Needle tube sampling method

Abstract

The invention provides a needle tube sampling method. The needle tube sampling method comprises the following steps: S1, communicating a first pipeline with a sampling needle and an oil discharge port; a second pipeline is communicated with the first pipeline and the waste oil tank, and a first switch valve is used for controlling on-off of the second pipeline; s2, an oil discharge outlet is opened, oil in to-be-detected equipment enters the sampling needle tube, after the oil entering the sampling needle tube reaches a preset volume, the oil discharge outlet stops discharging oil, a first switch valve is opened, a piston rod of the sampling needle tube is reversely pushed until the piston rod reaches a zero position, one-time cleaning is completed, and the cleaning steps are repeated until preset cleaning times are completed; s3, oil is discharged through an oil discharge port, oil in the to-be-detected equipment enters the cleaned sampling needle tube, after the oil entering the sampling needle tube reaches the preset volume, oil discharge is stopped through the oil discharge port, and sampling is completed. Compared with a conventional sampling mode, the sampling mode provided by the invention has the advantages that the insulating oil is not in contact with external air in the whole process, the final detection accuracy is ensured, and the waste is less.

Description

Technical Field

[0001] The invention relates to the technical field of power plant insulating oil extraction test, and in particular to a needle tube sampling method. Background Art

[0002] The statements herein merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] After the oil-immersed transformer is put into use for a period of time, it is necessary to sample and test the insulating oil inside it. The existing method of sampling the insulating oil is usually to use a sampling needle. The specific sampling process is: prepare an oil receiving basin, then open the oil drain port under the transformer, and the insulating oil inside the transformer is discharged through the oil drain port and received by the oil receiving basin, and then use the sampling needle to receive the insulating oil discharged from the oil drain port (not directly in the basin). In this process, it is necessary to first separate the piston rod inside the sampling needle from the tube body, and use the tube body of the needle tube to receive the insulating oil. After receiving the oil, the piston rod is inserted into the tube body, and the insulating oil is pushed out to complete a cleaning. After multiple cleanings are completed, the oil is filled again and the piston rod is inserted into the tube body again, and then the tube body is vertically and flicked to concentrate the bubbles in the tube body at the nipple of the needle tube, and the piston rod is slowly pushed until the bubbles are completely discharged from the nipple, and finally the rubber sleeve is covered on the nipple of the needle tube to complete the sampling.

[0004] In the above sampling method, the sampling time is long. When collecting the oil, the workers' hands will be stained with insulating oil, and it is easy to get it on their clothes and difficult to clean. At the same time, this sampling method will waste a lot of insulating oil (because during the sampling process, the oil drain port is fully open and the oil is collected by the oil receiving basin). In addition, since the insulating oil is in contact with the external air (gas is mixed in), it is easy to affect the accuracy of the final detection, and there is room for improvement. Summary of the invention

[0005] The main purpose of the present invention is to provide a needle sampling method which has a fast sampling speed, does not contact with the outside air, and has less waste when sampling insulating oil.

[0006] To achieve the above object, the technical solution of the present invention is implemented as follows: a needle sampling method, comprising a first pipeline, a second pipeline, a waste oil tank, a first switch valve and a sampling needle, the method comprising:

[0007] S1. Assemble the device, connect one end of the first pipeline to the nipple of the sampling needle tube, and the other end to the oil discharge port of the device to be tested; connect one end of the second pipeline to the first pipeline, and the other end to the waste oil tank, and set the first switch valve on the second pipeline to control the on-off of the second pipeline;

[0008] S2, cleaning step, open the oil drain port, the oil in the device to be detected enters the sampling needle tube through the first pipeline, the piston rod of the sampling needle tube moves outward, and when the oil entering the sampling needle tube reaches a predetermined volume, the oil drain port stops draining oil, opens the first switch valve and pushes the piston rod of the sampling needle tube in reverse until the piston rod reaches the zero position, and the oil in the sampling needle tube is discharged into the waste oil tank through the second pipeline, and then closes the first switch valve to complete one cleaning, and repeats the above cleaning steps until the predetermined number of cleaning times is completed;

[0009] S3, sampling step, the oil is discharged from the oil drain port, the oil in the device to be tested enters the cleaned sampling needle tube through the first pipeline, the piston rod of the sampling needle tube moves outward, and when the oil entering the sampling needle tube reaches a predetermined volume, the oil drain port stops discharging oil, and the sampling is completed.

