A bellows type measuring device capable of displaying a large range

Abstract

This invention provides a bellows-type measuring device with a large-range display, which can achieve continuous, accurate, and stable display of a large range, improve the safety of equipment operation monitoring, and meet the monitoring needs of the entire life cycle. It includes: a housing with a process chamber connected to the gas chamber of an external electrical switchgear; a display mechanism for large-range scale display; a transmission triggering mechanism connected to the display mechanism for triggering an alarm and driving the display mechanism; and a large-range displacement mechanism disposed within the housing and connected to the transmission triggering mechanism. The large-range displacement mechanism includes an independent and connected first bellows component and a second bellows component. Both the first and second bellows components have sealed cavities. The sealed cavity of the first or second bellows component is at least partially defined by an elastic component or a limiting member, and the sealed cavity of the first or second bellows component contains a temperature-compensating gas at a certain pressure.

Description

Technical Field

[0001] This invention relates to the field of gas density monitoring technology, specifically to a bellows-type measuring device capable of displaying a large range. Background Technology

[0002] Gas density relays are core components ensuring the safe operation of high-voltage electrical equipment. They monitor changes in the density of insulating gas inside the equipment to provide protection functions such as overvoltage alarm, undervoltage alarm, and output lockout. Currently, the industry widely uses density relays with bellows as the elastic sensing element. Their working principle is as follows: the gas inside the equipment acts on the bellows, causing the bellows to move axially with changes in gas pressure / density. This displacement drives a pointer to deflect via a transmission mechanism, thus displaying the density value on-site.

[0003] However, existing density relays using bellows structures are limited by housing size, bellows installation position, and mechanism structure. In other words, due to structural design limitations, the products can only display density in a narrow range near the rated operating point. They cannot display the density value of gas measurements over a large range, resulting in a relatively simple gas density display that cannot meet the monitoring needs of the entire life cycle. As a result, maintenance personnel cannot determine the true density level, which can easily lead to misjudgments such as the pointer not moving when there is leakage or the pointer deflecting to full deflection when there is overpressure, posing safety hazards. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a bellows-type measuring device with a large range display capability. This device enables continuous, accurate, and stable display of a large range, improving the safety of equipment operation monitoring and meeting the monitoring needs throughout the entire lifecycle.

[0005] This invention adopts the following technical solution: a bellows-type measuring device with a large range display, comprising: The housing has a process chamber that connects to the gas chamber of an external electrical switchgear; Display mechanism for large-scale display; A transmission triggering mechanism, connected to the display mechanism, is used to trigger an alarm and drive the display mechanism to move; A large-range displacement mechanism is disposed inside the housing and connected to the transmission triggering mechanism; The large-range displacement mechanism includes an independent but connected first corrugated component and a second corrugated component. Both the first and second corrugated components have sealed cavities inside. The sealed cavity of the first or second corrugated component is at least partially defined by an elastic component or a limiting component. The sealed cavity of the first or second corrugated component is provided with a temperature compensation gas at a certain pressure. When the gas pressure in the process cavity changes, the first corrugated component and / or the second corrugated component compresses or expands to generate an axial displacement to the transmission triggering mechanism.

