A load simulation test device for a circuit breaker operating mechanism

Abstract

The application discloses a load simulation test device of a circuit breaker operating mechanism, which comprises a sealed cylinder body, a damping piston arranged in the sealed cylinder body, a pull rod penetrating through the sealed cylinder body in the axial direction, the pull rod comprising two sections in threaded nested connection, the free end of one section penetrating through the damping piston and connected with the operating mechanism, the other section connected with a mechanical performance detection mechanism, the damping piston comprising a variable mass mechanism sleeved on the pull rod, the variable mass mechanism adopting a coaxial parallel connection structure and used for simulating the moving mass borne by the operating mechanism during the opening and closing of circuit breakers of different specifications, one through-flow adjusting mechanism arranged on each side of the variable mass mechanism, the through-flow adjusting mechanism used for changing the gas damping of the damping piston to simulate the pressure gas reaction force from an arc extinguishing chamber during the opening and closing of circuit breakers of different specifications, and the mechanical performance detection mechanism used for detecting the stroke information of circuit breakers of different specifications in real time and detecting the just opening point and the just closing point information.

Description

Technical Field

[0001] This invention belongs to the technical field of high-voltage electrical equipment, specifically relating to a load simulation test device for a circuit breaker operating mechanism. Background Technology

[0002] The operating mechanism is a crucial core component of high-voltage circuit breakers, and its stability and reliability have a significant impact on the performance of high-voltage electrical products. Because the operating mechanism is typically manufactured and assembled as a separate module, its mechanical characteristics and reliability cannot be tested and verified independently before leaving the factory. This often results in poor compatibility between the operating mechanism and the circuit breaker body, requiring repeated adjustments to relevant parameter settings to meet requirements. This not only leads to low production efficiency but also makes it impossible to anticipate potential problems in the mechanism. Using a real circuit breaker body with the operating mechanism for factory testing is not only costly but also results in the circuit breaker body quickly reaching the end of its service life and becoming unusable due to the increasing number of factory tests conducted on the operating mechanism, leading to significant waste.

[0003] Considering that the mechanical characteristics of the operating mechanism and the circuit breaker body during no-load testing are mainly affected by the compressed air reaction force and moving mass of the arc-extinguishing chamber, there are currently two main types of simulated loads commonly used for operating mechanisms. One type simply sets up a counterweight without considering the gas damping during the test of the mechanism and the circuit breaker body. The other type uses a sealed shell and designs a simple piston structure to generate a certain amount of gas buffer when the operating mechanism is in motion. The above mainly considers the test conditions of the compressed air arc-extinguishing chamber. It cannot be universally applied to intelligent arc-extinguishing chambers. Therefore, how to set up an equivalent and efficient simulated load device to a certain extent restricts the improvement of the operating mechanism's performance. At the same time, adapting an equivalent simulated load test device can greatly reduce the debugging process of adapting the operating mechanism to the circuit breaker body, greatly improve production efficiency, and save production costs.

[0004] Existing simulated load testing devices mainly suffer from the following technical problems:

[0005] 1) Although the existing simulated load test device is equipped with a special piston structure and damping air hole, the air hole is always open. However, the compressed air resistance of the actual circuit breaker body during the opening and closing process is determined by the valve plate and the air pressure in the cylinder. Therefore, there is still a certain error in equivalence. Moreover, the area of ​​the fixed damping air hole cannot be adjusted, resulting in poor adaptability.

[0006] 2) Existing simulated load test devices are mainly designed to be compatible with compressed air arc-extinguishing chambers. They do not take into account the airflow and compressed air resistance during the movement of intelligent arc-extinguishing chambers. Furthermore, the operating mechanism needs to be adapted to different circuit breaker bodies during use. Therefore, existing simulated load test devices have certain limitations in use.

[0007] 3) Existing simulated load test devices rarely have a structure that simulates the opening and closing of the main contacts of the arc-extinguishing chamber of a circuit breaker. Therefore, during the test, the state of the operating mechanism can only be judged by the auxiliary switch of the operating mechanism itself or by an externally designed auxiliary switch. The accuracy of the simulated opening and closing points is poor and needs further improvement. Summary of the Invention

[0008] This invention provides a load simulation test device for circuit breaker operating mechanisms. It is a load test device with adjustable load mass and gas resistance, simulating both compressed air and intelligent compressed air resistance conditions. At the same time, an adjustable simulated rigid opening and closing point structure and a stroke sensor device are set at the end of the simulated load device. It can accurately feed back the motion characteristics of the operating mechanism with the simulated load, and can accurately and efficiently debug the mechanical characteristics of the operating mechanism by adjusting the position of the simulated rigid opening and closing point and simulating test conditions with different overtravel.

