Switch machine contact life test bench and test circuit

Abstract

The application relates to the field of industrial automation testing, in particular to a switch machine contact point life test bench and a test circuit, which comprises a contact point seat, a plurality of static contact points fixedly connected on the contact point seat, a plurality of dynamic contact points corresponding to the static contact points, the bottom end of the dynamic contact points being hingedly connected to the contact point seat, the dynamic contact points being uniformly distributed at both ends of the contact point seat, the contact point seat being provided with a plurality of slots, a connecting rod being horizontally arranged and slidingly connected above a test bench table top, a groove being arranged on the test bench table top, a driving element being arranged below the test bench table top and driving the connecting rod to slide, a locking iron being connected to one end of the connecting rod and synchronously sliding horizontally with the connecting rod, one end of the locking iron extending towards the contact point seat, a clamping groove being arranged on the top side of the end of the locking iron, a roller being hingedly connected to the contact point seat, the hinging shafts of the plurality of dynamic contact points extending out of the contact point seat and being elastically connected with the roller shaft, and the roller surface abutting against the top end of the locking iron; and a test assembly being connected with the static contact points through wires. The application has the effects of improving the switch machine test efficiency and enhancing the reliability of test data.

Description

Technical Field

[0001] This application relates to the field of industrial automation testing, and in particular to a switch machine contact life test bench and test circuit. Background Technology

[0002] A switch machine is a key piece of equipment in a railway system, primarily used to control the switching of track switches, ensuring that trains travel accurately along the correct path. Moving and stationary contacts are crucial components of the switch machine, converting the mechanical position of the switch into electrical signals through contact and disconnection, used to monitor the track connection status. In recent years, the failure rate of switch machine contacts has been on the rise. Contact failures can cause erroneous indications in field signaling equipment, affecting normal railway operation. Therefore, contact life testing of switch machines is essential. Through testing, we can identify the key causes of failures and improve the overall service life of the switch machine.

[0003] In the past, the testing method for contact life typically involved installing the test contact into a switch machine to realistically simulate its condition in an actual working environment. However, this method has significant drawbacks. First, the switch machine's hydraulic system generates heat after prolonged operation, necessitating frequent shutdowns during the test. Furthermore, the smooth operation of the hydraulic system results in slow contact movement, leading to low testing efficiency. Second, the test requires manual control and monitoring, with data recorded manually based on experience, making the data highly subjective and unreliable. Summary of the Invention

[0004] To improve the efficiency of switch machine testing and enhance the reliability of test data, this invention provides a switch machine contact life test bench and test circuit.

[0005] On the one hand, the switch machine contact life test bench provided by the present invention adopts the following technical solution:

[0006] A switch machine contact life test bench includes a contact base, on which multiple stationary contacts and multiple movable contacts corresponding to the stationary contacts are fixedly connected. The bottom ends of the movable contacts are hinged to the contact base, and the movable contacts are evenly distributed at both ends of the contact base. Multiple contact bases are provided, and the bench further includes:

[0007] A connecting rod is horizontally set and slidably connected above the test bench surface. A groove is provided on the test bench surface, and a driving component is provided below the test bench surface to drive the connecting rod to slide.

[0008] A locking iron is connected to one end of the connecting rod and slides horizontally synchronously with the connecting rod. One end of the locking iron extends toward the contact seat, and a slot is provided on the top side of the end of the locking iron.

[0009] A roller is hinged to the contact seat, and the hinge shafts of the plurality of movable contacts extend out of the contact seat and are elastically connected to the roller shaft. The roller surface abuts against the top of the locking iron.

[0010] The test assembly is connected to the stationary contact via wires.

[0011] By adopting the above technical solution, the moving and stationary contacts are the same model of moving and stationary contact components as those on the actual railway turnout switch machine. They are replicated on the test bench for effective opening and closing tests of the moving and stationary contacts. During the test, it is necessary to ensure that the connection method of the moving and stationary contacts and the movement method of the moving contacts truly simulate the actual turnout switching scenario. Therefore, the moving and stationary contacts are matched one-to-one and grouped together. Each group includes at least three moving and stationary contacts. Two groups of moving and stationary contacts correspond to one contact seat. The two groups of contacts are set at both ends of the contact seat. Through the connection structure of connecting rod, locking iron and roller, one group of moving contacts at one end of the contact seat is driven to rotate around the bottom hinge axis and fit with the stationary contact. At the same time, the moving contact at the other end of the contact seat is disconnected from the stationary contact. That is, the engagement state of the moving and stationary contacts at both ends of the contact seat is opposite.

