A remote-reading sulfur hexafluoride density meter

Abstract

This invention provides a remote-reading sulfur hexafluoride density meter, belonging to the field of electrical instrumentation technology. Its structure includes: a gear rotatably connected to the dial, with the gear teeth engaging with each other; a first fixing post fixedly connected to the dial, with a fixing hole on the first fixing post; a helical bimetallic strip, fitted around the gear's rotating shaft, with its inner end connected to the shaft. This invention adds a helical bimetallic strip to the gear mechanism and fixes its outer end. Based on this structure, when the bimetallic strip responds to temperature changes, the rotational movement of its inner end can compensate for under-reading caused by excessively high ambient temperatures and offset over-reading caused by excessively low ambient temperatures, thereby improving detection accuracy within a certain range. Furthermore, this invention adds a protective plate to the rear of the instrument for the response element, improving assembly reliability and providing protection.

Description

Technical Field

[0001] This utility model relates to the field of electrical instrumentation technology, specifically a remote-transmitting sulfur hexafluoride density meter. Background Technology

[0002] Sulfur hexafluoride (SF6) circuit breakers utilize sulfur hexafluoride (SF6) gas as both the arc-extinguishing and insulating medium. The SF6 gas is sealed within a container of constant volume. At its rated pressure and temperature of 20°C, it possesses a specific density value. Within the permissible operating conditions of the circuit breaker, although the pressure of the SF6 gas varies with temperature, its density remains constant. Since the insulation and arc-extinguishing performance of SF6 circuit breakers largely depends on the purity and density of the SF6 gas, the detection of its purity and monitoring of its density are crucial. A typical SF6 density meter uses a Bourdon tube as the response element, offering advantages such as high sensitivity and wide applicability. However, its accuracy is highly dependent on the uniformity of the ambient temperature; significant temperature variations have a noticeable impact on the test results. Furthermore, the assembly structure of conventional SF6 density meters currently lacks protection for the response element, making it susceptible to damage from external impacts. Summary of the Invention

[0003] The first technical problem that this invention aims to solve is: how to offset the influence of temperature changes on the detection results of sulfur hexafluoride density meters.

[0004] The second technical problem to be solved by this utility model is: how to improve the assembly structure of the sulfur hexafluoride density meter.

[0005] To achieve the above technical objectives, the present invention adopts the following technical solution:

[0006] A remote-controlled sulfur hexafluoride density meter includes a case, a protective cover, a back cover, a dial, an input tube, a Bourdon tube, a rotating shaft, a rotating plate, a transmission rod, a toothed edge, a gear, a pointer, a first fixing post, a fixing hole, a bimetallic strip, and a stop post. The dial is fixedly connected to the center of the front end of the case; the protective cover is fixedly connected to the front edge of the case, covering the dial; the back cover is fixedly connected to the rear edge of the case; the input tube is fixedly connected to the dial and a Bourdon tube is connected to the input tube; a rotating shaft is located at the rear end of the dial, and a rotating plate is connected to the rotating shaft. The two ends of the transmission rod are connected to the end of the spring tube and the rotating plate, respectively. The rotating plate has a toothed edge. A gear is rotatably connected to the dial. A pointer is fixedly connected to the gear and is located in front of the dial. The toothed edge and the gear cooperate with each other. A first fixing post is fixedly connected to the dial. A fixing hole is provided on the first fixing post. The hot bimetallic strip is spiral-shaped and is sleeved on the outside of the rotating shaft of the gear. The inner end of the hot bimetallic strip is connected to the rotating shaft. The outer end of the hot bimetallic strip is fixedly connected to the fixing hole. A stop post is fixedly connected to the front side of the dial.

[0007] Preferably, the fixing hole is a blind hole, and a hook is provided at the outer end of the hot bimetallic strip. The hook is embedded in the fixing hole and fixedly connected to the inner wall of the fixing hole.

[0008] Preferably, a second fixing post is fixedly connected to the rear side of the dial, and a protective plate is fixedly connected between the rear end of the second fixing post and the rear end of the first fixing post. The protective plate covers the rear of the rotating plate, transmission rod, gear, and hot bimetallic strip.

[0009] Preferably, the rotating plate is provided with an arc-shaped clearance hole, and the second fixing post is located in the clearance hole.

[0010] Preferably, the connection structure between the upper end of the transmission rod and the end of the spring tube includes: a first connection hole is provided at both the upper end of the transmission rod and the end of the spring tube, and the two first connection holes are fitted onto the outer wall of the first connecting column.

