KR20240096110A - Explosion-proof vacuum gauge - Google Patents

Abstract

The explosion-proof vacuum gauge according to the present invention includes an epoxy molding that protects the front window made of tempered glass, a cover rack ring, a cover case, an anti-loosening O-ring that prevents the vacuum sensor portion from loosening, and a combination of the Pirani sensor and the diaphragm sensor of the vacuum sensor. By providing a supporting insulating pressure plate, damage is prevented even in the event of an explosion, which has the effect of safely measuring the vacuum chamber to be measured.

Description

Explosion-proof vacuum gauge

The present invention relates to an explosion-proof vacuum gauge, and more specifically, to a vacuum sensor unit combining a Pirani sensor and a diaphragm sensor that measures the vacuum pressure of a vacuum chamber, a cable connection hole to which a gland cable is connected, and a display unit that displays the vacuum pressure. This relates to an explosion-proof vacuum gauge in which a case equipped with is firmly coupled to improve explosion-proof performance.

In general, vacuum gauges are divided into direct measurement vacuum gauges and indirect measurement vacuum gauges depending on the measurement principle.

The direct measurement vacuum gauge directly measures the force per unit area, and the liquid level vacuum gauge measures pressure by the difference in liquid levels at both ends of a U-shaped tube, and uses the principle that the surface of a container connected to a vacuum undergoes elastic deformation under pressure. Divided into elastic element vacuum gauge,

An indirect measurement vacuum gauge refers to a vacuum gauge that indirectly measures changes in pressure based on changes in physical quantities related to gas pressure at low pressure rather than directly measuring force per unit area. It measures pressure using heat conduction of low-pressure gas. There are various types such as heat conduction vacuum gauges that use the principles of heat radiation and pressure, and ionization vacuum gauges.

Here, as a representative heat conduction vacuum gauge, the Pirani gauge is a gauge that utilizes the property of a platinum filament inside to always maintain a constant temperature. In other words, the Pirani gauge is a gauge that measures pressure using the principle that when heat is lost to gas molecules in contact with the filament, the amount of current flowing changes to compensate for the heat loss of the filament.

Meanwhile, a representative example of elastic element vacuum gauges is the diaphragm vacuum gauge. In other words, the pressure space is divided using a flexible diaphragm, and if there is a pressure difference in the divided pressure space, the diaphragm undergoes deformation according to the differential pressure, so it is a gauge that measures this deformation to obtain the pressure difference.

As a related prior art, Korean Patent No. 10-1727820 (April 11, 2017) discloses a 'diaphragm type vacuum gauge and a diaphragm type vacuum measuring device equipped with the same.'

The prior art, as shown in FIG. 1, includes a housing unit 20 having an internal space; A diaphragm-type vacuum gauge (10) mounted within the housing unit (20) to divide the internal space into a vacuum measurement space (S1) connected to the outside and a reference pressure space (S2) closed inside; And a microprocessor (30) connected to the diaphragm-type vacuum gauge (10) to calculate the vacuum pressure of the vacuum measurement space (S1),

The diaphragm-type vacuum gauge 10 includes a first to third gauge unit including a diaphragm member, a piezoelectric layer, a positive electrode, and a negative electrode inside the housing unit 20,

The microprocessor 30 is alternatively connected to each electrode unit and calculates the vacuum pressure of the vacuum measurement space S1 based on the magnitude of the voltage measured between the positive and negative electrodes of the electrode unit.

However, in the above-described prior art, multiple electrode layers such as a first gauge unit, a second gauge unit, and a third gauge unit are provided inside the housing unit 20, so even if the range that the diaphragm sensor can measure is expanded, There was a problem that the configuration to withstand shock transmitted from external shock and the pressure resistance performance to withstand pressure in a vacuum were not considered at all.

The present invention was created to solve the problems of the prior art as described above. The purpose of the present invention is to stabilize the vacuum pressure in the vacuum chamber by utilizing a Pirani sensor in the low vacuum area and a diaphragm vacuum sensor in the atmospheric pressure (760 torr) area. The vacuum sensor, case body, and case cover are equipped with an explosion-proof structure and combined to provide an explosion-proof vacuum gauge that can be operated stably in the high-pressure environment of the vacuum chamber and has improved explosion-proof performance.