[0009] This invention can be achieved through the following technical solutions:

[0010] A load simulation test device for a circuit breaker operating mechanism includes a sealed cylinder, a damping piston disposed inside the sealed cylinder, and a pull rod disposed along the axial direction of the sealed cylinder. One end of the pull rod passes through both ends of the sealed cylinder and is connected to the damping piston and a mechanical performance testing mechanism, and is fixedly connected to the damping piston. The other end of the pull rod is coaxially connected to the output shaft of the operating mechanism.

[0011] The damping piston includes a variable mass mechanism mounted on a tie rod. The variable mass mechanism adopts a coaxial parallel connection structure to simulate the motion mass experienced by the operating mechanism of different specifications of circuit breakers during the opening and closing process. A flow adjustment mechanism is set on each side of the piston to change the magnitude of gas damping flowing through the damping piston, so as to simulate the compressed air reaction force from the arc-extinguishing chamber when different specifications of circuit breakers are opened and closed.

[0012] The mechanical performance testing mechanism is used to detect the travel information of circuit breakers of different specifications in real time, simulate the on / off state of the moving and stationary contacts of circuit breakers of different specifications, and detect the corresponding rigid opening / rigid closing point information to achieve complete mechanical performance testing.

[0013] Furthermore, the variable mass mechanism includes multiple counterweights connected coaxially in parallel. These counterweights are detachably connected together by bolts. The outer diameter of each counterweight matches the inner diameter of the sealing cylinder. Each counterweight has a through hole at its center that matches the tie rod. Each counterweight has a notch in its circumference to accommodate a guide sealing ring. The guide sealing ring is slidably connected to the inner wall of the sealing cylinder.

[0014] Furthermore, each of the flow regulating mechanisms includes a valve plate fitted on the pull rod, which is set close to the counterweight on the corresponding side. The shape of each valve plate matches the shape of the counterweight, and a through hole that matches the pull rod is provided in its center. Multiple air passages and multiple mounting holes are evenly spaced on its circumference. Bolts pass through the spring, the mounting hole and the threaded hole on the corresponding side counterweight in sequence. The spring is in a compressed state, thereby pressing the valve plate onto the counterweight.

[0015] The two flow regulation mechanisms are respectively referred to as the closing flow regulation mechanism and the opening flow regulation mechanism. The two valve plates and their air flow holes and the springs connected to them are respectively referred to as the opening valve plate, the opening air flow hole, the opening spring, the closing valve plate, the closing air flow hole, and the closing spring. The opening air flow hole and the closing air flow hole are staggered.

[0016] Ventilation holes are provided at the positions corresponding to the opening and closing air passages of each counterweight block. These holes are connected in parallel with the opening and closing air passages to form the opening damping channel and the closing damping channel.

[0017] By adjusting the length of the bolt screwed into the threaded hole on the counterweight, the elastic pressure applied by the valve plate to the counterweight is adjusted to simulate the compressed air reaction force inside the arc-extinguishing chamber of the circuit breaker body of different specifications.

[0018] When the circuit is closed, the pressure in the left chamber of the damping piston is greater than the pressure in the right chamber. The closing flow adjustment mechanism is activated, and the gas pressure inside the closing damping channel pushes the closing valve plate to move away from the counterweight, opening the closing damping channel and compressing the closing spring.

[0019] When the circuit breaker is tripped, the pressure in the right chamber of the damping piston is greater than the pressure in the left chamber. The tripping flow adjustment mechanism is activated, and the gas pressure inside the tripping damping channel pushes the tripping valve plate away from the counterweight, opening the tripping damping channel and compressing the tripping spring.

[0020] Furthermore, both the opening and closing air passages adopt an elongated hole structure, the opening spring adopts a stacked structure of multiple butterfly springs, and multiple normally open vent holes are opened at corresponding positions of the opening valve plate, closing valve plate and each counterweight block to form multiple normally open airflow channels.

[0021] Furthermore, the inner diameter of the mounting hole is smaller than the outer diameter of the opening spring and the closing spring.

