Gas density monitoring device and shell sealing structure thereof

Abstract

The utility model relates to a shell sealing structure of a gas density monitoring device, the bottom end of a shell is sealed by a bottom cover, the top end of the shell is sealed by an observation cover, a first sealing ring is arranged between the side wall part of the observation cover and the side wall of the top end of a main cylinder body, and the first sealing ring is close to the corner position between a transparent sheet and the side wall part like the high structural rigidity of a wall corner. The closer the first sealing ring is to the corner position between the transparent piece and the side wall part, the side wall part is not prone to deformation, the higher the rigidity of the sealing structure is, and the better the sealing effect is. Therefore, the sealing performance of the gas density monitoring device is better.

Description

Technical Field

[0001] The utility model relates to a gas density monitoring device and a shell sealing structure thereof, in particular to a shell sealing structure of a gas density monitoring device suitable for high altitudes. Background Art

[0002] Gas density relays and gas density meters are widely used in power systems. They are commonly used gas density monitoring devices, generally divided into oil-free and oil-filled types. The performance of these gas density monitoring devices directly affects the reliable and safe operation of their related systems. Therefore, ensuring the reliable and safe operation of these gas density monitoring devices has become one of people's important tasks and work. Especially in high-altitude areas, as the altitude increases, the change in atmospheric pressure will have a greater impact on the accuracy, so we need the gas density monitoring device to achieve a sealed shell as a whole, to achieve complete isolation of the atmospheric pressure inside and outside the shell, and to avoid poor accuracy or oil and gas leakage.

[0003] At present, due to the poor sealing performance of the shells of these gas density monitoring devices, the internal pressure of the shells cannot maintain the set standard pressure, resulting in inaccurate measurement accuracy of the gas density monitoring devices. After research and analysis, it was found that the insufficient structural rigidity of the sealing parts related to the shell sealing position will affect the sealing performance of the shell, and the sealing structure is prone to deformation, resulting in poor sealing. The sealing effect of the shell is not good, and oil or gas leakage problems often occur, which also brings errors in accuracy, causing losses to users, and in serious cases, affecting normal use. Therefore, how to improve the sealing performance of the shell of the existing gas density monitoring device is a technical problem that urgently needs to be solved in this field. Utility Model Content

[0004] In view of the above-mentioned shortcomings of the prior art, the technical problem to be solved by the present invention is to provide a gas density monitoring device and a housing sealing structure thereof, which have good sealing performance.

[0005] To achieve the above-mentioned purpose, the utility model provides a shell sealing structure of a gas density monitoring device, including a sealed shell, the shell including a main cylinder, an observation cover and a bottom cover, the bottom end of the main cylinder is sealed by the bottom cover, the top end of the main cylinder is opened, the observation cover seals the top end opening of the main cylinder, the observation cover includes a circular transparent sheet and a side surrounding portion surrounded by the edge of the transparent sheet, the side surrounding portion is located on the inner / outer side of the side wall of the top end of the main cylinder, a first sealing ring is provided between the side surrounding portion and the side wall of the top end of the main cylinder to seal the opening of the top end of the main cylinder, and the first sealing ring is close to the corner position between the transparent sheet and the side surrounding portion.

[0006] Preferably, the side surrounding portion is located on the inner side of the side wall at the top end of the main cylinder body, the main cylinder body includes a sealing portion and a cylinder body portion, the sealing portion is located at the top end of the main cylinder body, the inner wall of the sealing portion is provided with a sealing groove, and the first sealing ring is provided in the sealing groove.

[0007] More preferably, the wall thickness of the sealing portion is greater than the wall thickness of the barrel portion.

[0008] More preferably, a positioning ring is further provided in the main cylinder, and the positioning ring abuts against the bottom end of the side surrounding part.

[0009] Furthermore, the positioning ring is welded to the inner wall of the main cylinder.

[0010] Furthermore, an annular limiting lip is extended from the edge of the top end of the sealing portion toward the center of the main cylinder, and the transparent sheet of the observation cover abuts against the limiting lip.