[0010] Furthermore, the “oil in the device to be detected” is pressurized oil, and the oil can push the piston rod of the sampling needle tube to move outward by its own pressure.

[0011] Furthermore, a pump body is arranged on the first pipeline, and the pump body is located between the connecting node of the first pipeline and the second pipeline and the oil discharge port of the equipment to be detected. When the pump body is in a stopped state, the two ends of the corresponding pump body of the first pipeline are not conductive, and the oil discharge port stops discharging oil by stopping the action of the pump body.

[0012] Furthermore, a pressure detection device is provided on the first pipeline, and the pressure detection device is located between the pump body and the oil discharge port of the equipment to be detected, and is used to detect the oil pressure at the oil discharge port. When the pressure value of the pressure detection device is lower than a predetermined value, the pump body stops starting.

[0013] Furthermore, the pump body is a gas-liquid mixing pump, the waste oil tank is sealed as a whole, and an air port and a second switch valve for controlling the opening and closing of the air port are provided on the waste oil tank; a waste oil discharge port and a third switch valve for controlling the opening and closing of the waste oil discharge port are also provided on one side of the waste oil tank; a fourth switch valve is also provided on the first pipeline, and the fourth switch valve is located between the connecting node of the first pipeline and the second pipeline and the sampling needle tube;

[0014] The sampling method also includes an oil discharge step: closing the second switch valve and the fourth switch valve, opening the first switch valve and the third switch valve, starting the pump body to pump gas into the first pipeline, and the gas enters the waste oil tank through the second pipeline to accelerate the oil discharge of the waste oil tank.

[0015] Furthermore, the sampling needle tube is placed on a pulling device, and the piston rod of the sampling needle tube is pushed back by the pulling device until the piston rod reaches the zero position.

[0016] Furthermore, the pulling device comprises a fixed platform, a needle tube drag arranged on one side of the fixed platform, and a push-pull mechanism for driving the needle tube drag to reciprocate along the length direction of the sampling needle tube, the tube body of the sampling needle tube is fixed on the fixed platform, and the end of the piston rod of the sampling needle tube is located in the needle tube drag and moves with the needle tube drag;

[0017] In step S3, before the oil discharge port discharges oil, it is first confirmed whether the piston rod has returned to zero. If so, the oil discharge port starts to discharge oil. If not, the piston rod is returned to zero through the push-pull mechanism, and then step S3 is re-entered.

[0018] Furthermore, per unit time, when the push-pull mechanism drives the piston rod to move away from the tube body, the volume of space generated in the tube body is smaller than the volume of oil that can flow out of the oil drain port per unit time, so that the tube body always maintains a positive pressure state.

[0019] Furthermore, the needle tube drag includes a sliding block and a holder which is ball-hinged on the sliding block, the end of the piston rod is located on the holder, and the push-pull mechanism is connected to the sliding block to drive the sliding block to move.

[0020] Furthermore, a bottom plate is provided at the bottom of the fixing platform, and the fixing platform is rotatably mounted on the bottom plate.

