Vacuum pump oil changing device

Abstract

A kind of vacuum pump oil changing device, characterized in that, including main control module, signal detection module, alarm device, valve and first container and second container.The first container and second container are connected with the oil inlet of vacuum pump and the oil outlet of vacuum pump respectively by pipeline, first container is installed or placed at the position higher than the oil inlet of vacuum pump, and oiling valve is arranged between first container and the oil inlet of vacuum pump, and second container is installed or placed at the position lower than the oil outlet of vacuum pump, and oil drain valve is also arranged between second container and the oil outlet of vacuum pump.The signal detection module is installed in the working circuit of vacuum pump, and signal detection module sends the running signal of vacuum pump to main control module, and main control module can accumulate timing to the running time of vacuum pump.

Description

Technical Field

[0001] This utility model relates to the field of vacuum equipment, specifically to a vacuum pump oil changing device. Background Technology

[0002] Vacuum pumps are frequently used equipment in laboratories and industrial production. For vacuum pumps that require frequent oil changes to ensure normal operation, manual operation is currently the norm. However, due to installation issues or site limitations—for example, many rotary vane pumps used in laboratories are placed in corners or under lab benches—it's difficult to determine the optimal oil change time. Firstly, these devices are typically heavy, requiring them to be moved from the ground to a higher position for oil changes. Secondly, changing the oil necessitates dismantling the vacuum piping, which can easily lead to oil contamination and leaks. More importantly, the optimal oil change time is difficult to determine due to varying usage frequencies. Regular oil changes are suitable for vacuum pumps that operate continuously without interruption, but in laboratory settings, usage frequency is inconsistent. Some pumps are only used occasionally when needed for experiments. In some cases, they may only be used a few times a month. However, other times, different requirements necessitate frequent and prolonged operation. This situation makes it difficult for users to accurately judge oil change times. While an oil immersion lens can be used to observe the oil contamination, the location of the vacuum pump may make observation inconvenient. Therefore, a device or method is needed to simplify the process of changing vacuum pump oil. This ensures timely replacement of the vacuum pump oil. On one hand, it prevents a decrease in vacuum pump efficiency and avoids pump aging or damage. On the other hand, considering the high price of certain grades of vacuum pump oil, proper oil changes prevent unnecessary waste, which, from a long-term perspective, greatly benefits environmental protection and resource conservation.

[0003] To achieve automatic oil changes in vacuum pumps, many existing technologies employ various methods, most relying on additional pumps for extraction or compressed air for filling and evacuation. While feasible, this approach is problematic for laboratory environments, especially for rotary vane vacuum pumps. Adding an extra pump increases equipment costs and the likelihood of system malfunction. Maintenance and repair become more complex. Furthermore, adding an oil pump doesn't address determining the optimal oil change time, nor does it prevent oil waste or damage from prolonged use of inferior oil. Therefore, it's not the best solution. Regarding automatic oil change detection and implementation, some solutions have been disclosed, such as the utility model patent (CN 205578229 U), which uses compressed air for oil changes and a counter to determine the optimal time. However, this solution primarily targets large-scale units. For general users, especially in laboratories, this approach may not be suitable. Even with multiple vacuum pumps, it's difficult to coordinate their placement, hindering centralized air supply. Especially when using compressed air for filling, air compressors, air tanks, and complex piping are required. This approach places certain demands on the site and application environment. Furthermore, equipping one or a few vacuum pumps with air compressors and related equipment for automatic oil changes can incur significant additional costs. Purchasing an air compressor incurs extra expenses, in addition to piping and construction costs. The total cost, after calculation, may far exceed the value of the vacuum pump itself. The method for determining oil change timing described in utility model patent CN 205578229 U is based on the number of vacuum pump starts. The technical solution uses a counter and controller to set a certain number of pump starts. When the set number of starts is reached, the vacuum pump stops and activates various valves to replace the pump oil using compressed air. This solution is highly suitable for vacuum pumps operating in specific environments and with limited workloads. However, for individual or laboratory users, the operating conditions and environments of each pump can vary greatly. In other words, many pumps do not actually run continuously for extended periods. For example, depending on the individual user or the specific experimental needs, sometimes two hours of operation is sufficient, while other times continuous operation for over ten hours is required. Therefore, using the number of times the pump is turned on to determine the optimal oil change time is clearly inappropriate, as the duration of each operation is inconsistent. More importantly, the pump's operating conditions and environment must be considered. Some pumps are used to extract general air, such as suction cups in electromechanical devices or for degassing liquids, while others are used in scenarios with high water content, such as freeze dryers.Some pumps may be used to extract toxic or corrosive gases, such as in rotary evaporators, while others are used to extract high-temperature or other harmful gases, such as in vacuum drying ovens. In short, the lifespan of pump oil can vary significantly depending on the equipment the vacuum pump is used with or the operating environment. Therefore, relying on the number of times the pump is run to determine when to change the oil may be more suitable for vacuum pumps operating under specific conditions in a factory, but it is not applicable to all scenarios. Utility Model Content

[0004] Based on the above problems, in practical applications and production, there is a need for a device that can accurately determine the oil change time of a vacuum pump, simplify the oil change process, and reduce the workload of oil change.