[0011] More preferably, a step surface is provided at the transition between the transparent sheet of the observation cover and the outer side wall of the side surrounding portion, the top end of the main cylinder body is pressed against the step surface, a reinforced protective cover is sleeved on the outside of the observation cover, an observation port is provided on the top end of the reinforced protective cover, the observation cover is exposed from the observation port, the reinforced protective cover presses the observation cover against the top end of the main cylinder body, and the reinforced protective cover is fixed on the main cylinder body.

[0012] Preferably, the side surrounding portion is located on the outer side of the side wall of the top end of the main cylinder, and the top end of the main cylinder is against the inner side surface of the transparent sheet; a reinforced protective cover is sleeved on the outer side of the observation cover, and an observation port is provided at the top end of the reinforced protective cover, and the observation cover is exposed from the observation port, and the reinforced protective cover presses the observation cover to the top end of the main cylinder, and the reinforced protective cover is fixed on the main cylinder.

[0013] Corresponding to the shell sealing structure of a gas density monitoring device of the utility model, the utility model also provides a gas density monitoring device, which adopts the shell sealing structure of the gas density monitoring device described in the above technical scheme. The gas density monitoring device is a gas density relay, and a pressure detection tube, an indicating mechanism and an alarm switch are arranged in the shell.

[0014] Corresponding to the shell sealing structure of a gas density monitoring device of the utility model, the utility model also provides a gas density monitoring device, which adopts the shell sealing structure of the gas density monitoring device described in the above technical solution. The gas density monitoring device is a gas density meter, and a pressure detection tube and an indicating mechanism are provided in the shell.

[0015] As described above, the shell sealing structure of a gas density monitoring device involved in the utility model has the following beneficial effects: the bottom end of the shell of the gas density monitoring device is sealed by the bottom cover, the top end is sealed by the observation cover, a first sealing ring is provided between the side surrounding part of the observation cover and the top side wall of the main cylinder, the first sealing ring is close to the corner position between the transparent sheet and the side surrounding part, just like the structural rigidity of the corner is high, the closer the first sealing ring is to the corner position between the transparent sheet and the side surrounding part, the side surrounding part here is not easy to deform, the higher the rigidity of the sealing structure, the better the sealing effect. Therefore, the sealing performance of the gas density monitoring device is better.

[0016] The gas density relay and gas density meter involved in the utility model certainly also have the above-mentioned beneficial effects, which will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Shown is a front view of a gas density relay, viewed from the axial direction of the housing, with the viewing shield removed.

[0018] Figure 2-1 Shown is a cross-sectional view of Embodiment 1, Figure 2-2 for Figure 2-1 A magnified partial view of point C in the middle.

[0019] Figure 3 A cross-sectional view of the second embodiment is shown.

[0020] Figure 4 Shown is a cross-sectional view of the third embodiment.

[0021] Figure 5-1 Shown is a front view of a gas density gauge, viewed from the axial direction of the housing, with the sight glass removed.

[0022] Figure 5-2 Displayed as a cutaway view of a gas density table.

[0023] Component number description

[0024]

[0025] DETAILED DESCRIPTION

[0026] The following is a description of the implementation of the present invention by means of specific embodiments. People familiar with the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0027] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the utility model, so they have no substantial technical significance. Any modification of the structure, change of the proportion relationship or adjustment of the size, without affecting the effects and purposes that can be achieved by the utility model, should still fall within the scope of the technical content disclosed by the utility model. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and so on quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the utility model. The change or adjustment of the relative relationship, without substantial change of the technical content, should also be regarded as the scope of the implementation of the utility model.

[0028] Please refer to Figures 1 to 4 The utility model provides a shell sealing structure of a gas density monitoring device, including a sealed shell 1, the shell 1 includes a main cylinder 2, an observation cover 9 and a bottom cover 12, the bottom end of the main cylinder 2 is sealed by the bottom cover 12, the top end of the main cylinder 2 is opened, the observation cover 9 seals the top end opening of the main cylinder 2, the observation cover 9 includes a circular transparent sheet 10 and a side surrounding portion 11 surrounded by the edge of the transparent sheet 10, the side surrounding portion 11 is located on the inner side / outer side of the top end side wall of the main cylinder 2, a first sealing ring 8 is provided between the side surrounding portion 11 and the top end side wall of the main cylinder 2 to seal the top end opening of the main cylinder 2, and the first sealing ring 8 is close to the corner position between the transparent sheet 10 and the side surrounding portion 11.