[0006] Furthermore, the first corrugated assembly and the second corrugated assembly are arranged in series, and the sealing cavities correspond to the first sealing cavity and the second sealing cavity of the first corrugated assembly and the second corrugated assembly, respectively; the elastic component and the limiting component can be respectively or simultaneously disposed in the first sealing cavity and the second sealing cavity. Furthermore, the first corrugated assembly includes a top cover and a bottom cover, and a first corrugated tube is sealed between the top cover and the bottom cover to form the first sealed cavity; the second corrugated assembly includes an upper cover and a base, and a second corrugated tube is sealed between the upper cover and the base to form the second sealed cavity. Furthermore, the elastic component includes a limiting block and a first spring, the limiting block being mounted on the lower cover, and the first spring being connected between the limiting block and the top cover; Furthermore, the limiting member is a limiting rod, which is disposed in the first sealing cavity or the second sealing cavity, and the length of the limiting rod is less than the height of the first sealing cavity or the second sealing cavity; Furthermore, it also includes a housing, in which the transmission triggering mechanism and the display mechanism are both installed; a circuit board is fixed inside the housing, and multiple micro switches are installed on the circuit board, which are connected to an external control circuit via connectors; Furthermore, the transmission triggering mechanism includes a connecting rod, one end of which is connected to the large-range displacement mechanism; a transmission block is connected to the other end of the connecting rod, the transmission block is located above the micro switch, a switch triggering screw corresponding to the micro switch is mounted on the transmission block, and the top end of the connecting rod is in contact with the display mechanism. Furthermore, the base is fixed to the bottom of the housing, the limiting member is fixed to the base, and the lower cover is fixedly connected to the upper cover; the connecting rod passes through the housing and is connected to the top cover, and a third bellows is installed on the outer wall of the connecting rod located in the process chamber, and a second spring is installed on the outside of the third bellows; Furthermore, the top cover is fixed to the top of the housing, the limiting member is fixed to the top cover, and the base is fixedly connected to the top cover; the limiting member is a hollow structure, and the connecting rod passes through the housing, the limiting member, and the top cover in sequence before connecting to the limiting block; Furthermore, the display mechanism uses a pointer dial, and the top of the connecting rod is in contact with the movement of the pointer dial; the housing is provided with a process connector, and external electrical equipment is connected to the process chamber through the process connector.

[0007] The beneficial effects of this invention are that, through the independent but interconnected first and second bellows components, when the air pressure in the process chamber changes, the first and / or second bellows components compress or expand to generate axial displacement towards the transmission trigger mechanism. By superimposing two or more bellows components, displacement occurs step by step according to different pressure ranges, thereby expanding the large-range scale display of the display mechanism, thus covering the complete measurement range, breaking through the limitation of the compression stroke of a single bellows, balancing reliability and large-range capability, and maintaining high stability, thereby improving the safety of equipment operation monitoring and meeting the monitoring needs of the entire life cycle. Attached Figure Description

[0008] Figure 1 This is a schematic diagram of the structure in Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the structure of the first corrugated component in Embodiment 1 of the present invention; Figure 3 This is a schematic diagram of the structure of the second corrugated component in Embodiment 1 of the present invention; Figure 4 This is a schematic diagram of the displacement stroke change of the large-range displacement mechanism in Embodiment 1 of the present invention; Figure 5 This is a pressure-displacement change curve of the second corrugated component compressed first in Embodiment 1 of the present invention; Figure 6 This is a schematic diagram of the structure after the cover is hidden in Embodiment 2 of the present invention; Figure 7 This is a schematic diagram of the structure in Embodiment 3 of the present invention; Figure 8 This is a schematic diagram of the structure of the second corrugated component in Embodiment 3 of the present invention; Figure 9 This is a pressure-displacement change curve of the first corrugated component compressed in this embodiment of the invention; Figure 10 This is a schematic diagram of the displacement stroke change of the first corrugated component during compression in an embodiment of the present invention. Detailed Implementation