[0012] Specifically, the connecting rod is a power transmission component that connects the driving component and the moving contact hinge shaft. The locking iron connects the connecting rod and the contact seat, ensuring that the sliding driving force is transmitted to the moving contact hinge shaft on the contact seat through the connecting rod. The top side of the locking iron abuts against the roller surface, and slots are opened on the top sides of both ends. When the length of the locking iron is the preset length, after the locking iron slides to the bottom of the roller, the roller slides into the slot under the action of elastic force to achieve locking. The slots are opened smoothly to allow the roller to slide in smoothly.

[0013] In summary, the test procedure for the switch machine contact life test is as follows: the drive component drives the connecting rod to slide, which in turn drives the locking iron to slide. The locking iron slides against the roller surface. When the locking iron's slotted part slides directly under the roller, the roller falls under the action of elastic force, causing the moving contact on the same side of the slot to fall into the stationary contact. At the same time, the state of the moving contact on the other side changes synchronously, realizing the opening and closing of the moving and stationary contacts. With the test components connected by wires, the closure of the moving and stationary contacts in a single operation forms a complete closed loop. By monitoring the operating current, the closure of the moving and stationary contacts can be determined, thereby judging whether it is effective.

[0014] Optionally, the driving element includes:

[0015] The lower slider is vertically set and slidably connected in the through groove, with both ends protruding from the top and bottom surfaces of the test bench. The part of the lower slider protruding from the test bench is detachably connected to multiple connecting rods.

[0016] The drive cylinder is horizontally positioned on the bottom side of the test bench, with the piston rod end fixedly connected to the lower slider.

[0017] By adopting the above technical solution, the drive cylinder is the power component. The piston rod acts on the lower slider to make the lower slider slide along the opening direction of the slot, thereby driving the lower slider to pull the connecting rod. The connecting rod and the lower slider are detachably connected. In practical applications, a pin connection is generally used. That is, a pin hole is opened at the part of the lower slider that protrudes from the top side of the test bench. The part of the connecting rod corresponding to the pin hole is set as a U-shaped groove to cover the lower slider, and a through hole is also opened corresponding to the pin hole. Technicians insert a metal pin into the through hole to connect the lower slider and the connecting rod.

[0018] Furthermore, the portion of the lower slider protruding from the test bench surface can simultaneously have two pin holes. These two pin holes are used to connect multiple connecting rods. In practical applications, two rods are generally selected. By making reasonable use of the pin connection structure of the lower slider and connecting rods, two or more connecting rods can be connected to a driving cylinder, so that one driving cylinder drives multiple locking irons to slide. Thus, multiple sets of contact seats can be set on both sides of the test bench and connected to a driving cylinder through the lower slider, connecting rods, and locking irons. A single driving cylinder can drive all the moving contacts on the contact seats to rotate around the hinge point.

[0019] In addition, the multiple contact seats on the test bench can easily and flexibly change the number of tests. Technicians can remove the metal pins, lift the connecting rod, and cancel the connection between the lower slider and the connecting rod, thus reducing the number of contact life tests.

[0020] Optional, also includes:

[0021] A mounting plate is horizontally positioned on the opposite side of multiple contact seats at the same end of the test bench. A spring is inclined downward on the mounting plate, with its top end connected to the mounting plate and its bottom end connected to the roller axle.

[0022] By adopting the above technical solution, the mounting plate is the main structure supporting the elastic component, which is connected to the hinge shaft of the moving contact point for connecting the spring. The roller axle can be formed with a structure connecting the spring, so that the spring is connected to the roller axle. Thus, one end of the downward-sloping spring abuts against the mounting plate and is supported by the mounting plate, while the other end provides elastic pressure to the downward-sloping roller axle. In this solution, the roller axle is non-rotating, so it can be fixedly connected to the spring.

[0023] The connection between the top of the spring and the mounting plate is a bolt connection. That is, the mounting plate has a through hole for bolt insertion. The bottom end of the bolt extends out of the bottom side of the mounting plate, close to the spring, and the top of the spring is inserted into the bottom end of the bolt. The bolt is then fixed with a nut. Therefore, when the slot on the top side of the locking iron slides below the roller surface, the downward elastic force of the spring causes the roller to slide into the slot. The roller is chosen as the locking component because the roller surface is round, which provides high stability.