[0022] Furthermore, the mechanical performance testing mechanism includes a connecting plate, the center of which is clamped to the end of the pull rod. One end of the connecting plate is connected to a stroke detection module, and the other end is connected to a main contact simulation mechanism. The stroke detection module is used to detect the stroke information of the operating mechanism in real time. The main contact simulation mechanism includes an auxiliary switch. The drive shaft of the auxiliary switch is rotatably connected to the other end of the connecting plate through a variable-length linkage structure. Both its contacts and the stroke detection module are connected to the circuit breaker switch tester.

[0023] By adjusting the length of the linkage structure, the rotation angle of the drive shaft of the auxiliary switch is changed, causing different contacts in the auxiliary switch to be connected, thereby realizing the detection of the rigid open / rigid close point of circuit breakers of different specifications.

[0024] Furthermore, the linkage structure includes an adjustable screw, the length of which is set according to the break point / close point of the circuit breaker. One end of the screw is rotatably connected to the end of the mounting plate, and the other end is rotatably connected to one end of the crank arm. The other end of the crank arm is mounted on the drive shaft of the auxiliary switch.

[0025] Furthermore, the connecting plate has a through hole at its center that mates with the pull rod, one end of which has a vertical connecting surface for connecting the detection end of the stroke detection module, and the other end has a horizontal connecting surface that is rotatably connected to the U-shaped part at the end of the adjustable screw via a rotating shaft.

[0026] Furthermore, the pull rod includes a first pull rod and a second pull rod that are coaxially nested and connected together by a threaded connection. The free end of the first pull rod passes through one end of the sealed cylinder and is connected to the mechanical performance testing mechanism. The second pull rod is provided with a damping piston, and its free end passes through the other end of the sealed cylinder and is connected to the operating mechanism.

[0027] By adjusting the length of the nested overlapping portion of the first and second tie rods, the initial position of the damping piston inside the sealed cylinder is changed to adapt to the stroke requirements of circuit breakers of different specifications.

[0028] The beneficial technical effects of this invention are as follows:

[0029] 1. The load simulation test device of the present invention has strong reliability and adaptability, and high accuracy. During the factory test of the operating mechanism, it can accurately simulate the mechanical characteristics of the operating mechanism with the actual circuit breaker body. It can achieve fine adjustment or no adjustment of mechanical characteristics when the operating mechanism is equipped with the actual circuit breaker body, which greatly improves production efficiency. At the same time, when using the operating mechanism with the simulated load of the present invention for life test, it is not necessary to test with the actual circuit breaker body, which greatly reduces the test cost. Compared with the circuit breaker body, it has a longer service life.

[0030] 2. The load simulation of the operating mechanism, composed of a variable mass mechanism and a flow regulation mechanism, uses a detachable counterweight structure to simulate the motion mass borne by the operating mechanism during actual operation, adapting to the motion mass requirements of different circuit breaker specifications. The vent holes of the counterweight and the air flow holes on the valve plate are cleverly combined to form the opening damping channel and the closing damping channel. The spring / disc spring applied to the valve plate by the bolt adjustment simulates the compressed air reaction force borne by the operating mechanism driving the arc-extinguishing chamber within the circuit breaker body of different specifications. The combination of these two methods can fully and equivalently simulate the operating environment of the operating mechanism inside the circuit breaker body, achieving high realism. Furthermore, the load simulation device of this invention can adapt to different circuit breaker specifications, exhibiting strong versatility, high adaptability, and good practicality. Simultaneously, the overall structure is simple, facilitating widespread application.

[0031] 3. The mechanical performance testing mechanism, consisting of a stroke detection module and a main contact simulation mechanism, can not only simulate the closing and opening positions of circuit breakers with different strokes using a variable-length linkage structure, but also detect the rigid opening / rigid closing point through an auxiliary switch. Combined with the stroke information detected in real time by the stroke detection module, more detailed and accurate breaking performance parameters such as the average opening and closing speed can be calculated, and a more comprehensive breaking performance curve can be obtained. Thus, it can not only accurately reflect the motion characteristics of the operating mechanism with the simulated load, i.e., the load simulation test device of this invention, but also accurately and efficiently debug the mechanical characteristics of the operating mechanism by adjusting the position of the simulated rigid opening and rigid closing point and simulating test conditions with different overtravels. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0033] Figure 2 This is a schematic diagram of the counterweight block of the present invention;

[0034] Figure 3 This is a schematic diagram of the variable mass mechanism of the present invention;

[0035] Figure 4 , Figure 5 These are schematic diagrams of the opening and closing valve plates of the present invention.

[0036] Figure 6 This is a schematic diagram of the airflow damping channels corresponding to the opening and closing valve plates during the opening and closing of the present invention.