[0005] To achieve the above objectives, the present invention adopts the following technical solution.

[0006] A vacuum pump oil changing device includes a main control module, a signal detection unit, a container, and a valve. The main control module can be a timer or a PLC. The signal input terminal of the main control module is connected to the signal detection unit, which is installed in the vacuum pump body or the working circuit. The signal detection unit can be a current transformer, voltage / current transmitter, flow rate sensor, speed sensor, or relay, etc. Voltage, current, or switching signals from the signal detection unit are input to the main control module, which accumulates the working time of the vacuum pump based on the signals from the signal detection unit. The control signal output terminal of the main control module drives the relay and the vacuum pump or alarm device such as a buzzer connected to the relay. The main control module also has a reset port for resetting the timing signal. The container includes a first container and a second container. The first container and the second container are respectively connected to the oil filling port and the oil drain port of the vacuum pump through pipes. The first container is installed or placed above the oil filling port of the vacuum pump and an oil filling valve is provided between the first container and the oil filling port of the vacuum pump. The second container is installed or placed below the oil drain port of the vacuum pump and an oil drain valve is also provided between the second container and the oil drain port of the vacuum pump.

[0007] Optionally, the signal detection unit can also be a turbidity detector or a liquid color sensor. The detector or sensor is installed at the oil immersion sight of the vacuum pump to assist other monitoring units in making a comprehensive judgment on the quality of the vacuum pump oil.

[0008] Preferably, the first and second containers, along with the vacuum pump, can be mounted on a three-tiered shelf, with the vacuum pump on the middle tier, the first container on the top tier, and the third container on the bottom tier. The shelf may also be equipped with casters at the bottom for easy transport.

[0009] Optionally, the main control module can be a PLC. When the main control module is a PLC, the vacuum pump operation signal from the signal detection unit is sent to the signal input terminal of the PLC. The control signal output terminal of the PLC can be directly connected to a low-power vacuum pump, or connected to a high-power vacuum pump through relays, AC contactors, etc. The PLC can be set so that when the vacuum pump's running time reaches a preset value but no oil draining or zeroing operation is performed, the vacuum pump can continue to run, but after this shutdown, it will not be able to start next time. The PLC can also be set so that when the vacuum pump's running time reaches the PLC's preset time, the alarm signal output from another signal output terminal of the PLC will drive the buzzer or indicator light connected to it to sound an alarm, prompting the user to change the pump oil in time. At this time, the user only needs to manually open the oil drain valve and the oil filler valve to change the pump oil after stopping the machine. After the change is completed, the timer of the PLC can be reset by using the zeroing button connected to the PLC.

[0010] Besides the PLC, the main control module can also be a timer or a timing module with input / output (such as the SD76 timer from Shanding Electronics or the ZN48 measuring relay from Xinling Electronics). When the vacuum pump's operating signal is transmitted through a corresponding signal detection unit, such as a YN8588V wind speed sensor installed at the vacuum pump's exhaust port, an E35-SFD11 infrared photoelectric sensor installed on the vacuum pump motor fan blade cover, or an AC contactor or relay installed at the vacuum pump's power supply terminal, these signal acquisition units transmit the voltage, current, or switching signals of the vacuum pump during operation to the timer's signal input terminal. When the timing parameter reaches the set duration, the timer output terminal outputs an alarm signal, prompting the user to perform an oil change operation.

[0011] One method of using this device involves pre-setting the maximum operating time on the main control module and starting or stopping the vacuum pump via a button connected to the main control module. The cumulative operating time of the vacuum pump does not depend on an external signal detection unit; instead, the main control module directly controls or drives the port connected to the vacuum pump's power supply terminal, or the relays or AC contactors connected to these ports, to time the cumulative power supply time. When the timer reaches the set value, the main control module issues an alarm signal to drive a buzzer and / or indicator light. This prompts the user to change the pump oil. Following the prompts, the user can promptly understand the pump oil status. The pump oil can be changed by turning off the machine and opening the corresponding valve after each use or during the current use. After oil change, a zeroing operation can be performed to allow the device to enter the next operation cycle. Because the usage scenarios for each pump are different, users can experiment or calculate a reasonable pump oil usage time based on recommendations or their own usage conditions to set a targeted usage time. To ensure the reliability of the oil change time, other sensors can also be equipped. Sensors such as turbidity sensors or liquid color sensors can be installed on the oil sump of the vacuum pump. An alarm will be triggered immediately if any discoloration or abnormal liquid level is detected in the pump oil.