[0024] On the one hand, the test circuit of the switch machine contact life test bench provided by the present invention adopts the following technical solution:

[0025] A test circuit for a switch machine contact life test bench includes a control circuit for the drive cylinder, multiple sets of moving contacts and stationary contacts with contacts connected to the power grid at both ends, and multiple moving contacts and stationary contacts at both ends of a set are connected in parallel.

[0026] Each group of multiple static contacts and each of the moving contacts is provided with a contact at both ends;

[0027] Also includes;

[0028] The computing component connects the control circuit of the drive cylinder to the contact points at both ends of each set of moving contacts and stationary contacts.

[0029] By adopting the above technical solution, each of the two sets of moving and stationary contacts at both ends of each contact seat has a corresponding line contact and is connected to a current wire, so that each moving and stationary contact is connected to the test circuit. Specifically, it is necessary to determine whether each moving and stationary contact is effectively engaged, that is, to determine whether the moving contact effectively rotates and fits against both sides of the stationary contact. This can be achieved by connecting each stationary contact through the above-mentioned line contact to form an open circuit. When the moving contact fits against both sides of the stationary contact, since the moving contact is made of conductive metal, the moving contact and the stationary contact form a complete closed circuit, and the open circuit is closed. At this time, the calculation component receives a complete current signal.

[0030] In practical applications, the computing component can be a microcontroller or a programmable logic device (PLC), with PLC being recommended. Specifically, a Siemens PLC-based controller can be selected. Siemens controllers have industry-leading anti-electromagnetic interference capabilities, effectively ensuring data validity. They also feature high-precision timing and low-delay interrupt mechanisms to guarantee data immediacy, making them well-suited for switch machine lifespan testing in this field. The Siemens controller also has a built-in microsecond-level ammeter capable of receiving sensitive current signals.

[0031] In summary, the above scheme constitutes the basic function of the test circuit. The connection of the dynamic and static contacts forms a complete circuit under the action of power. When connected to the computing component, the computing component can receive the electrical signal and count it. If the current value of the electrical signal is above the preset current value, that is, the current intensity meets the requirements, the current is recorded as a valid connection. Thus, the connection life test of hundreds of thousands or millions of times can be completed automatically, continuously and efficiently.

[0032] Optionally, a set of moving contacts and stationary contacts at one end of the contact base are connected to a single-phase rectifier bridge;

[0033] The two sets of moving contacts and stationary contacts at both ends of the contact base are respectively connected to a DC power supply and an AC power supply.

[0034] By adopting the above technical solution, in the actual application environment of railway turnouts, a switch machine is equipped with two sets of moving and stationary contacts to display the closed state of the road closure side and the separated state of the road separation side. Therefore, in order to realistically simulate the actual application situation, two sets of moving and stationary contacts are set on the contact seat, so that one contact seat can realistically simulate the contact situation of the switch machine. The engagement states of the moving and stationary contacts at both ends of one contact seat are opposite. Therefore, one contact seat can simultaneously measure the operating state of two sets of moving and stationary contacts. On this basis, one set of moving and stationary contacts on one contact seat is connected to a DC power supply, and the other set is connected to an AC power supply. The DC power supply and the AC power supply are connected to the test circuit through the contact to make each set of moving and stationary contacts form an open circuit.

[0035] In the laboratory, the inadequacy of the test conditions needs to be considered. A single-phase rectifier bridge is connected to one of the dynamic and static contacts. When two AC power supplies are connected to the contacts at the same time, the AC current is converted into DC current under the action of the single-phase rectifier bridge. This is suitable for situations where DC power is lacking.

[0036] The reason for using AC and DC for comparison in the above scheme is twofold. Firstly, it takes into account the diversity of practical application scenarios, as both DC and AC are used in practice. Secondly, it is due to the difference in arc behavior. As is well known, when DC is disconnected, the voltage continues to exist, making it more difficult to extinguish the arc. The arc duration is longer than that of AC, which makes the contact erosion of the moving and stationary contacts more severe. Contact erosion is an important factor in reducing the lifespan of switch machine contacts. Therefore, it is necessary to measure the arc tolerance of switch machine contacts and observe the effective number of contact opening and closing under DC or AC conditions.