[0037] Figure 7 This is a schematic diagram of the main contact simulation mechanism of the present invention;

[0038] Figure 8 This is a schematic diagram of the connector of the present invention;

[0039] Figure 9This is a schematic diagram showing the state changes of the variable-length linkage mechanism during the opening and closing of the circuit breaker according to the present invention.

[0040] Among them, 1-cylinder, 2-flange, 3-sealing seat, 4-second tie rod, 5-first tie rod, 6-counterweight, 601-vent hole, 602-normally open vent hole, 7-guide sealing ring, 8-opening valve plate, 801-opening air passage, 9-closing valve plate, 901-closing air passage, 10-opening spring, 11-closing spring, 12-opening adjusting bolt, 13-closing adjusting bolt, 14-connecting piece, 15-stroke detection module, 16-main contact detection mechanism, 1601-auxiliary switch, 1602-adjustable screw, 1603-crank arm. Detailed Implementation

[0041] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings and preferred embodiments.

[0042] Through a thorough analysis of the pressure resistance of the operating mechanism and circuit breaker during no-load operation, this invention designs a load testing device with adjustable load mass and gas resistance, simulating both compressed air and intelligent compressed air resistance conditions. Simultaneously, an adjustable simulated break-off / break-on point structure and a stroke detection module are installed at the end of the simulated load device. Figure 1As shown, this invention proposes a load simulation test device for a circuit breaker operating mechanism, including a sealed cylinder with a damping piston inside. A pull rod is arranged along the axial direction of the sealed cylinder, with one end of the pull rod passing through both ends of the sealed cylinder and the damping piston, and connected to a mechanical performance testing mechanism. The pull rod is fixedly connected to the damping piston, and the other end is coaxially connected to the output shaft of the operating mechanism. The damping piston includes a variable mass mechanism mounted on the pull rod. This variable mass mechanism adopts a coaxial parallel connection structure and is used to simulate the motion mass experienced by the operating mechanism of different specifications of circuit breakers during opening and closing. A flow adjustment mechanism is arranged on each side of the variable mass mechanism to change the gas damping magnitude flowing through the damping piston, so as to simulate the compressed air reaction force from the arc-extinguishing chamber when different specifications of circuit breakers open and close. The mechanical performance testing mechanism is used to detect the stroke information of different specifications of circuit breakers in real time, simulate the start of connection / opening of the moving and stationary contacts of different specifications of circuit breakers, and detect the corresponding rigid opening / rigid closing point information to achieve complete mechanical performance testing. In this way, since the characteristic parameters of circuit breakers of different specifications are different, different moving masses can be simulated by using a variable mass mechanism. Furthermore, by using a flow adjustment mechanism to change the magnitude of the gas damping flowing through the damping piston, the compressed air reaction force from the arc-extinguishing chamber during the opening and closing of circuit breakers of different specifications can be simulated. The combination of the two can fully and accurately simulate the operating environment of the operating mechanism inside the circuit breaker body with high realism. At the same time, the mechanical performance testing mechanism simulates the opening / closing positions of the moving and stationary contacts of different specifications of circuit breakers, detects the corresponding rigid opening / rigid closing points, and combines the real-time detected stroke information to obtain accurate breaking characteristic curves. This allows for comprehensive and accurate feedback on the motion characteristics of the operating mechanism with simulated loads. By adjusting the position of the simulated rigid opening / rigid closing points and simulating test conditions with different overtravel, the mechanical characteristics of the operating mechanism can be accurately and efficiently debugged. In addition, the entire device has strong versatility and high adaptability, and can well equivalently meet the testing and adaptation requirements of hydraulic operating mechanisms with different circuit breaker bodies and mechanical strokes.

[0043] Specifically as follows:

[0044] To adapt to the actual working environment of the circuit breaker, we fill the sealed cylinder with a corresponding arc-extinguishing gas to simulate the gas pressure environment of the circuit breaker body, according to the actual needs of the circuit breaker. The sealed cylinder includes a cylindrical cylinder 1, whose two ends are connected by flanges 2 and sealing seats 3 to form a gas environment similar to that of the circuit breaker body. A through hole is opened in the center of the sealing seat 3 to allow the pull rod to pass through. With the help of a sealing ring, the sealed cylinder is formed. The operating mechanism moves the pull rod and the damping piston inside the sealed cylinder to simulate the motion mass experienced by the operating mechanism. The pull rod is adjustable in length to adapt to the stroke requirements of different specifications of circuit breakers. That is, the pull rod includes a first pull rod that is coaxially nested. The first pull rod 5 and the second pull rod 4 are connected by a threaded connection. The free end of the first pull rod 5 passes through one end of the sealing cylinder and is connected to the mechanical performance testing mechanism. The second pull rod 4 is equipped with a damping piston, the free end of which passes through the other end of the sealing cylinder and is connected to the operating mechanism. The connection between the first pull rod 5 and the second pull rod 4 is threaded. By adjusting the length of the nested overlapping part, such as controlling the length of the second pull rod 4 screwed into / out of the first pull rod 5, the initial position of the damping piston inside the sealing cylinder will change, and the corresponding moving length inside the sealing cylinder can also be changed, thereby adapting to the travel requirements of circuit breakers of different specifications.

