Portable high-reliability valve action life testing machine

Abstract

The invention discloses a portable high-reliability valve action life testing machine, and belongs to the technical field of automatic testing equipment. The testing machine comprises a switching power supply, a PLC all-in-one machine, an input module, an output module and a solid-state relay. The input module is connected between a power supply positive electrode and a PLC input point through an input switch, and a PLC input common end is connected with a power supply negative electrode to form a source type input circuit; the PLC output common end of the output module is connected with the negative electrode of the power supply to form a drain type output circuit; the control side of the solid-state relay is connected among the power supply anode, the PLC output point and the cathode, and the load side is connected in series between the power supply anode and the tested valve coil. The solid-state relay is used for replacing a traditional electromechanical relay, PLC control is combined, and the technical problems that in the prior art, a control system is short in service life, poor in reliability, low in control precision, large in electromagnetic interference and inconvenient to adjust parameters are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of automatic test equipment, in particular to a life test machine for performing high-frequency and long-period on-off action test on solenoid valves, pneumatic valves and other actuating elements, and a control system thereof. BACKGROUND

[0002] Valves are key actuating elements in industrial fluid control systems, and their reliability and service life are crucial to the safety and stability of the entire system. Therefore, before leaving the factory and during application and selection, valves must undergo rigorous action life tests, i.e., simulating their actual working conditions, to perform millions or even tens of millions of reciprocating on-off actions under specified conditions to test their durability.

[0003] Currently, existing valve life test devices usually use a combination of "time relay + electromechanical relay" or a simple single-chip microcomputer control board for the control part.

[0004] However, the above existing technology has the following significant technical defects in actual application: 1. Short service life of control elements and poor system reliability: Electromechanical relays rely on internal physical contacts and electromagnetic coils for attraction and release. In the high-frequency (e.g., several times per second) and long-period (millions of times) tests required by life machines, the mechanical contacts will quickly fail due to arc erosion, high temperature, and physical wear, and even cause contact sticking. This results in the service life of the control system itself being much shorter than that of the tested valve, often causing the control system to fail before the valve during testing, resulting in interrupted testing, invalid data, and severely affecting testing efficiency.

[0005] 2. Low control accuracy and slow response speed: Electromechanical relays have millisecond-level attraction and release delays, and the contacts have physical bounce problems during switching. This results in the inability to accurately control the on and off times of the valve, and under high-frequency testing, this time error accumulates, affecting the accuracy and effectiveness of the test results.

[0006] 3. Parameter adjustment is inconvenient and has poor flexibility: Based on relays or solidified program single-chip microcomputers, the test parameters (such as on-off time, cycle number) are usually fixed or need to be adjusted through complex hardware (such as potentiometers, dial switches). When the testing requirements change (such as replacing different specifications of valves), the adjustment is very tedious and cannot flexibly adapt to diversified testing tasks.

[0007] 4. Severe electromagnetic interference: The mechanical contacts of electromechanical relays produce strong electric arcs and electromagnetic interference when disconnecting large current loads (valve coils), which may affect the stable operation of PLCs or other precision instruments. SUMMARY

[0008] 1. Technical problems to be solved: The present application aims to overcome the technical defects of short service life, poor reliability, low control precision and inflexible parameter configuration of the control system of the existing valve service life tester due to the use of electromechanical relays, and to provide a portable, high-reliability, long-life, high-precision valve action service life tester with flexible parameter configuration.

[0009] 2. Technical solutions: To solve the above problems, the present application adopts the following technical solutions.

[0010] A portable high-reliability valve action service life tester, comprising: A switching power supply for providing a DC working voltage, preferably DC 24V and 0V (ground); A PLC whose power supply end is connected to the switching power supply and integrates a man-machine interface for setting test parameters; An input module including at least one input switch connected between the positive electrode of the switching power supply and the input point of the PLC, and the input common end of the PLC is connected to the negative electrode of the switching power supply, constituting a source-type input circuit; An output module, the output common end of the PLC is connected to the negative electrode of the switching power supply, constituting a drain-type output circuit; At least one solid-state relay, whose control side is connected between the positive electrode of the switching power supply, one output point of the PLC and the negative electrode of the switching power supply; and whose load side is connected between the positive electrode of the switching power supply and the electromagnetic coil of the tested valve; Wherein, the PLC is configured to: respond to input instructions and control its output points to turn on and off according to the set test parameters, so as to drive the tested valve to perform periodic action service life test through the solid-state relay.

[0011] As a further improvement of the present application, the test parameters include the energization time, de-energization time and target cycle number of the valve.

[0012] As a further improvement of the present application, the PLC is a touch screen PLC all-in-one machine.

[0013] As a further improvement of the present application, the input switch includes a self-resetting button switch for starting and stopping the test.

[0014] As a further improvement of the present application, the number of solid-state relays, output points of the PLC and tested valves is multiple, forming multiple independent test channels.

[0015] As a further improvement of the present application, the multiple test channels are configured to work independently or cooperatively.