[0037] Optionally, the control circuit of the driving cylinder is connected to a current sensor; a current sensor is connected to one side of each group of moving contacts and stationary contacts.

[0038] By adopting the above technical solution, current sensors are set on both sides of the moving and stationary contacts to monitor the operating current in the circuit. When a sudden change in current occurs in the circuit, the current sensor can send a monitoring electrical signal in real time. The current sensor is connected to the above-mentioned computing component and sends the monitoring result to the computing component in the form of an electrical signal. The computing component or PLC calculates the electrical signal of the current sensor and alarms when a sudden change occurs or when the current exceeds the safety value.

[0039] Additionally, the above technical solution also includes a current sensor on the side of the drive cylinder to monitor the operating current of the drive cylinder. This sensor is used to monitor the operating status of the cylinder. Insufficient cylinder power is also a factor contributing to the instability of the dynamic and static contact connection, especially in situations requiring continuous measurement over a long period of time.

[0040] Optionally, it also includes a computing component circuit breaker and a contact base circuit breaker;

[0041] The circuit breaker for the computing component is located between the computing component and the protection line;

[0042] The contact base circuit breaker is installed between the moving contact, the stationary contact, the to-contact, and the protection line.

[0043] By adopting the above technical solution, the circuit breaker plays the role of overload and short circuit protection in the test circuit. During the service life test of the switch machine contact, the contact is frequently opened and closed. During the frequent opening and closing, local overheating or even short circuit may occur due to arc, increased contact resistance or material deterioration. Especially when the DC current is used for testing, the damage rate increases. When the service life cannot be accurately predicted, a circuit breaker needs to be set up to play a protective role.

[0044] The circuit breaker for the computing component, specifically the PLC circuit breaker, also serves a protective function, quickly disconnecting the connection between the PLC and the test circuit in the event of a short circuit.

[0045] Optionally, the measuring device is connected to the contact point, and protective wires are connected to both ends of the moving contact and the stationary contact.

[0046] By adopting the above technical solution, which differs from the above-mentioned technical solution of connecting the power supply to the contact, this technical solution provides another wiring scheme for the test circuit, that is, the two contacts are connected to current and voltage measuring equipment, which can be used immediately after plugging and unplugging. At the same time, the PLC keeps measuring the number of opening and closing. Therefore, each set of moving contacts and stationary contacts needs to be connected to a normally open power supply and connected to a protection line.

[0047] In summary, this application includes at least one of the following beneficial technical effects:

[0048] 1. By cooperating with the connecting rod and the locking iron, the synchronous operation of multiple moving contacts can be achieved, which significantly improves the testing efficiency and ensures the uniformity of force distribution, effectively solving the problem that traditional methods cannot take into account the synchronous testing of multiple points.

[0049] 2. By employing technologies such as driving cylinders as the power source, designing specialized mechanical structures, and integrating specialized software, significant improvements in testing efficiency, data reliability, and testing safety have been achieved, along with cost savings and increased economic benefits.

[0050] 3. The driving component moves the connecting rod by sliding the lower slider, achieving precise control in the horizontal direction. Combined with the electrical connection of the test components, it can fully simulate the actual working environment and enhance the authenticity and reliability of the test results. Attached Figure Description

[0051] Figure 1 This is a schematic diagram of the switch's mechanical and static contact points.

[0052] Figure 2 This is a schematic diagram of the overall structure of an embodiment of this application.

[0053] Figure 3 This is a schematic diagram of the contact seat in the embodiment of this application.

[0054] Figure 4 yes Figure 3 Enlarged view of part A.

[0055] Figure 5 This is a circuit diagram of the experimental circuit according to an embodiment of this application.

[0056] Explanation of reference numerals in the attached drawings: 1. Contact base; 11. Stationary contact; 12. Moving contact; 13. Mounting plate; 14. Roller; 15. Snap ring; 16. Waist-shaped groove; 2. Frame; 21. Frame plate; 22. Drive cylinder; 23. Lower slider; 24. Lower slider seat; 25. Connecting rod; 26. Locking iron; 261. Slot; 3. Table surface; 4. Current sensor. Detailed Implementation

[0057] The following is in conjunction with the appendix Figure 1-5 This application will be described in further detail.

