Intelligent plunger pump fault diagnosis system and diagnosis method

Abstract

The invention discloses an intelligent plunger pump fault diagnosis system and a diagnosis method, which realize accurate monitoring of the tilt angle of a swash plate, can adjust and accurately control the output flow of a pump in real time in combination with a built-in control operation unit, and meanwhile, outputs pressure data in cooperation with a proportional pressure reducing valve, and compares the pressure data with a threshold value in a first fault diagnosis module, so that the fault diagnosis accuracy is improved. Judging whether a proportional pressure reducing valve and a variable adjusting mechanism of the pump are abnormal or not; and in cooperation with shell pressure data, whether the leakage amount of the pump is abnormal or not is judged by comparing the pressure data with a threshold value in the second fault diagnosis module, and faults caused by flow fluctuation or abnormality are effectively prevented. And whether the volumetric efficiency of the pump is too low or not is judged by comparing with a threshold value in the third fault diagnosis module, so that the universality and accuracy of a volumetric efficiency diagnosis algorithm are remarkably improved.

Description

Technical Field

[0001] The invention relates to an intelligent plunger pump fault diagnosis system and a diagnosis method, belonging to the technical field of engineering machinery hydraulic pressure and fault diagnosis. Background Art

[0002] In the vast application field of construction machinery, axial piston pumps are indispensable core power components. The stability and reliability of their operating status are directly related to the working efficiency, long-term durability and operational safety of mechanical equipment. Especially in the harsh environment of mining, the busy scenes of construction sites, the diverse conditions of agricultural farming, and the harsh challenges of heavy transportation, axial piston pumps need to continuously withstand high-intensity, high-frequency cyclic loads while resisting unforeseen external shocks. These extreme working conditions accelerate the wear process of key components inside the pump body, such as the plunger, slipper, and distribution plate, and even cause deformation and fatigue fracture, which seriously threatens the performance stability and service life of the pump, and then causes performance degradation, leakage problems and even complete failure.

[0003] Traditionally, fault diagnosis of axial piston pumps relies on traditional periodic manual inspections and disassembly analysis after a fault occurs. This method is not only time-consuming and labor-intensive, but also inefficient. It is difficult to capture early signs of faults and miss the opportunity for prevention, resulting in frequent unplanned downtime, increased maintenance costs, and adverse effects on production continuity. Obviously, the traditional diagnostic model can no longer meet the urgent needs of modern engineering machinery for efficient and accurate maintenance.

[0004] With the rapid progress and popularization of sensor technology, modern engineering machinery has integrated advanced sensor networks to achieve real-time monitoring and recording of key operating parameters such as oil temperature, inlet and outlet pressure, and speed. This technological breakthrough provides unprecedented data support for fault diagnosis, making in-depth analysis and intelligent diagnosis based on data possible. By extracting characteristic parameters such as pump pressure fluctuations from real-time monitoring data, and then using algorithms to identify characteristic patterns under abnormal conditions, early warning of common faults such as wear and leakage can be achieved.

[0005] The failure of the piston pump motor of construction machinery often occurs within the system. In addition, the inspection conditions at the construction machinery work site are poor, so it is difficult to detect directly, and fault analysis and judgment are difficult.

[0006] The first existing technology uses high-precision vibration acceleration sensors and complex signal processing systems, which are relatively expensive and not conducive to large-scale applications. The accuracy and reliability of the algorithm model directly affect the fault diagnosis results and require continuous optimization and verification. In addition, the vibration signal is greatly affected by the working environment, such as temperature, noise, etc., which may affect the diagnosis results.

[0007] The second existing technology uses regular inspections, which requires a lot of manpower and has a delay in fault detection, which is not conducive to timely maintenance. It relies on manual experience and subjective judgment and is prone to misdiagnosis or missed diagnosis. When the pump fails, it needs to be disassembled and analyzed, which increases maintenance costs and downtime.

[0008] The third existing technology uses integrated multiple sensors and valve blocks, which has high system complexity, difficult maintenance, and a complex monitoring system that increases costs. Affected by the machining accuracy of the unloading valve and the ambient temperature, the error is relatively large under different test ambient temperatures or different plunger pumps.

[0009] Therefore, how to overcome the deficiencies in the prior art and better diagnose the plunger pump is a technical problem that technical personnel in this field urgently need to solve. Summary of the invention

[0010] Purpose: In order to overcome the deficiencies in the prior art, the present invention provides an intelligent plunger pump fault diagnosis system and a diagnosis method.

[0011] Technical solution: To solve the above technical problems, the technical solution adopted by the present invention is:

[0012] In a first aspect, an intelligent plunger pump fault diagnosis system includes: a hydraulic system, a control unit, a controller, and a multi-way reversing valve.

[0013] The hydraulic system is used to connect the engine, the plunger pump, the pilot pump hydraulic circuit and the control circuit.

[0014] The control unit is used to input the plunger pump outlet pressure, housing pressure, proportional pressure reducing valve pressure and swash plate inclination sensor signal, the operation unit of the control unit outputs the corresponding control current PWM signal, and the fault diagnosis module of the control unit outputs the fault code and information by comparing the fault threshold.

[0015] The controller is used to control the switch of the unloading valve in the multi-way reversing valve and store the fault information transmitted by the control unit.

[0016] The multi-way reversing valve is used to control the flow direction and flow rate of the hydraulic oil by adjusting the unloading valve of the multi-way reversing valve.

[0017] As a preferred solution, the hydraulic system includes: a hydraulic oil tank, an engine, a plunger pump, and a pilot pump.

