CN110552933A - Device and method for monitoring leakage rate in hydraulic cylinder in real time - Google Patents
Device and method for monitoring leakage rate in hydraulic cylinder in real time Download PDFInfo
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- CN110552933A CN110552933A CN201910813396.4A CN201910813396A CN110552933A CN 110552933 A CN110552933 A CN 110552933A CN 201910813396 A CN201910813396 A CN 201910813396A CN 110552933 A CN110552933 A CN 110552933A
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B19/00—Testing; Calibrating; Fault detection or monitoring; Simulation or modelling of fluid-pressure systems or apparatus not otherwise provided for
- F15B19/005—Fault detection or monitoring
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B21/00—Common features of fluid actuator systems; Fluid-pressure actuator systems or details thereof, not covered by any other group of this subclass
- F15B21/02—Servomotor systems with programme control derived from a store or timing device; Control devices therefor
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- Mechanical Engineering (AREA)
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- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Examining Or Testing Airtightness (AREA)
- Fluid-Pressure Circuits (AREA)
Abstract
The invention discloses a device and a method for monitoring leakage in a hydraulic cylinder in real time. The power oil source is connected with a rodless cavity and a rod cavity of the hydraulic oil cylinder through a reversing valve; an accumulation type high-pressure flow meter is arranged in an oil way from the reversing valve to a rodless cavity of the hydraulic oil cylinder; a linear displacement sensor for detecting the displacement of a piston rod of the hydraulic oil cylinder is arranged on the hydraulic oil cylinder; and the linear displacement sensor and the accumulation type high-pressure flowmeter transmit signals to the PLC. And the PLC compares the actual displacement value with the theoretical displacement value and converts the difference value into the internal leakage amount. According to the invention, other hydraulic auxiliary circuits are not needed in the detection process, the host does not need to stop working, the detection efficiency is high, and the real-time performance is high; the detection precision is high, the detection data is simple and clear, the PLC controller obtains the real-time internal leakage amount through the relation between the real-time flow and the displacement of the hydraulic cylinder, a real-time internal leakage amount curve can be formed in the display, and the fatigue wear degree of the sealing component inside the hydraulic cylinder can be judged by observing the curve.
Description
Technical Field
The invention relates to the technical field of hydraulic cylinders, in particular to a device and a method for monitoring the leakage rate in a hydraulic cylinder in real time.
background
the internal leakage is an index commonly used by the hydraulic cylinder, and the exceeding of the internal leakage amount is also a common fault of the hydraulic cylinder. The internal leakage mainly refers to the leakage of oil liquid in the hydraulic cylinder from a high-pressure area to a low-pressure area, so that a rod cavity and a rodless cavity of the hydraulic cylinder are communicated, and the output force of the hydraulic cylinder is reduced. The internal leakage quantity exceeds the standard and can lead to causing the pneumatic cylinder can not normally work, and the main manifestation has: the hydraulic cylinder is not locked, the hydraulic cylinder slightly sinks, the hydraulic cylinder slowly stretches and contracts and the like.
the leakage detection in the hydraulic cylinder is divided into two conditions, namely delivery test in the production process and data monitoring in the use process;
For internal leakage in the factory test process, the internal leakage amount of a single-acting hydraulic cylinder and a double-acting hydraulic cylinder is specified in GB/T15622-2005, and the internal leakage test formula is defined as follows: the working cavity of the tested cylinder is charged with oil, pressurized to rated pressure or pressure designated by a user, and the leakage quantity of the piston leaking to the unpressurized cavity is measured. The existing method for detecting the internal leakage amount of the hydraulic cylinder comprises the following steps: opening an oil port of a low-pressure cavity, counting the number of drops of hydraulic oil after the leakage amount is stable, wherein each drop is 0.05 mL; an oil port of the low-pressure cavity is opened, and after the leakage amount is stable, the internal leakage amount within a certain time is measured by using a measuring cup;
The internal leakage of the hydraulic cylinder in the use process of the engineering machinery can be judged only according to the use condition of a main engine at present, and a sealing system of the hydraulic cylinder cannot be used any more after the judgment usually, so that the whole cylinder is scrapped and even the accident of the main engine is caused. If a method can be found to monitor the internal leakage of the sealing system, early warning can be achieved, planned maintenance can be achieved, maintenance downtime is shortened, and safety problems possibly caused by temporary faults are avoided.