[0021] The beneficial effects of the present invention are embodied in:

[0022] Compared with conventional sampling methods, the present invention uses a sampling method in which the insulating oil does not come into contact with the outside air throughout the entire process, thereby ensuring the ultimate detection accuracy. Furthermore, during the sampling operation, there is less waste, and the operation is clean and convenient, with a short sampling time and a high speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In the attached picture:

[0024] Figure 1 The flowchart of the needle sampling method of the present invention is as follows;

[0025] Figure 2 This is a working principle diagram of the needle sampling method of the present invention;

[0026] Figure 3 It is a schematic diagram of the structure of the pulling device in the present invention;

[0027] Figure 4 It is a structural schematic diagram of the fixing platform described in the present invention;

[0028] Figure 5 It is a front view of the pulling device described in the present invention.

[0029] Description of reference numerals:

[0030] 1. Sampling needle tube; 11. Tube body; 111. End plate; 12. Piston rod; 121. Push plate; 2. First pipeline; 21. Pump body; 22. Pressure detection device; 23. Fourth switch valve; 3. Second pipeline; 31. First switch valve; 4. Waste oil tank; 41. Second switch valve; 42. Liquid level gauge; 43. Third switch valve; 5. Fixing platform; 51. Groove; 52. First card slot; 53. Pressing and fixing component; 6. Needle tube drag; 61. Sliding block; 62. Card seat; 621. Second card slot; 63. Pressure cover; 64. Elastic member; 7. Push-pull mechanism; 8. Bottom plate. DETAILED DESCRIPTION

[0031] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. Obviously, the described embodiments are only part of the embodiments of the invention, rather than all of the embodiments. In the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other. Based on the embodiments in the invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the invention.

[0032] See also Figures 1 to 5 .

[0033] The present invention discloses a needle sampling method, comprising a first pipeline 2, a second pipeline 3, a waste oil tank 4, a first switch valve 31 and a sampling needle 1, the method comprising:

[0034] S1. Assemble the device, connect one end of the first pipeline 2 to the nipple of the sampling needle tube 1 (i.e., the part of the needle tube used to install the needle), and connect the other end to the oil discharge port of the device to be tested; connect one end of the second pipeline 3 to the first pipeline 2, and connect the other end to the waste oil tank 4, and set the first switch valve 31 on the second pipeline 3 to control the on-off of the second pipeline 3;

[0035] S2, cleaning step, open the oil drain port, the oil in the device to be detected enters the sampling needle tube 1 through the first pipeline 2, the piston rod 12 of the sampling needle tube 1 moves outward, and after the oil entering the sampling needle tube 1 reaches a predetermined volume or the piston rod 12 moves outward to a set position, the oil drain port stops draining oil, the first switch valve 31 is opened and the piston rod 12 of the sampling needle tube 1 is pushed back until the piston rod 12 reaches the zero position, the oil in the sampling needle tube 1 is discharged into the waste oil tank 4 through the second pipeline 3, and then the first switch valve 31 is closed to complete one cleaning, and the above cleaning steps are repeated until the predetermined number of cleaning times is completed;

[0036] S3, sampling step, the oil is discharged from the oil drain port, the oil in the device to be tested enters the cleaned sampling needle tube 1 through the first pipeline 2, the piston rod 12 of the sampling needle tube 1 moves outward, and when the oil entering the sampling needle tube 1 reaches a predetermined volume, the oil drain port stops discharging oil, and the sampling is completed.

[0037] In a specific implementation, the nipple of the sampling needle tube 1 is connected to the oil drain port of the device to be detected through the first pipeline 2, and then the oil drain port on the device to be detected is opened (that is, the oil drain port of the oil-immersed transformer, the conventional oil drain port structure is similar to a valve and can be opened and closed by rotating), and the cleaning state begins. The oil in the device to be detected enters the sampling needle tube 1 through the first pipeline 2. After the oil entering the sampling needle tube 1 reaches a predetermined volume, the oil drain port stops draining oil (which can be achieved by closing the oil drain port), and then the first switch valve 31 is opened (in the initial state, the first switch valve 31 is in the closed state) and the piston rod 12 of the sampling needle tube 1 is pushed back until the piston rod 12 reaches the zero position (the push back can be achieved manually), and the oil in the sampling needle tube 1 is discharged into the waste oil tank 4 through the second pipeline 3, and then the first switch valve 31 is closed to complete one cleaning, and the above cleaning steps are repeated until the predetermined number of cleanings are completed; after the cleaning is completed, sampling is started, the oil discharge port is opened to start oil intake again, and the oil in the device to be tested enters the sampling needle tube 1 through the first pipeline 2. After the oil entering the sampling needle tube 1 reaches a predetermined volume, the oil discharge port stops discharging oil, and sampling is completed.