[0018] Wherein, the swash plate on the plunger pump is provided with a plunger pump swing angle sensor, the oil drain port of the plunger pump is connected to the hydraulic oil tank, the oil drain port of the plunger pump is provided with an oil drain pressure sensor, the oil port of the swash plate of the plunger pump is connected to the P port of the plunger pump proportional pressure reducing valve, the A port of the plunger pump proportional pressure reducing valve is connected to the oil outlet of the pilot pump, and the oil port of the swash plate of the plunger pump is provided with a plunger pump proportional pressure reducing valve pressure sensor. The oil inlet of the plunger pump is connected to the hydraulic oil tank, the oil outlet of the plunger pump is connected to the oil inlet of the unloading valve of the multi-way reversing valve, the oil outlet of the unloading valve of the multi-way reversing valve is connected to the hydraulic oil tank, the oil outlet of the plunger pump is provided with a plunger pump outlet pressure sensor, the control port of the unloading valve of the multi-way reversing valve is connected to the P port of the unloading valve proportional pressure reducing valve, and the A port of the unloading valve proportional pressure reducing valve is connected to the oil outlet of the pilot pump.

[0019] The engine is used to drive the plunger pump and the pilot pump.

[0020] As a preferred solution, the plunger pump swing angle sensor, oil leakage pressure sensor, plunger pump proportional pressure reducing valve, plunger pump proportional pressure reducing valve pressure sensor, and plunger pump outlet pressure sensor are all arranged on the body of the plunger pump.

[0021] As a preferred solution, the control unit is arranged on the body of the plunger pump.

[0022] In a second aspect, an intelligent plunger pump fault diagnosis system includes: a hydraulic system, a control unit, a controller, and a multi-way reversing valve.

[0023] The hydraulic system is used to connect the engine, the plunger pump, the pilot pump hydraulic circuit and the control circuit.

[0024] The control unit is used to input the plunger pump outlet pressure, housing pressure, proportional pressure reducing valve pressure and swash plate inclination sensor signal, the operation unit of the control unit outputs the corresponding control current PWM signal, and the fault diagnosis module of the control unit outputs the fault code and information by comparing the fault threshold.

[0025] The controller is used to control the switch of the unloading valve in the multi-way reversing valve and store the fault information transmitted by the control unit.

[0026] The multi-way reversing valve is used to control the flow direction and flow rate of the hydraulic oil by adjusting the unloading valve of the multi-way reversing valve.

[0027] As a preferred solution, the hydraulic system includes: a hydraulic oil tank, an engine, a first plunger pump, a second plunger pump, and a pilot pump.

[0028] Among them, the swash plate on the first plunger pump is provided with a first plunger pump swing angle sensor, the oil drain port of the first plunger pump is connected to the hydraulic oil tank, the oil drain port of the first plunger pump is provided with a first oil drain pressure sensor, the oil port of the swash plate of the first plunger pump is connected to the P port of the first plunger pump proportional pressure reducing valve, the A port of the first plunger pump proportional pressure reducing valve is connected to the oil outlet of the pilot pump, and the oil port of the swash plate of the first plunger pump is provided with a first plunger pump proportional pressure reducing valve pressure sensor. The oil inlet of the first plunger pump is connected to the hydraulic oil tank, the oil outlet of the first plunger pump is connected to the oil inlet of the unloading valve of the first multi-way reversing valve, the oil outlet of the unloading valve of the first multi-way reversing valve is connected to the hydraulic oil tank, the oil outlet of the first plunger pump is provided with a first plunger pump outlet pressure sensor, the control port of the unloading valve of the first multi-way reversing valve is connected to the P port of the first unloading valve proportional pressure reducing valve, and the A port of the first unloading valve proportional pressure reducing valve is connected to the oil outlet of the pilot pump.

[0029] The swash plate on the second plunger pump is provided with a second plunger pump sway angle sensor, the oil drain port of the second plunger pump is connected to the hydraulic oil tank, the oil drain port of the second plunger pump is provided with a second oil drain pressure sensor, the oil port of the swash plate of the second plunger pump is connected to the P port of the second plunger pump proportional pressure reducing valve, the A port of the second plunger pump proportional pressure reducing valve is connected to the oil outlet of the pilot pump, and the oil port of the swash plate of the second plunger pump is provided with a second plunger pump proportional pressure reducing valve pressure sensor. The oil inlet of the second plunger pump is connected to the hydraulic oil tank, the oil outlet of the second plunger pump is connected to the oil inlet of the unloading valve of the second multi-way reversing valve, the oil outlet of the unloading valve of the second multi-way reversing valve is connected to the hydraulic oil tank, the oil outlet of the second plunger pump is provided with a second plunger pump outlet pressure sensor, the control port of the unloading valve of the second multi-way reversing valve is connected to the P port of the second unloading valve proportional pressure reducing valve, and the A port of the second unloading valve proportional pressure reducing valve is connected to the oil outlet of the pilot pump.

[0030] The engine is used to drive the first plunger pump, the second plunger pump and the pilot pump.

[0031] As a preferred solution, the first plunger pump swing angle sensor, the first oil leakage pressure sensor, the first plunger pump proportional pressure reducing valve, the first plunger pump proportional pressure reducing valve pressure sensor, and the first plunger pump outlet pressure sensor are all arranged on the body of the first plunger pump.

[0032] As a preferred solution, the second plunger pump swing angle sensor, the second oil leakage pressure sensor, the second plunger pump proportional pressure reducing valve, the second plunger pump proportional pressure reducing valve pressure sensor, and the second plunger pump outlet pressure sensor are all arranged on the body of the second plunger pump.

[0033] As a preferred solution, the control unit is arranged on the bodies of the first plunger pump and the second plunger pump.

