A method for filling silicone oil for differential pressure transmitter

Abstract

The present invention discloses a method for filling silicone oil in a differential pressure transmitter. The differential pressure transmitter is equipped with two filling devices, each of which includes an injection tube for connecting to the silicone oil holding chamber of the differential pressure transmitter, and a sealing groove. The sealing groove is provided with a water injection port, and a sealing plug is provided in the water injection port. The bottom of the sealing groove is covered with a deformable diaphragm, and a telescopic mechanism is fixedly connected to the middle part of the outer side of the deformable diaphragm. The method for filling silicone oil in a differential pressure transmitter includes connecting the sealing groove, filling silicone oil into the silicone oil holding chamber, injecting water into the sealing groove, and adjusting the flow of silicone oil into or out of the silicone oil holding chamber through a telescopic mechanism. The present invention adjusts the telescopic mechanism to achieve precise control of the amount of silicone oil flowing in or out, ensuring that the pressure on both sides of the measuring diaphragm is equal and always in a neutral position, thereby preventing the measuring diaphragm from being offset and deformed during the silicone oil filling process.

Description

Technical Field

[0001] The invention belongs to the technical field of liquid medium filling, and particularly relates to a silicone oil filling method for a differential pressure transmitter. Background Art

[0002] A differential pressure transmitter measures the pressure difference between media in process pipelines or tanks, converting the measured differential pressure into a current signal through data conversion and square root extraction. The transmitter consists of two disc-shaped diaphragms, each with a separator diaphragm on its outer wall to block the fluid. A measuring diaphragm is sandwiched between the two diaphragms. Pressure-inducing channels are located between the separator and measuring diaphragms, each filled with silicone oil, a pressure-inducing medium. When the separator diaphragm senses the external pressure to be measured, it introduces the pressure into both sides of the measuring diaphragm through the pressure-inducing channels. Due to the different pressures on both sides, the measuring diaphragm deforms toward the side with lower pressure, and the amount of deformation is reflected as a change in the capacitance signal.

[0003] When adding silicone oil to the pressure-introducing channels, an injection tube is typically connected to the channel inlet and the oil is added directly. This method makes it difficult to precisely control the amount of silicone oil injected. If the silicone oil volume in the two pressure-introducing channels deviates, causing unequal pressures on both sides of the measuring diaphragm, the measuring diaphragm can easily shift and deform, introducing significant errors in the measurement results and reducing detection accuracy. Therefore, a method is needed that can precisely control the amount of silicone oil injected and ensure that the measuring diaphragm is always in a neutral position. Summary of the Invention

[0004] In view of this, the present invention provides a method for filling silicone oil in a differential pressure transmitter.

[0005] The technical solutions of the present invention are as follows:

[0006] A method for filling silicone oil in a differential pressure transmitter, the key of which is that the differential pressure transmitter is equipped with two filling devices, each of which includes a liquid filling pipe for connecting to the silicone oil receiving chamber of the differential pressure transmitter, and a sealing groove, the sealing groove having a water filling port, the water filling port being provided with a sealing plug, the bottom of the sealing groove being covered with a deformable diaphragm, and the middle portion of the outer side of the deformable diaphragm being fixedly connected to a telescopic mechanism;

[0007] The differential pressure transmitter silicone oil filling method comprises the following steps:

[0008] S1: Align the sealing grooves of the two filling devices with the side walls of the differential pressure transmitter provided with the separation diaphragm, and seal them with the corresponding side walls;

[0009] S2: Connecting the outlet ends of the two injection tubes to the corresponding filling ports of the silicone oil containing chamber, respectively, and injecting silicone oil into the two silicone oil containing chambers from the inlet ends of the injection tubes, and making the silicone oil liquid level in the injection tubes close to the inlet ends;

[0010] S3: Open the water inlet and inject water into the sealing groove;

[0011] S4: After the sealing groove is filled with water, the water inlet is closed;

[0012] S5: Adjust the telescopic mechanism to drive the corresponding deformable diaphragm to expand outward or contract inward, and the separation diaphragm is displaced synchronously, so that the silicone oil flows into or out of the corresponding silicone oil containing chamber through the injection tube, so that the measuring diaphragm of the differential pressure transmitter is in the middle position, completing the silicone oil filling, closing the silicone oil containing chamber filling port and removing the injection tube.