[0045] like Figure 2-5 As shown, the variable mass mechanism includes multiple counterweights 6 connected coaxially in parallel. They can be detachably connected together by bolts and threaded holes to adjust the moving mass according to the specifications of the circuit breaker. The outer diameter of each counterweight 6 matches the inner diameter of the sealing cylinder. Each counterweight 6 has a through hole at its center that matches the tie rod. Each counterweight 6 has a notch around its circumference to accommodate a guide sealing ring 7. The guide sealing ring 7 is slidably connected to the inner wall of the sealing cylinder. The guide sealing ring 7 can be made of wear-resistant material so that it can seal while also supporting the sliding of the counterweight.

[0046] To facilitate the assembly of the counterweights, we can set a step for limiting the position on the second tie rod 4, and then install the counterweights 6 onto the second tie rod 4 in sequence. The second tie rod 4 can adopt a screw structure, and all the counterweights 4 can be locked onto the second tie rod 4 with the help of the step and nuts.

[0047] Considering the gas pressure experienced by the operating mechanism in the arc-extinguishing chamber as it drives the contact, we set up a flow regulation mechanism on each side of the variable mass mechanism. By using the angle matching of the air flow holes on the valve plate and the counterweight, the damping piston has different gas flow characteristics during the opening and closing process to simulate the gas pressure changes in actual working conditions. Each flow regulation mechanism includes a valve plate fitted on the pull rod, which is set close to the counterweight on the corresponding side. The shape of each valve plate matches the shape of the counterweight, and a through hole that matches the pull rod is set in its center. Multiple air flow holes and multiple mounting holes are evenly spaced on its circumference. The bolt passes through the spring, the mounting hole and the threaded hole on the corresponding side of the counterweight in sequence. The spring is in a compressed state, thereby pressing the valve plate onto the counterweight. The inner diameter of the mounting hole is smaller than the outer diameter of the spring. The bolt can be a hexagonal bolt, and its end size is larger than the outer diameter of the spring, so as to ensure that the valve plate can be elastically pressed onto the counterweight.

[0048] like Figure 4-5 As shown, the two flow regulation mechanisms are respectively denoted as the closing flow regulation mechanism and the opening flow regulation mechanism. The two valve plates and their air flow holes, the springs and bolts connected to them are respectively denoted as the opening valve plate 8, the opening air flow hole 801, the opening spring 10, the opening adjusting bolt 12, the closing valve plate 9, the closing air flow hole 901, the closing spring 11, and the closing adjusting bolt 13. During assembly, the opening air flow hole 801 and the closing air flow hole 901 should be misaligned.

[0049] Each counterweight 6 has a ventilation hole 601 at a position corresponding to the opening air passage 801 and the closing air passage 901. They are connected in parallel to form an airflow channel. However, due to the misaligned air passages on the valve plates in the two flow adjustment mechanisms, when these counterweights 6 and valve plates are assembled together, half of the airflow channel will be blocked by the closing valve plate, forming a closing damping channel, and the other half of the airflow channel will be blocked by the opening valve plate, forming a closing damping channel. For example, we can set the air passage and the mounting hole at a position on the outer edge of the circumference. The air passage can adopt a long waist hole structure, and three of them are evenly spaced. In this way, the opening air passage 801 and the closing air passage 901 can be assembled with a 60-degree offset.

[0050] like Figure 6As shown, when the circuit breaker is closed, the operating mechanism drives the lever to move to the left. The gas inside the left cavity of the damping piston is compressed. At this time, the closing valve plate is forced to press against the counterweight due to the spring pressure. As the lever continues to move, the pressure in the left cavity becomes greater than the pressure in the right cavity. The closing flow adjustment mechanism starts to work. The gas pressure inside the closing damping channel is greater than the spring pressure, which pushes the closing valve plate to move away from the counterweight, causing the closing damping channel to open. At this time, the closing spring is further compressed, which produces a damping and deceleration effect on the entire operating mechanism, realistically simulating the force process of the gas reaction force when the circuit breaker body is closed.