[0009] Example 1 like Figures 1-5 As shown, the present invention provides a bellows-type measuring device with a large range display, comprising: The housing 1 has a process chamber 2 connected to the gas chamber of an external electrical switchgear; The display mechanism can convert the displacement of a large-range displacement mechanism for large-range scale display; The transmission triggering mechanism is connected to the display mechanism and is used to trigger the alarm and drive the display mechanism to move; A large-range displacement mechanism is housed within housing 1 and connected to a transmission triggering mechanism; The large-range displacement mechanism includes an independent but connected first corrugated assembly 3 and a second corrugated assembly 4. Both the first corrugated assembly 3 and the second corrugated assembly 4 have sealed cavities. The sealed cavity of the first corrugated assembly 3 or the second corrugated assembly 4 is at least partially defined by an elastic component or a limiting component. The sealed cavity of the first corrugated assembly 3 or the second corrugated assembly 4 is provided with a temperature compensation gas at a certain pressure. The corresponding sealed cavity with the temperature compensation gas forms a compensation chamber. When the gas pressure in the process chamber 2 changes, the first corrugated assembly 3 and / or the second corrugated assembly 4 compresses or expands to generate an axial displacement to the transmission triggering mechanism. When the pressure changes due to the temperature change, the pressure of the sealing gas inside the sealed cavity can offset the pressure inside the process chamber, playing a compensation role and preventing the transmission triggering mechanism from generating an axial displacement.

[0010] The first corrugated assembly 3 and the second corrugated assembly 4 are arranged in series, and the sealing cavities correspond to the first sealing cavity 5 and the second sealing cavity 6 of the first corrugated assembly 3 and the second corrugated assembly 4, respectively. The elastic component and the limiting component can be respectively or simultaneously disposed in the first sealing cavity 5 and the second sealing cavity 6. The first corrugated assembly 3 includes a top cover 8 and a bottom cover 9, and a first corrugated pipe 10 is sealed between the top cover 8 and the bottom cover 9 to form the first sealing cavity 5. The second corrugated assembly 4 includes an upper cover 11 and a base 12, and a second corrugated pipe 13 is sealed between the upper cover 11 and the base 12 to form the second sealing cavity 6. Specifically, in the first embodiment, the elastic component is disposed in the first sealing cavity 5 and the limiting component is disposed in the second sealing cavity 6.

[0011] The elastic component includes a limiting block 14 and a first spring 15. The limiting block 14 is mounted on the lower cover 9, and the first spring 15 is connected between the limiting block 14 and the top cover 8. The limiting member 7 uses a limiting rod, which is set in the first sealing cavity 5 or the second sealing cavity 6, and the length of the limiting rod is less than the height of the first sealing cavity 5 or the second sealing cavity 6.

[0012] It also includes a housing 16, within which the transmission triggering mechanism and display mechanism are installed. A circuit board 18 is mounted on the bottom of the housing 16 via a fixing member 17. Multiple microswitches 19 are mounted on the circuit board 18, and these microswitches 19 are connected to an external control circuit (not shown) via a connector (not shown in the figure). The transmission triggering mechanism includes a connecting rod 20, one end of which passes sequentially through the circuit board 18, housing 16, and housing 1 before connecting to a large-range displacement mechanism. The top end of the connecting rod 20 contacts the display mechanism, and a transmission block 21 is threaded onto the other end of the connecting rod 20. The transmission block 21 is located above the microswitches 19, and corresponding microswitches are mounted on the transmission block 21. The microswitch 19 and the switch trigger screw 22 can be provided in multiple ways, and the height of the switch trigger screw 22 can also be adjusted according to the actual situation. Generally, the height of multiple switch trigger screws 22 can be adjusted to different heights, so that they can be triggered in stages with the corresponding microswitch 19, thus realizing a graded alarm. Typically, each product will be equipped with at least two microswitches 19. If only one switch trigger screw 22 is triggered with the corresponding microswitch 19, only a low-density alarm will be triggered. If multiple switch trigger screws 22 are triggered with the corresponding microswitch 19, a low-density interlock will be triggered.

[0013] The base 12 is fixed to the bottom of the housing 1, the limiting member 7 is fixed to the base 12, and the lower cover 9 is fixedly connected to the upper cover 11; the connecting rod 20 passes through the housing 1 and is connected to the top cover 8, and the outer wall of the connecting rod 20 located in the process chamber 2 is equipped with a third bellows 23, and a second spring 24 is assembled on the outside of the third bellows 23.