[0034] In a third aspect, according to the diagnostic method of the intelligent plunger pump fault diagnosis system described in the first aspect, the method specifically includes:

[0035] During the time Δt2, the plunger pump control current PWM signal is maintained at the maximum value I max .

[0036] The pressure value p of the oil leakage pressure sensor is collected after Δt2 壳体 .

[0037] The pressure value p 壳体 With pressure threshold P 壳体阈值 For comparison, if the pressure value p 壳体 Greater than the pressure threshold P 壳体阈值 , then the plunger pump leakage is abnormal, otherwise, the plunger pump is normal.

[0038] As a preferred solution, the pressure threshold P 壳体阈值 The acquisition method is as follows:

[0039] By conducting pressure tests on different batches of plunger pumps, the plunger pump control current PWM signal is controlled to maintain the maximum value I max , and collect the casing pressure of each plunger pump in a time period of Δt2.

[0040] From each piston pump case pressure, obtain the maximum value p max壳体 , the minimum value p min壳体 .

[0041] According to the maximum value p max壳体 , the minimum value p min壳体 , calculate the pressure threshold P 壳体阈值 , pressure threshold P 壳体阈值 The expression is as follows:

[0042] P 壳体阈值 = k1*(p max壳体 +p min壳体 ) / 2

[0043] Wherein, k1 represents the shell pressure threshold coefficient.

[0044] In a fourth aspect, according to the diagnostic method of the intelligent plunger pump fault diagnosis system described in the first aspect, the method specifically includes:

[0045] During the time Δt3, the plunger pump control current PWM signal is maintained at the maximum value I max .

[0046] After Δt3, the pressure value p of the piston pump proportional pressure reducing valve pressure sensor is collected. 阀 , the swing angle value α of the plunger pump swing angle sensor, the pressure value p of the plunger pump outlet pressure sensor 出口 .

[0047] The pressure value p 阀 With pressure threshold P 阈值 For comparison, if the pressure value p 阀 Less than the pressure threshold P 阈值 , then the piston pump proportional pressure reducing valve is degraded abnormally.

[0048] The swing angle value α and the swing angle threshold α 阈值 Compare, if the swing angle value α is less than the swing angle threshold α 阈值 , then the piston pump variable adjustment block is degraded abnormally.

[0049] The pressure value p 出口 Pressure threshold P in different hydraulic oil temperature ranges 出口阈值 For comparison, if the pressure value p 出口 Less than the pressure threshold P 出口阈值 , the output flow of the plunger pump will degrade abnormally and the volumetric efficiency will be low.

[0050] As a preferred solution, the pressure threshold P 阈值 The acquisition method is as follows:

[0051] The plunger pump control current PWM signal of different batches of plunger pumps is kept at the maximum value I max , using time Δt3, collect the pressure of the piston pump proportional pressure reducing valve of each piston pump.

[0052] From the pressure of the piston pump proportional pressure reducing valve of each piston pump, obtain the maximum value P MAX阀 .

[0053] According to the maximum value P MAX阀 , calculate the pressure threshold P 阈值 , pressure threshold P 阈值 The expression is as follows:

[0054] P 阈值 =k2*P MAX阀

[0055] Wherein, k2 represents the pressure threshold coefficient of the proportional pressure reducing valve.

[0056] As a preferred solution, the swing angle threshold α 阈值 The acquisition method is as follows:

[0057] The plunger pump control current PWM signal of different batches of plunger pumps is kept at the maximum value I max, and it takes time Δt3 to collect the swing angle value of the piston pump swing angle sensor of each piston pump column.

[0058] From the swing angle value of the piston pump swing angle sensor of each piston pump, obtain the maximum value α MAX .

[0059] According to the maximum value P MAX阀 , calculate the swing angle threshold α 阈值 , swing angle threshold α 阈值 The expression is as follows:

[0060] α 1阈值 =k3*α MAX

[0061] Wherein, k3 represents the swing angle threshold coefficient.

[0062] As a preferred solution, the pressure thresholds P of the different hydraulic oil temperature ranges are 出口阈值 The acquisition method is as follows:

[0063] The plunger pump control current PWM signal of different batches of plunger pumps is kept at the maximum value I under different hydraulic oil temperature ranges. max , it takes time Δt3 to collect the pressure value of the plunger pump outlet pressure sensor of each plunger pump column in different hydraulic oil temperature ranges.

[0064] From the pressure value of the plunger pump outlet pressure sensor of each plunger pump column in different hydraulic oil temperature ranges, the maximum value p in different hydraulic oil temperature ranges is obtained. max出口 , the minimum value p min出口 .

[0065] According to the maximum value p max出口 , the minimum value p min出口 , calculate the pressure threshold P for different hydraulic oil temperature ranges 出口阈值 , the pressure threshold P in different hydraulic oil temperature ranges 出口阈值 The expression is as follows:

[0066] P 出口阈值 =k4*k5*(p max出口 +p min出口 ) / 2

[0067] Among them, k4 represents the outlet pressure threshold coefficient, and k5 represents the temperature coefficient.

[0068] In a fifth aspect, according to the diagnostic method of the intelligent plunger pump fault diagnosis system described in the second aspect, the method specifically includes:

[0069] Within the time Δt1, the first plunger pump control current PWM signal and the second plunger pump control current PWM signal are respectively changed from the minimum value I minGradually increase to the maximum value I max .

[0070] The pressure value p of the pressure sensor of the proportional pressure reducing valve of the first plunger pump is collected at several time points within the time Δt1. 1阀 , the pressure value p of the pressure sensor of the proportional pressure reducing valve of the second piston pump 2阀 , the swing angle value α1 of the first plunger pump swing angle sensor, and the swing angle value α2 of the second plunger pump swing angle sensor.