[0051] When the circuit breaker is tripped, the operating mechanism moves the lever to the right, compressing the gas inside the right chamber of the damping piston. At this time, the tripping valve plate, under the pressure of the spring, will press tightly against the counterweight. As the lever continues to move, the pressure in the right chamber becomes greater than that in the left chamber, and the tripping flow adjustment mechanism starts to work. The gas pressure inside the tripping damping channel is greater than the spring pressure, which pushes the tripping valve plate away from the counterweight, causing the tripping damping channel to open. At this time, the tripping spring will be further compressed, producing a damping and deceleration effect on the entire operating mechanism, realistically simulating the force process of the gas reaction force when the circuit breaker body trips.

[0052] Therefore, for different arc-extinguishing chambers, we only need to adjust the initial compression of the closing spring 11 and the opening spring 10 to simulate the corresponding compressed air reaction force. That is, we only need to adjust the screw-in length of the closing adjusting bolt 13 and the opening adjusting bolt 12 connected to them.

[0053] When performing motion mass adaptation and compressed air reaction force simulation, we can first open one end cover of the sealing cylinder, then pull out the entire pull rod along with the damping piston, then unscrew the first pull rod 5, and install the corresponding number of counterweights into the second pull rod 4 as needed. Then, assemble the two valve plates onto the two outermost counterweights 6, noting that the air passage holes on them should be staggered so that they can cooperate with the air passages 601 on the counterweights 6 to form the closing damping channel and the opening damping channel. Then, according to the actual situation of the arc-extinguishing chamber in the circuit breaker body, adjust the length of the closing adjusting bolt 13 and the opening adjusting bolt 12 screwed into the counterweights 6 to adjust the elastic pressure applied by the spring or disc spring to the valve plate to realize the compressed air reaction force simulation. Finally, adjust the nesting length of the second pull rod into the first pull rod according to the stroke requirements, and then install the entire pull rod along with the damping piston into the sealing cylinder.

[0054] Considering that the disc spring has a large force and good stability, and the damping during the opening process is large, the opening spring 10 can be a disc spring, and multiple disc springs are stacked in a stacked structure. The closing spring 11 can be a regular spring. In addition, multiple normally open vent holes 602 are opened at the corresponding positions of the opening valve plate 8, the closing valve plate 9 and each counterweight block 6 to form multiple normally open airflow channels, which truly simulates the normally open airflow channel state of the circuit breaker body.

[0055] Considering the feedback of mechanical performance and status signals after load simulation, we added a mechanical performance testing mechanism to the end of the tie rod, such as... Figure 7-9 As shown, by simulating the start of closing / opening of the moving and stationary contacts, detecting the point of just closing / just opening, and combining this with real-time detection of the stroke, the stroke-time variation curve and the position of the point of just closing / just opening on the curve can be obtained in real time. Then, the average opening speed / average closing speed, etc., can be calculated to obtain multiple parameters characterizing the circuit breaker's breaking performance. The mechanical characteristic curve is accurately recorded by the testing instrument.

[0056] Specifically, the mechanical performance testing mechanism includes a connecting plate 14, the center of which is clamped to the end of the pull rod. One end of the connecting plate 14 is connected to a stroke detection module 15, and the other end is connected to a main contact simulation mechanism 16. The stroke detection module 15 uses a stroke sensor to detect the stroke information of the operating mechanism in real time. The main contact simulation mechanism 16 includes an auxiliary switch 1601, which can be a commonly used auxiliary switch for circuit breakers. Its drive shaft is rotatably connected to the other end of the connecting plate 14 through a variable-length linkage structure. Both its contacts and the stroke detection module 15 are connected to a circuit breaker switch tester. In this way, since different circuit breakers have different strokes, the positions of the rigid opening / rigid closing points of the corresponding moving and stationary contacts will also be different. By adjusting the length of the linkage structure, the rotation angle of the drive shaft of the auxiliary switch 1601 can be changed, so that different contacts in the auxiliary switch are connected, thereby realizing the simulation of the start of closing and opening of circuit breakers of different specifications, as well as the detection of the rigid opening / rigid closing points.