[0029] In the shell sealing structure of a gas density monitoring device of the utility model, the bottom end of the shell 1 is sealed by the bottom cover 12, and the top end is sealed by the observation cover 9. A first sealing ring 8 is provided between the side surrounding portion 11 of the observation cover 9 and the top side wall of the main cylinder 2. The first sealing ring 8 is close to the corner position between the transparent sheet 10 and the side surrounding portion 11. Just like the structural rigidity of the corner is high, the closer the first sealing ring 8 is to the corner position between the transparent sheet 10 and the side surrounding portion 11, the side surrounding portion 11 is not easy to deform, the higher the rigidity of the sealing structure, and the better the sealing effect. Therefore, the gas density monitoring device has good sealing performance.

[0030] The shell sealing structure of the gas density monitoring device of the utility model can be used for a gas density relay or a gas density meter (a gas density meter may also be called a gas pressure meter or the like).

[0031] Gas density relays are commonly used in gas insulated switchgear (GIS). Their main function is to monitor gas density (generally the density of insulating gas such as sulfur hexafluoride (SF6) gas, and sulfur hexafluoride (SF6) gas is taken as an example below) to ensure that the equipment operates under safe and reliable conditions. The gas density relay for monitoring the density of sulfur hexafluoride (SF6) mainly includes a housing 1, a pressure detection tube 13, an indicating mechanism 14 and an alarm switch 15 arranged in the housing 1, wherein:

[0032] The pressure detection tube 13 can generally be called a pressure detection element, a bellows, a spring metal curved tube or a Baden tube, etc. One end of the pressure detection tube 13 is connected to the trachea connector 16, the trachea connector 16 is connected to the trachea 23, the trachea 23 is connected to the sulfur hexafluoride gas chamber in the equipment, and the other end of the pressure detection tube 13 is sealed. In this way, the sulfur hexafluoride gas density in the pressure detection tube 13 is the same as the gas density in the sulfur hexafluoride gas chamber of the equipment. The pressure detection tube 13 is very sensitive to changes in the gas pressure in its inner cavity and can expand and contract according to changes in the gas pressure in its inner cavity. The other end of the pressure detection tube 13 (i.e., the end of the pressure detection tube 13 that is blocked, in the following description, the other end of the pressure detection tube 13 is the end of the pressure detection tube 13 that is blocked) is connected to the indicating mechanism 14 and the alarm switch 15 in a transmission manner. Under the action of the pressure in its inner cavity, the pressure detection tube 13 is deformed according to the gas pressure in the tube, so that the other end of the pressure detection tube 13 acts on the indicating mechanism 14, so that the indicating mechanism 14 indicates the gas density in the pressure detection tube 13. The deformation of the other end of the pressure detection tube 13 can also drive the alarm switch 15 to close or open. In order to compensate for the error caused by the ambient temperature on the deformation of the pressure detection tube 13, a temperature compensation device can also be connected to the other end of the pressure detection tube 13. The temperature compensation device generally adopts a double-layer metal sheet 25. The temperature compensation device can compensate for the influence of temperature changes on gas pressure. The double-layer metal sheet 25 is made of two metals with different expansion coefficients. When the temperature changes, they expand and contract to different degrees, thereby compensating for the influence of temperature on the pressure reading.

[0033] The indicating mechanism 14 generally includes a gear mechanism and a pointer 26. The gear mechanism and the pointer 26 are generally connected to a movement 28. The movement 28 and the pressure detecting tube 13 are both installed on the air pipe joint 16 (the air pipe joint 16 is fixed together with the housing 1 as the installation basis for related parts). The deformation and expansion and contraction movement generated at the other end of the pressure detecting tube 13 is converted into the rotational movement of the pointer 26 through the gear mechanism. Generally, the pressure detecting tube 13 is connected to the temperature compensation device, and the temperature compensation device is connected to the gear mechanism. After the temperature compensation device performs temperature compensation correction on the expansion and contraction deformation of the pressure detecting tube 13, the movement is transmitted to the gear mechanism. The gear mechanism converts the expansion and contraction movement of the pressure detecting tube 13 into the rotational movement of the pointer 26. The pointer 26 indicates the scale value on the dial 27 of the gas density relay, indicating the current SF6 gas density.