[0071] Compare the pressure value p at each time point 1阀 With pressure value p 2阀 Is it consistent? If the pressure value p 1阀 With pressure value p 2阀 Inconsistent, and the pressure value p 1阀 With pressure value p 2阀 The difference is greater than the pressure threshold p 阀阈值 When the first plunger pump and the second plunger pump are abnormal.

[0072] Compare the swing angle values ​​α1 and α2 at each time point to see if they are consistent. If the swing angle values ​​α1 and α2 are inconsistent, and the difference between the swing angle values ​​α1 and α2 is greater than the angle threshold α 阈值 When the first plunger pump and the second plunger pump are abnormal.

[0073] In a sixth aspect, according to the diagnostic method of the intelligent plunger pump fault diagnosis system described in the second aspect, the method specifically includes:

[0074] During the time Δt2, the first plunger pump control current PWM signal and the second plunger pump control current PWM signal are respectively maintained at the maximum value I max .

[0075] After Δt2, the pressure value p of the first oil leakage pressure sensor is collected respectively. 1壳体 and the pressure value p of the second oil leakage pressure sensor 2壳体 .

[0076] The pressure value p 1壳体 , pressure value p 2壳体 With pressure threshold P 壳体阈值 For comparison, if the pressure value p 1壳体 Greater than the pressure threshold P 壳体阈值 , then the first plunger pump has leakage abnormality, otherwise, the first plunger pump has no abnormality. 2壳体 Greater than the pressure threshold P 壳体阈值 , then the second plunger pump has leakage abnormality, otherwise, the second plunger pump has no abnormality.

[0077] As a preferred solution, the pressure threshold P 壳体阈值The acquisition method is as follows:

[0078] By conducting pressure tests on different batches of plunger pumps, the plunger pump control current PWM signal is controlled to maintain the maximum value I max , and collect the casing pressure of each plunger pump in a time period of Δt2.

[0079] From each piston pump case pressure, obtain the maximum value p max壳体 , the minimum value p min壳体 .

[0080] According to the maximum value p max壳体 , the minimum value p min壳体 , calculate the pressure threshold P 壳体阈值 , pressure threshold P 壳体阈值 The expression is as follows:

[0081] P 壳体阈值 = k1*(p max壳体 +p min壳体 ) / 2

[0082] Wherein, k1 represents the shell pressure threshold coefficient.

[0083] In a seventh aspect, a diagnostic method of an intelligent plunger pump fault diagnosis system according to the second aspect specifically includes:

[0084] During the time Δt3, the first plunger pump control current PWM signal and the second plunger pump control current PWM signal are respectively maintained at the maximum value I max .

[0085] After Δt3, the pressure value p of the pressure sensor of the proportional pressure reducing valve of the first plunger pump is collected respectively. 1阀 , the pressure value p of the pressure sensor of the proportional pressure reducing valve of the second piston pump 2阀 , the swing angle value α1 of the first plunger pump swing angle sensor, the swing angle value α2 of the second plunger pump swing angle sensor, the pressure value p of the first plunger pump outlet pressure sensor 1出口 and the pressure value p of the second plunger pump outlet pressure sensor 2出口 .

[0086] The pressure value p 1阀 With pressure threshold P 阈值 Or the pressure value p 2阀 With pressure threshold P 阈值 For comparison, if the pressure value p 1阀 Less than the pressure threshold P 阈值 , then the proportional pressure reducing valve of the first plunger pump is degraded abnormally. If the pressure value p 2阀 Less than the pressure threshold P 阈值 , then the second piston pump proportional pressure reducing valve is degraded abnormally.

[0087] The swing angle value α1 and the swing angle threshold α 阈值 Or the swing angle value α2 and the swing angle threshold α 阈值 Compare, if the swing angle value α1 is less than the swing angle threshold α 阈值 , then the first plunger pump variable adjustment block is degraded abnormally. If the swing angle value α2 is less than the swing angle threshold α 阈值 , then the second piston pump variable adjustment block is degraded abnormally.

[0088] The pressure value p 1出口 Pressure threshold P in different hydraulic oil temperature ranges 出口阈值 Or the pressure value p 2出口 Pressure threshold P in different hydraulic oil temperature ranges 出口阈值 For comparison, if the pressure value p 1出口 Less than the pressure threshold P 出口阈值 , the output flow of the first plunger pump degrades abnormally and the volumetric efficiency is low. If the pressure value p 2出口 Less than the pressure threshold P 出口阈值 , the output flow of the second plunger pump degrades abnormally and the volumetric efficiency is low.

[0089] As a preferred solution, the pressure threshold P 阈值 The acquisition method is as follows:

[0090] The plunger pump control current PWM signal of different batches of plunger pumps is kept at the maximum value I max , using time Δt3, collect the pressure of the piston pump proportional pressure reducing valve of each piston pump.

[0091] From the pressure of the piston pump proportional pressure reducing valve of each piston pump, obtain the maximum value P MAX阀 .

[0092] According to the maximum value P MAX阀 , calculate the pressure threshold P 阈值 , pressure threshold P 阈值 The expression is as follows:

[0093] P 阈值 =k2*P MAX阀

[0094] Wherein, k2 represents the pressure threshold coefficient of the proportional pressure reducing valve.

[0095] As a preferred solution, the swing angle threshold α 阈值 The acquisition method is as follows:

[0096] The plunger pump control current PWM signal of different batches of plunger pumps is kept at the maximum value I max , and it takes time Δt3 to collect the swing angle value of the piston pump swing angle sensor of each piston pump column.