[0013] With the above design, filling devices are connected to the outer walls of the two separation diaphragms of the differential pressure transmitter. By adjusting the displacement of the telescopic mechanism, the inflow or outflow of silicone oil can be precisely controlled to ensure that the pressure on both sides of the measuring diaphragm is equal and always in the neutral position.

[0014] Preferably, in step S5, the amounts of silicone oil added to the two silicone oil containing chambers are equal.

[0015] The above design ensures that both sides of the measuring diaphragm are subjected to equal silicone oil pressure.

[0016] Preferably, the telescopic mechanism comprises a screw-nut mechanism, a fixing seat and a connecting plate, one side of the connecting plate is abutted against and connected to the outer side of the deformable diaphragm, and the fixing seat is fixedly mounted on the other side of the connecting plate;

[0017] The screw-nut mechanism includes a screw and a nut, wherein the screw is arranged perpendicular to the deformable diaphragm, one end of the screw is rotatably connected to the fixing seat, the screw is sleeved with the nut, and the nut is fixedly mounted on a bracket, which is fixedly connected to the sealing groove;

[0018] In step S5, the screw rod is rotated, and after cooperating with the nut, the screw rod drives the fixing seat and the connecting plate to perform telescopic movement, so that the connecting plate drives the deformable diaphragm to deflect and deform.

[0019] With the above design, the deformable diaphragm is driven to expand or contract through the screw-nut mechanism, and the structure is simple.

[0020] Preferably, a cavity is provided in the fixing seat, and the cavity is provided with an opening corresponding to the screw rod;

[0021] After one end of the screw rod freely penetrates the cavity, it is fixedly connected to a rotating piece, which is close to the opening. The diameter of the rotating piece is larger than the diameter of the opening to prevent the screw rod from falling out. The rotating piece rotates in conjunction with the cavity.

[0022] With the above design, a rotating piece is provided at the end of the screw rod, which can prevent the screw rod from falling out of the fixed seat without affecting the rotation of the screw rod itself, so as to achieve the purpose of the screw rod driving the fixed seat, connecting plate and deformable diaphragm to perform telescopic movement at the same time.

[0023] Preferably, a dial is provided at one end of the screw rod away from the fixing seat, the dial is close to the nut, and the dial, nut and screw rod form a micrometer screw;

[0024] In step S5, the dial is rotated to drive the screw to rotate.

[0025] With the above design, the screw is driven to rotate by the dial, making it easy to read the displacement of the deformed diaphragm.

[0026] Preferably, the shape of the notch of the sealing groove is adapted to the shape of the side wall of the separation diaphragm, and a sealing step is provided on the inner wall of the notch of the sealing groove, and a sealing ring is provided on the sealing step;

[0027] In step S1 , the sealing ring is sandwiched between the side wall of the separation membrane and the sealing step.

[0028] The above design facilitates the sealing connection between the sealing groove and the side wall of the separation diaphragm.

[0029] Preferably, the injection tube is made of a transparent material. In step S2, the silicone oil level in the injection tube is observed to confirm that the silicone oil holding chamber is fully filled with silicone oil.

[0030] With the above design, when silicone oil is continuously added through the injection tube, if it is observed that the silicone oil level in the injection tube no longer moves, it can be confirmed that the silicone oil holding chamber has been fully filled with silicone oil.

[0031] Preferably, the injection tube is marked with scale lines. In step S5, when adjusting the telescopic mechanism, the scale changes of the liquid level in the injection tube are observed to determine whether the silicone oil flows into or out of the silicone oil containing chamber.

[0032] With the above design, a decrease in the liquid level scale indicates that the silicone oil flows into the silicone oil containing chamber, and an increase in the liquid level scale indicates that the silicone oil flows out of the silicone oil containing chamber.

[0033] Preferably, the deformable diaphragm and the separation diaphragm are made of the same material.

[0034] The above design facilitates the consistency of the offset deformation of the deformed diaphragm and the separation diaphragm.

[0035] Preferably, the differential pressure sensor of the differential pressure transmitter is connected to a signal processing device, which receives the output signal of the differential pressure sensor and processes it to output the pressure difference between the two sides of the measuring diaphragm;

[0036] In step S5, the two telescopic mechanisms are slowly adjusted until the pressure difference value output by the signal processing device is minimum, and it is determined that the measuring diaphragm of the differential pressure transmitter is in the middle position at this time.