[0038] Compared with conventional sampling methods, in the sampling method of the present application, the insulating oil will not come into contact with the outside air throughout the entire process, thereby ensuring the final detection accuracy. In addition, there is less waste during the sampling operation, and the operation is clean and convenient, with a short sampling time and a fast speed, which is a great improvement.

[0039] In one embodiment, the "oil in the device to be tested" is a pressurized oil, which can push the piston rod 12 of the sampling needle tube 1 outward by its own pressure. With this design, when sampling, the interior of the sampling needle tube 1 is in a positive pressure state, so that even if the sealing performance of the piston rod 12 is not very good, there is no need to worry about external air entering the sampling needle tube 1 from the side of the piston rod 12.

[0040] In one embodiment, a pump body 21 is provided on the first pipeline 2, and the pump body 21 is located between the connecting node between the first pipeline 2 and the second pipeline 3 and the oil discharge port of the equipment to be detected. When the pump body 21 is in a stopped state, the two ends of the first pipeline 2 corresponding to the pump body 21 are not conductive, and the pump body 21 stops moving, so that the oil discharge port stops discharging oil.

[0041] In specific implementation, the provision of the pump body 21 has two advantages. First, since the pressure of the insulating oil inside different transformers is different, the provision of a pump body 21 helps the staff to control the speed at which the oil enters the sampling needle tube 1, so that the speed of the oil is not too fast or too slow, and ensures that the oil in the first pipeline 2 has sufficient pressure to push the piston rod 12 of the sampling needle tube 1 to move, and is convenient for automatic control; another advantage is that when the oil outlet needs to stop draining oil, the pump body 21 can be directly controlled to stop the action, without the need for the staff to frequently operate the opening and closing of the oil outlet of the equipment to be tested.

[0042] In one embodiment, a pressure detection device 22 is provided on the first pipeline 2, and the pressure detection device 22 is located between the pump body 21 and the oil discharge port of the equipment to be detected, and is used to detect the oil pressure at the oil discharge port. When the pressure value of the pressure detection device 22 is lower than a predetermined value, the pump body 21 stops starting.

[0043] In a specific implementation, although the pressure of the insulating oil inside transformers of different specifications is different, the pressure of the insulating oil inside transformers of the same specification is approximately equal. Therefore, a predetermined value can be preset for transformers of different specifications, or a predetermined value can be uniformly preset for multiple transformers. When the pressure value of the pressure detection device 22 is lower than the predetermined value, it indicates that the oil drain port is not open at this time, or the oil drain port is blocked, or the opening amplitude of the oil drain port is too small.

[0044] In practice, a control processor may be provided, and the control processor may be connected to the pressure detection device 22 and the pump body 21, and when the pressure value of the pressure detection device 22 is lower than a predetermined value, the pump body 21 may be controlled to stop starting. An alarm device, such as an audible and visual alarm, may also be provided, and when the pressure value of the pressure detection device 22 is lower than a predetermined value, the pump body 21 may stop starting and an alarm may be sounded at the same time.

[0045] Preferably, the pressure detection device 22 may be a pressure gauge or a pressure sensor.