therefore, the Chinese patent discloses a high-precision hydraulic cylinder internal leakage detection device (CN 201620351996), which comprises a hydraulic cylinder internal leakage detector, a pressure sensor A, a pressure sensor B, a displacement sensor and a hydraulic control loop; the displacement sensor is connected between the leakage detector in the hydraulic cylinder and the detected hydraulic cylinder and is used for detecting a position signal of the hydraulic cylinder; the pressure sensor A is connected between the detected hydraulic cylinder and the hydraulic cylinder control loop and used for acquiring the pressure at one end of the hydraulic cylinder, and the pressure sensor A is connected with the leakage detector in the hydraulic cylinder; and the pressure sensor B is connected between the detected hydraulic cylinder and the hydraulic cylinder control loop and used for acquiring the pressure at the other end of the hydraulic cylinder, and the pressure sensor B is connected with the leakage detector in the hydraulic cylinder.
However, the above techniques have the following disadvantages:
1, during testing, the host computer is required to stop working for detection, and real-time monitoring cannot be carried out; cut-off isolation valves are connected between the pressure sensor and the hydraulic cylinder control loop, and the work is required to be stopped for detection during detection, so that the working efficiency of a host is reduced;
2, the hydraulic cylinder internal leakage detector judges whether internal leakage exists by adopting pressure changes of two cavities of the hydraulic cylinder, and judges whether the internal leakage exists by only utilizing pressure difference, namely qualitative analysis is carried out, and quantitative analysis cannot be carried out;
In addition, due to the problem of processing inside the hydraulic cylinder, the leakage amount of the hydraulic cylinder at different positions is inconsistent, and no device can measure the leakage amount of each point of the full stroke of the hydraulic cylinder at present; in the use process of a hydraulic cylinder product end user, the internal leakage amount of a sealing system cannot be acquired, the hydraulic cylinder fault can be judged only after the phenomena of arm falling, recovery failure, sinking and the like are caused in the serious failure of the hydraulic cylinder in the use process, and the leakage amount and the sealing fatigue wear condition of the sealing system cannot be monitored in real time in the process.
disclosure of Invention
In order to solve the technical problems, the invention provides a device and a method for monitoring the leakage rate in a hydraulic cylinder in real time.
the invention is realized by the following technical scheme: a real-time monitoring device for the internal leakage amount of a hydraulic cylinder comprises a power oil source, wherein the power oil source is connected with a rodless cavity and a rod cavity of the hydraulic cylinder through a reversing valve; an accumulation type high-pressure flow meter is arranged in an oil way from the reversing valve to a rodless cavity of the hydraulic oil cylinder; a linear displacement sensor for detecting the displacement of a piston rod of the hydraulic oil cylinder is arranged on the hydraulic oil cylinder; and the linear displacement sensor and the accumulation type high-pressure flowmeter transmit signals to the PLC.
A method for monitoring leakage in a hydraulic cylinder in real time comprises the following steps: after passing through the accumulation type high-pressure flowmeter, a power oil source enters a rodless cavity of the hydraulic oil cylinder to push a piston rod of the hydraulic oil cylinder to extend out;
step two: monitoring the actual displacement value of a piston rod of the hydraulic oil cylinder in real time through a linear displacement sensor;
Step three: the accumulative high-pressure flowmeter transmits the flow signal to the PLC in real time, and the PLC converts the theoretical displacement value of the piston rod of the hydraulic oil cylinder according to the flow signal;
step four: and comparing the actual displacement value with the theoretical displacement value through the PLC, and converting the difference value of the actual displacement value and the theoretical displacement value into the internal leakage amount through the PLC.
it further comprises the following steps: the power oil source is connected with a rodless cavity and a rod cavity of the hydraulic oil cylinder through a reversing valve; the accumulation type high-pressure flow meter is arranged in an oil way from the reversing valve to a rodless cavity of the hydraulic oil cylinder; the hydraulic oil cylinder is provided with the linear displacement sensor for detecting the displacement of the piston rod of the hydraulic oil cylinder; and the linear displacement sensor and the accumulation type high-pressure flowmeter transmit signals to the PLC.