[0057] The linkage structure includes an adjustable screw 1602. The length of the adjustable screw 1602 is set according to the rigid opening / rigid closing point of the circuit breaker. It can be composed of two small screws and a sleeve to form a variable screw structure. The extension length of the two small screws can be changed by rotating the sleeve. One end of the adjustable screw 1602 is rotatably connected to the end of the mounting plate, and the other end is rotatably connected to one end of the crank arm. The other end of the crank arm is clamped on the drive shaft of the auxiliary switch 1601.

[0058] We can set a through hole in the center of the connecting plate 14 to cooperate with the pull rod. One end of the plate has a vertical connecting surface for connecting the detection end of the stroke detection module 15, and the other end has a horizontal connecting surface. A U-shaped part is set at one end of the adjustable screw 1602, and then the shaft passes through the horizontal connecting surface to rotate and connect to the inside of the U-shaped part. The other end of the adjustable screw 1602 is rotatably connected to one end of the crank arm 1603 in the same way. The other end of the crank arm 1603 can be opened with a square hole to cooperate with the drive shaft. The rotating pair formed in this way has one degree of freedom. The change of the length of the adjustable screw will inevitably drive the rotation angle of the auxiliary switch drive shaft to change, so as to control the operation of the corresponding contact, thereby meeting the circuit breaker simulation setting requirements of different overtravel. Combined with the stroke detection module, the mechanical characteristics of the operating mechanism simulation test device can be detected and fed back in real time.

[0059] In summary, the load simulation test device and operating mechanism of the present invention are connected by a tie rod. The tie rod drives the damping piston to move inside the sealed cylinder to simulate the movement of the moving contact driven by the operating mechanism. The sealed cylinder is filled with an arc-extinguishing gas, such as sulfur hexafluoride gas, to simulate the gas pressure environment of the circuit breaker body. The first tie rod and the second tie rod are connected by a threaded nest to adapt to the stroke requirements of circuit breakers of different specifications. The perforated counterweight and valve plate are assembled together at a specific angle so that the counterweight and valve plate have different gas flow characteristics during the opening and closing process. The opening degree of the valve plate makes the airflow adjustable to simulate the compressed air reaction force applied by the arc-extinguishing chamber. The tie rod drives the stroke sensor and the simulated main contact to provide real-time feedback on the mechanical characteristics of the hydraulic mechanism and the simulated load. The mechanical stroke and the simulated main contact of the simulation device are adjustable, which is equivalent to the mechanical characteristics of the circuit breaker body.

[0060] In addition, the present invention has strong versatility and high adaptability, and can well meet the testing and adaptation requirements of hydraulic operating mechanisms with different circuit breaker bodies and mechanical strokes.

[0061] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples. Various changes or modifications can be made to these embodiments without departing from the principles and essence of the present invention. Therefore, the scope of protection of the present invention is defined by the appended claims.

Claims

1. A load simulation test device for a circuit breaker operating mechanism, characterized in that: The device includes a sealed cylinder, inside which a damping piston is disposed. A pull rod is disposed through the sealed cylinder along its axial direction. The pull rod comprises two coaxially threaded sections. The free end of one section passes through the damping piston and is connected to an operating mechanism, and is fixedly connected to the damping piston. The free end of the other section is connected to a mechanical performance testing mechanism. The damping piston includes a variable mass mechanism mounted on a tie rod. The variable mass mechanism adopts a coaxial parallel connection structure to simulate the motion mass experienced by the operating mechanism of different specifications of circuit breakers during the opening and closing process. A flow adjustment mechanism is set on each side of the piston to change the magnitude of gas damping flowing through the damping piston, so as to simulate the compressed air reaction force from the arc-extinguishing chamber when different specifications of circuit breakers are opened and closed. The mechanical performance testing mechanism is used to detect the travel information of circuit breakers of different specifications in real time, simulate the opening / closing state of the moving and stationary contacts of circuit breakers of different specifications, and detect the corresponding rigid opening / rigid closing point information to achieve complete mechanical performance testing. The variable mass mechanism includes multiple counterweights connected coaxially in parallel. They are detachably connected together by bolts. The outer diameter of each counterweight matches the inner diameter of the sealing cylinder. Each counterweight has a through hole at its center that matches the tie rod. Each counterweight has a notch in its circumference to accommodate the guide sealing ring. The guide sealing ring is slidably connected to the inner wall of the sealing cylinder. Each of the flow regulating mechanisms includes a valve plate fitted on a pull rod, which is set close to the counterweight on the corresponding side. The shape of each valve plate matches the shape of the counterweight, and a through hole that matches the pull rod is provided in its center. Multiple air passages and multiple mounting holes are evenly spaced on its circumference. Bolts pass through the spring, the mounting hole and the threaded hole on the corresponding side counterweight in sequence. The spring is in a compressed state, thereby pressing the valve plate onto the counterweight. The two flow regulation mechanisms are respectively referred to as the closing flow regulation mechanism and the opening flow regulation mechanism. The two valve plates and the air flow holes on them, and the springs connected to them are respectively referred to as the opening valve plate, the opening air flow hole, the opening spring, the closing valve plate, the closing air flow hole, and the closing spring. The opening air flow hole and the closing air flow hole are staggered. Ventilation holes are provided at the positions corresponding to the opening and closing air passages of each counterweight block. These holes are connected in parallel with the opening and closing air passages to form the opening damping channel and the closing damping channel. By adjusting the length of the bolt screwed into the threaded hole on the counterweight, the elastic pressure applied by the valve plate to the counterweight is adjusted to simulate the compressed air reaction force inside the arc-extinguishing chamber of the circuit breaker body of different specifications.

