voltage is output via the electric conduction path 800. Supplied to the unit 600, the voltage output unit 600 issues an alarm.

In addition, since the detection needle part 400 is not directly connected to the electric wire 820 when the pattern 810 exists, it can be inserted and removed from the surface of the scale plate 300. When changing the differential pressure value at the alarm level, the glass plate 150 of the differential pressure gauge unit 100 may be removed and the detection needle unit 400 may be replaced with the detection needle hole 320 to be changed. It is relatively easy to make the glass plate 150 detachable.
According to this structure, it is possible to easily change the differential pressure value at the alarm level without opening the case 140.
In addition, since it is only necessary to change the detection needle unit 400, the operation can be easily changed while continuing the differential pressure measurement, and the work efficiency of the manager can be improved.

The movement up to the alarm will be described with reference to FIG.
The differential pressure detection unit 130 connected to the air filter 700 measures the differential pressure, and the pointer main body 210 normally indicates a pressure of 0.1 Mpa or less. When the pressure difference between the inflow port 710 and the outflow port 720 exceeds 0.1 MPa due to clogging of the filter 730 or the like (in this case, near 0.11 MPa), the pointer main body 210 and the detection needle unit 400 come into contact with each other. Then, an electrical closed circuit is formed, and an alarm is issued from the voltage output unit 600.

  In this way, when the pressure difference between the inlet 710 and the outlet 720 of the air filter 700 reaches the alarm level, an alarm can be automatically issued. When the administrator or the control side that has received the warning confirms the warning, the air filter 700 that has issued the warning can be dealt with immediately. Therefore, regular patrols and the like are not necessary, and the work burden on the manager is reduced.

Circuits using fluids, particularly compressed air circuits, are used in a great many applications, and the “differential pressure monitoring device” according to the present invention can be widely applied to such circuits.
Therefore, it is thought that the industrial applicability of the “differential pressure monitoring device” according to the present invention is great.

DESCRIPTION OF SYMBOLS 1 Differential pressure monitoring apparatus 100 Differential pressure gauge part 110 High pressure side input part 120 Low pressure side input part 130 Differential pressure detection part 140 Case 150 Glass plate 200 Pointer part 210 Pointer main body 300 Scale plate 310 Scale 320 Detection needle hole 330 Needle shaft hole 400 Detection needle part 500 Voltage input part 600 Voltage output part 700 Air filter 710 Inlet 720 Outlet 730 Filter 800 Electric conduction path 810 Pattern 820 Electric wire

Claims (5)

A differential pressure detector that detects a differential pressure that is a difference between two pressures;
A pointer portion and a pointer body that are electrically connected to the voltage input portion while the rotational position changes according to the detection amount of the differential pressure detection portion,
A scale plate showing the value of the differential pressure;
A detection needle portion and a detection needle hole which are provided on the scale plate and are electrically connected to the voltage output portion, respectively;
An electrical pressure closed circuit is configured when the detection needle part and the pointer main body come into contact with each other, and the voltage output part outputs an alarm.   The differential pressure monitoring apparatus according to claim 1, wherein the pointer main body is an elastic body coated or painted with a conductor.   The differential pressure monitoring apparatus according to claim 1, wherein the detection needle portion is an elastic body that is rod-shaped and coated or coated with a conductor. A plurality of the detection needle holes are provided, and the detection needle portion is inserted into at least one of the detection needle holes,
The differential pressure monitoring device according to any one of claims 1 to 3, wherein the detection needle part is detachable. The scale plate is a substrate on which an electric circuit pattern that connects the detection needle hole and the voltage output unit is generated,
The differential pressure monitoring device according to claim 1, wherein the detection needle hole is a through hole formed of a conductor.