[0046] In one embodiment, the pump body 21 is a gas-liquid mixing pump, the waste oil tank 4 is sealed as a whole, an air port and a second switch valve 41 for controlling the opening and closing of the air port are provided on the waste oil tank 4, and a liquid level meter 42 (a laser liquid level meter 42 is shown in the figure) is also provided on the waste oil tank 4 for measuring the oil height in the tank body; a waste oil discharge port and a third switch valve 43 for controlling the opening and closing of the waste oil discharge port are also provided on one side of the waste oil tank 4; a fourth switch valve 23 is also provided on the first pipeline 2, and the fourth switch valve 23 is located between the connecting node of the first pipeline 2 and the second pipeline 3 and the sampling needle tube 1;

[0047] The sampling method also includes an oil discharge step: closing the second switch valve 41 and the fourth switch valve 23, opening the first switch valve 31 and the third switch valve 43, starting the pump body 21 to pump gas into the first pipeline 2, and the gas enters the waste oil tank 4 through the second pipeline 3 to accelerate the oil discharge of the waste oil tank 4.

[0048] In a specific implementation, when draining oil, the first pipeline 2 can be separated from the oil discharge port and connected to the outside, or a branch pipe connected to the outside can be connected in parallel to the first pipeline 2, and the parallel branch pipe can be connected to the first pipeline 2 through a reversing valve, so that the pump body 21 can pump gas into the first pipeline 2; this oil discharge method can accelerate the speed of oil discharge and quickly empty the waste oil tank 4.

[0049] In one embodiment, the sampling needle tube 1 is placed on a pulling device, and the pulling device is used to push back the piston rod 12 of the sampling needle tube 1 until the piston rod 12 reaches the zero position.

[0050] The pulling device comprises a fixed platform 5, a needle tube drag 6 arranged on one side of the fixed platform 5, and a push-pull mechanism 7 for driving the needle tube drag 6 to reciprocate along the length direction of the sampling needle tube 1. The tube body 11 of the sampling needle tube 1 is fixed on the fixed platform 5, and the end of the piston rod 12 of the sampling needle tube 1 is located in the needle tube drag 6 and moves with the needle tube drag 6. In step S3, before the oil discharge port discharges oil, first confirm whether the piston rod 12 is reset to zero. If so, the oil discharge port starts to discharge oil. If not, the piston rod 12 is reset to zero through the push-pull mechanism 7, and then re-enters step S3.

[0051] In the specific implementation, the push-pull mechanism 7 is started, driving the needle tube pull 6 to move away from the sampling needle tube 1. Of course, since the oil discharged from the oil discharge port has a certain oil pressure, the piston rod 12 can also be pushed by the oil pressure to push the needle tube pull 6 and the push-pull mechanism 7 to move in turn (the push-pull mechanism 7 in this state can be a gear rack mode driven by a motor, or of course it can be a pneumatic telescopic mode, but in the pneumatic telescopic mode, when the piston rod 12 pushes back, the chambers on both sides of the telescopic cylinder are connected to the outside world). After the insulating oil in the tube body 11 reaches the specified volume, the oil stops entering, the first switch valve 31 is opened, and then the push-pull mechanism 7 pushes the needle tube pull 6 to move in the direction close to the sampling needle tube 1, and the piston rod 12 discharges the insulating oil through the second pipeline into the waste oil tank 4 until the piston rod 12 reaches the zero position, and then the first switch valve 31 is closed, so that the cleaning of the sampling needle tube 1 is completed. Of course, the push-pull mechanism 7 has a certain stroke limit to prevent the piston rod 12 from moving out of the tube body 11 of the sampling needle tube 1.

[0052] When confirming the position of the piston rod 12, on the one hand, the position of the piston rod 12 can be directly sensed by a proximity sensor, and on the other hand, the position of the piston rod 12 can be indirectly determined by directly using the push-pull mechanism 7 and detecting the position state of the push-pull mechanism 7.