[0097] From the swing angle value of the piston pump swing angle sensor of each piston pump, obtain the maximum value α MAX .

[0098] According to the maximum value P MAX阀 , calculate the swing angle threshold α 阈值 , swing angle threshold α 阈值 The expression is as follows:

[0099] α 1阈值 =k3*α MAX

[0100] Wherein, k3 represents the swing angle threshold coefficient.

[0101] As a preferred solution, the pressure thresholds P of the different hydraulic oil temperature ranges are 出口阈值 The acquisition method is as follows:

[0102] The plunger pump control current PWM signal of different batches of plunger pumps is kept at the maximum value I under different hydraulic oil temperature ranges. max , it takes time Δt3 to collect the pressure value of the plunger pump outlet pressure sensor of each plunger pump column in different hydraulic oil temperature ranges.

[0103] From the pressure value of the plunger pump outlet pressure sensor of each plunger pump column in different hydraulic oil temperature ranges, the maximum value p in different hydraulic oil temperature ranges is obtained. max出口 , the minimum value p min出口 .

[0104] According to the maximum value p max出口 , the minimum value p min出口 , calculate the pressure threshold P for different hydraulic oil temperature ranges 出口阈值 , the pressure threshold P in different hydraulic oil temperature ranges 出口阈值 The expression is as follows:

[0105] P 出口阈值 =k4*k5*(p max出口 +p min出口 ) / 2

[0106] Among them, k4 represents the outlet pressure threshold coefficient, and k5 represents the temperature coefficient.

[0107] Beneficial effects: Compared with the prior art, the intelligent plunger pump fault diagnosis system and method provided by the present invention have the following advantages:

[0108] 1. Through precise monitoring and control of the swash plate angle, the fault diagnosis function module can evaluate the operating status of the pump in real time and accurately, detect and prevent potential faults in a timely manner, and effectively avoid equipment shutdown or damage caused by flow fluctuations or abnormalities, greatly improving the operating stability and reliability of the equipment.

[0109] 2. In view of the limitation of the flow calculation accuracy caused by the consistency difference of unloading valves in the traditional algorithm, the volumetric efficiency diagnosis algorithm proposed in this invention incorporates the consistency avoidance mechanism of unloading valves. This mechanism can accurately calculate and compensate for the differences between unloading valves of different batches, so that the algorithm can be more widely applied to plunger pumps of different models and batches, significantly improving the versatility and accuracy of the diagnosis algorithm. This not only reduces the cost of individual debugging and calibration for different models of pumps, but also greatly improves the efficiency of fault diagnosis, allowing maintenance personnel to locate and solve problems more quickly and accurately.

[0110] 3. Considering the important influence of ambient temperature changes on hydraulic oil viscosity and pump performance, the present invention innovatively incorporates a temperature correction model into the volumetric efficiency diagnosis algorithm. The model can obtain ambient temperature data in real time and dynamically adjust the algorithm parameters accordingly to accurately calculate the influence of hydraulic oil viscosity changes on pump flow at different temperatures. This design not only improves the accuracy of flow diagnosis, but also makes the diagnosis results more reliable and stable, and enhances the system's adaptability to different working environments and conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0111] Figure 1 It is a structural framework diagram of the plunger pump fault diagnosis system of the present invention.

[0112] Figure 2 It is a structural schematic diagram of the hydraulic system, the hydraulic circuit and the control circuit of the multi-way reversing valve of the present invention.

[0113] Figure 3 It is a flowchart of the diagnostic method of the plunger pump fault diagnosis system in Example 1 of the present invention. DETAILED DESCRIPTION

[0114] The following is a clear and complete description of the technical solutions in the examples of the present invention in conjunction with the accompanying drawings in the examples of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the protection scope of the present invention.

[0115] The present invention will be further described below in conjunction with specific embodiments.

[0116] Embodiment 1:

[0117] This embodiment introduces an intelligent plunger pump fault diagnosis system. Figure 1 As shown, it includes: a hydraulic system 100, a control unit 101, a controller 102, an electric control handle 103, a display 104, and a multi-way reversing valve 105.

[0118] The hydraulic system 100 is used to connect the engine, the plunger pump, the pilot pump hydraulic circuit and the control circuit.

[0119] The control unit 101 is used to input the plunger pump outlet pressure, housing pressure, proportional pressure reducing valve pressure and swash plate inclination sensor signal. The calculation unit of the control unit 101 performs constant power calculation based on the pressure signal value to output the corresponding control current PWM signal. The fault diagnosis module of the control unit 101 outputs the fault code and information by comparing the fault threshold.

[0120] The controller 102 is used to control the opening and closing of the unloading valve in the multi-way reversing valve 105 and store the fault information transmitted by the control unit 101, wherein the unloading valve is always open during fault diagnosis.

[0121] The electric control handle 103 is used to control the action of the vehicle actuator. When the operator controls the handle to start manipulating the construction machinery, the fault diagnosis module program is terminated.

[0122] The display 104 is used to display fault alarm prompts and fault codes and information recorded by the controller.

[0123] The multi-way reversing valve 105 is used to control the flow direction and flow rate of the hydraulic oil by adjusting the position of the valve core, thereby driving the actuator to operate. This diagnostic system mainly uses the unloading valve of the multi-way reversing valve 105 and the unloading valve proportional pressure reducing valve.

[0124] Furthermore, in one embodiment, the hydraulic system 100 includes: a hydraulic oil tank 1 , an engine 5 , a first plunger pump 6 , a second plunger pump 7 , and a pilot gear pump 8 .