compared with the prior art, the invention has the beneficial effects that:
1, various environments of factory test or use sites can be met, the operation is simple, other hydraulic auxiliary circuits are not needed in the detection process, a host does not need to stop working, the detection efficiency is high, and the real-time performance is high; no external leakage, no waste of hydraulic oil and no environmental pollution;
2, the detection precision is high, the detection data is simple and clear, the PLC obtains the real-time internal leakage amount through the relation between the real-time flow and the displacement of the hydraulic cylinder, a real-time internal leakage amount curve can be formed in a display, and the fatigue wear degree of the sealing component in the hydraulic cylinder can be judged by observing the curve;
3, the device for monitoring the internal leakage amount of the hydraulic cylinder in real time can be arranged on an important oil cylinder in machinery and can detect the internal leakage amount of the oil cylinder in real time; a threshold value of the maximum leakage quantity can be set, and an alarm is given after the maximum leakage quantity reaches a fixed value;
and 4, storing the detected data and conclusion in a memory card through a PLC (programmable logic controller), and using the memory card for subsequent work such as calculation, analysis and the like.
drawings
FIG. 1 is a schematic structural diagram of a device for monitoring leakage in a hydraulic cylinder in real time according to an embodiment of the present invention;
FIG. 2 is a graph illustrating a real-time monitoring curve of an internal leakage rate according to a real-time monitoring method of an internal leakage rate of a hydraulic cylinder according to a second embodiment of the present invention;
In the figure: 1. a source of motive oil; 2. a diverter valve; 3. an accumulation high pressure flow meter; 4. a hydraulic cylinder; 5. a linear displacement sensor; 6. a PLC controller.
Detailed Description
in order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.
Example one
Referring to fig. 1, a real-time monitoring device for leakage in a hydraulic cylinder, a power oil source 1 is connected with a rodless cavity and a rod cavity of a hydraulic cylinder 4 through a reversing valve 2. The accumulation type high-pressure flow meter 3 is arranged in an oil path from the reversing valve 2 to a rodless cavity of the hydraulic oil cylinder 4 and is used for detecting the flow value of the rodless cavity of the hydraulic oil cylinder 4 in real time. And the high-precision linear displacement sensor 5 is connected to the piston rod end of the hydraulic oil cylinder 4 and is used for detecting the displacement value of the piston rod of the hydraulic oil cylinder 4 in real time. The linear displacement sensor 5 and the accumulation type high-pressure flowmeter 3 transmit detected real-time signals to the PLC 6.
Example two
a method for monitoring the leakage rate in a hydraulic cylinder in real time adopts a device for monitoring the leakage rate in the hydraulic cylinder in the first embodiment;
The method comprises the following steps: the power oil source 1 provides high-pressure oil, and the reversing valve 2 reverses to a left working position; high-pressure oil enters a rodless cavity of the hydraulic oil cylinder 4 after passing through the accumulation type high-pressure flow meter 3, and a piston rod of the hydraulic oil cylinder 4 is pushed to extend out; the accumulative high-pressure flowmeter 3 transmits the flow value monitored in real time to the PLC 6;
Step two: the linear displacement sensor 5 monitors the actual displacement value of the piston rod of the hydraulic oil cylinder 4 in real time and transmits the actual displacement value to the PLC 6;
Step three: the PLC 6 converts a real-time theoretical displacement value of a piston rod of the hydraulic oil cylinder 4 according to the flow value signal and the size parameter of the hydraulic oil cylinder 4;
Step four: the PLC 6 compares the actual displacement value with the theoretical displacement value, and then the PLC 6 converts the difference value of the actual displacement value and the theoretical displacement value into the internal leakage amount according to the size parameters of the hydraulic oil cylinder 4, and records and stores the internal leakage amount;
step five: the PLC 6 plots the internal leakage amount into a curve chart of the operation time and the internal leakage amount of the hydraulic oil cylinder shown in the figure 2, and the curve chart is displayed on an operation interface of the PLC 6; by observing the curve, the fatigue wear degree of the sealing component in the hydraulic oil cylinder can be judged.
the device and the method for monitoring the internal leakage amount of the hydraulic cylinder in real time in the embodiment have the advantages of simple structure, convenience in installation, low cost, safety and reliability, and can completely meet the requirement of internal leakage amount detection.
Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.
Claims (3)
1. The utility model provides a leak leakage quantity real-time supervision device in pneumatic cylinder which characterized in that: the hydraulic cylinder power oil supply device comprises a power oil source (1), wherein the power oil source (1) is connected with a rodless cavity and a rod cavity of a hydraulic cylinder (4) through a reversing valve (2); an accumulation type high-pressure flow meter (3) is arranged in an oil way from the reversing valve (2) to a rodless cavity of the hydraulic oil cylinder (4); a linear displacement sensor (5) for detecting the displacement of a piston rod of the hydraulic oil cylinder (4) is arranged on the hydraulic oil cylinder (4); the linear displacement sensor (5) and the accumulation type high-pressure flowmeter (3) transmit signals to the PLC (6).