[0053] In one embodiment, when the push-pull mechanism 7 drives the piston rod 12 to move away from the tube body 11 per unit time, the volume of space left in the tube body 11 is smaller than the volume of oil that can flow out from the oil discharge port per unit time, so that the tube body 11 always maintains a positive pressure state, thereby preventing air from entering the sampling needle tube 1 from the side of the piston rod 12.

[0054] In one embodiment, a groove 51 for supporting the tube body 11 is provided at a position of the fixing platform 5 corresponding to the tube body 11, and the groove 51 is used to limit the posture of the tube body 11 relative to the fixing platform 5. One end of the tube body 11 has an end plate 111, and a first clamping groove 52 is provided at a position of the fixing platform 5 corresponding to the end plate 111. The end plate 111 is clamped in the first clamping groove 52, and is used to limit the movement of the tube body 11 along its own length direction, and the position of the tube body 11 relative to the fixing platform 5;

[0055] One end of the piston rod 12 has a push plate 121, and the needle tube pull 6 is provided with a second slot 621. The push plate 121 is stuck in the second slot 621 and moves with the needle tube pull 6. This design is convenient for limiting and taking and placing the sampling needle tube 1, and for the push-pull mechanism 7 to control the stroke of the piston rod 12.

[0056] In one embodiment, the needle tube drag 6 includes a sliding block 61 and a holder 62 which is ball-hinged on the sliding block 61, the second slot 621 is arranged on the holder 62, and the push-pull mechanism 7 is connected to the sliding block 61 to drive the sliding block 61 to move. This design can ensure that the needle tube keeps the tube body 11 and the piston rod 12 on the same axis during the push-pull process, avoiding the problem of the tube body 11 and the piston rod 12 being stuck or stuck.

[0057] Preferably, a pressing cover 63 is provided on the top of the card seat 62, and the pressing cover 63 is used to press the push plate 121 into the card seat 62 from top to bottom.

[0058] In a specific implementation, a first stud is provided on the top of the holder 62, and a through hole matching the first stud is provided on the gland 63. The gland 63 passes through the first stud and is pressed on the push plate 121. Then, the gland 63 is squeezed by the nut to prevent the gland 63 from moving upward. More preferably, a spring can be provided between the nut and the gland 63, and the squeezing force is transmitted to the gland 63 through the nut spring, so that the pressure of the gland 63 can be maintained. When the push plate 121 is taken out, the gland 63 can be manually moved up to facilitate the removal of the push plate 121.

[0059] Preferably, the pressure cover 63 is provided with a third slot that cooperates with the push plate 121 , so that the push plate 121 can be better limited to prevent the push plate 121 from being separated from the card seat 62 .

[0060] In one embodiment, the ball joint between the socket 62 and the sliding block 61 is located in the middle of the socket 62, and a plurality of elastic members 64 are evenly distributed around the ball joint. The elastic members 64 are located between the socket 62 and the sliding block 61, and are respectively in contact with the socket 62 and the sliding block 61, so as to adjust the posture of the socket 62.

[0061] In a specific implementation, if the elastic member 64 is not provided, the relative position of the holder 62 and the sliding block 61 in the initial state is not easy to determine, and it is inconvenient to install the push plate 121 without the support of the elastic member 64. In addition, the elastic member 64 can use a spring with a relatively high hardness, so that the accuracy will be better.

[0062] In one embodiment, a bottom plate 8 is provided at the bottom of the fixing platform 5, and the fixing platform 5 is rotatably mounted on the bottom plate 8. Specifically, the fixing platform 5 is penetrated through the bottom plate 8 by a pin shaft, so that the fixing platform 5 can rotate relative to the top surface of the bottom plate 8, which is adapted to the ball-hinged clamping seat 62, and can better ensure that the tube body 11 and the piston rod 12 are on the same axis, avoiding the problem of the tube body 11 and the piston rod 12 being stuck or stuck.

[0063] Preferably, the rotation center of the fixing platform 5 is close to one side of the needle tube pull 6, so that it is easier to adjust the posture of the fixing platform 5 when the piston rod 12 moves into the tube body 11.