2. The load simulation test device for the circuit breaker operating mechanism according to claim 1, characterized in that: When the circuit is closed, the pressure in the left chamber of the damping piston is greater than the pressure in the right chamber. The closing flow adjustment mechanism is activated, and the gas pressure inside the closing damping channel pushes the closing valve plate to move away from the counterweight, opening the closing damping channel and compressing the closing spring. When the circuit breaker is tripped, the pressure in the right chamber of the damping piston is greater than the pressure in the left chamber. The tripping flow adjustment mechanism is activated, and the gas pressure inside the tripping damping channel pushes the tripping valve plate away from the counterweight, opening the tripping damping channel and compressing the tripping spring.

3. The load simulation test device for the circuit breaker operating mechanism according to claim 2, characterized in that: Both the opening and closing air passages adopt an elongated hole structure. The opening spring adopts a stacked structure of multiple disc springs. Multiple normally open vent holes are opened at corresponding positions of the opening valve plate, closing valve plate, and each counterweight block to form multiple normally open airflow channels.

4. The load simulation test device for the circuit breaker operating mechanism according to claim 2, characterized in that: The inner diameter of the mounting hole is smaller than the outer diameter of the opening spring and the closing spring.

5. The load simulation test device for the circuit breaker operating mechanism according to claim 1, characterized in that: The mechanical performance testing mechanism includes a connecting plate, the center of which is clamped to the end of the pull rod. One end of the connecting plate is connected to a stroke detection module, and the other end is connected to a main contact simulation mechanism. The stroke detection module is used to detect the stroke information of the operating mechanism in real time. The main contact simulation mechanism includes an auxiliary switch. The drive shaft of the auxiliary switch is rotatably connected to the other end of the connecting plate through a variable-length linkage structure. Both its contacts and the stroke detection module are connected to the circuit breaker switch tester. By adjusting the length of the linkage structure, the rotation angle of the drive shaft of the auxiliary switch is changed, causing different contacts in the auxiliary switch to be connected, thereby realizing the detection of the rigid open / rigid close point of circuit breakers of different specifications.

6. The load simulation test device for the circuit breaker operating mechanism according to claim 5, characterized in that: The linkage structure includes an adjustable screw, the length of which is set according to the break point / close point of the circuit breaker. One end of the adjustable screw is rotatably connected to the end of the connecting plate, and the other end is rotatably connected to one end of the crank arm. The other end of the crank arm is mounted on the drive shaft of the auxiliary switch.

7. The load simulation test device for the circuit breaker operating mechanism according to claim 6, characterized in that: The connecting plate has a through hole at its center that mates with the pull rod. One end of the plate has a vertical connecting surface for connecting the detection end of the stroke detection module, and the other end has a horizontal connecting surface that is rotatably connected to the U-shaped part at the end of the adjustable screw via a rotating shaft.

8. The load simulation test device for the circuit breaker operating mechanism according to claim 1, characterized in that: The pull rod includes a first pull rod and a second pull rod that are coaxially nested and connected by a threaded connection. The free end of the first pull rod passes through one end of the sealed cylinder and is connected to the mechanical performance testing mechanism. The second pull rod is provided with a damping piston, and its free end passes through the other end of the sealed cylinder and is connected to the operating mechanism. By adjusting the length of the nested overlapping portion of the first and second tie rods, the initial position of the damping piston inside the sealed cylinder is changed to adapt to the stroke requirements of circuit breakers of different specifications.

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