[0125] Among them, the swash plate on the first plunger pump 6 is provided with a first plunger pump swing angle sensor 2, the oil drain port of the first plunger pump 6 is connected to the hydraulic oil tank 1, the oil drain port of the first plunger pump 6 is provided with a first oil drain pressure sensor 4.1, the oil port of the swash plate of the first plunger pump 6 is connected to the P port of the first plunger pump proportional pressure reducing valve 11, the A port of the first plunger pump proportional pressure reducing valve 11 is connected to the oil outlet of the pilot gear pump 8, and the oil port of the swash plate of the first plunger pump 6 is provided with a first plunger pump proportional pressure reducing valve pressure sensor 9. The oil inlet of the first plunger pump 6 is connected to the hydraulic oil tank 1, the oil outlet of the first plunger pump 6 is connected to the oil inlet of the unloading valve 17 of the first multi-way reversing valve, the oil outlet of the unloading valve 17 of the first multi-way reversing valve is connected to the hydraulic oil tank 1, the oil outlet of the first plunger pump 6 is provided with a first plunger pump outlet pressure sensor 15, the control port of the unloading valve 17 of the first multi-way reversing valve is connected to the P port of the first unloading valve proportional pressure reducing valve 19, and the A port of the first unloading valve proportional pressure reducing valve 19 is connected to the oil outlet of the pilot gear pump 8.

[0126] The swash plate on the second plunger pump 7 is provided with a second plunger pump swing angle sensor 3, the oil drain port of the second plunger pump 7 is connected to the hydraulic oil tank 1, the oil drain port of the second plunger pump 7 is provided with a second oil drain pressure sensor 4.2, the oil port of the swash plate of the second plunger pump 7 is connected to the P port of the second plunger pump proportional pressure reducing valve 13, the A port of the second plunger pump proportional pressure reducing valve 13 is connected to the oil outlet of the pilot gear pump 8, and the oil port of the swash plate of the second plunger pump 7 is provided with a second plunger pump proportional pressure reducing valve pressure sensor 10. The oil inlet of the second plunger pump 7 is connected to the hydraulic oil tank 1, the oil outlet of the second plunger pump 7 is connected to the oil inlet of the unloading valve 18 of the second multi-way reversing valve, the oil outlet of the unloading valve 18 of the second multi-way reversing valve is connected to the hydraulic oil tank 1, the oil outlet of the second plunger pump 7 is provided with a second plunger pump outlet pressure sensor 16, the control port of the unloading valve 18 of the second multi-way reversing valve is connected to the P port of the second unloading valve proportional pressure reducing valve 21, and the A port of the second unloading valve proportional pressure reducing valve 21 is connected to the oil outlet of the pilot gear pump 8.

[0127] The engine 5 is used to drive a first plunger pump 6 , a second plunger pump 7 and a pilot gear pump 8 .

[0128] Furthermore, the control unit 101 is used to send a first plunger pump control current PWM signal 12 to the control end of the first plunger pump proportional pressure reducing valve 11 , and send a second plunger pump control current PWM signal 14 to the control end of the second plunger pump proportional pressure reducing valve 13 .

[0129] Furthermore, the controller 102 is used to send a first unloading valve proportional pressure reducing valve control current PWM signal 20 to the control end of the first unloading valve proportional pressure reducing valve 19 , and to send a second unloading valve proportional pressure reducing valve control current PWM signal 22 to the control end of the second unloading valve proportional pressure reducing valve 21 .

[0130] Furthermore, the first plunger pump swing angle sensor 2 , the first oil leakage pressure sensor 4 . 1 , the first plunger pump proportional pressure reducing valve 11 , the first plunger pump proportional pressure reducing valve pressure sensor 9 , and the first plunger pump outlet pressure sensor 15 are all arranged on the body of the first plunger pump 6 .

[0131] Furthermore, the second plunger pump swing angle sensor 3 , the second oil leakage pressure sensor 4 . 2 , the second plunger pump proportional pressure reducing valve 13 , the second plunger pump proportional pressure reducing valve pressure sensor 10 , and the second plunger pump outlet pressure sensor 16 are all arranged on the body of the second plunger pump 7 .

[0132] Furthermore, the control unit is arranged on the bodies of the first plunger pump and the second plunger pump.

[0133] Example 2

[0134] This embodiment introduces an intelligent plunger pump fault diagnosis system, including: a hydraulic system 100, a control unit 101, a controller 102, an electric control handle 103, a display 104, and a multi-way reversing valve 105.

[0135] The hydraulic system 100 is used to connect the engine, the plunger pump, the pilot pump hydraulic circuit and the control circuit.

[0136] The control unit 101 is used to input the plunger pump outlet pressure, housing pressure, proportional pressure reducing valve pressure and swash plate inclination sensor signal. The calculation unit of the control unit 101 performs constant power calculation based on the pressure signal value to output the corresponding control current PWM signal. The fault diagnosis module of the control unit 101 outputs the fault code and information by comparing the fault threshold.

[0137] The controller 102 is used to control the opening and closing of the unloading valve in the multi-way reversing valve 105 and store the fault information transmitted by the control unit 101, wherein the unloading valve is always open during fault diagnosis.

[0138] The electric control handle 103 is used to control the action of the vehicle actuator. When the operator controls the handle to start manipulating the construction machinery, the fault diagnosis module program is terminated.

[0139] The display 104 is used to display fault alarm prompts and fault codes and information recorded by the controller.

[0140] The multi-way reversing valve 105 is used to control the flow direction and flow rate of the hydraulic oil by adjusting the position of the valve core, thereby driving the actuator to operate. This diagnostic system mainly uses the unloading valve of the multi-way reversing valve 105 and the unloading valve proportional pressure reducing valve.