[0012] In other embodiments, the alarm information output terminal of the main control module can also be connected to a relay or an AC contactor. These devices can, on the one hand, drive alarm devices with higher power. On the other hand, they can form a self-locking circuit with the vacuum pump switch. This self-locking circuit ensures that if the vacuum pump switch is turned off without oil changing and circuit resetting when an alarm signal is issued, the vacuum pump will not be able to restart. This design is based on considerations of noise levels in laboratory or other production environments, and the fact that the pump's installation location may not be convenient for users to promptly detect alarm information. For example, if the vacuum pump is placed in another room, under a test bench, or in a cabinet at the bottom of a fume hood, continuous noise in the laboratory or other operating environment can easily cause an alarm to occur but go unnoticed. In this case, the entire device will not function as intended. Therefore, by setting the device so that the vacuum pump cannot start when the preset oil change time has been reached without oil changing and resetting, the user can easily understand and detect the situation, thus preventing the entire device from failing.

[0013] In some other embodiments, the corresponding signal detection unit located in the vacuum pump's operating circuit or on the vacuum pump can not only detect and transmit the vacuum pump's operating signals, but also transmit the electrical signals indicating the vacuum pump's operating status to the PLC. When the PLC receives signals such as vacuum pump operating current parameters, motor rotation parameters, or exhaust gas flow parameters, the PLC can compare the received signals according to preset parameters. If the parameters are significantly abnormal, an alarm will be issued to promptly alert the user. These include current transformers installed on the vacuum pump's power line, infrared speed sensors installed on the vacuum pump motor impeller casing, anemometers or flow meters installed at the vacuum pump's exhaust port, and temperature sensors installed on the pump body. These sensors can not only detect whether the vacuum pump is running and send the operating signals to the PLC for cumulative timing, but also supplement the judgment of the optimal oil change time based on changes in the detected parameters. These sensors can all detect the actual operating status of the vacuum pump, so they can be installed individually on the vacuum pump or several can be installed simultaneously on the vacuum pump. Through multi-parameter coordination, multiple signals are sent to the PLC for comprehensive judgment of various parameters. When this sensor is used for multiple purposes, its synergistic operation allows for more accurate and reliable assessment of the pump oil condition. Through extensive experience in vacuum pump repair, the applicant has discovered that in laboratory environments, when rotary vane vacuum pumps extract high-temperature, acidic, or high-humidity gases, the pump oil undergoes adverse changes far below the recommended replacement interval. These changes are manifested through variations in motor operating current, exhaust velocity, and pump body temperature. For example, prolonged extraction of high-temperature gases may cause oxidation and polymerization of the pump oil, increasing its viscosity. Similarly, when extracting high-humidity gases, the pump oil may emulsify and increase in viscosity. Increased viscosity pump oil flowing within the vacuum pump increases the agitation resistance within the pump chamber and the friction between the oil and internal pump components. This requires the motor to output more power to maintain normal operation, resulting in an increased motor operating current. Furthermore, a decline in pump oil performance can also lead to fluctuations in motor current. For example, when pumping acidic gases, the additives in the pump oil are consumed, resulting in decreased performance and poorer lubrication and cooling of the pump's internal metal components. This leads to increased wear between components and potential changes in clearances. This causes instability in the pump's internal motion resistance, resulting in fluctuations in the motor's operating current. Pump oil contamination can also cause blockages in the exhaust passage. When pumping gases containing impurities, tiny particles carried by the gas or water droplets in high-humidity gases can mix into the pump oil and gradually accumulate, clogging exhaust valves or exhaust pipes. This hinders the normal discharge of gas, causing a decrease in exhaust velocity.In summary, when pump oil deteriorates due to the extraction of special gases, such as undergoing oxidation or decomposition to generate polymers or gel-like substances, these substances will deposit on the surfaces of key components inside the pump, such as the rotor and vanes. This affects their movement and sealing performance, increasing the pump's operating current and reducing its pumping efficiency, leading to current fluctuations and a decrease in exhaust velocity. Under normal circumstances, pump oil can remove heat generated inside the pump from compressed gases. However, when pump oil becomes contaminated or contains impurities, it can cause wear and tear on the pump's mechanical structure, increasing friction in rotating parts during operation and causing the pump body temperature to rise continuously. These are all signs that indicate the need for pump oil replacement. Therefore, these detection devices provide a reliable auxiliary detection method in addition to scheduled oil replacement, compensating for the difficulty in determining the appropriate oil replacement time for vacuum pumps operating under special gas conditions.

[0014] Preferably, to ensure the actual implementation of the oil change operation, a sensor can be installed on the oil change valve. This sensor can be a microswitch or photoelectric switch, etc. When the sensor detects the opening and closing of the corresponding valve, it sends a signal to the corresponding port of the main control module as a zeroing or reset signal. Since the volume of the vacuum pump is fixed, the oil draining and oil change time is also relatively fixed. Therefore, after the sensor on the valve sends the oil change signal to the main control module, the module can detect and judge the oil draining and oil change time through a pre-designed time. When the time reaches a certain range, that is, to ensure that the pump has completed the oil change within this time, the corresponding signal output terminal of the main control module outputs a signal. This signal serves as a reset signal for the vacuum pump's operating time and can be directly connected to the reset circuit, or it can be used in conjunction with a manual reset button, such as in series. This avoids unauthorized operation by the user. For example, when the oil should be changed, in order to eliminate the interference of the alarm signal, the user may manually zero the valve without changing the oil, thus causing the protection device to fail.