[0058] First, this application discloses a contact assembly for a switch machine. This contact assembly is disassembled and installed inside a switch machine of the same model used in actual turnout applications to simulate a more realistic situation. (Refer to...) Figure 1 A switch machine contact assembly includes a contact seat 1, which is a rectangular seat. Each segment is equipped with a set of stationary contacts 11. The two sets of stationary contacts 11 at both ends of the contact seat 1 are symmetrically distributed along the center of the contact seat 1. Of the two stationary contacts 11 in a set, one stationary contact 11 near the end of the contact seat 1 is inclined, and the other is vertical. Each end of the contact seat 1 is hinged with a movable contact 12. The hinge shaft is horizontally set at the bottom of the movable contact 12. The movable contact 12 can rotate around the hinge shaft until one end is in contact with the stationary contact 11. That is, a movable contact 12 at one end of the contact seat 1 can reciprocate between the two stationary contacts 11 at the same end of the contact seat 1. The two movable contacts 12 are connected by a spring rod so that the two movable contacts 12 rotate synchronously and in the same direction. When one of the movable contacts 12 is in contact with the inclined stationary contact 11 at the same end of the contact seat 1, the movable contact 12 at the other end of the contact seat 1 is in contact with the vertical stationary contact 11. The contacts of the switch machine are existing technology, used to indicate the switching direction and switching status of the turnout; the specific principles will not be elaborated here.

[0059] On one hand, this application discloses a switch machine contact life test bench. (Refer to...) Figure 2A switch machine contact life test bench includes a frame 2, with a platform 3 horizontally positioned at the top of the frame 2. Four contact seats 1 are distributed on the platform 3, resulting in a total of eight sets of contacts available for life testing. The four contact seats 1 are symmetrically distributed at both ends of the test bench. A frame plate 21 is horizontally positioned below the platform 3 on the frame 2, with a predetermined spacing between the frame plate 21 and the platform 3. A drive cylinder 22 is horizontally positioned at one end of the frame plate 21. A lower slider seat 24 is fixedly connected to the center of the frame plate 21. A lower slider 23 is slidably connected to the lower slider seat 24. A sliding groove is provided at the bottom of the lower slider 23, with the width of the groove equal to the width of the lower slider seat 24, for engaging the lower slider 23 and the lower slider seat 24. The piston rod end of the drive cylinder 22 is fixedly connected to the lower slider 23, and the lower slider 23 is slidably moved by the extension and retraction of the piston rod of the drive cylinder 22.

[0060] Reference Figure 2 and Figure 3 A through groove is vertically provided on the platform 3. The length of the through groove is parallel to the extension and retraction direction of the piston rod of the drive cylinder 22. The top of the lower slider 23 extends out of the through groove and protrudes from the platform 3. Two connecting rods 25 are hinged to the top of the lower slider 23 on both sides. The specific hinge method is as follows: two through holes are provided parallel to each other on the top of the lower slider 23 for the insertion of the hinge shaft. The end of the connecting rod 25 near the lower slider 23 is U-shaped. The two ends of the U-shaped groove are also provided with through holes adapted to the hinge shaft for the insertion of the hinge shaft. This connection method allows technicians to easily connect and disassemble the connecting rod 25 and the lower slider 23 and adjust the number of contact seats 1 participating in the test. One end of the connecting rod 25, away from the lower slider 23, extends between two contact seats 1 at one end of the platform 3. A locking iron 26, rectangular in shape, is fixedly connected to the end of the connecting rod 25 away from the lower slider 23. These locking irons 26 are vertically arranged, corresponding one-to-one with the surface of each contact seat 1, and are positioned on opposite sides of the two contact seats 1 at the same end of the platform 3. Therefore, the end of the connecting rod 25 extending away from the lower slider 23 is hinged to the two locking irons 26 in the same way as its hinge to the lower slider 23, i.e., by inserting the locking iron 26 into the hinge shaft at the end of the connecting rod 25. Thus, the sliding of the connecting rod 25 causes the locking iron 26 to slide synchronously.