An explosion-proof vacuum gauge according to the present invention for achieving the above object is an explosion-proof vacuum gauge for measuring the vacuum pressure in a vacuum chamber to be measured, and includes a vacuum sensor connected to the vacuum chamber to measure the vacuum pressure; A case in which the vacuum sensor is fastened to the lower part, a control unit that converts the electric signal of the vacuum sensor into vacuum pressure and transmits it, and a display unit that displays the transmission signal of the control unit is mounted inside,

The case includes a case body having a plurality of PCB fixing rods extending forward on the inner surface so that the control unit and the display unit mounted on the front of the control unit are coupled, and a grounding point to which a ground wire is connected; A case cover is provided, which is coupled to the front of the case body and through which the display information of the display unit is transmitted,

In the case body, there is a cable connection hole at the top where the ground cable connected to the control unit is fastened, a sensor connection hole at the bottom where the vacuum sensor is fastened, and a display hole at the center so that the display information of the display unit is transparent at the center of the front. A display stage extending forward is provided,

The display end is fastened to the rear inner surface of the case cover on the outer peripheral surface, and has a first anti-loosening ring interposed thereto to prevent loosening when the case cover is fastened.

The vacuum sensor includes a sensor guide housing having a case fastening end fastened to the case on an upper outer periphery, a PCB housing that is recessed in the inner upper part of the sensor guide housing and from which a harness extending to the control unit is pulled out to the upper part, and A sensor upper housing whose upper part is coupled to the lower part of the PCB housing, the upper part of which is coupled to the sensor upper housing and the lower part of which is coupled to the lower part of the sensor guide housing, and a sensor lower housing which is coupled to the lower part of the sensor lower housing to be measured. A sensor port connected to the vacuum chamber is provided,

Inside the sensor upper housing and sensor lower housing, a Pirani sensor measuring a range of 10 torr to 10 ^-3 torr and a diaphragm sensor measuring a range of 1500 torr to 10 torr are provided, and inside the PCB housing, the blood A sensor PCB is provided that amplifies and transmits the electrical signals transmitted from the Raney sensor and diaphragm sensor.

At the lower end of the sensor upper housing, the inner space of the sensor upper housing and the sensor lower housing is divided up and down, and a pair of electrode holes to which both electrodes of the Pirani sensor are fixed are formed, and a diaphragm hole to which the diaphragm sensor is coupled is formed. It is characterized by being provided with a plate.

The case cover includes a front window through which the display information is transparent, a front end on which the front window is seated on the inner rear, and a screw thread extending to the rear of the front end and joining the inner periphery to the outer periphery of the display end. A coupling end and an annular cover rack ring rotatably coupled to the inside of the case coupling end are provided to support the rear circumference of the front window,

The inner rear surface of the front finishing end is characterized in that it is provided with a molding groove recessed forward, and an epoxy molding applied to the molding groove to support the front circumference of the front window.

The insulating pressure plate is provided with a housing support end extending upward to be supported on the lower inner end of the sensor upper housing, and an upper and lower separation end extending inward from the lower end of the housing support end and having the electrode hole and the diaphragm hole, The electrode hole is characterized by being provided with an electrode support piece extending upward to support a wider circumference of the electrode.

The electrode hole is characterized in that a glass seal is formed surrounding the circumference of the electrode to insulate the electrode of the Pirani sensor.

A powder filter is provided between the sensor lower housing and the sensor port to block dust transmitted by vacuum pressure from entering the interior,

A second anti-loosening geo-ring is disposed at the lower end of the case fastening end to prevent loosening of the case fastening end and the sensor fastening hole.

The lower part of the sensor upper housing is provided with a laser welded end recessed inward to support the housing support end of the insulating pressure plate and the upper end of the sensor lower housing, and the upper part of the sensor lower housing is provided with the outer peripheral surface of the housing support end and the An insertion end with a reduced inner and outer diameter is provided to be inserted between the inner surfaces of the laser welding end,

The lower part of the sensor lower housing is characterized in that it is provided with a contact protrusion extending outward to come into close contact with the lower end of the sensor guide housing.

As such, the explosion-proof vacuum gauge according to the present invention has the following effects.