[0015] In other embodiments, to further automate oil changes and achieve unattended operation, the corresponding valves were replaced with solenoid valves. The solenoid valves are controlled by control signals output from the main control module to open or close within a specified time, replacing manual valve operation. To accurately determine the valve opening time, a signal detection unit or a solenoid valve with signal feedback can be incorporated into the solenoid valve's operating circuit. For more accurate control of the vacuum pump's oil dispensing and refilling, a sensor can be installed at the vacuum pump's oil level gauge to monitor the oil level. The sensor's detection signal is sent to the main control module to control the start and stop of the corresponding solenoid valves.

[0016] In some other embodiments, to quickly achieve the oil change function, a three-way solenoid valve is also provided at the vacuum pump's suction port. The three ports of this three-way solenoid valve are respectively connected to the vacuum pump's suction port, the evacuated pipeline, and the second container. A second solenoid valve is also provided between the three-way valve and the second container. The second container is connected to the vacuum pump's oil drain port via an oil drain solenoid valve, and the second container has a top cover, which makes it a sealed container. An oil filler solenoid valve is provided between the vacuum pump's oil filler port and the first container. When the main control module outputs the corresponding oil change signal, the three-way solenoid valve connected to the vacuum pump's suction port operates, closing the evacuated pipeline and simultaneously opening the pipeline connected to the second container and the second solenoid valve. At this time, the vacuum pump will evacuate the second container. Since the volume of the second container is much larger than the volume of the vacuum pump's internal cavity, when the evacuation time reaches a certain value, the second solenoid valve between the second container and the three-way valve closes, and the vacuum pump stops. The oil drain solenoid valve located between the vacuum pump's oil drain port and the second container opens, at which point the negative pressure inside the second container is released. Oil in the vacuum pump is rapidly drawn into the second container. Based on the discharge time or the sensor at the oil level indicator, once the oil in the pump is completely discharged, the drain solenoid valve between the vacuum pump's drain port and the second container closes. Then, the fill solenoid valve between the vacuum pump's fill port and the first container opens, connecting the first container to the vacuum pump's fill port. Pump oil in the first container is then rapidly drawn into the vacuum pump due to the negative pressure inside the vacuum pump. When the signal detection unit detects that the fill process has lasted for a certain period or determines from the sensor signal at the oil level indicator that the oil level is sufficient, the fill solenoid valve closes, and the main control module resets, resetting all solenoid valves and related timers. This allows the entire system to begin the next process.

[0017] Preferably, in order to ensure that the vacuum pump oil is not contaminated, a top cover can be installed on the open first container, and a one-way valve can be installed on the top cover. The one-way valve allows air to enter the first container in one direction so as to facilitate pressure balance inside and outside the container when adding oil.

[0018] Compared to existing technologies, this invention achieves pump oil discharge and filling by rationally arranging the positions of the vacuum pump and various containers, utilizing gravity and atmospheric pressure, without relying on external extraction facilities or external power support. Furthermore, this invention, through corresponding sensors based on the vacuum pump's operating parameters, cumulative operating time, and / or by monitoring the physical condition of the pump oil, can more accurately determine the timing of pump oil replacement. When used in conjunction with other components such as solenoid valves and relays, it can avoid the problem of alarm information being difficult to detect in complex situations and prevent alarm prompt failure due to improper operation. It also enables unattended and automated pump oil replacement. Attached Figure Description

[0019] Figure 1 is a schematic diagram of the connection structure of each component in Embodiment 1 of this utility model.

[0020] Figure 2 is a schematic diagram of the connection structure of each component in Embodiment 2 of this utility model.

[0021] Figure 3 is a schematic diagram of the connection structure of each component in Embodiment 3 of this utility model.

[0022] In the diagram: 1. Live wire; 2. Neutral wire; 3. Main control module; 4. Reset button; 5. First relay; 6. Switch; 7. Indicator light; 8. Buzzer; 9. Signal detection unit; 10. Vacuum pump; 11. Second relay; 12. Signal detection unit 2; 13. Third relay; 14. Fourth relay; 15. Drain valve; 16. Filling valve; 17. Fifth relay; 18. Signal detection unit 3. Detailed Implementation

[0023] To make the technical solution of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. Example 1

[0024] As shown in Figure 1, this utility model mainly includes 3. main control module, 4. reset button, 5. relay, 6. switch, 7. indicator light, 8. buzzer, 9. signal detection unit, and 10. vacuum pump.

[0025] In addition, this embodiment also includes a first container installed or placed above the vacuum pump filling port and a second container installed or placed below the vacuum pump drain port, a filling valve disposed between the first container and the vacuum pump filling port, and a drain valve disposed between the vacuum pump drain port and the second container.

[0026] Preferably, the main control module 3 is a PLC, such as the OSM-16R-2AI-PUL simple PLC from Aoshangming, or the QJ-24R2 simple PLC from Huaqingjun. The signal detection unit 9 is a voltage transmitter.