[0014] The display mechanism uses a pointer dial 25, and the top of the connecting rod 20 is in contact with the movement of the pointer dial 25; the housing 1 is provided with a process connector 26, and external electrical equipment (not shown in the figure) is connected to the process chamber 2 through the process connector 26.

[0015] In the first embodiment, the micro switch 19 and the switch trigger screw 22 are separate in the initial state.

[0016] Example 2 like Figure 6 As shown, the difference between Embodiment 2 and Embodiment 1 is that: the top cover 11 is fixed to the top of the housing 1, the limiting member 7 is fixed to the top cover 11, and the base 12 is fixedly connected to the top cover 8; the limiting member 7 is a hollow structure, and the connecting rod 20 passes through the housing 1, the limiting member 7, and the top cover 8 in sequence and is connected to the limiting block 14.

[0017] In Embodiment 2, the elastic component is disposed within the first sealing cavity 5, and the limiting component is disposed within the second sealing cavity 6. In the second embodiment, in the initial state, the micro switch 19 and the switch trigger screw 22 are in contact. As the connecting rod 20 is raised, the switch trigger screw 22 and the micro switch 19, which are set at different heights, separate one after another. As they separate in stages, the alarm can also be classified into different levels.

[0018] Example 3 like Figure 7 , Figure 8 As shown, the difference between Embodiment 3 and Embodiment 1 is that both the first sealing cavity 5 and the second sealing cavity 6 are provided with elastic components; that is, both the first corrugated component 3 and the second corrugated component 4 are provided with elastic components. Therefore, by adjusting the stiffness of the first spring 15 in the elastic components of the first sealing cavity 5 and the second sealing cavity 6 accordingly, the sequential compression or expansion of the first corrugated component 3 and the second corrugated component 4 can still be achieved. The stiffness of one of the first springs 15 can be set to achieve the same compression limiting effect as the limiting member.

[0019] Through Embodiments 1, 3, and 2, both upper and lower fixing methods of the large-range displacement mechanism were implemented. Embodiments 1 and 3 implemented the lower fixing method, meaning that when the external pressure of the large-range displacement mechanism is greater than the internal pressure, the mechanism generates a downward axial displacement, and vice versa. Embodiment 2 implemented the upper fixing method, meaning that when the external pressure of the large-range displacement mechanism is greater than the internal pressure, the mechanism generates an upward axial displacement, and vice versa. In fact, Embodiments 1, 3, and 2 operate on the same principle, all enabling gas density change monitoring with overpressure alarm, underpressure alarm, and interlocking output protection functions. The microswitch is an existing device with corresponding normally open and normally closed contacts. The switch trigger screw contacts or separates from the normally open or normally closed contacts of the microswitch to achieve the alarm principle of Embodiments 1 to 3, which can be specifically configured according to actual conditions.

[0020] Since the working principles of Examples 1 to 3 are the same, only Example 1 will be used for explanation: When the pressure inside the external electrical equipment chamber changes, it affects the pressure inside the process chamber 2 through the connected process connector 26. When the air pressure inside the process chamber 2 changes, that is, when a pressure difference is formed between the process chamber 2 and the compensating gas inside the second sealing chamber 6, the stiffness of the first spring 15 is greater than the stiffness of the second bellows assembly 4. Therefore, when the bellows assembly compresses or expands, the second bellows assembly 4 compresses or expands first, followed by the first bellows assembly 3. Alternatively, the stiffness of the first spring 15 can be changed according to the actual situation, thus enabling the first bellows assembly 3 and the second bellows assembly 4 to move sequentially. Then, when the pressure in the process chamber 2 is greater than the compensating gas pressure inside the second sealing chamber 6, the second bellows 13 compresses, driving the first bellows assembly 3 and the connecting rod 20. Moving linearly downwards along the axis, the top of the connecting rod 20 pushes the movement of the pointer dial 25, causing the pointer on the pointer dial 25 to deflect. As the second bellows 13 continues to be compressed and reaches its maximum allowable compression value, when the upper cover 11 is pressed down to the limit member 7, the limit member 7 can prevent the second bellows 13 from being over-compressed and undergoing plastic deformation. Then, the stroke can be extended through the first bellows 10. That is, after the second bellows 13 is compressed to its limit and stops compressing, the first bellows 10 continues to compress and causes the connecting rod 20 to move downwards, which can extend the pointer on the pointer dial 25 to achieve a large range of deflection, covering the entire measurement range. At the same time, the micro switch 19 is triggered by the switch trigger screw 22 to realize the alarm. It is important to note that, to ensure the continuity of the bellows compression process, when the gas pressure inside process chamber 2 continues to rise, and the second bellows is compressed first, followed by the first bellows assembly, the combined stiffness resulting from the increased pressure of the compensating gas in the second bellows assembly and the second sealing chamber 6 should be slightly less than the stiffness of the first bellows assembly before it touches the limit rod. Conversely, when the first bellows is compressed first, followed by the second bellows assembly, the combined stiffness resulting from the increased pressure of the compensating gas in the first bellows assembly and the first sealing chamber 5 should be slightly less than the stiffness of the second bellows assembly before it touches the limit rod.