[0034] The alarm switch 15 generally has alarm and locking functions. The alarm switch 15 is also generally called a micro switch, a magnetically assisted electric contact, etc. When the gas density in the pressure detection tube 13 is lower than the preset safety threshold, the deformation of the pressure detection tube 13 can drive the alarm switch 15 to operate, thereby triggering an alarm signal. If the gas density continues to drop to the locking value, the deformation of the pressure detection tube 13 can drive the alarm switch 15 to operate and further trigger the locking mechanism to prevent the equipment from operating under unsafe conditions.

[0035] The basic structure and working principle of the gas density relay are prior art. Although the names of the relevant basic structures and parts are different in different existing documents, the structure, function and principle are basically the same and are all included in the density relay related to the technical solution of the utility model, and will not be further elaborated here.

[0036] The shell sealing structure of a gas density monitoring device of the utility model can be used for a gas density relay. Therefore, accordingly, the utility model also provides a gas density monitoring device, which adopts the shell sealing structure of the gas density monitoring device described in the above technical solution. The gas density monitoring device is a gas density relay, and a pressure detection tube, an indicating mechanism and an alarm switch are arranged in the shell.

[0037] A gas density meter is also a common gas density monitoring device. Compared with a gas density relay, a gas density meter lacks an alarm switch and parts such as a cable connected to the alarm switch. The shell sealing structure of a gas density monitoring device of the utility model can be used for a gas density meter. Therefore, accordingly, the utility model also provides a gas density monitoring device, which adopts the shell sealing structure of the gas density monitoring device described in the above technical solution. The gas density monitoring device is a gas density meter, and a pressure detection tube and an indicating mechanism are provided in the shell.

[0038] In the shell sealing structure of a gas density monitoring device of the utility model, the first sealing ring 8 is close to the corner position between the transparent sheet 10 and the side surrounding portion 11. Generally, one or two sealing rings can be installed between the main cylinder 2 and the observation cover 9. In order to ensure that there is enough space in the width direction of the side surrounding portion 11 of the observation cover 9 to install the first sealing ring 8 and the first sealing ring 8 will not be too far away from the corner position between the transparent sheet 10 and the side surrounding portion 11, as a preferred embodiment, the distance between the cross-sectional center of the first sealing ring 8 and the inner side surface of the transparent sheet 10 is within 5 times the cross-sectional diameter of the first sealing ring 8, so that the two first sealing rings 8 can be better ensured to be close to the corner position between the transparent sheet 10 and the side surrounding portion 11; if only one first sealing ring 8 is provided, the distance between the cross-sectional center of the first sealing ring 8 and the inner side surface of the transparent sheet 10 can be within 3 times the cross-sectional diameter of the first sealing ring 8 or even closer; in the actual design process, reasonable design choices can be made according to the number of sealing rings and the structural dimensions of the sealing rings. Preferably, the inner wall of the sealing portion 3 is provided with two sealing grooves 4, and a first sealing ring 8 is provided in each sealing groove 4. The two sealing rings have a better sealing effect.

[0039] A gas density monitoring device and a shell sealing structure technical solution of the utility model are described below in conjunction with specific embodiments.

[0040] Embodiment 1:

[0041] As shown in Figure 2-1 and Figure 2-2 As shown, a pressure detection tube 13, an indicating mechanism 14 and an alarm switch 15 are arranged in the housing 1 of the gas density relay. The housing 1 includes a main cylinder 2, an observation cover 9 and a bottom cover 12. The observation cover 9 seals the opening at the top of the main cylinder 2. The bottom cover 12 is sealed and connected to the bottom end of the main cylinder 2. Generally, the bottom cover 12 can be welded to the bottom end of the main cylinder 2 by welding. The air pipe connector 16 and the cable connector 17 are both arranged on the bottom cover 12. Generally, the air pipe connector 16 and the cable connector 17 can be welded to the bottom cover 12 by welding. The welding method is relatively firm, has high structural strength and good sealing performance; of course, the air pipe connector 16 and the cable connector 17 can also be connected to the bottom cover 12 in a detachable manner. The air pipe is connected to the air pipe connector 16, and the air pipe connector 16 has an airway 24, which is connected to the pressure detection tube 13. The cable connector 17 is connected to an external cable, and the cable connector 17 is also connected to the alarm switch 15 inside the housing 1 through a signal connection line (not shown in the figure).