[0061] Reference Figure 3 and Figure 4On the two contact seats 1 at the same end of the platform 3, there are mounting plates 13 on the opposite side edges. The mounting plates 13 are inclined. The hinge shaft of the moving contact 12 protrudes from the contact seat 1 and extends from the contact seat 1. The contact seat 1 has a waist-shaped groove 16 corresponding to the hinge shaft. A threaded hole is provided at the center of the mounting plate 13. The threaded hole is directly opposite the part of the hinge shaft of the moving contact 12 that protrudes from the contact seat 1 and is parallel to the waist-shaped groove 16. A bolt is threaded in the threaded hole. A spring is threaded at the end of the bolt. The spring is fixed by a metal round plate threaded to the end of the bolt, preferably by welding. The axial direction of the spring is parallel to the direction of the bolt. A roller 14 is rotatably connected to the part of the hinge shaft of the moving contact 12 that protrudes from the contact seat 1. The axle of the roller 14 is horizontally set and its axle is located on the extension line of the spring. A pin structure is provided at the top of the roller surface corresponding to the spring for inserting the bottom end of the spring to fix the spring. The locking iron 26 has notches at both ends on its top side, forming slots 261. The bottom end of the roller 14 abuts against the top side of the locking iron 26. As the top of the locking iron 26 slides with the connecting rod 25, aligning the end of the locking iron 26 with the roller 14, the roller 14 slides down into the slot 261 under the action of the spring. To achieve both fixing the spring and ensuring the roller 14 presses against the locking iron 26, a circumferential groove is formed in the center of the roller 14. The roller 14 is rotatably connected to the groove by a retaining ring 15, which is fixedly connected to the aforementioned pin structure.

[0062] The implementation principle of the switch machine contact life test bench in this application embodiment is as follows: the technician first determines the number of contact seats 1 to be tested according to the test situation, the drive cylinder 22 drives the lower slider 23 to slide, the lower slider 23 drives one or two connecting rods 25, and then drives the locking iron 26 to slide.

[0063] Because the height of the axle of the moving contact 12 is a preset height, and due to the structural limitation of the top wall of the waist-shaped groove 16, the surface of the roller 14 can press against the locking iron 26. As the locking iron 26 slides back and forth, the roller 14 rotates under the action of friction, which in turn drives the moving contact 12 to rotate clockwise and counterclockwise around the bottom hinge axis to abut against the two stationary contacts 11 on both sides.

[0064] After the locking iron 26 slides to the slots at both ends, the spring pushes the roller 14 axle to move down along the waist-shaped groove 16, so that the roller 14 surface abuts against the bottom wall of the slot 261. The locking iron 26 is of a preset length. When the moving contact 12 abuts against the stationary contact 11 on one side, the slot 261 causes the roller 14 to move down, thereby causing the moving contact 12 to move down, so that the contact rod of the moving contact 12 can stably and effectively abut against the two contact pieces of the stationary contact 11.

[0065] The above process is repeated 100,000 times or 1 million times under the rapid and efficient push of the drive cylinder 22 to complete the contact life test process.

[0066] On the other hand, this application discloses a test circuit for a switch machine contact life test bench, which is applied in the aforementioned switch machine contact life test. (Refer to...) Figure 5 A test circuit for a switch machine contact life test bench includes a U / E / PE protection circuit. The components mounted on the contact life test bench are connected to the protection line. In this embodiment, a U / E / PE protection circuit system is used. A main switch is set on the protection line. When the main switch is off, the entire test circuit cannot be grounded and does not constitute a complete circuit, which is an open circuit state.

[0067] The diagram uses a contact seat 1 on the platform 3 as an example.

[0068] Reference Figure 5 Two sets of moving contacts 12 and stationary contacts 11 on one set of contact sockets 1 are connected to the protection circuit. Contacts 11, 12, 13, 14, 15, and 16 at both ends of the contact switch are the wire contacts of the two stationary contacts 11 at both ends of the contact socket 1. Contacts 21, 22, 23, 24, 25, and 26 are the two sets of stationary contacts 11 on another contact socket 1. When the moving contact 12 contacts one of the two stationary contacts 11, the contact switch closes, and the moving contact 12 is in the intermediate state, thus opening the contact switch. Switches QF3 and QF4 are installed on the parts of both contact sockets 1 that connect to the protection circuit, allowing for on / off switching when one of the contacts in the two contact sockets 1 does not need to participate in the test, improving operability.

[0069] Reference Figure 5 Each set of moving and stationary contacts 11 in a contact socket 1 is equipped with a to-contact at both ends. The to-contact is used to connect an additional power supply or an additional current / voltage measuring device. If a power supply is connected, it is necessary to ensure that the N line of the protection circuit is engaged and the U line is disengaged, that the test voltage is the preset voltage, and that the circuit is grounded. If a measuring device is connected, it is necessary to ensure that both the U line and the N line of the protection circuit are engaged, providing the rated voltage while grounding. One of the contacts in a contact socket 1 is connected to a single-phase rectifier bridge to integrate the AC current, so as to test the contact life under AC and DC current conditions simultaneously. R1 and R2 are variable resistors that can adjust the current magnitude, as one of the necessary experimental conditions.