[0141] Further, an embodiment wherein the structure is Figure 2 The structure of the first plunger pump will not be described in detail here with the attached drawings. The hydraulic system 100 includes: a hydraulic oil tank, an engine, a plunger pump, and a pilot gear pump.

[0142] Wherein, the swash plate on the plunger pump is provided with a plunger pump swing angle sensor, the oil drain port of the plunger pump is connected to the hydraulic oil tank, the oil drain port of the plunger pump is provided with an oil drain pressure sensor, the oil port of the swash plate of the plunger pump is connected to the P port of the plunger pump proportional pressure reducing valve, the A port of the plunger pump proportional pressure reducing valve is connected to the oil outlet of the pilot gear pump, and the oil port of the swash plate of the plunger pump is provided with a plunger pump proportional pressure reducing valve pressure sensor. The oil inlet of the plunger pump is connected to the hydraulic oil tank, the oil outlet of the plunger pump is connected to the oil inlet of the unloading valve of the multi-way reversing valve, the oil outlet of the unloading valve of the multi-way reversing valve is connected to the hydraulic oil tank, the oil outlet of the plunger pump is provided with a plunger pump outlet pressure sensor, the control port of the unloading valve of the multi-way reversing valve is connected to the P port of the unloading valve proportional pressure reducing valve, and the A port of the unloading valve proportional pressure reducing valve is connected to the oil outlet of the pilot gear pump.

[0143] The engine is used to drive a plunger pump and a pilot gear pump.

[0144] Furthermore, the control unit 101 is used to send a plunger pump control current PWM signal to the control end of the plunger pump proportional pressure reducing valve.

[0145] Furthermore, the controller 102 is used to send a control current PWM signal of the unloading valve proportional pressure reducing valve to the control end of the unloading valve proportional pressure reducing valve.

[0146] Furthermore, the plunger pump swing angle sensor, oil leakage pressure sensor, plunger pump proportional pressure reducing valve, plunger pump proportional pressure reducing valve pressure sensor, and plunger pump outlet pressure sensor are all arranged on the body of the plunger pump.

[0147] Furthermore, the control unit is arranged on the body of the plunger pump.

[0148] Embodiment 3:

[0149] This embodiment introduces a diagnostic method of an intelligent plunger pump fault diagnosis system in embodiment 1, such as Figure 3As shown, after the construction machinery is ignited and started, the electric control handle is in the middle position, and the action detection module in the plunger pump control unit is started. At this time, the engine is in the idle state. After the control unit detects that this state is ≥2s, it enters the first fault diagnosis function module, which specifically includes:

[0150] Within the time Δt1, the first plunger pump control current PWM signal and the second plunger pump control current PWM signal are respectively changed from the minimum value I min Gradually increase to the maximum value I max .

[0151] At several time points within the time Δt1, the pressure value p of the pressure sensor of the proportional pressure reducing valve of the first plunger pump is collected respectively. 1阀 , the pressure value p of the pressure sensor of the proportional pressure reducing valve of the second piston pump 2阀 , the swing angle value of the first plunger pump swing angle sensor is α1, and the swing angle value of the second plunger pump swing angle sensor is α2.

[0152] Compare the pressure value p at each time point 1阀 With pressure value p 2阀 Is it consistent? If the pressure value p 1阀 With pressure value p 2阀 Inconsistent, and the pressure value p 1阀 With pressure value p 2阀 The difference is greater than the pressure threshold p 阀阈值 When the first plunger pump and the second plunger pump are abnormal.

[0153] Compare the swing angle values ​​α1 and α2 at each time point to see if they are consistent. If the swing angle values ​​α1 and α2 are inconsistent, and the difference between the swing angle values ​​α1 and α2 is greater than the angle threshold α 阈值 When the first plunger pump and the second plunger pump are abnormal.

[0154] Further, when the diagnosis result is abnormal, the display fault alarm prompts, and the controller fault information is stored. Further, when the diagnosis result is not abnormal, enter other fault diagnosis function modules.

[0155] Furthermore, when the operator starts to manipulate the construction machinery by controlling the handle, the diagnostic program is terminated, or when the running time reaches a set value, the diagnostic program stops and outputs the plunger pump fault diagnosis result.

[0156] Embodiment 4:

[0157] This embodiment introduces a diagnostic method of an intelligent plunger pump fault diagnosis system in embodiment 1. After the engineering machinery is ignited and started, the electric control handle is in the middle position, and the action detection module in the plunger pump control unit is started. At this time, the engine is in an idle state. After the control unit detects that this state is ≥ 2s, it enters the second fault diagnosis function module, which specifically includes:

[0158] During the time Δt2, the first plunger pump control current PWM signal and the second plunger pump control current PWM signal are respectively maintained at the maximum value I max .

[0159] After Δt2, the pressure value p of the first oil drain pressure sensor is collected respectively. 1壳体 and the pressure value p of the second oil leakage pressure sensor 2壳体 .

[0160] The pressure value p 1壳体 , pressure value p 2壳体 With pressure threshold P 壳体阈值 For comparison, if the pressure value p 1壳体 Greater than the pressure threshold P 壳体阈值 , then the first plunger pump has leakage abnormality, otherwise, the first plunger pump has no abnormality. 2壳体 Greater than the pressure threshold P 壳体阈值 , then the second plunger pump has leakage abnormality, otherwise, the second plunger pump has no abnormality.

[0161] Furthermore, when the diagnosis result is abnormal, the display will give a fault alarm prompt and the controller will store fault information.

[0162] Furthermore, when the diagnosis result shows no abnormality, other fault diagnosis function modules are entered.