[0042] like Figure 2-1 and Figure 2-2As shown, the main cylinder 2 includes a sealing portion 3 and a cylinder body 5, the sealing portion 3 is located at the top end of the main cylinder 2, and the edge of the top end of the sealing portion 3 extends an annular limiting lip 6 toward the center of the main cylinder 2, the inner wall of the sealing portion 3 is provided with a sealing groove 4, and the sealing groove 4 is provided with a first sealing ring 8; the observation cover 9 includes a transparent sheet 10 and a side surrounding portion 11 arranged at the edge of the transparent sheet 10, the sealing portion 3 of the main cylinder 2 is surrounded by the outer side of the side surrounding portion 11 of the observation cover 9, and the side surrounding portion 11 is located on the inner side of the side wall of the top end of the main cylinder 2, and the first sealing ring 8 is squeezed between the side surrounding portion 11 of the observation cover 9 and the sealing portion 3 of the main cylinder 2 so that the outer wall of the observation cover 9 and the inner wall of the sealing portion 3 are sealed; the transparent sheet 10 of the observation cover 9 is against the limiting lip 6 and exposed from the opening at the top of the main cylinder 2, so that the observation cover 9 cannot be detached from the opening at the top of the main cylinder 2 and the scale value indicated by the pointer 26 can be observed from the opening at the top of the main cylinder 2. Moreover, since the limiting lip 6 and the sealing portion 3 form a corner structure similar to a wall corner, the limiting lip 6 strengthens the structural rigidity of the sealing portion 3, and the sealing portion 3 is not easily deformed to cause the seal to loosen, shift, and leak.

[0043] As shown in Figure 2-1 and Figure 2-2 As shown, a positioning ring 7 is also provided in the main cylinder 2, and the positioning ring 7 abuts against the bottom end of the side surrounding portion 11 of the observation cover 9, so that the transparent sheet 10 at the top of the observation cover 9 abuts against the limiting lip 6, and the bottom end of the side surrounding portion 11 of the observation cover 9 abuts against the positioning ring 7, and the observation cover 9 is positioned on the axis and cannot move axially, and the seal between the first sealing ring 8 and the observation cover 9 and the sealing portion 3 will not loosen or shift to cause leakage. The positioning ring 7 can be welded to the inner wall of the main cylinder 2. In order to achieve a better sealing effect, two sealing grooves 4 are provided on the inner wall of the sealing portion 3, and a first sealing ring 8 is provided in each sealing groove 4. In addition, a sealing groove can be provided at the side surrounding portion corresponding to the inner wall of the sealing portion, and the first sealing ring is provided in the sealing groove, that is, the sealing groove can also be provided at the side surrounding portion of the observation cover.

[0044] like Figure 2-1 and Figure 2-2 As shown, in order to achieve a better sealing effect, the sealing portion 3 is thickened, and the wall thickness of the sealing portion 3 is greater than the wall thickness of the barrel portion 5. In this way, the structural rigidity of the sealing portion 3 is high and it is not easy to deform and cause the first sealing ring 8 to loosen and shift, thereby causing leakage.

[0045] like Figure 2-1As shown, the bottom cover 12 is also provided with an air filling port 18 for filling gas of set pressure into the housing 1, and a sealing plug 19 is connected to the air filling port 18. After the set pressure is filled into the housing 1 through the air filling port 18, the air filling port 18 is sealed with the sealing plug 19. The sealing plug 19 includes a screw head 20 and a gland 21 connected to the screw head 20. The air filling port 18 is a threaded hole structure. The screw head 20 of the sealing plug 19 is screwed into the air filling port 18. A second sealing ring 22 is provided between the gland 21 and the bottom cover 12. Of course, the sealing plug 19 can adopt a self-sealing valve structure, which is automatically sealed after being filled with gas.