[0027] The first container is installed or placed at a position higher than 10° of the vacuum pump filler port, and the second container is installed or placed at a position lower than 10° of the vacuum pump drain port. The first container is connected to the vacuum pump filler port via a pipe, and a valve is provided between the first container and the vacuum pump filler port. The second container 20 is also connected to the vacuum pump drain port via a pipe, and a valve is also provided between the second container and the vacuum pump drain port.

[0028] When the main control module 3 uses a 220V powered PLC, its power supply terminal is connected to the neutral wire 2 and the live wire 1. If DC power is used, the neutral wire 2 and the live wire 1 are connected to the main control module 3 through the corresponding power supply module. The signal input terminal of the main control module 3 is connected to the signal detection unit 9. The signal detection unit 9. is a voltage transmitter. The I terminal of switch 6 is connected to the live wire, and the O terminal of switch 6 is connected to the motor of vacuum pump 10. When switch 6 is closed, the motor of vacuum pump 10 receives voltage and starts to work. At this time, the signal detection unit 9. installed at the O terminal of switch 6 sends the collected voltage signal to the main control module 3 for cumulative timing. A predetermined working time of vacuum pump 10 is set on the main control module 3. When the cumulative working time of the signal sent from the signal detection unit 9. reaches the preset working time, the signal output terminal of the main control module 3 outputs a control signal. This control signal is sent to relay 5 through the line. When relay 5 receives the control signal from the main control module, relay 5 works. The contacts engage, energizing the buzzer 8 and indicator light 7. The alarm circuit activates, alerting the user to change the pump oil. To change the pump oil, the user simply needs to open the drain valve 15 (located between the vacuum pump 10's drain port and the second container) after stopping the pump, allowing the waste oil to flow completely into the second container. Then, close the drain valve 15 and open the filler valve 16. Once the filler is complete, close the filler valve 16 to finish changing the vacuum pump oil. Finally, press the reset button 4 to reset the timer on the main control module 3. The entire system can then resume operation.

[0029] Preferably, the first and second containers, along with the vacuum pump, can be mounted on a three-tiered shelf, with the vacuum pump 10 on the middle tier, the first container on the top tier, and the third container on the bottom tier. The shelf may also be equipped with casters at the bottom for easy transport.

[0030] Preferably, the signal detection unit can also be a current transformer, a wind speed sensor, an infrared photoelectric switch, a temperature sensor, etc. These can all be used to collect operating signals of the vacuum pump, such as the current on the power supply line when the vacuum pump is running, the airflow velocity at the exhaust port when the vacuum pump is working, the rotation signal of the vacuum pump motor blades detected by the infrared photoelectric switch, and the significant increase in pump body temperature compared to the ambient temperature within a few minutes of vacuum pump operation. These signals can not only serve as feedback signals for vacuum pump operation, but also reflect the working status of the vacuum pump. For example, a sudden and sharp increase in the operating current indicates power overload, winding short circuit, jamming of rotating parts of the vacuum pump, or bearing abnormality. These signals are fed back to the PLC, which automatically compares the preset normal operating parameters or the relevant parameter values ​​in the alarm conditions to determine the abnormality of the vacuum pump and issue a timely warning (e.g., triggering an alarm when the current continuously exceeds the rated value by 15%). Similarly, the wind speed sensor at the vacuum pump exhaust port and the infrared photoelectric sensor that collects the rotation signal of the vacuum pump motor blades can also reflect the abnormal state of the vacuum pump. For example, if the airflow is consistently lower or higher than normal, it indicates exhaust obstruction or a decrease in vacuum. For example, if a photoelectric sensor detects that the motor rotation is consistently below normal, it indicates that the load is excessive, or there may be a winding fault or bearing jamming. Since these signal detection units can independently acquire and feedback the vacuum pump's operating signals, in addition to being used individually to achieve their main functions, multiple units can be installed and used in conjunction. This not only fulfills the functions required by this technical solution but also offers the synergistic advantages of multi-functionality.

[0031] Optionally, the main control module 3 can also be a timer or timer module with signal output function (such as the SD76 timer from Shanding Electronics). When the main control module 3 is a timer or timer module, it can accumulate the signal sent by the signal detection unit 9. When the count reaches the set value, its corresponding signal output terminal outputs a voltage or switching signal, which is sent to the relay 5 or the alarm device.

[0032] Optionally, in some application scenarios, to simplify the circuit, the signal output terminal of the main control module 3 can also be directly connected to an alarm device such as an indicator light or a buzzer.

[0033] Optionally, in some embodiments, the PLC can be a model with integrated high-power relay output. When the PLC has a high-power relay output, the PLC output terminal can be directly connected to and drive a low-power vacuum pump. After the signal detection unit sends the vacuum pump's operating signal to the corresponding port of the PLC, the PLC monitors the cumulative running time of the vacuum pump. When the vacuum pump's running time reaches the PLC's set value, the corresponding port of the PLC can output an alarm signal to drive the alarm device. In addition, the PLC can also be set so that when its running time reaches a preset duration, after the vacuum pump is turned off after this use, if the corresponding signal input terminal of the PLC does not receive a change in the oil change signal from the oil sight glass sensor, or the opening / closing duration signal of the corresponding sensor at the valve does not reach the normal opening / closing duration, or the zeroing button is not pressed, the vacuum pump cannot be restarted.