[0011] Preferably, the connection structure between the lower end of the transmission rod and the rotating plate includes: a second connecting hole at the lower end of the transmission rod, the second connecting hole being fitted onto the outer wall of the second connecting post, a strip-shaped hole on the rotating plate, and the second connecting post being located in the strip-shaped hole.

[0012] Preferably, threads are provided on the outer wall of the input tube.

[0013] Preferably, a wireless module is provided on the outside of the watch case, and an angle sensor is provided on the shaft of the gear, the angle sensor being communicatively connected to the wireless module.

[0014] In the above technical solution, the case, cover, and back cover together constitute the external protective structure of this utility model; the dial is used to set the scale, thereby playing an indicating role; the space between the dial and the back cover is used to accommodate the instrument's response element. The input tube is connected to the space to be measured and is used to introduce pressure into the Bourdon tube; the Bourdon tube itself is a conventional structure, also known as a Bourdon tube, with a fixed lower end and a movable upper end. Its cross-sectional shape is elliptical or flat. The non-circular cross-section tube gradually expands into a circle under the action of internal pressure. At this time, the movable end generates a displacement that is related to the magnitude of the pressure. This displacement drives the rotating plate to rotate via the transmission rod, thereby driving the pointer to rotate and generate a reading. The rotating shaft is used to mount the rotating plate, allowing it to rotate along the shaft when driven by the transmission rod; the toothed edge of the rotating plate meshes with a gear, so that when the rotating plate rotates, it can drive the gear to rotate, and the pointer located on the gear rotates accordingly. Based on this, the present invention incorporates a helical bimetallic strip fitted outside the gear shaft. The bimetallic strip has a conventional structure, composed of two metals with different coefficients of thermal expansion. When the temperature changes, due to the different coefficients of thermal expansion of the constituent layers, the deformation of the active layer is greater than that of the passive layer, causing the bimetallic strip to bend towards the passive layer, thus generating deformation. During deformation, the inner end of the helical bimetallic strip undergoes circumferential movement, which to some extent counteracts the pressure changes caused by temperature variations (i.e., when the temperature is low and the reading is small, this movement compensates for the reading; when the temperature is high and the reading is large, this movement cancels out the reading). The first fixing post and its fixing hole are used to fix the outer end of the bimetallic strip, thereby ensuring that the inner end of the bimetallic strip rotates when the temperature changes. The stop post is used to limit the pointer to the zero position of the scale.

[0015] In the preferred technical solution, the hook body facilitates the fixing of the outer end of the bimetallic strip to the fixing hole. The second fixing post is used to install a protective plate, which shields and protects the responding element; the clearance hole prevents the second fixing post from obstructing the rotating plate. The first connecting hole at the upper end of the transmission rod and the first connecting hole at the end of the spring tube are used to fit onto the first connecting post, realizing the rotatable connection between the end of the spring tube and the upper end of the transmission rod; the second connecting hole at the lower end of the transmission rod is used to rotatably connect with the second connecting post. Since the second connecting post is inserted into the strip hole on the rotating plate, the transmission between the lower end of the transmission rod and the rotating plate can be realized.

[0016] This invention provides a remote-reading sulfur hexafluoride density meter. The technical solution adds a spiral-shaped bimetallic strip to the gear mechanism and fixes the outer end of the bimetallic strip. Based on this structure, when the bimetallic strip responds to temperature changes, its inner end rotates. This rotational motion compensates for under-reading caused by excessively high ambient temperatures and cancels out over-reading caused by excessively low ambient temperatures, thereby improving detection accuracy within a certain range. Furthermore, this invention adds a protective plate to the response element on the rear side of the instrument, which not only improves assembly reliability but also protects the response element. Attached Figure Description

[0017] Figure 1 This is a perspective view of the front of this utility model;

[0018] Figure 2 This is a perspective view of the rear of this utility model;

[0019] Figure 3 This is a perspective view of the rear of the present invention after the protective cover and rear cover have been removed.

[0020] Figure 4 This is a perspective view of the rear of the present invention after the protective cover, back cover and protective plate have been removed;

[0021] Figure 5 This is a perspective view of the connection position between the thermal bimetallic strip and the first fixing post in this utility model;

[0022] Figure 6 This is a perspective view of the meshing position of the tooth edge and the gear in this utility model;

[0023] Figure 7 This is a perspective view of the connection position between the transmission rod and the rotating plate in this utility model;

[0024] Figure 8 This is a perspective view of the transmission rod in this utility model;

[0025] Figure 9 This is a perspective view of the connection position between the gear and the pointer in this utility model;

[0026] Figure 10 This is a perspective view of the front of this utility model after the protective cover and back cover have been removed.