First, the Pirani sensor and diaphragm sensor are combined with the insulating pressure plate of the vacuum sensor, which is connected to the case consisting of the case body and case cover, to detect the vacuum pressure, making it possible to accurately measure the vacuum pressure of the vacuum chamber with a wide band vacuum pressure area. can,

Second, an anti-loosening geo-ring is inserted when the case cover and vacuum sensor are connected to the case body, so that the connection is maintained even if external vibration or shock is transmitted for a long time.

Third, as the tempered glass front window mounted on the case cover is supported by epoxy molding and cover rack ring, the pressure resistance performance is improved, making it safer to use even in shocks caused by explosions or abnormal environments.

Fourth, the insulating pressure plate and sensor lower housing are laser welded to the sensor upper housing, and the contact jaw of the sensor lower housing is laser welded to the bottom of the sensor guide housing, and the structure of the insulating pressure plate maximizes pressure resistance performance. By providing a housing support as much as possible, durability and explosion-proof pressure resistance are significantly improved.

1 is a cross-sectional view of a diaphragm-type vacuum measuring device according to the prior art;
Figure 2 is a perspective view of an explosion-proof vacuum gauge according to the present invention;
Figure 3 is an exploded perspective view of the vacuum gauge according to the present invention;
Figure 4 is a cross-sectional view of the vacuum sensor according to the present invention;
Figure 5 is a cross-sectional view of the case cover according to the present invention,
Figure 6 is a diagram explaining a pressure-resistant insulating plate according to the present invention;
Figure 7 is a front view of the case body according to the present invention.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the attached drawings.

As shown in FIGS. 2 to 7, the explosion-proof vacuum gauge according to the present invention is an explosion-proof vacuum gauge for measuring the vacuum pressure in a vacuum chamber to be measured, and includes a vacuum sensor ( 1) and; The vacuum sensor (1) is fastened to the bottom, a control unit (C) that converts the electrical signal of the vacuum sensor (1) into vacuum pressure and transmits it, and a display unit (D) that displays the transmission signal of the control unit (C). It consists of a case (2) mounted inside.

Here, the case 2 has a plurality of PCB fixing rods 212 extending forward on the inner surface so that the control unit C and the display unit D mounted on the front of the control unit C are connected, and a ground wire is connected. A case body 21 having a grounding point 213 formed thereon; A case cover 22 is coupled to the front of the case body 21 and through which display information of the display unit D is transmitted.

Meanwhile, the case body 21 has a cable connection hole 21a at the top into which the ground cable connected to the control unit C is fastened, and a sensor connection hole 21b at the bottom into which the vacuum sensor 1 is fastened. And, a display stage 21c extending forward through a display hole 211 in the center is provided at the front center so that the display information of the display unit D is transparent. That is, the case body 21 is processed into one body.

In addition, the display end 21c is fastened to the rear inner surface of the case cover 22 on the outer peripheral surface, and a first anti-loosening ring 23 is interposed to prevent loosening when the case cover 22 is fastened, The case cover 22 is prevented from being separated from the case body 21, loosening is prevented even from frequent external impacts, and explosion-proof performance is strengthened.

In addition, the vacuum sensor 1 has a sensor guide housing 11 having a case fastening end 11a fastened to the case 2 on the upper outer periphery, and a recess in the inner upper part of the sensor guide housing 11. a PCB housing 12 from which a harness extending to the control unit C is pulled out to the top, a sensor upper housing 13 whose upper end is coupled to the lower end of the PCB housing 12, and the upper part of which is the sensor upper housing ( 13), the lower part of which is coupled to the lower part of the sensor guide housing 11, and the sensor port 15, which is coupled to the lower part of the sensor lower housing 14 and is connected to the vacuum chamber to be measured. ) is provided.

Here, on the outside of the sensor guide housing 11, a separate bolt-shaped fastener is provided on the outer periphery to facilitate fastening to the case fastening end 11a.

And, inside the sensor upper housing 13 and sensor lower housing 14, there is a Pirani sensor (R) measuring the 10 torr to 10 ^-3 torr range, and a diaphragm sensor (P) measuring the 1500 torr to 10 torr range. ) is provided, and a sensor PCB (T) is provided inside the PCB housing 12 to amplify and transmit the electrical signal transmitted from the Pirani sensor (R) and the diaphragm sensor (P).