[0037] With the above design, the pressure difference value output by the signal processing device is used to determine whether the measuring diaphragm is in an offset deformation state. The corresponding telescopic mechanism is adjusted according to the current pressure difference value to minimize the pressure difference on both sides of the measuring diaphragm and ensure that it is in the middle position.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] By connecting filling devices to the outer walls of the two separation diaphragms of the differential pressure transmitter, the telescopic mechanism is used to drive the displacement of the deformed diaphragm to cause a slight change in the volume of the silicone oil holding chamber, and the silicone oil flows into or out of the silicone oil holding chamber. During the silicone oil filling process, the amount of silicone oil in the two silicone oil holding chambers is finely adjusted to keep the silicone oil pressure on both sides of the measuring diaphragm equal, and it is always in the middle position. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 Schematic diagram of the structure when filling the differential pressure transmitter;

[0041] Figure 2 for Figure 1 A partial enlarged view of point a in the middle. DETAILED DESCRIPTION

[0042] The present invention will be further described below with reference to the embodiments and accompanying drawings.

[0043] like Figure 1 The differential pressure transmitter shown is equipped with two filling devices. Each filling device includes an injection tube 2 for connecting to the silicone oil chamber 1 of the differential pressure transmitter, and a sealing groove 3 with a water inlet 3a. The sealing groove 3 has a sealing plug installed in the water inlet 3a. The bottom of the sealing groove 3 is covered with a deformable diaphragm 4, and a telescopic mechanism 5 is fixedly connected to the middle of the outer side of the deformable diaphragm 4.

[0044] The silicone oil filling method of the differential pressure transmitter comprises the following steps:

[0045] S1: Align the notches of the sealing grooves 3 of the two filling devices with the side walls of the differential pressure transmitter provided with the separation diaphragm 6, and seal them with the corresponding side walls. This arrangement can form a water storage cavity in the sealing grooves 3.

[0046] S2: Connect the outlet ends of the two injection tubes 2 to the corresponding filling ports of the silicone oil chamber 1. Fill the two silicone oil chambers 1 from the inlet ends of the injection tubes 2, and ensure that the silicone oil level in the injection tubes 2 is close to the inlet ends. Specifically, the silicone oil chambers 1 need to be completely filled with silicone oil to avoid bubbles in the silicone oil chamber 1 and to ensure that the silicone oil pressure on both sides of the measuring diaphragm is equal to avoid offset deformation.

[0047] S3: Open the water injection port 3a and inject water into the sealing groove 3.

[0048] S4: After the sealing groove 3 is filled with water, the water inlet 3a is closed.

[0049] S5: Adjust the telescopic mechanism 5 to drive the corresponding deformable diaphragm 4 to expand outward or contract inward, and the separation diaphragm 6 is displaced synchronously, so that the silicone oil flows into or out of the corresponding silicone oil containing chamber 1 through the injection tube 2, so that the measuring diaphragm 8 of the differential pressure transmitter is in the middle position, completing the silicone oil filling, closing the filling port of the silicone oil containing chamber 1 and removing the injection tube 2.

[0050] Specifically, the amount of silicone oil added to the two silicone oil containing chambers 1 is equal, which further ensures that the silicone oil pressure on both sides of the measuring diaphragm 8 is equal.

[0051] In this embodiment, the telescopic mechanism 5 specifically comprises a screw-nut mechanism, a fixing seat 51, and a connecting plate 52. One side of the connecting plate 52 abuts against and connects to the outer side of the deformable diaphragm 4, while the fixing seat 51 is fixedly mounted on the other side of the connecting plate 52. The screw-nut mechanism comprises a screw 53 and a nut 54. The screw 53 is arranged perpendicular to the deformable diaphragm 3. One end of the screw 53 is rotatably connected to the fixing seat 51. The nut 54 is sleeved on the screw 53 and fixedly mounted on a bracket 55, which is fixedly connected to the sealing groove 3.

[0052] In step S5, the specific method of adjusting the telescopic mechanism 5 to drive the deformation diaphragm 4 to move is to rotate the screw rod 53, which cooperates with the nut 54 to perform telescopic movement, thereby driving the fixing seat 51 and the connecting plate 52 to move together, and the connecting plate 52 drives the deformation diaphragm 4 to deflect and deform.