[0027] In the picture:

[0028] Detailed Implementation

[0029] The specific embodiments of this utility model will be described in detail below. To avoid excessive and unnecessary details, well-known structures or functions will not be described in detail in the following embodiments. The approximate language used in the following embodiments can be used for quantitative descriptions, indicating that a certain degree of variation in quantity is permissible without changing the basic function. Unless otherwise defined, the technical and scientific terms used in the following embodiments have the same meaning as commonly understood by those skilled in the art to which this utility model pertains.

[0030] Example 1

[0031] A remote-reading sulfur hexafluoride density meter, such as Figures 1-10 As shown, the watch includes a case 1, a protective cover 2, a back cover 3, a dial 4, an input tube 5, a spring tube 6, a rotating shaft 7, a rotating plate 8, a transmission rod 9, a toothed edge 10, a gear 11, a pointer 12, a first fixing post 13, a fixing hole 14, a hot bimetallic strip 15, and a stop post 16. The dial 4 is fixedly connected to the center of the front end of the case 1. The protective cover 2 is fixedly connected to the front edge of the case 1, covering the dial 4. The back cover 3 is fixedly connected to the rear edge of the case 1. The input tube 5 is fixedly connected to the dial 4, and a spring tube 6 is connected to the input tube 5. A rotating shaft 7 is located at the rear end of the dial 4, and a rotating plate 8 is connected to the rotating shaft 7. The two ends of the transmission rod 9... The ends are respectively connected to the end of the spring tube 6 and the rotating plate 8. The edge of the rotating plate 8 is provided with a toothed edge 10. A gear 11 is rotatably connected to the dial 4. A pointer 12 is fixedly connected to the gear 11. The pointer 12 is located in front of the dial 4. The toothed edge 10 and the gear 11 cooperate with each other. A first fixing post 13 is fixedly connected to the dial 4. A fixing hole 14 is provided on the first fixing post 13. The hot bimetallic strip 15 is spiral-shaped. The hot bimetallic strip 15 is sleeved on the outside of the rotating shaft of the gear 11. The inner end of the hot bimetallic strip 15 is connected to the rotating shaft. The outer end of the hot bimetallic strip 15 is fixedly connected to the fixing hole 14. A stop post 16 is fixedly connected to the front side of the dial 4.

[0032] In the above technical solution, the case 1, the protective cover 2, and the back cover 3 together constitute the external protective structure of this utility model; the dial 4 is used to set the scale, thereby playing an indicating role; the space between the dial 4 and the back cover 3 is used to accommodate the instrument's response element. The input tube 5 is connected to the space to be measured and is used to introduce pressure into the Bourdon tube 6; the Bourdon tube 6 itself is a conventional structure, also known as a Bourdon tube, with its lower end fixed and its upper end movable. Its cross-sectional shape is elliptical or flat. The non-circular cross-section tube gradually expands into a circle under the action of internal pressure. At this time, the movable end generates a displacement that is related to the magnitude of the pressure. This displacement drives the rotating plate 8 to rotate via the transmission rod 9, thereby driving the pointer 12 to rotate and generate a reading. The rotating shaft 7 is used to mount the rotating plate 8, allowing the rotating plate 8 to rotate along the rotating shaft 7 when driven by the transmission rod 9; the toothed edge 10 of the rotating plate 8 meshes with the gear 11, so that when the rotating plate 8 rotates, it can drive the gear 11 to rotate, and the pointer 12 located on the gear 11 rotates accordingly. Based on this, the present invention includes a spiral-shaped bimetallic strip 15 fitted outside the shaft of the gear 11. The bimetallic strip 15 has a conventional structure and is composed of two metal materials with different coefficients of thermal expansion. When the temperature changes, due to the different coefficients of thermal expansion of the constituent layers, the deformation of the active layer is greater than that of the passive layer, causing the bimetallic strip to bend towards the passive layer, thus producing deformation. When the spiral-shaped bimetallic strip 15 deforms, its inner end generates circumferential movement, which is used to offset the pressure change caused by temperature changes to a certain extent (i.e., when the temperature is low and the reading is small, the movement compensates for the reading; when the temperature is high and the reading is large, the movement offsets the reading). The first fixing post 13 and its fixing hole 14 are used to fix the outer end of the bimetallic strip 15, thereby ensuring that the inner end of the bimetallic strip 15 rotates when the temperature changes. The stop post 16 is used to limit the pointer 12 to the zero position of the scale line.