[0070] Reference Figure 5 The Siemens PLC is connected to the protection circuit to control the drive cylinder 22. When current and voltage measuring devices are connected to the contacts, the measuring devices are also connected to the Siemens PLC, which processes the data according to a preset programming file. The PLC is also connected to the control circuit of the drive cylinder 22, which controls the extension and retraction speed of the piston rod according to a programming file preset by the technician. To protect the PLC, a circuit breaker QF2 is installed between the PLC and the protection circuit wiring; when the circuit current changes abruptly, the circuit is disconnected.

[0071] Reference Figure 5 The control circuit of the drive cylinder 22 and the contact side of the contact seat 1 are both equipped with current sensors 4 to monitor the current value in the test circuit.

[0072] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A switch machine contact life test bench, comprising a contact seat (1), a plurality of static contacts (11) fixed on the contact seat (1), a plurality of dynamic contacts (12) corresponding to the static contacts (11), the bottom end of the dynamic contacts (12) being hinged to the contact seat (1), and the dynamic contacts (12) being uniformly distributed at both ends of the contact seat (1), characterized in that, The contact seat (1) is provided with a plurality of, and further comprises: A connecting rod (25) is horizontally arranged and slidably connected above the test bench table (3), a through slot is provided on the test bench table (3), and a driving member is arranged below the test bench table (3) to drive the connecting rod (25) to slide; A locking iron (26) is connected to one end of the connecting rod (25) and synchronously slides with the connecting rod (25), one end of the locking iron (26) extends to the contact seat (1), and a clamping groove (261) is formed on the top side of the end of the locking iron (26); A roller (14) is hinged to the contact seat (1), the hinge shafts of a plurality of the movable contact points (12) extend out of the contact seat (1) and are elastically connected with the wheel shaft of the roller (14), and the wheel surface of the roller (14) abuts against the top end of the locking iron (26); A test assembly is connected to the static contact point (11) through a wire; An installation plate (13) is horizontally arranged on the opposite side of a plurality of the contact seats (1) at the same end of the test bench, a spring is arranged on the installation plate (13) and inclined downward, the top end of the spring is connected to the installation plate (13), and the bottom end of the spring is connected to the wheel shaft of the roller (14); The contact seat (1) is provided with a waist-shaped groove (16) corresponding to the hinge shaft.

2. The switch machine contact life test bench of claim 1, wherein, The driving member comprises: A lower sliding block (23) is vertically arranged and slidably connected in the through slot, and protrudes from the top and bottom surfaces of the test bench, and the part protruding from the table (3) of the lower sliding block (23) is detachably connected with a plurality of the connecting rods (25); A driving cylinder (22) is horizontally arranged on the bottom side of the test bench, and the end of the piston rod is fixedly connected with the lower sliding block (23).

3. The switch machine contact life test bench of claim 2, wherein, A plurality of groups of the movable contact points (12) and the static contact points (11) are provided with contact points connected to the power grid, and the contact points at the two ends of a plurality of the movable contact points (12) and the static contact points (11) in one group are connected in parallel; The two ends of each group of a plurality of the static contact points (11) and the movable contact points (12) are provided with a to-contact point; Further comprising: A calculation assembly is connected between the control circuit of the driving cylinder (22) and the to-contact point at the two ends of each group of the movable contact points (12) and the static contact points (11).

4. The switch machine contact life test bench of claim 3, wherein, The control circuit of the driving cylinder (22) is connected with a current sensor (4), and each group of the movable contact points (12) and the static contact points (11) is connected with a current sensor (4) on one side.

5. The switch machine contact life test bench of claim 4, wherein, Further comprising a calculation assembly breaker and a contact seat (1) breaker; The calculation assembly breaker is arranged between the calculation assembly and the protection wire; The contact seat (1) breaker is arranged between the to-contact point of the movable contact point (12) and the static contact point (11) and the protection wire.

6. The switch machine contact life test bench of claim 5, wherein, The to-contact point is connected with a measuring member, and the two ends of the movable contact point (12) and the static contact point (11) are connected to the protection wire.

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