[0053] like Figure 2As shown, a cavity 51a is defined within the fixing seat 51, and the cavity 51a has an opening corresponding to the screw rod 53. One end of the screw rod 53 freely penetrates the cavity 51a and is fixedly connected to a rotating piece 53a. The rotating piece 53a abuts against the opening, and the diameter of the rotating piece 53a is larger than the diameter of the opening to prevent the screw rod 53 from falling out. The rotating piece 53a rotates in conjunction with the cavity 51a.

[0054] Furthermore, a dial 7 is provided at one end of the screw rod 53 away from the fixing base 51. The dial 7 is close to the nut 54. The dial 7, the nut 54, and the screw rod 53 form a micrometer screw. In step S5, the dial 7 is rotated to drive the screw rod 53 to rotate. The displacement is controlled by reading the dial 7.

[0055] The shape of the sealing groove 3's opening matches the shape of the sidewall of the separator diaphragm 6. A sealing step is provided on the inner wall of the sealing groove 3, and a sealing ring 3b is provided on the sealing step. In step S1, the sealing ring 3b is sandwiched between the sidewall of the separator diaphragm 6 and the sealing step, thereby sealingly connecting the sealing groove 3 to the sidewall of the separator diaphragm 6.

[0056] The injection tube 2 is made of a transparent material. When silicone oil is added in step S2, whether the silicone oil containing chamber 1 is filled with silicone oil can be confirmed by observing whether the silicone oil liquid level in the injection tube 2 continues to move toward the silicone oil containing chamber 1.

[0057] The injection tube 2 is marked with scale lines. In step S5, when the telescopic mechanism 5 is adjusted, if the liquid level scale in the injection tube 2 decreases, it means that the silicone oil flows into the silicone oil containing chamber 1. Otherwise, it increases, which means that the silicone oil flows out of the silicone oil containing chamber 1.

[0058] In order to ensure that the displacement deformation of the deformable diaphragm 4 and the separation diaphragm 6 are consistent, the two are made of the same material.

[0059] The differential pressure sensor of the differential pressure transmitter is connected to a signal processing device, which receives the output signal of the differential pressure sensor and processes it to output the pressure difference on both sides of the measuring diaphragm 8. The signal processing device is a prior art and can use the signal processing circuit and digital display module of the differential pressure transmitter. Since the measured pressure difference value is related to the deformation offset of the measuring diaphragm 8 to one side, the closer the pressure difference value is to zero, the smaller the deformation of the measuring diaphragm 8 is. In step S5, the two telescopic mechanisms are slowly adjusted until the pressure difference value output by the signal processing device is the smallest, and it is determined that the measuring diaphragm of the differential pressure transmitter is in the middle position at this time.

[0060] The purpose of this silicone oil filling method is to ensure that, although the two silicone oil containing chambers 1 are filled with silicone oil in step S2 and the silicone oil containing chambers 1 are filled with equal amounts of silicone oil in step S5, the pressure on both sides of the measuring diaphragm is kept equal as much as possible. However, during all operations, a pressure difference may still occur due to the influence of air or other factors. Therefore, the signal processing device outputs the pressure difference value on both sides of the measuring diaphragm 8 for adjustment. The side with higher pressure compresses the telescopic mechanism 5 inward, causing the silicone oil to flow out of the silicone oil containing chamber 1, while the side with lower pressure stretches the telescopic mechanism 5 outward, causing the silicone oil to flow into the silicone oil containing chamber 1, ultimately achieving equal pressure on both sides of the measuring diaphragm 8.

[0061] Finally, it should be noted that the above description is only a preferred embodiment of the present invention. Under the guidance of the present invention, ordinary technicians in this field can make various similar expressions without violating the purpose and claims of the present invention. Such changes fall within the scope of protection of the present invention.