[0033] Example 2

[0034] Based on the technical solution of Embodiment 1: the fixing hole 14 is a blind hole, and a hook 17 is provided at the outer end of the hot bimetallic strip 15. The hook 17 is embedded in the fixing hole 14 and fixedly connected to the inner wall of the fixing hole 14. A second fixing post 18 is fixedly connected to the rear side of the dial 4. A protective plate 19 is fixedly connected between the rear end of the second fixing post 18 and the rear end of the first fixing post 13. The protective plate 19 covers the rear of the rotating plate 8, the transmission rod 9, the gear 11, and the hot bimetallic strip 15. An arc-shaped clearance hole 20 is provided on the rotating plate 8, and the second fixing post 18 is located in the clearance hole 20. The connection structure between the upper end of the transmission rod 9 and the end of the spring tube 6 includes: a first connecting hole 21 is provided at the upper end of the transmission rod 9 and the end of the spring tube 6. Both first connecting holes 21 are sleeved on the outer wall of the first connecting post 22. The connection structure between the lower end of the transmission rod 9 and the rotating plate 8 includes: a second connecting hole 23 at the lower end of the transmission rod 9, the second connecting hole 23 being fitted onto the outer wall of the second connecting post 24; a strip-shaped hole 25 on the rotating plate 8, with the second connecting post 24 located within the strip-shaped hole 25; and a threaded connection on the outer wall of the input tube 5. A wireless module is located on the outside of the case 1, and an angle sensor is located on the shaft of the gear 11, the angle sensor being communicatively connected to the wireless module.

[0035] In the above technical solution, the hook body 17 facilitates the fixing of the outer end of the hot bimetallic strip 15 to the fixing hole. The second fixing post 18 is used to set the protective plate 19, which shields and protects the responding element; the clearance hole 20 prevents the second fixing post 18 from blocking the rotating plate 8. The first connecting hole 21 at the upper end of the transmission rod 9 and the first connecting hole 21 at the end of the spring tube 6 are used to fit on the first connecting post 22, realizing the rotational connection between the end of the spring tube 6 and the upper end of the transmission rod 9; the second connecting hole 23 at the lower end of the transmission rod 9 is used to rotately connect with the second connecting post 24. Since the second connecting post 24 is inserted into the strip hole 25 on the rotating plate 8, the transmission between the lower end of the transmission rod 9 and the rotating plate 8 can be realized.

[0036] The communication protocol of this utility model is as follows:

[0037] Baud rate: 9600bps

[0038] Data Protocol: Modbus-RTU

[0039] Data bits: 8

[0040] Parity check: None

[0041] Stop bit: 1

[0042] Each communication can only be initiated by the host computer and then received by the queried wireless receiver.

[0043] The machine returns data in the following format:

[0044] Read operation

[0045] Send frame:

[0046] Direction: PC->Table

[0047] Format:

[0048]

[0049] Return frame:

[0050] Direction: Table->Host computer

[0051] Format:

[0052]

[0053] CRC calculation method:

[0054] CRC16 polynomial: 0xA001

[0055] CRC calculation reference routine:

[0056] / / ---------------------------------------------------------

[0057] unsigned int Caculate_CRC16_Byte(unsigned int DAT, unsigned

[0058] int CRC)

[0059] {

[0060] unsigned char j;

[0061] CRC = CRC ^ DAT; / / XOR with the current byte once

[0062] for(j=0; j<8; j++) / / Loop 8 times

[0063] {

[0064] if(CRC & 0x01) / / Check the least significant bit; if it is 1

[0065] {

[0066] CRC = CRC >> 1; / / Shift right by one bit

[0067] CRC = CRC ^ 0xA001; / / XOR with multiphase

[0068] }

[0069] else / / Check the least significant bit; if it is 0

[0070] {

[0071] CRC = CRC >> 1; / / Shift right by one bit

[0072] }

[0073] }

[0074] return(CRC); / / Returns the CRC up to the current byte.