In addition, at the lower end of the sensor upper housing 13, the inner space of the sensor upper housing 13 and the sensor lower housing 14 is divided up and down, and the electrodes (E) on both sides of the Pirani sensor (R) are fixed. An insulating pressure plate 16 is provided with a pair of electrode holes 16a and a diaphragm hole 16b to which the diaphragm sensor P is coupled.

Based on the insulating pressure plate 16, normal pressure is applied to the upper part, and the vacuum pressure of the vacuum chamber, which is the device to be measured, is applied to the lower part.

Meanwhile, the case cover 22 includes a front window 22a through which the display information is transparent, a front end 22b on which the front window 22a is seated on the inner rear, and a front end 22b of the front end 22b. A case coupling end (22c) extending rearward and having a threaded inner periphery coupled to the outer periphery of the display end (21c), and the case coupling end (22c) to support the rear circumference of the front window (22a). By providing an annular cover rack ring (22d) rotatably coupled to the inside, the front window (22a) made of tempered glass is stably fixed.

In addition, there is a molding groove 221 recessed forward on the inner rear side of the front finishing end 22b, and an epoxy molding 222 applied to the molding groove 221 to support the front circumference of the front window 22a. By being provided, the front window 22a is prevented from being damaged by external impact.

Meanwhile, the insulating pressure plate 16 has a housing support end 16c extending upward to be supported on the lower inner end of the sensor upper housing 13, and extending inward from the lower end of the housing support end 16c. By providing an upper and lower separation stage 16d through which the electrode hole 16a and the diaphragm hole 16b are formed, it is possible to withstand the vacuum pressure of the device to be measured connected to the lower part.

In addition, the electrode hole (16a) is provided with an electrode support piece (16e) extending upward to support the circumference of the electrode (E) more widely, and the electrode hole (16a) is provided with the Pirani sensor (R). A glass sealing 15f is formed surrounding the electrode E to insulate the electrode E, thereby reducing the error in the electrical signal transmitted through the electrode E.

In addition, a powder filter 17 is provided between the sensor lower housing 14 and the sensor port 15 to block dust transmitted by vacuum pressure from entering the interior, thereby eliminating contamination transmitted from the measured device. Dust is prevented from penetrating into the vacuum sensor (1).

In addition, a second anti-loosening ring 111 is interposed at the lower end of the case fastening end 11a to prevent the case fastening end 11a and the sensor fastening hole 21b from loosening, thereby preventing the vacuum sensor from loosening even against frequent external shocks. (1) is prevented from being separated from the case body 21.

Meanwhile, at the lower part of the sensor upper housing 13, there is a laser welded end 13a recessed inward to support the housing support end 16c of the insulating pressure plate 16 and the upper end of the sensor lower housing 14. An insertion end (14a) whose inner and outer diameters are reduced to be inserted between the outer peripheral surface of the housing support end (16c) and the inner surface of the laser welded end (13a) is provided on the upper part of the sensor lower housing (14), The lower part of the sensor lower housing 14 is provided with a contact protrusion 14b that extends outward to come into close contact with the lower end of the sensor guide housing 11.

That is, the housing support end 16c of the insulating pressure plate 16 and the insertion end 14a of the sensor lower housing 14 are in close contact with each other and supported on the laser welding end 13a of the sensor upper housing 13. It is laser welded, and the contact jaw 14b of the sensor lower housing 14 is in close contact with the lower end of the sensor guide housing 11 and is subjected to laser welding processing.

The operation of the explosion-proof vacuum gauge according to the present invention configured as described above is as follows.

As shown in FIGS. 2 to 7, the explosion-proof vacuum gauge according to the present invention is composed of a vacuum sensor (1) connected to a vacuum chamber and a case (2) exposed to normal pressure, and the vacuum sensor (1) The Pirani sensor ( The vacuum pressure of the vacuum chamber is measured using R) and the diaphragm sensor (P).

At this time, the case 2 has a first anti-loosening ring 23 interposed when the case body 21 and the case cover 22 are combined to improve the pressure resistance performance, so that the case cover 22 remains intact even against frequent external impacts. This prevents it from being separated from the case (2), and the front window (22a) made of tempered glass provided in the case cover (22) is connected to the epoxy molding (222) of the front finishing end (22b) and the cover rack ring (22d). This support prevents damage due to impact.