Claims

1. A method for filling silicone oil in a differential pressure transmitter, characterized in that: The differential pressure transmitter is equipped with two filling devices, each of which comprises a liquid injection pipe (2) for connecting to the silicone oil receiving chamber (1) of the differential pressure transmitter, and a sealing groove (3), wherein the sealing groove (3) is provided with a water injection port (3a), and a sealing plug is provided in the water injection port (3a). The bottom of the sealing groove (3) is covered with a deformable diaphragm (4), and a telescopic mechanism (5) is fixedly connected to the middle of the outer side of the deformable diaphragm (4); The differential pressure transmitter silicone oil filling method comprises the following steps: S1: Align the notches of the sealing grooves (3) of the two filling devices with the side walls of the differential pressure transmitter provided with the separation diaphragm (6), and seal them with the corresponding side walls; S2: Connect the outlet ends of the two injection tubes (2) to the corresponding filling ports of the silicone oil containing chamber (1), respectively, and inject silicone oil into the two silicone oil containing chambers (1) from the inlet ends of the injection tubes (2), and make the silicone oil liquid level in the injection tubes (2) close to the inlet ends; S3: opening the water injection port (3a) and injecting water into the sealing groove (3); S4: After the sealing groove (3) is filled with water, the water inlet (3a) is closed; S5: adjusting the telescopic mechanism (5) to drive the corresponding deformable diaphragm (4) to expand outward or contract inward, and the separation diaphragm (6) to be displaced synchronously, so that the silicone oil flows into or flows out of the corresponding silicone oil receiving chamber (1) through the injection pipe (2), so that the measuring diaphragm (8) of the differential pressure transmitter is in the middle position, completing the silicone oil filling, closing the filling port of the silicone oil receiving chamber (1) and removing the injection pipe (2); In step S5, the amount of silicone oil added to the two silicone oil containing chambers (1) is equal; The telescopic mechanism (5) comprises a screw-nut mechanism, a fixing seat (51) and a connecting plate (52); one side of the connecting plate (52) is abutted against and connected to the outer side of the deformable diaphragm (4); the other side of the connecting plate (52) is fixedly mounted with the fixing seat (51); The screw-nut mechanism comprises a screw (53) and a nut (54), wherein the screw (53) is arranged perpendicular to the deformable diaphragm (4), one end of the screw (53) is rotatably connected to the fixing seat (51), the screw (53) is sleeved with the nut (54), and the nut (54) is fixedly mounted on a bracket (55), and the bracket (55) is fixedly connected to the sealing groove (3); In step S5, the screw rod (53) is rotated, and after cooperating with the nut (54), the screw rod (53) drives the fixing seat (51) and the connecting plate (52) to perform telescopic movement, so that the connecting plate (52) drives the deformable diaphragm (4) to deflect and deform; A cavity (51a) is provided in the fixing seat (51), and the cavity (51a) is provided with an opening corresponding to the screw rod (53); One end of the screw rod (53) freely penetrates the cavity (51a) and is fixedly connected to a rotating piece (53a). The rotating piece (53a) is close to the opening. The diameter of the rotating piece (53a) is larger than the diameter of the opening to prevent the screw rod (53) from falling out. The rotating piece (53a) rotates in conjunction with the cavity (51a). A dial (7) is provided at one end of the screw rod (53) away from the fixing seat (51), and the dial (7) is close to the nut (54). The dial (7), the nut (54) and the screw rod (53) form a micrometer screw. In step S5, the dial (7) is rotated to drive the screw (53) to rotate; The differential pressure sensor of the differential pressure transmitter is connected to a signal processing device, which receives the output signal of the differential pressure sensor and processes it to output the pressure difference between the two sides of the measuring diaphragm (8); In step S5, the two telescopic mechanisms (5) are slowly adjusted until the pressure difference value output by the signal processing device is minimum, and it is determined that the measuring diaphragm (8) of the differential pressure transmitter is in the middle position at this time.

2. A method for filling silicone oil in a differential pressure transmitter according to claim 1, characterized in that: The shape of the notch of the sealing groove (3) is adapted to the shape of the side wall of the separation diaphragm (6); a sealing step is provided on the inner wall of the notch of the sealing groove (3); and a sealing ring (3b) is provided on the sealing step; In step S1, the sealing ring (3b) is sandwiched between the side wall of the separation membrane (6) and the sealing step.

3. The method for filling silicone oil in a differential pressure transmitter according to claim 1, wherein: The injection tube (2) is made of a transparent material. In step S2, the silicone oil level in the injection tube (2) is observed to confirm that the silicone oil containing cavity (1) is fully filled with silicone oil.

4. A method for filling silicone oil in a differential pressure transmitter according to claim 3, characterized in that: The injection tube (2) is marked with scale lines. In step S5, when adjusting the telescopic mechanism (5), the scale changes of the liquid level in the injection tube (2) are observed to determine whether the silicone oil flows into or out of the silicone oil containing chamber (1).

5. The method for filling silicone oil in a differential pressure transmitter according to claim 1, wherein: The deformable diaphragm (4) and the separation diaphragm (6) are made of the same material.

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