[0034] Optionally, the oil filling valve located between the first container and the vacuum pump filling port, and the oil drain valve located between the vacuum pump drain port and the second container, can be solenoid valves. When using solenoid valves, the power supply line of the solenoid valve is connected to the control signal output terminal of the main control module (taking Huaqingjun QJ-24R2 simple PLC as an example). When the timing parameter or sensor monitoring parameter triggers the set value (such as when the timing time reaches the set value or the vacuum pump operating current continuously exceeds the rated value by 15%), the control signal output terminal of the main control module issues an alarm. After the vacuum pump finishes its current operation, it automatically outputs a control signal to open the oil drain solenoid valve. The opening time is determined by the oil drain time set on the main control module. After oil draining is completed, the main control module cuts off the power supply signal to the oil drain solenoid valve and connects the power supply line to the oil filling solenoid valve. The oil filling time is determined by the oil filling time set on the main control module. After the oil filling time is reached, the main control module cuts off the power supply line to the oil filling solenoid valve and clears the timing parameter to zero. It waits for the next start signal to trigger the cumulative timing of the next process.

[0035] Optionally, the main control module may also be connected to a wireless module. The wireless module connects to a mobile phone or computer via Bluetooth or Wi-Fi. After connection, the user can receive alarm information from the device on the mobile phone or computer software. Example 2

[0036] As shown in Figure 2, this embodiment adds a second relay 11 to the original embodiment 1, and disconnects the line originally connected to the I terminal of switch 6. The normally closed terminal of the first relay 5 is connected to the I terminal of switch 6, while the O terminal of switch 6 is connected to the motor of vacuum pump 10, just as in embodiment 1. The coil of the second relay 11 is connected to the neutral wire 2 and the O terminal of switch 6, respectively. At the same time, the common terminal of the second relay 11 is connected to the ignition wire 1, and the normally open terminal of the second relay 11 is connected to the I terminal of switch 6 to form a self-locking circuit.

[0037] Optionally, the main control module in this embodiment can be a PLC or a multi-channel timing module.

[0038] Optionally, a sensor may also be installed at the manual knob of the filler valve 16 and / or the drain valve 15. This sensor can be a microswitch, photoelectric switch, or other proximity sensor. The sensor signal can be sent to the corresponding timing channel of the main control module 3 (PLC or multi-channel timing module). The main control module (PLC or multi-channel timing module) can time the signals from the sensors located at the filler valve 16 and / or the drain valve 15. The PLC or multi-channel timing module can only be reset when the valve opening / closing time matches the set time required for oil change. In other words, a judgment condition regarding the sensor signal at the filler valve and / or the drain valve can be set in the PLC. The reset button 4 or automatic reset function can only function effectively when the corresponding valve action time matches the preset time. Otherwise, it cannot be reset. When the main control module uses a multi-channel timing module, the sensor signals from the refueling valve 16 and / or the drain valve 15 are sent to the corresponding timing channel of the timer. When the timing of this channel meets the set value, the corresponding port of the multi-channel timer outputs a signal. This signal can be used directly as a reset signal or to drive a relay connected in series with the reset button 4. Only when the signal output from the relevant path of the multi-channel timer drives the relay to activate can the reset button 4 connected in series with the relay be reset normally. Example 3

[0039] As shown in Figure 3, this embodiment adds a signal detection unit 2, a third relay 13, a fourth relay 14, a fifth relay 17, and a signal detection unit 3 to the original embodiment 2. Furthermore, in this embodiment, the original refueling valve and drain valve are replaced with solenoid valves 15 and 16.