Meanwhile, a second anti-loosening ring 111 is interposed between the vacuum sensors 1 coupled to the case 2. That is, the second anti-loosening geo-ring 111 interposed between the case fastening end (11a) of the vacuum sensor (1) and the sensor fastening hole (21b) of the case (2) is the vacuum sensor (1) in the case ( By preventing deviation from 2), the pressure resistance performance is further improved.

In addition, the vacuum sensor 1 includes a sensor guide housing 11 coupled to the case fastening end 11a, a PCB housing 12 recessed inside the sensor guide housing 11, a sensor upper housing 13, and By providing a sensor lower housing 14 integrally formed by laser welding to the sensor guide housing 11 and the sensor upper housing 13, not only is the pressure resistance performance strengthened, but the sensor upper housing 13 and the sensor lower housing 13 are integrated with each other. The insulating pressure plate 16 coupled between the housings 14 is also laser welded to enhance durability.

Here, the insulating pressure plate 16 is provided with a housing support end 16c extending upward around an upper and lower separation end 16d through which the electrode hole 16a and the diaphragm hole 16b are perforated, thereby forming a lower vacuum chamber. The pressure resistance performance is improved for the vacuum pressure transmitted through the sensor port 15 connected to.

In addition, a Pirani sensor (R) extending through the electrode hole (16a) and a diaphragm sensor (P) exposed through the diaphragm hole (16b) are provided inside the vacuum sensor (1), and have a voltage of 1500 torr ~ 10 The torr is measured by the diaphragm sensor (P), and the 10 torr to 10 ^-3 torr range is measured by the Pirani sensor (R), making it possible to accurately measure the vacuum state of the vacuum chamber.

As such, the explosion-proof vacuum gauge according to the present invention can measure vacuum pressure over a wide range using a Pirani sensor and a diaphragm sensor, and is equipped with an anti-loosening geo-ring and a cover rack ring and epoxy molding to support the tempered glass front window, thereby protecting the exterior. There is an effect of improving explosion-proof performance even against impact.

The present invention is not limited to the specific preferred embodiments described above, and various modifications can be made by anyone skilled in the art without departing from the gist of the invention as claimed in the claims. Of course, such changes are within the scope of the claims.

<Explanation of symbols for main parts of the drawing>
1: Vacuum sensor 2: Case
11: Sensor guide housing 11a: Case fastening end
12: PCB housing
13: Sensor upper housing 13a: Laser welding end
14: Sensor lower housing 14a: Insertion end
14b: Close jaw
15: sensor port 16: insulating pressure plate
16a: electrode hole 16b: diaphragm hole
16c: Housing support end 16d: Top and bottom separation end
16e: Electrode support piece 16f: Glass sealing
17: Powder filter 111: Second loosening prevention geo-ring
21: Case body 21a: Cable connection hole
21b: sensor fastening hole 21c: display end
211: Marking hole 212: PCB fixing rod
213: ground point
22: case cover 22a: front window
22b: Front finishing end 22c: Case joining end
22d: Cover rack ring 221: Molding groove
222: Epoxy molding
23: 1st anti-loosening geo-ring
C: Control unit D: Display unit R: Pirani sensor
P: Diaphragm sensor T: Sensor PCB E: Electrode
Z: Laser welding point

Claims (7)