[0064] In one embodiment, the push-pull mechanism 7 is a screw-nut mechanism, which drives the screw to rotate through a servo motor, so that the nut moves back and forth on the screw, and the needle tube drag 6 is connected to the nut and moves with the nut.

[0065] In a specific implementation, although the push-pull mechanism 7 can also be implemented by a pneumatic telescopic cylinder, a hydraulic telescopic cylinder or an electric telescopic rod, the combination of the lead screw nut mechanism and the servo motor can more accurately control the moving speed and moving distance of the needle tube drag 6, and is also convenient for speed adjustment, and is suitable for sampling needle tubes 1 of different specifications and oil discharge ports of different openings. Since the specific structure of the lead screw nut mechanism is common knowledge to those skilled in the art, it will not be described in detail here.

[0066] Preferably, the push-pull mechanism 7 is arranged below the base plate 8, the needle tube drag 6 is located on the top surface of the base plate 8, a slide groove is opened at the position of the base plate 83 corresponding to the needle tube drag 6, and the bottom of the needle tube drag 6 extends to the bottom of the base plate 8 and is connected to the moving end of the push-pull mechanism 7.

[0067] Preferably, a pressing and fixing component 53 is provided on the fixing platform 5 , and the pressing and fixing component 53 is used to press and fix the tube body 11 on the fixing platform 5 .

[0068] In a specific implementation, the pressing and fixing component 53 includes bosses arranged on both sides of the corresponding groove 51 of the fixing platform 5, and also includes a pressure plate arranged between the two bosses, wherein a vertical rod body is arranged on one of the bosses, one end of the pressure plate is passed through the rod body, and an external thread can be arranged on the rod body, and one end of the pressure plate is pressed by screwing a nut; a C-shaped pressing groove is opened on the other boss, and one end of the pressure plate extends into the pressing groove, and a screw rod is spirally passed through the pressing groove, one end of the screw rod passes through the boss, and the other end extends into the pressing groove. Rotating the screw rod can press one end of the screw rod on the pressure plate, so that the pressure plate presses and fixes the tube body 11 on the fixing platform 5.

[0069] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

[0070] It should be noted that if the embodiments of the invention involve directional indications (such as up and down), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0071] In addition, the meaning of "and / or" appearing in the full text includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, "multiple" means more than two. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the invention.

Claims

1. A needle sampling method, characterized in that: The method comprises a first pipeline (2), a second pipeline (3), a waste oil tank (4), a first switch valve (31) and a sampling needle tube (1), and the method comprises: S1. Assembling the device, one end of the first pipeline (2) is connected to the nipple of the sampling needle tube (1), and the other end is connected to the oil discharge port of the device to be tested; one end of the second pipeline (3) is connected to the first pipeline (2), and the other end is connected to the waste oil tank (4), and a first switch valve (31) is arranged on the second pipeline (3) to control the on and off of the second pipeline (3); S2, a cleaning step, opening the oil discharge port, allowing the oil in the device to be detected to enter the sampling needle tube (1) through the first pipeline (2), and the piston rod (12) of the sampling needle tube (1) moves outward. When the oil entering the sampling needle tube (1) reaches a predetermined volume, the oil discharge port stops discharging oil, opening the first switch valve (31) and pushing the piston rod (12) of the sampling needle tube (1) in reverse until the piston rod (12) reaches the zero position, and the oil in the sampling needle tube (1) is discharged into the waste oil tank (4) through the second pipeline (3), and then closing the first switch valve (31), completing one cleaning, and repeating the above cleaning steps until the predetermined number of cleaning times is completed; S3, sampling step, the oil is discharged from the oil discharge port, the oil in the device to be detected enters the cleaned sampling needle tube (1) through the first pipeline (2), the piston rod (12) of the sampling needle tube (1) moves outward, and when the oil entering the sampling needle tube (1) reaches a predetermined volume, the oil discharge port stops discharging oil, and sampling is completed.