[0021] like Figure 4 As shown, the structures from left to right are identical to those in Embodiment 1. Figure 4 The left side shows the state diagram at the starting position. Figure 4 The middle point is when the measuring device moves to the action point 1, which is the maximum stroke of the second bellows assembly 4. At this time, the limiting member 7 can prevent the second bellows 13 from being over-compressed and undergoing plastic deformation. Figure 4 The right side shows the maximum stroke of the first corrugated component 3 when the measuring device moves to the action point 2, which is the stroke amount after being extended by the first corrugated component 3.

[0022] like Figure 5As shown, the red curve segment represents the stroke of the second corrugated component 4, the blue curve segment represents the stroke of the first corrugated component 3 after expansion, thus realizing the measurement of a large range, and the gray area represents the stroke range of the second corrugated component 4 at its operating point.

[0023] In summary, by using the first corrugated component 3 and the second corrugated component 4, the bellows stroke can be linearly extended to the full angle of pointer deflection, covering the entire measurement range. This invention uses a bellows as the sensitive element without changing the core measurement principle, maintaining high stability, and breaking through stroke limitations, while being compatible with reliability and large range capability. Maintenance personnel can intuitively obtain real, complete, and continuous density values, and the equipment's inflation, operation, leakage, and overpressure status are clear at a glance, avoiding misjudgments and omissions due to missing displays, and significantly improving the operational safety of high-voltage equipment.

[0024] It should be noted that the present invention achieves different action points through the timing of the first corrugated component 3 and the second corrugated component 4, and the present invention is not limited to the order in which the second corrugated component 4 compresses first and the first corrugated component 3 compresses later. The corresponding stiffness can also be adjusted to change the compression order of the first corrugated component 3 and the second corrugated component 4, thereby achieving different setpoint ranges, such as... Figure 9 , Figure 10 As shown, the structural combination of Embodiment 1 is still adopted, but the overall stiffness of the first corrugated component 3 and the second corrugated component 4 is changed. That is, the overall stiffness of the first corrugated component 3 is less than that of the second corrugated component 4, so that the first corrugated component 3 is compressed first and the second corrugated component 4 is compressed later. That is, the blue curve segment is the stroke of the first corrugated component 3 and the red curve segment is the stroke of the second corrugated component 4, thus realizing the measurement of a large range. The gray area is the stroke range of the second corrugated component 4.

[0025] like Figure 10 As shown, the structures from left to right are identical to those in Embodiment 1. Figure 10 The left side shows the state diagram at the starting position. Figure 10 The middle position represents the point where the measuring device reaches action point 1, which is also the maximum stroke of the first corrugated component 3. Figure 4 The right side shows the measurement device when it reaches the action point 2, which is the maximum stroke of the second corrugated assembly 4, i.e. the stroke amount after the second corrugated assembly 4 is extended. At the same time, the limiting member 7 can prevent the second corrugated tube 13 from being over-compressed and undergoing plastic deformation.