[0040] The coil of the third relay 13 is connected to the normally closed terminal of the second relay 11 and the normally closed terminal of the fourth relay 14. The common terminal of the third relay is connected to the normally open terminal of the first relay. The normally open terminal of the third relay is connected to one end of the coil of the refueling solenoid valve 15, and the other end of the coil of the refueling solenoid valve 15 is also connected to the normally closed terminal of the fourth solenoid valve 14. A signal detection unit 2 (a voltage transmitter) is installed on the connection line between the coil of the third relay 13 and the normally closed terminal of the second relay. The live wire terminal of the signal detection unit 2 is connected to the normally open terminal of the first relay, and the neutral wire terminal is connected to the neutral wire 2. The signal output terminal of the signal detection unit is connected to the main control module. The fourth relay is a DC relay. One end of its coil is connected to the signal output terminal of the main control module, and the other end is connected to DC ground. Its common terminal is connected to neutral line 2. Its normally closed terminal is connected to the coil of the third relay 13 and the coil of the drain solenoid valve 15. Its normally open terminal is connected to the coil of the filler solenoid valve 16. The other end of the coil of the filler solenoid valve 16 is connected to the normally open terminal of the first relay 5. When the vacuum pump runs for a set time, the first relay 5 is energized, and the normally open terminal of the first relay is powered, triggering an audible and visual alarm. If switch 6 is not disconnected at this time, the vacuum pump is still running, and the second relay is also energized. Therefore, the normally closed terminal of the second relay is not connected, and the coil of the third relay is not powered and cannot work. Only when switch 6 is disconnected and the vacuum pump stops, the normally open terminal of the second relay is released, and the normally closed terminal is connected. At this time, the live wire 1 is connected to the coil of the third relay, and the live wire passes through the coil of the third relay to the normally closed terminal of the fourth relay. The normally closed terminal of the fourth relay is connected to neutral line 2. The third relay is thus energized, and its normally open contact is closed. The voltage signal from the normally open terminal of the first relay is then connected to the coil of the drain solenoid valve 15. The other end of the coil of the drain solenoid valve 15 is connected to the neutral wire through the normally closed terminal of the fourth relay, thereby causing the drain solenoid valve to be attracted. The waste oil in the vacuum pump is discharged into the second container through this solenoid valve.Signal detection unit 2, located on the coil of the third relay 13, sends the working signal of the third relay 13 to the main control module 3. The main control module 3 determines, based on the working signal of the third relay 13, that when the discharge time reaches the set value, it outputs a control signal from the corresponding port. This control signal is sent to the working coil of the fourth relay 14, causing the fourth relay 14 to engage. When the fourth relay 14 engages, its normally closed terminal disconnects, connecting to its normally open terminal, thus stopping the third relay 13 and closing the drain solenoid valve 15. Since the fourth relay 14 is connected to the coil of the fill solenoid valve 16, when the drain solenoid valve 15 closes, the fill solenoid valve 16 opens, allowing the vacuum pump oil in the first container to flow into the vacuum pump through the fill solenoid valve 16. Signal detection unit 3 is located at the oil sight glass of the vacuum pump. After the signal detection unit 3 detects that the vacuum pump oil level has reached the preset value, it sends a signal to the coil of the fifth solenoid valve 17. When the fifth solenoid valve 17 is energized and engaged, it connects the reset terminal of the main control module 3, resetting the entire circuit. This allows the next process to begin.

[0041] Optionally, the solenoid valve may also be a solenoid valve with signal feedback, the feedback signal of which is sent to the main control module.

[0042] Optionally, the signal detection unit 3 can also be a voltage transmitter. When the signal detection unit 3 is a voltage transmitter, it is connected to the working circuit of the refueling solenoid valve 16 and inputs the working signal of the refueling solenoid valve 16 to the main control module 3. The main control module 3 uses this signal to detect the working time of the refueling solenoid valve to determine whether refueling is complete. When the refueling time reaches the preset value, the main control module automatically resets to zero and starts the next working process. Of course, the main control module can also be equipped with a manual reset button so that the user can confirm the refueling result and manually reset. Example 4

[0043] To quickly achieve the oil change function, this embodiment, based on Embodiment 2 or Embodiment 3, also includes a three-way solenoid valve at the vacuum pump's suction port. The three ports of this three-way solenoid valve are connected to the vacuum pump's suction port, the evacuated pipeline, and the second container, respectively. A second solenoid valve is located between the three-way valve and the second container. The second container is connected to the vacuum pump's oil drain port via an oil drain solenoid valve 15, and the second container also has a top cover, which makes the second container a sealed container. An oil filling solenoid valve 16 is located between the vacuum pump's oil filling port and the first container. When the main control module outputs a corresponding oil change signal, the three-way solenoid valve connected to the vacuum pump's suction port operates, closing the evacuated pipeline and simultaneously opening the pipeline connected to the second container and the second solenoid valve. At this time, the vacuum pump will evacuate the second container. Since the volume of the second container is much larger than the volume of the vacuum pump's internal cavity, when the evacuation time or vacuum level reaches a certain value, the second solenoid valve between the second container and the three-way valve closes, and the vacuum pump stops. At this time, the oil drain solenoid valve located between the vacuum pump drain port and the second container opens. Due to the negative pressure inside the second container, the oil in the vacuum pump is quickly drawn into the second container. Based on the discharge time or the sensor at the oil level indicator, once the oil in the pump has been completely drained, the oil drain solenoid valve between the vacuum pump drain port and the second container closes. At this time, the main control module controls the filling solenoid valve between the vacuum pump filling port and the first container to open, connecting the pipeline between the first container and the vacuum pump filling port. The pump oil in the first container is quickly drawn into the vacuum pump due to the negative pressure inside the vacuum pump cavity. When the signal detection unit detects that the filling activity has reached a certain time or determines from the sensor signal at the oil level indicator that the oil level is sufficient, the filling solenoid valve 16 closes, and the main control module 3 resets, resetting all solenoid valves and related timers. This allows the entire system to begin the next process.

[0044] Optionally, the first container can be an open container or a sealed container with a lid. When the first container is a sealed container with a lid, a one-way valve is provided on the top cover of the first container or above the liquid surface of the first container. This one-way valve allows external air to flow into the first container in one direction to ensure the pressure balance inside and outside the first container.