In the explosion-proof vacuum gauge for measuring the vacuum pressure in the vacuum chamber to be measured,
A vacuum sensor (1) connected to the vacuum chamber to measure vacuum pressure; The vacuum sensor (1) is fastened to the bottom, a control unit (C) that converts the electrical signal of the vacuum sensor (1) into vacuum pressure and transmits it, and a display unit (D) that displays the transmission signal of the control unit (C). It consists of a case (2) mounted inside,
The case 2 has a plurality of PCB fixing rods 212 extending forward on the inner surface so that the control unit C and the display unit D mounted on the front of the control unit C are coupled, and a ground wire is connected. A case body 21 having a grounding point 213; A case cover (22) is provided, which is coupled to the front of the case body (21) and through which the display information of the display unit (D) is transmitted,
The case body 21 includes a cable connection hole 21a at the top into which a ground cable connected to the control unit C is fastened, and a sensor connection hole 21b at the bottom into which the vacuum sensor 1 is fastened, A display stage 21c is provided at the center of the front and extends forward through a display hole 211 in the center so that the display information of the display portion D is transparent,
The display end 21c is fastened to the rear inner surface of the case cover 22 on the outer peripheral surface, and a first anti-loosening ring 23 is interposed to prevent loosening when the case cover 22 is fastened. Explosion proof vacuum gauge. According to paragraph 1,
The vacuum sensor (1) is
The case fastening end (11a) fastened to the case (2) has a sensor guide housing (11) provided on the upper outer periphery, and is recessed in the inner upper part of the sensor guide housing (11) and extends to the control unit (C). A PCB housing (12) with a harness pulled out to the top, a sensor upper housing (13) whose upper end is coupled to the lower end of the PCB housing (12), the upper part of which is coupled to the sensor upper housing (13), and the lower part of which is connected to the sensor. A sensor lower housing 14 coupled to the lower part of the guide housing 11 and a sensor port 15 coupled to the lower part of the sensor lower housing 14 and connected to the vacuum chamber to be measured are provided,
Inside the sensor upper housing (13) and sensor lower housing (14),
A Pirani sensor (R) measuring the 10 torr to 10 ^-3 torr range and a diaphragm sensor (P) measuring the 1500 torr to 10 torr range are provided,
Inside the PCB housing 12, a sensor PCB (T) is provided that amplifies and transmits the electrical signals transmitted from the Pirani sensor (R) and the diaphragm sensor (P),
At the lower end of the sensor upper housing 13, the inner space of the sensor upper housing 13 and the sensor lower housing 14 is divided up and down, and a pair of electrodes (E) on both sides of the Pirani sensor (R) are fixed. An explosion-proof vacuum gauge, characterized in that it is provided with an insulating pressure plate (16) having an electrode hole (16a) and a diaphragm hole (16b) to which the diaphragm sensor (P) is coupled. According to paragraph 1,
The case cover 22 is
A front window 22a through which the display information is transparent, a front end 22b on which the front window 22a is seated on the inner rear, and a front end 22b extending rearward of the front end 22b and displaying the display on the inner periphery. A threaded case coupling end 22c coupled to the outer periphery of the stage 21c, and an annular cover rack ring rotatably coupled to the inside of the case coupling end 22c to support the rear circumference of the front window 22a. (22d) is provided,
At the inner rear of the front end (22b),
An explosion-proof vacuum gauge, characterized in that it is provided with a molding groove (221) recessed forward, and an epoxy molding (222) applied to the molding groove (221) to support the front circumference of the front window (22a). According to paragraph 2,
The insulating pressure plate 16 is
A housing support end (16c) extending upward to be supported on the lower inner end of the sensor upper housing (13), extending inward from the lower end of the housing support end (16c) and including the electrode hole (16a) and the diaphragm hole ( 16b) is provided with a perforated upper and lower separation stage (16d),
An explosion-proof vacuum gauge, characterized in that the electrode hole (16a) is provided with an electrode support piece (16e) extending upward to support a wider circumference of the electrode (E). According to paragraph 4,
In the electrode hole 16a,
An explosion-proof vacuum gauge, characterized in that a glass sealing (15f) is formed surrounding the electrode (E) to insulate the electrode (E) of the Pirani sensor (R). According to paragraph 2,
Between the sensor lower housing (14) and the sensor port (15)
A powder filter (17) is provided to block dust transmitted by vacuum pressure from entering the interior,
At the lower end of the case fastening end (11a)
An explosion-proof vacuum gauge, characterized in that a second loosening prevention geo-ring (111) is interposed to prevent loosening of the case fastening end (11a) and the sensor fastening hole (21b). According to paragraph 4,
At the bottom of the sensor upper housing (13)
A laser welding end (13a) is provided that is recessed inward to support the housing support end (16c) of the insulating pressure plate (16) and the upper end of the sensor lower housing (14),
The upper part of the sensor lower housing 14 is provided with an insertion end 14a whose inner and outer diameters are reduced to be inserted between the outer peripheral surface of the housing support end 16c and the inner surface of the laser welded end 13a,
An explosion-proof vacuum gauge, characterized in that the lower part of the sensor lower housing (14) is provided with a contact jaw (14b) that extends outward to come into close contact with the lower end of the sensor guide housing (11).

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