2. The needle sampling method according to claim 1, characterized in that: The "oil in the device to be detected" is pressurized oil, which can push the piston rod (12) of the sampling needle tube (1) to move outwards through its own pressure.

3. The needle sampling method according to claim 1 or 2, characterized in that: A pump body (21) is arranged on the first pipeline (2), and the pump body (21) is located between the connection node of the first pipeline (2) and the second pipeline (3) and the oil discharge port of the device to be detected. When the pump body (21) is in a stopped state, the two ends of the first pipeline (2) corresponding to the pump body (21) are not connected, and the pump body (21) stops operating, so that the oil discharge port stops discharging oil.

4. The needle sampling method according to claim 3, characterized in that: A pressure detection device (22) is provided on the first pipeline (2), and the pressure detection device (22) is located between the pump body (21) and the oil discharge port of the equipment to be detected, and is used to detect the oil pressure at the oil discharge port. When the pressure value of the pressure detection device (22) is lower than a predetermined value, the pump body (21) stops starting.

5. The needle sampling method according to claim 3, characterized in that: The pump body (21) is a gas-liquid mixing pump; the waste oil tank (4) is in a sealed shape as a whole; a gas port and a second switch valve (41) for controlling the opening and closing of the gas port are provided on the waste oil tank (4); a waste oil discharge port and a third switch valve (43) for controlling the opening and closing of the waste oil discharge port are also provided on one side of the waste oil tank (4); a fourth switch valve (23) is also provided on the first pipeline (2); the fourth switch valve (23) is located between the connection node between the first pipeline (2) and the second pipeline (3) and the sampling needle tube (1); The sampling method further comprises an oil discharge step: closing the second switch valve (41) and the fourth switch valve (23), opening the first switch valve (31) and the third switch valve (43), starting the pump body (21) to pump gas into the first pipeline (2), and the gas enters the waste oil tank (4) through the second pipeline (3), thereby accelerating the oil discharge from the waste oil tank (4).

6. The needle sampling method according to claim 1 or 2, characterized in that: The sampling needle tube (1) is placed on a pulling device, and the piston rod (12) of the sampling needle tube (1) is pushed back by the pulling device until the piston rod (12) reaches the zero position.

7. The needle sampling method according to claim 6, characterized in that: The pulling device comprises a fixed platform (5), a needle tube drag (6) arranged on one side of the fixed platform (5), and a push-pull mechanism (7) for driving the needle tube drag (6) to reciprocate along the length direction of the sampling needle tube (1); the tube body (11) of the sampling needle tube (1) is fixed on the fixed platform (5), and the end of the piston rod (12) of the sampling needle tube (1) is located in the needle tube drag (6) and moves with the needle tube drag (6); In step S3, before the oil is discharged from the oil discharge port, it is first confirmed whether the piston rod (12) has returned to zero. If so, the oil discharge port starts to discharge oil. If not, the piston rod (12) is returned to zero through the push-pull mechanism (7), and then step S3 is re-entered.

8. The needle sampling method according to claim 7, characterized in that: When the push-pull mechanism (7) drives the piston rod (12) to move away from the tube body (11) per unit time, the volume of the space generated in the tube body (11) is smaller than the volume of oil that can flow out of the oil discharge port per unit time, so that the tube body (11) always maintains a positive pressure state.

9. The needle sampling method according to claim 7, characterized in that: The needle tube drag (6) comprises a sliding block (61) and a holder (62) which is ball-hinged on the sliding block (61); the end of the piston rod (12) is located on the holder (62); the push-pull mechanism (7) is connected to the sliding block (61) to drive the sliding block (61) to move.

10. The needle sampling method according to claim 7, characterized in that: A bottom plate (8) is provided at the bottom of the fixing platform (5), and the fixing platform (5) is rotatably mounted on the bottom plate (8).

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