[0016] As a further improvement of the present application, an alarm device is connected between the positive pole of the switching power supply and an alarm output point of the PLC.

[0017] As a further improvement of the present application, the alarm device is a buzzer.

[0018] As a further improvement of the present application, a portable housing is further included, and the switching power supply, the PLC, the input module and the solid-state relay are integrated in the portable housing.

[0019] As a further improvement of the present application, the portable housing is a suitcase structure.

[0020] 3. Beneficial effects: Compared with the prior art, the technical scheme provided by the present application has the following beneficial effects: (1) The present application uses a solid-state relay to replace a traditional mechanical relay which is prone to wear and tear. Since the solid-state relay has no mechanical contact, the switching process is completed by semiconductor elements, and there is no physical wear and tear or arc ablation. The switching life of the solid-state relay can reach hundreds of millions of times. This makes the service life of the test machine control system itself far exceed that of the measured valve, and enables the test machine to easily complete millions or even tens of millions of continuous uninterrupted tests, thereby fundamentally solving the technical problem of test interruption caused by control element failure, greatly improving the reliability and service life of the test machine, and ensuring the continuity of the test.

[0021] (2) The present application uses a PLC for high-precision timing, and combines a solid-state relay with microsecond-level switching speed for output. This combination eliminates the attraction delay, release delay and contact jitter caused by physical inertia of mechanical relays, and can achieve millisecond-level precise control of the valve on-off time, ensuring that each switching action strictly conforms to the set parameters, thereby ensuring the high accuracy and repeatability of the test results, significantly improving the control precision and response speed, and ensuring the accuracy of the test results.

[0022] (3) The present application uses a touch screen PLC all-in-one machine. The operator does not need to change hardware or programming, but only needs to set and modify all key test parameters such as power-on time, power-off time and target cycle number through the intuitive man-machine interface at any time, so that one test machine can flexibly adapt to the test requirements of valves of different specifications, greatly improving the universality and ease of use of the equipment, realizing flexible configuration and convenient operation of test parameters, and enhancing the universality of the equipment.

[0023] (4) Reduced electromagnetic interference during system operation and improved electromagnetic compatibility. The solid-state relay used in this invention generates no electric arc during switching, which fundamentally eliminates the strong electromagnetic interference generated by the arcing of electromechanical relay contacts, ensuring the stable operation of the PLC central controller and its peripheral electronic equipment, and improving the anti-interference capability of the entire test system.

[0024] It should be noted that the structures not described in this invention are not related to the design points and improvement directions of this invention, and are the same as or can be implemented using existing technologies, so they will not be elaborated here. Attached Figure Description

[0025] Figure 1 The system principle block diagram of the valve operation life testing machine provided in the embodiment of the present invention. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in more detail below with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can implement this invention based on this description, but it should be understood that this is not a limitation on the scope of protection of this invention.

[0027] Reference Figure 1 The present invention provides a portable high-reliability valve operation life testing machine. Its system architecture uses a programmable logic controller (PLC) as the core control unit and a solid-state relay (SSR) as the key execution component. Through the circuit design that combines source input and sink output, it together constitutes a high-precision, long-life, and low-interference testing platform.

[0028] The system composition and electrical principles are as follows: The hardware system of this testing machine mainly consists of the following parts: 1. Power Supply: The system is powered by an industrial-grade switching power supply, which converts external AC power into a stable and clean 24V DC power supply. The output terminals are defined as DC24V (positive) and 0V (common ground, negative), providing power to the entire system. The use of a safe DC24V voltage also takes into account the safety and reliability of the equipment.

[0029] 2. Control Core: The system's control center utilizes a touchscreen PLC integrated unit. This device integrates the logic control functions of the PLC with the human-machine interface functions of the touchscreen, allowing operators to directly set and modify all key test parameters on the screen, such as the "energizing time," "de-energizing time," and "target cycle count" of the valve coil, without the need for external programming tools or hardware modifications.

[0030] 3. Instruction Input Circuit (Source Input): Operation instructions are input via self-resetting push-button switches (such as "Start" and "Stop"). The circuit connection uses source input (PNP connection): the PLC's common input terminal (S / S) is uniformly connected to 0V of the power supply; one end of each push-button switch is connected in parallel to DC24V, and the other end is connected to a specific input point of the PLC (X0, X1, etc.). When a button is pressed, a high-level DC24V signal is sent to the corresponding PLC input point, forming a valid instruction signal.

[0031] Power drive circuit (sinking output and solid-state relay): This is the core component for achieving high reliability in this invention.

[0032] Output circuit: The common output terminal (COM0) of the PLC is connected to the 0V power supply to form a sinking output (NPN connection). The output points of the PLC (Y0, Y1, etc.) adopt transistor output form.

[0033] 4. Solid State Relay Connection: The DC+ and DC- terminals of the control side (equivalent to the coil circuit) of each solid state relay are connected to the system's DC24V and 0V respectively, providing operating power to its internal optocoupler; its signal input terminal (IN) is connected to an output point of the PLC (such as Y0). The input terminal of the load side (equivalent to the contact circuit) of the solid state relay is connected to DC24V, and the output terminal is connected in series to the solenoid coil of the valve being measured, with the other end of the coil returning to the 0V power supply.