[0046] like Figure 2-1 As shown, there are no holes or grooves on the side wall of the main cylinder 2, so that the side wall of the main cylinder 2 is smooth and complete, without stress concentration points, and the main cylinder 2 is not easy to deform and cause the sealing position to loosen and shift and leak. The main cylinder 2 can be cut and processed by metal pipes, such as steel pipes or aluminum pipes. This manufacturing method has higher structural rigidity and strength than the main cylinder 2 formed by stamping or rolling, and the main cylinder 2 is not easy to deform and cause the sealing position to loosen and shift and leak.

[0047] Embodiment 2:

[0048] like Figure 3 As shown, Figure 2-1 The structure of the gas density relay is different in that: Figure 3 The main cylinder 2 of the medium gas density relay is a straight cylinder structure with no change in the inner and outer diameters in the length direction (the sealing part and the cylinder body are not distinguished and marked in the figure). The inner and outer diameters of the sealing part and the cylinder body are basically the same, and the sealing surface of the sealing part is processed according to the sealing requirements. The main cylinder 2 is made of metal pipes such as steel pipes or aluminum pipes, and the straight cylinder structure is easy to process. Figure 3The side surrounding portion 11 of the observation cover 9 of the gas density relay is lined on the inner side of the sealing portion of the main cylinder 2, and the inner wall of the sealing portion (the top section of the main cylinder 2 is the sealing portion, not shown in the figure) is the sealing surface, and the sealing portion is not provided with a sealing groove. The sealing groove is provided on the outer wall of the side surrounding portion 11 of the observation cover 9, and a first sealing ring 8 is provided in the sealing groove; a step surface (not shown in the figure) is provided at the transition between the transparent sheet 10 of the observation cover 9 and the outer wall of the side surrounding portion 11, and the top end of the main cylinder 2 is supported on the step surface. In order to enhance the strength and rigidity of the observation cover 9, the observation cover 9 is provided with a first sealing ring 8. A reinforced protective cover 29 is sleeved on the outside of the observation cover 9, and an observation port 30 is provided on the top of the reinforced protective cover 29. The observation cover 9 is exposed from the observation port 30. The reinforced protective cover 29 presses the observation cover 9 on the top of the main cylinder 2. The reinforced protective cover 29 is fixed on the main cylinder 2. The edge of the bottom of the reinforced protective cover 29 can be welded to the main cylinder 2 by welding, or an internal thread can be set on the inner side wall of the bottom end of the reinforced protective cover 29, and an external thread can be set on the top of the main cylinder 2 to thread the reinforced protective cover 29 and the main cylinder 2 together.

[0049] Embodiment three:

[0050] like Figure 4 As shown, Figure 3 The structure of the gas density relay is different in that: Figure 4 The observation cover 9 is sleeved on the outside of the sealing part 3 (the top section of the main cylinder 2 is the sealing part, not shown in the figure), the side surrounding part 11 is located on the outside of the top side wall of the main cylinder 2, the top of the main cylinder 2 is against the inner side of the transparent sheet 10, and the outer side wall of the sealing part is the sealing surface. Figure 3 The gas density relay has the same structure as the Figure 4 The sealing portion is not provided with a sealing groove, and the sealing groove is provided on the inner wall of the side surrounding portion 11 of the observation cover 9. A first sealing ring 8 is provided in the sealing groove. In order to enhance the strength and rigidity of the observation cover 9, a reinforced protective cover 29 is sleeved on the outer side of the observation cover 9. An observation port 30 is provided at the top of the reinforced protective cover 29, and the top of the observation cover 9 is exposed from the observation port 30. The reinforced protective cover 29 presses the observation cover 9 against the top of the main cylinder body 2, and the reinforced protective cover 29 is fixed on the main cylinder body 2. The edge of the bottom of the reinforced protective cover 29 can be welded to the main cylinder body 2.