[0026] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0027] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A bellows-type measuring device with a large range display, characterized in that: It includes: The housing has a process chamber that connects to the gas chamber of an external electrical switchgear; Display mechanism for large-scale display; A transmission triggering mechanism, connected to the display mechanism, is used to trigger an alarm and drive the display mechanism to move; A large-range displacement mechanism is disposed inside the housing and connected to the transmission triggering mechanism; The large-range displacement mechanism includes an independent but connected first corrugated component and a second corrugated component. Both the first and second corrugated components have sealed cavities inside. The sealed cavity of the first or second corrugated component is at least partially defined by an elastic component or a limiting component. The sealed cavity of the first or second corrugated component is provided with a temperature compensation gas at a certain pressure. When the gas pressure in the process cavity changes, the first corrugated component and / or the second corrugated component compresses or expands to generate an axial displacement to the transmission triggering mechanism.

2. The bellows-type measuring device with large range display according to claim 1, characterized in that: The first corrugated component and the second corrugated component are arranged in series, and the sealing cavity corresponds to the first sealing cavity and the second sealing cavity of the first corrugated component and the second corrugated component, respectively; the elastic component and the limiting component can be respectively or simultaneously disposed in the first sealing cavity and the second sealing cavity.

3. The bellows-type measuring device with large range display according to claim 2, characterized in that: The first corrugated assembly includes a top cover and a bottom cover, and a first corrugated tube is sealed between the top cover and the bottom cover to form the first sealed cavity; the second corrugated assembly includes an upper cover and a base, and a second corrugated tube is sealed between the upper cover and the base to form the second sealed cavity.

4. A bellows-type measuring device with large range display according to claim 3, characterized in that: The elastic component includes a limiting block and a first spring. The limiting block is mounted on the lower cover, and the first spring is connected between the limiting block and the top cover.

5. A bellows-type measuring device with large range display according to claim 2, characterized in that: The limiting member is a limiting rod, which is disposed in the first sealing cavity or the second sealing cavity, and the length of the limiting rod is less than the height of the first sealing cavity or the second sealing cavity.

6. A bellows-type measuring device with large range display according to claim 4, characterized in that: It also includes a housing, in which the transmission triggering mechanism and the display mechanism are installed; a circuit board is fixed inside the housing, and multiple micro switches are installed on the circuit board, which are connected to the peripheral control circuit through connectors.

7. A bellows-type measuring device with large range display according to claim 6, characterized in that: The transmission triggering mechanism includes a connecting rod, one end of which is connected to the large-range displacement mechanism; a transmission block is connected to the other end of the connecting rod, the transmission block is located above the micro switch, and a switch trigger screw corresponding to the micro switch is mounted on the transmission block; the top end of the connecting rod is in contact with the display mechanism.

8. A bellows-type measuring device with large range display according to claim 7, characterized in that: The base is fixed to the bottom of the housing, the limiting member is fixed to the base, and the lower cover is fixedly connected to the upper cover; the connecting rod passes through the housing and is connected to the top cover, and a third bellows is installed on the outer wall of the connecting rod located in the process chamber, and a second spring is installed on the outside of the third bellows.

9. A bellows-type measuring device with large range display according to claim 7, characterized in that: The top cover is fixed to the top of the housing, the limiting member is fixed to the top cover, and the base is fixedly connected to the top cover; the limiting member is a hollow structure, and the connecting rod passes through the housing, the limiting member, and the top cover in sequence before connecting to the limiting block.

10. A bellows-type measuring device with large range display according to claim 8 or 9, characterized in that: The display mechanism uses a pointer dial, and the top of the connecting rod is in contact with the movement of the pointer dial; the housing is provided with a process connector, and external electrical equipment is connected to the process chamber through the process connector.

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