2. a method for monitoring leakage in a hydraulic cylinder in real time is characterized in that:
The method comprises the following steps: after passing through the accumulation type high-pressure flowmeter (3), the power oil source (1) enters a rodless cavity of the hydraulic oil cylinder (4) and pushes a piston rod of the hydraulic oil cylinder (4) to extend out;
step two: the actual displacement value of the piston rod of the hydraulic oil cylinder (4) is monitored in real time through a linear displacement sensor (5);
Step three: the accumulative high-pressure flowmeter (3) transmits the flow signal to the PLC (6) in real time, and the PLC (6) converts the theoretical displacement value of the piston rod of the hydraulic oil cylinder (4) according to the flow signal;
Step four: the actual displacement value is compared with the theoretical displacement value through the PLC (6), and the difference value between the actual displacement value and the theoretical displacement value is converted into the internal leakage amount through the PLC (6).
3. the method for monitoring the leakage rate of the hydraulic cylinder in real time according to claim 2, wherein the method comprises the following steps: the power oil source (1) is connected with a rodless cavity and a rod cavity of the hydraulic oil cylinder (4) through the reversing valve (2); the accumulation type high-pressure flow meter (3) is arranged in an oil way from the reversing valve (2) to a rodless cavity of the hydraulic oil cylinder (4); the hydraulic oil cylinder (4) is provided with the linear displacement sensor (5) for detecting the displacement of the piston rod of the hydraulic oil cylinder (4); the linear displacement sensor (5) and the accumulation type high-pressure flowmeter (3) transmit signals to the PLC (6).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910813396.4A CN110552933A (en) | 2019-08-30 | 2019-08-30 | Device and method for monitoring leakage rate in hydraulic cylinder in real time |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201910813396.4A CN110552933A (en) | 2019-08-30 | 2019-08-30 | Device and method for monitoring leakage rate in hydraulic cylinder in real time |
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| CN110552933A true CN110552933A (en) | 2019-12-10 |
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| CN201910813396.4A Pending CN110552933A (en) | 2019-08-30 | 2019-08-30 | Device and method for monitoring leakage rate in hydraulic cylinder in real time |
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Cited By (5)
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| CN113294406A (en) * | 2020-02-21 | 2021-08-24 | 北京福田康明斯发动机有限公司 | Hydraulic cylinder state monitoring system and method and hydraulic clamp system |
| CN113358300A (en) * | 2021-05-27 | 2021-09-07 | 中冶赛迪工程技术股份有限公司 | Hydraulic system pipeline leakage state detection system |
| CN113700702A (en) * | 2021-08-04 | 2021-11-26 | 中国人民解放军火箭军工程大学 | Digital hydraulic cylinder working state non-intervention real-time monitoring system and using method |
| CN114323493A (en) * | 2021-12-29 | 2022-04-12 | 广东南曦液压机械有限公司 | Automatic detection device and detection method for tiny leakage flow |
| CN114483711A (en) * | 2022-02-04 | 2022-05-13 | 浙江大学 | Constant parameter method for detecting and evaluating leakage in hydraulic cylinder and detection device thereof |
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Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113294406A (en) * | 2020-02-21 | 2021-08-24 | 北京福田康明斯发动机有限公司 | Hydraulic cylinder state monitoring system and method and hydraulic clamp system |
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| CN113700702A (en) * | 2021-08-04 | 2021-11-26 | 中国人民解放军火箭军工程大学 | Digital hydraulic cylinder working state non-intervention real-time monitoring system and using method |
| CN113700702B (en) * | 2021-08-04 | 2023-09-26 | 中国人民解放军火箭军工程大学 | Non-intervention real-time monitoring system for working state of digital hydraulic cylinder and use method |
| CN114323493A (en) * | 2021-12-29 | 2022-04-12 | 广东南曦液压机械有限公司 | Automatic detection device and detection method for tiny leakage flow |
| CN114483711A (en) * | 2022-02-04 | 2022-05-13 | 浙江大学 | Constant parameter method for detecting and evaluating leakage in hydraulic cylinder and detection device thereof |
| CN114483711B (en) * | 2022-02-04 | 2022-11-29 | 浙江大学 | Constant parameter method for detecting and evaluating leakage in hydraulic cylinder and detection device thereof |
| WO2023147740A1 (en) * | 2022-02-04 | 2023-08-10 | 浙江大学 | Constant value parameter method for detecting and evaluating leakage in hydraulic cylinder and detection device thereof |
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Application publication date: 20191210 |