[0051] Please refer to Figures 1 to 4In the gas density relay of the utility model, the pressure detection tube 13 is deformed according to the gas pressure in the tube, thereby acting on the indicating mechanism 14 so that the indicating mechanism 14 indicates the gas density in the pressure detection tube 13. The deformation of the pressure detection tube 13 can drive the alarm switch 15 to close or open; the shell 1 is connected with an air pipe connector 16 and a cable connector 17; the air pipe connector 16 is connected to the pressure detection tube 13 and is used to inflate the pressure detection tube 13, and the cable connector 17 is connected to the alarm switch 15; the air pipe connector 16 and the cable connector 17 are both arranged on the bottom cover 12, and the bottom cover 12 is also provided with an inflation port 18 for filling the shell 1 with set pressure gas, and the inflation port 18 is connected with a sealing plug 19. The outer end of the air pipe connector 16 is exposed outside the shell 1 and is used to connect the gas pipeline. The inner end of the air pipe connector 16 is located inside the shell 1 and connected to the pressure detection tube 13. The outer end of the cable connector 17 is exposed outside the shell 1 and is used to connect the cable. The inner end of the cable connector 17 is connected to the alarm switch 15. Please refer to Figures 1 to 4Since the interior of the shell 1 is sealed into a sealed space, gas of set pressure (such as air, nitrogen, sulfur hexafluoride gas, etc. at standard atmospheric pressure) can be injected into the shell 1 through the inflation port 18, so that the interior of the shell 1 maintains a stable set pressure and the pressure detection tube 13 is accurately deformed according to the gas pressure in the tube without being affected by the change of the air pressure outside the shell 1. The gas density relay is zeroed and calibrated according to the set pressure, and the air pressure inside the shell 1 is kept at the set pressure, so that the accuracy of the density relay will be higher; the gas density relay of the utility model achieves complete isolation of the atmospheric pressure inside the shell 1 and outside the shell 1 by sealing the shell 1, thereby eliminating the influence of atmospheric pressure changes caused by different altitudes on the accuracy, and its structure is simpler and more reliable; moreover, since the air pipe The connector 16, the cable connector 17 and the inflation port 18 are all arranged on the bottom cover 12, so that it is not necessary to open a hole groove structure on the side wall of the main cylinder 2 of the shell 1 to affect the structural rigidity of the main cylinder 2 of the shell 1. The main cylinder 2 of the shell 1 has good rigidity, and the side wall of the main cylinder 2 will not be pulled by parts such as the air pipe or the cable. Therefore, the main cylinder 2 of the shell 1 is not easy to deform, and the seal between the observation cover 9 and the main cylinder 2 is not easily affected. The sealing performance of the shell 1 is good, and the gas inside the shell 1 will not leak, and the external gas will not leak into the shell 1. The shell 1 maintains a stable set air pressure. Therefore, the pressure detection tube 13 produces accurate deformation according to the gas pressure in the tube without being affected by the change of the air pressure outside the shell 1, and the detection accuracy of the gas density relay will be higher. The gas density relay of the utility model is very suitable for application environments where the ambient air pressure is greatly different from the standard atmospheric pressure, such as high altitude areas. The gas density relay of the utility model greatly improves the reliability of the sealing performance of the gas density relay housing 1 in terms of structure, and can effectively avoid the influence of atmospheric pressure changes on the accuracy. At the same time, in the oil-filled density relay, oil leakage or gas leakage can also be completely avoided.

[0052] Embodiment 4:

[0053] As mentioned above, the difference between a gas density meter and a gas density relay is that a gas density meter does not need an alarm switch, and the corresponding signal connection wires, cable connectors and other parts of the alarm switch. The other basic structures and basic principles are the same as those of a gas density relay. Figure 5-1 and Figure 5-2 As shown, the housing 1 of the gas density meter is provided with a pressure detection tube 13 and an indicating mechanism 14. Figure 2-1 and Figure 2-2 The gas density relay is different from the Figure 5-1 and Figure 5-2 The gas density meter has no alarm switch in the housing 1, and no cable connector is required on the bottom cover 12. Figure 5-1 and Figure 5-2As shown, the gas density meter housing 1 includes a main cylinder 2, an observation cover 9 and a bottom cover 12. The observation cover 9 seals the opening at the top of the main cylinder 2. The bottom cover 12 is sealed to the bottom end of the main cylinder 2. The air pipe connector 16 is arranged on the bottom cover 12. Generally, the air pipe connector 16 can be welded to the bottom cover 12 by welding. The welding method is relatively firm, has a high structural strength and good sealing performance.