Claims

1. A vacuum pump oil changing device, characterized in that: The system includes a main control module, a signal detection unit, containers, and valves. The signal input terminal of the main control module is connected to the signal detection unit installed on the vacuum pump's operating circuit and / or the vacuum pump body. After the vacuum pump's operating signal from the signal detection unit is input to the main control module, the main control module uses this signal to accumulate the vacuum pump's operating time. When the timing result reaches a set value, the control signal output terminal of the main control module outputs an electrical signal, which drives an alarm device and / or controls the vacuum pump motor to stop operating. The containers include a first container and a second container. The first container is placed above the vacuum pump's filler port, and a filler valve is installed in the pipe between the first container and the vacuum pump's filler port. The second container is placed below the vacuum pump's drain port, and a drain valve is installed in the pipe between the second container and the vacuum pump's drain port.

2. The vacuum pump oil changing device as described in claim 1, characterized in that: The signal detection unit also includes a second signal detection unit installed at the oil sight glass. The second signal detection unit inputs the oil pumping detection signal into the main control module. When the main control module receives an abnormal electrical signal from the second signal detection unit regarding the oil pumping, it issues an alarm first.

3. A vacuum pump oil changing device as described in claim 1 or claim 2, characterized in that: The first and second containers, along with the vacuum pump, can be mounted on a three-tiered shelf, with the vacuum pump on the middle tier, the first container on the top tier, and the second container on the bottom tier. The shelf can also be equipped with casters at the bottom for easy transport.

4. The vacuum pump oil changing device as described in claim 1, characterized in that: The refueling valve and the drain valve are also equipped with sensors, and the signal output terminals of the sensors are connected to the main control module.

5. The vacuum pump oil changing device as described in claim 1, characterized in that: The signal output terminal of the main control module can also be connected to the first relay. The first relay is driven by the control signal of the main control module. The common terminal of the first relay is connected to the live wire. The normally open terminal of the first relay is connected to an indicator light and / or a buzzer. The normally closed terminal of the first relay is connected to the normally open terminal of the second relay and the power switch I terminal of the vacuum pump. The coil of the second relay is connected to the neutral wire and the power switch O terminal of the vacuum pump. The common terminal of the second relay is connected to the live wire, and the normally open terminal of the second relay is connected to the power switch I terminal of the vacuum pump to form a self-locking circuit. The O terminal of the vacuum pump power switch is finally connected to the vacuum pump motor.

6. The vacuum pump oil changing device as described in claim 5, characterized in that: The refueling valve and the drain valve are solenoid valves, and their coils are directly connected or connected to the corresponding control signal output terminals on the main control module through intermediate relays.

7. The vacuum pump oil changing device as described in claim 6, characterized in that: The device also includes a third relay (13) and a fourth relay (14), as well as signal detection units 2 (12) and 3 (18). The coil of the third relay (13) is connected to the normally closed terminals of the second relay (11) and the fourth relay (14) respectively. The normally open terminal of the third relay (13) is connected to one end of the coil of the refueling solenoid valve (16), and the other end of the coil of the refueling solenoid valve (16) is connected to the normally closed terminal of the fourth relay (14). One end of the coil of the fourth relay (14) is connected to the DC or AC signal output terminal of the main control module (3), and the other end of the coil of the fourth relay (14) is connected to the DC ground or neutral line. The common terminal of the fourth relay (14) is connected to the power supply circuit. The neutral wire, the normally closed terminal of the fourth relay (14) is connected to the coil of the refueling solenoid valve (16) and the coil of the third relay (13) respectively. The normally open terminal of the fourth relay (14) is connected to one end of the coil of the drain solenoid valve (15). The other end of the coil of the drain solenoid valve (15) is connected to the normally open terminal of the first relay (5). The signal detection unit 2 (12) is installed in the working circuit of the third relay (13). Its signal output terminal is connected to the corresponding signal input terminal of the main control module (3). The signal detection unit 3 (18) is installed at the oil sight glass of the pump body or in the working circuit of the refueling solenoid valve (16). The output signal of the signal detection unit 3 (18) is directly connected to or connected to the signal input terminal of the main control module (3) through the relay.

8. A vacuum pump oil changing device as described in claim 6, characterized in that... The vacuum pump has a three-way solenoid valve at its suction port. The first port of the three-way solenoid valve is connected to the suction port of the vacuum pump, the second port of the three-way solenoid valve can be connected to the equipment that needs to be evacuated, and the third port of the three-way solenoid valve is connected to a second solenoid valve. The second solenoid valve is connected to a second container. The second container can be made into a sealed cavity by means of a top cover. The second container is connected to the inner cavity of the pump body through a pipe and an oil drain valve, and the volume of the second container is larger than the volume of the inner cavity of the vacuum pump.

9. The vacuum pump oil changing device as described in claim 1, characterized in that: The main control module is also connected to a wireless module, which can connect to a mobile phone or computer via Bluetooth or WIFI signal.

10. A vacuum pump oil changing device as described in claim 1, characterized in that: The refueling valve and the drain valve are solenoid valves, and the power supply terminal of the solenoid valve is connected to the control terminal of the main control module.

Images