[0075] value

[0076] }

[0077] / / ------------------------------------------------------------

[0078] unsigned int Caculate_CRC16(unsigned char *DAT, unsigned int

[0079] Lenth)

[0080] {

[0081] unsigned int CRC = 0xffff; / / Initial CRC value

[0082] The initial value is FFFF

[0083] unsigned char i;

[0084] for(i=0; i <Lenth; i++)

[0085] {

[0086] CRC = Caculate_CRC16_Byte(DAT[i], CRC); / / Calculate the array

[0087] CRC value

[0088] }

[0089] return(CRC);

[0090] }

[0091] / / -----------------------------------------------------

[0092] The embodiments of this utility model have been described in detail above, but the content described is only a preferred embodiment of this utility model and is not intended to limit this utility model. Any modifications, equivalent substitutions, and improvements made within the scope of this utility model application should be included within the protection scope of this utility model.

Claims

1. A remote-reading sulfur hexafluoride density meter, characterized in that... The watch includes a case (1), a protective cover (2), a back cover (3), a dial (4), an input tube (5), a spring tube (6), a rotating shaft (7), a rotating plate (8), a transmission rod (9), a toothed edge (10), a gear (11), a pointer (12), a first fixing post (13), a fixing hole (14), a hot bimetallic strip (15), and a stop post (16). The dial (4) is fixedly connected to the middle of the front end of the case (1), the protective cover (2) is fixedly connected to the front edge of the case (1), the protective cover (2) covers the outside of the dial (4), the back cover (3) is fixedly connected to the rear edge of the case (1), the input tube (5) is fixedly connected to the dial (4), the spring tube (6) is connected to the input tube (5), the rotating shaft (7) is provided at the rear end of the dial (4), and the rotating plate (8) is connected to the rotating shaft (7). The two ends of the transmission rod (9) are connected to the end of the spring tube (6) and the rotating plate (8) respectively. The edge of the rotating plate (8) is provided with a toothed edge (10). A gear (11) is rotatably connected to the dial (4). A pointer (12) is fixedly connected to the gear (11). The pointer (12) is located in front of the dial (4). The toothed edge (10) and the gear (11) cooperate with each other. A first fixed post (13) is fixedly connected to the dial (4). A fixed hole (14) is provided on the first fixed post (13). The hot bimetallic strip (15) is spiral-shaped. The hot bimetallic strip (15) is sleeved outside the rotating shaft of the gear (11). The inner end of the hot bimetallic strip (15) is connected to the rotating shaft. The outer end of the hot bimetallic strip (15) is fixedly connected to the fixed hole (14). A stop post (16) is fixedly connected to the front side of the dial (4).

2. The remote-reading sulfur hexafluoride density meter according to claim 1, characterized in that, The fixing hole (14) is a blind hole. A hook (17) is provided at the outer end of the hot bimetallic strip (15). The hook (17) is embedded in the fixing hole (14) and fixedly connected to the inner wall of the fixing hole (14).

3. The remote-reading sulfur hexafluoride density meter according to claim 1, characterized in that, A second fixing post (18) is fixedly connected to the rear side of the dial (4). A protective plate (19) is fixedly connected between the rear end of the second fixing post (18) and the rear end of the first fixing post (13). The protective plate (19) covers the rear of the rotating plate (8), the transmission rod (9), the gear (11), and the hot bimetallic strip (15).

4. A remote-reading sulfur hexafluoride density meter according to claim 3, characterized in that, An arc-shaped clearance hole (20) is provided on the rotating plate (8), and the second fixing post (18) is located in the clearance hole (20).

5. A remote-reading sulfur hexafluoride density meter according to claim 1, characterized in that, The connection structure between the upper end of the transmission rod (9) and the end of the spring tube (6) includes: a first connection hole (21) is provided at the upper end of the transmission rod (9) and the end of the spring tube (6), and the two first connection holes (21) are fitted on the outer wall of the first connecting column (22).

6. A remote-reading sulfur hexafluoride density meter according to claim 1, characterized in that, The connection structure between the lower end of the transmission rod (9) and the rotating plate (8) includes: a second connecting hole (23) is provided at the lower end of the transmission rod (9), the second connecting hole (23) is sleeved on the outer wall of the second connecting post (24), and a strip hole (25) is provided on the rotating plate (8), with the second connecting post (24) located in the strip hole (25).

7. A remote-reading sulfur hexafluoride density meter according to claim 1, characterized in that, A thread is provided on the outer wall of the input pipe (5).

8. A remote-reading sulfur hexafluoride density meter according to claim 1, characterized in that, A wireless module is provided on the outside of the watch case (1), and an angle sensor is provided on the shaft of the gear (11). The angle sensor is communicatively connected to the wireless module.

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