[0034] 5. Status Indication and Alarm: The system is equipped with a buzzer as an alarm device, one end of which is connected to DC24V, and the other end is connected to a dedicated output point of the PLC (such as Y3). When the test is completed or an alarm is required, the PLC controls Y3 to conduct, causing the buzzer to sound.

[0035] Workflow and Typical Testing Cycle Taking the life test of a single-head valve as an example, its working process is as follows: Start-up: After setting parameters via the touchscreen, the operator presses the "Start" button. The PLC's X0 input receives a high-level signal, and the program begins running.

[0036] Valve Action: When the program logic determines that the valve needs to be opened, the PLC controls its output point Y0 to conduct. In the sinking output circuit, Y0 conduction pulls its potential down to near 0V. At this time, the current path is: DC24V → solid-state relay control side (DC+) → internal optocoupler → signal input terminal (IN) → PLC's Y0 point → COM0 → 0V. This current triggers the solid-state relay, causing its contactless switch (such as a MOSFET) on the load side to conduct momentarily.

[0037] Power Output: After the solid-state relay is turned on, the main circuit is connected: DC24V → solid-state relay load side input terminal → load side output terminal → valve solenoid coil → 0V. The valve coil is energized, driving the valve core to complete the switching action.

[0038] Precise shutdown: When the preset "power-on time" is reached, the PLC shuts off the Y0 output. The Y0 point returns to a high-resistance state, the solid-state relay control circuit is de-energized, and its load-side switch quickly shuts off, cutting off the power supply to the valve coil. The valve returns to its initial position under the action of the reset mechanism.

[0039] Cycle and Termination: The PLC then enters the "power-off time" timer. After the timer ends, it immediately starts the next "power-on-off" cycle and automatically counts. This process repeats until the number of cycles reaches the preset target value. At this point, the PLC drives the buzzer at point Y3 to emit a test completion signal.

[0040] The extended functionality and physical implementation are as follows: Multi-channel testing: This invention can be easily expanded into a multi-channel testing system. For example, using multiple output points such as Y0, Y1, and Y2 of the PLC, the corresponding solid-state relays and the valve under test can be independently controlled to form multiple parallel and isolated test stations. These channels can be configured by the PLC program to run synchronously, alternately, or according to a specific logical sequence to adapt to complex testing requirements.

[0041] Portable Integration: To achieve portability in the field, all electrical components, including the switching power supply, PLC, buttons, solid-state relays, terminal blocks, and internal wiring, are compactly and rationally housed within a carrying case. This design not only facilitates carrying and field deployment, but its orderly internal layout also ensures excellent heat dissipation and long-term operational stability.

[0042] The above-described embodiments are merely illustrative of certain implementations of the present invention, and are described in a relatively specific and detailed manner. However, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements are all within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A portable high-reliability valve action life tester, comprising a switching power supply, a programmable logic controller (PLC), an input module, an output module and at least one solid-state relay, characterized in that: the switching power supply is configured to provide a DC operating voltage; the PLC is connected to the switching power supply and is integrated with a human-machine interface for setting test parameters; the input module comprises at least one input switch connected between the positive terminal of the switching power supply and an input point of the PLC, and the input common terminal of the PLC is connected to the negative terminal of the switching power supply, forming a source-type input circuit; in the output module, the output common terminal of the PLC is connected to the negative terminal of the switching power supply, forming a drain-type output circuit; the control side of the solid-state relay is connected between the positive terminal of the switching power supply, an output point of the PLC and the negative terminal of the switching power supply, and the load side is connected between the positive terminal of the switching power supply and the electromagnetic coil of the valve under test; wherein the PLC is configured to control the output point to turn on and off in response to an input instruction and according to the set test parameters, so as to drive the valve under test to perform periodic action life test through the solid-state relay.

2. The portable high-reliability valve operation life tester according to claim 1, characterized in that: The test parameters include the energization time, de-energization time and target cycle number of the valve.

3. The portable high reliability valve operation life tester according to claim 1, characterized in that: The PLC is a touch screen PLC all-in-one machine.

4. The portable high reliability valve operation life tester according to claim 1, characterized in that: The number of solid-state relays, output points of the PLC and valves under test is multiple, forming multiple independent test channels.

5. The portable high reliability valve operation life tester according to claim 4, characterized in that: The multiple test channels are configured to work independently or cooperatively.

6. The portable high reliability valve operation life tester according to claim 1, characterized in that: An alarm device is further included, which is connected between the positive terminal of the switching power supply and an alarm output point of the PLC.

7. The portable high reliability valve operation life tester according to claim 1, characterized in that: A portable housing is further included, and the switching power supply, the PLC, the input module and the solid-state relay are integrated in the portable housing.

8. The portable high-reliability valve operation life tester according to claim 7, characterized in that: The portable housing is in the form of a suitcase.

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