[0054] Based on the technical solution of the above embodiment, the utility model relates to a gas density monitoring device and a housing sealing structure thereof, the sealing structure has high rigidity and good sealing performance. Similarly, the gas density relay and gas density meter of the utility model also have the above beneficial effects, which will not be repeated here.

[0055] In summary, the utility model effectively overcomes various shortcomings of the prior art and has high industrial utilization value.

[0056] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the technology may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed in the present invention shall still be covered by the claims of the present invention.

Claims

1. A housing sealing structure of a gas density monitoring device, comprising a housing with a sealing arrangement, characterized in that: The shell includes a main cylinder, an observation cover and a bottom cover, the bottom end of the main cylinder is sealed by the bottom cover, the top end of the main cylinder is opened, and the observation cover seals the top end opening of the main cylinder, the observation cover includes a circular transparent sheet and a side surrounding portion surrounded by the edge of the transparent sheet, the side surrounding portion is located on the inner / outer side of the side wall of the top end of the main cylinder, a first sealing ring is provided between the side surrounding portion and the side wall of the top end of the main cylinder to seal the opening of the top end of the main cylinder, and the first sealing ring is close to the corner position between the transparent sheet and the side surrounding portion.

2. The housing sealing structure of the gas density monitoring device according to claim 1, characterized in that: The side surrounding part is located on the inner side of the side wall at the top end of the main cylinder body. The main cylinder body includes a sealing part and a cylinder body part. The sealing part is located at the top end of the main cylinder body. The inner wall of the sealing part is provided with a sealing groove. The first sealing ring is arranged in the sealing groove.

3. The housing sealing structure of the gas density monitoring device according to claim 2, characterized in that: The wall thickness of the sealing portion is greater than the wall thickness of the barrel portion.

4. The housing sealing structure of the gas density monitoring device according to claim 3, characterized in that: A positioning ring is also provided in the main cylinder, and the positioning ring abuts against the bottom end of the side surrounding part.

5. The housing sealing structure of the gas density monitoring device according to claim 4, characterized in that: The positioning ring is welded on the inner wall of the main cylinder.

6. The housing sealing structure of the gas density monitoring device according to claim 5, characterized in that: The edge of the top end of the sealing portion extends an annular limiting lip toward the center of the main cylinder, and the transparent sheet of the observation cover abuts against the limiting lip.

7. The housing sealing structure of the gas density monitoring device according to claim 2, characterized in that: A step surface is provided at the transition between the transparent sheet of the observation cover and the outer side wall of the side surrounding part, and the top end of the main cylinder body is on the step surface. A reinforced protective cover is sleeved on the outside of the observation cover, and an observation port is provided on the top end of the reinforced protective cover. The observation cover is exposed from the observation port, and the reinforced protective cover presses the observation cover against the top end of the main cylinder body, and the reinforced protective cover is fixed on the main cylinder body.

8. The housing sealing structure of the gas density monitoring device according to claim 1, characterized in that: The side surrounding portion is located on the outer side of the side wall at the top end of the main cylinder, and the top end of the main cylinder is against the inner side of the transparent sheet; a reinforced protective cover is sleeved on the outer side of the observation cover, and an observation port is provided at the top end of the reinforced protective cover, and the observation cover is exposed from the observation port. The reinforced protective cover presses the observation cover against the top end of the main cylinder, and the reinforced protective cover is fixed on the main cylinder.

9. A gas density monitoring device, characterized in that: The shell of the gas density monitoring device adopts the shell sealing structure of the gas density monitoring device according to any one of claims 1 to 8. The gas density monitoring device is a gas density relay, and a pressure detection tube, an indicating mechanism and an alarm switch are arranged in the shell.

10. A gas density monitoring device, characterized in that: The shell of the gas density monitoring device adopts the shell sealing structure of the gas density monitoring device according to any one of claims 1 to 8. The gas density monitoring device is a gas density meter, and a pressure detection tube and an indicating mechanism are arranged in the shell.

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