[0163] Furthermore, the pressure threshold P 壳体阈值 The acquisition method is as follows:

[0164] By conducting pressure resistance tests on the shaft end seals of different batches of plunger pumps, the control current PWM signal of the plunger pump is controlled to maintain the maximum value I max , using time Δt2, collect the housing pressure p of each plunger pump 壳体 .

[0165] From each piston pump case pressure p 壳体 In the above example, we obtain the maximum value p max壳体 , the minimum value p min壳体 .

[0166] According to the maximum value p max壳体 , the minimum value p min壳体 , calculate the pressure threshold P 壳体阈值 , pressure threshold P 壳体阈值The expression is as follows:

[0167] P 壳体阈值 = k1*(p max壳体 +p min壳体 ) / 2

[0168] Wherein, k1 represents the shell pressure threshold coefficient.

[0169] Furthermore, when the operator starts to manipulate the construction machinery by controlling the handle, the diagnostic program is terminated, or when the running time reaches a set value, the diagnostic program stops and outputs the plunger pump fault diagnosis result.

[0170] Embodiment 5:

[0171] This embodiment introduces a diagnostic method of an intelligent plunger pump fault diagnosis system in embodiment 1. After the engineering machinery is ignited and started, the electric control handle is in the middle position, and the action detection module in the plunger pump control unit is started. At this time, the engine is in an idle state. After the control unit detects that this state is ≥ 2s, it enters the third fault diagnosis function module, which specifically includes:

[0172] During the time Δt3, the first plunger pump control current PWM signal and the second plunger pump control current PWM signal are respectively maintained at the maximum value I max .

[0173] After Δt3, the pressure value p of the pressure sensor of the proportional pressure reducing valve of the first plunger pump is collected respectively. 1阀 , the pressure value p of the pressure sensor of the proportional pressure reducing valve of the second piston pump 2阀 , the swing angle value α1 of the first plunger pump swing angle sensor, the swing angle value α2 of the second plunger pump swing angle sensor, the pressure value p of the first plunger pump outlet pressure sensor 1出口 and the pressure value p of the second plunger pump outlet pressure sensor 2出口 .

[0174] The pressure value p 1阀 With pressure threshold P 阈值 Or the pressure value p 2阀 With pressure threshold P 阈值 For comparison, if the pressure value p 1阀 Less than the pressure threshold P 阈值 , then the proportional pressure reducing valve of the first plunger pump is degraded abnormally. If the pressure value p 2阀 Less than the pressure threshold P 阈值 , then the second piston pump proportional pressure reducing valve is degraded abnormally.

[0175] The swing angle value α1 and the swing angle threshold α 阈值 Or the swing angle value α2 and the swing angle threshold α 阈值 Compare, if the swing angle value α1 is less than the swing angle threshold α阈值 , then the first piston pump variable adjustment block is degraded abnormally. If the swing angle value α2 is less than the swing angle threshold α 阈值 , then the second piston pump variable adjustment block is degraded abnormally.

[0176] The pressure value p 1出口 Pressure threshold P in different hydraulic oil temperature ranges 出口阈值 Or the pressure value p 2出口 Pressure threshold P in different hydraulic oil temperature ranges 出口阈值 For comparison, if the pressure value p 1出口 Less than the pressure threshold P 出口阈值 , the output flow of the first plunger pump degrades abnormally and the volumetric efficiency is low. If the pressure value p 2出口 Less than the pressure threshold P 出口阈值 , the output flow of the second plunger pump degrades abnormally and the volumetric efficiency is low.

[0177] Furthermore, when the diagnosis result is abnormal, the display will give a fault alarm prompt and the controller will store fault information.

[0178] Furthermore, when the diagnosis result shows no abnormality, other fault diagnosis function modules are entered.

[0179] Furthermore, the pressure threshold P 阈值 The acquisition method is as follows:

[0180] The plunger pump control current PWM signal of different batches of plunger pumps is kept at the maximum value I max , using time Δt3, collect the pressure of the piston pump proportional pressure reducing valve of each piston pump.

[0181] From the pressure of the piston pump proportional pressure reducing valve of each piston pump, obtain the maximum value P MAX阀 .

[0182] According to the maximum value P MAX阀 , calculate the pressure threshold P 阈值 , pressure threshold P 阈值 The expression is as follows:

[0183] P 阈值 =k2*P MAX阀

[0184] Wherein, k2 represents the pressure threshold coefficient of the proportional pressure reducing valve.

[0185] Furthermore, the swing angle threshold α 阈值 The acquisition method is as follows:

[0186] The plunger pump control current PWM signal of different batches of plunger pumps is kept at the maximum value I max, and it takes time Δt3 to collect the swing angle value of the piston pump swing angle sensor of each piston pump column.

[0187] From the swing angle value of the piston pump swing angle sensor of each piston pump, obtain the maximum value α MAX .

[0188] According to the maximum value P MAX阀 , calculate the swing angle threshold α 阈值 , swing angle threshold α 阈值 The expression is as follows:

[0189] α 1阈值 =k3*α MAX

[0190] Wherein, k3 represents the swing angle threshold coefficient.

[0191] Furthermore, the pressure thresholds P of the different hydraulic oil temperature intervals are 出口阈值 The acquisition method is as follows:

[0192] The plunger pump control current PWM signal of different batches of plunger pumps is kept at the maximum value I under different hydraulic oil temperature ranges. max , it takes time Δt3 to collect the pressure value of the plunger pump outlet pressure sensor of each plunger pump column in different hydraulic oil temperature ranges.

[0193] From the pressure value of the plunger pump outlet pressure sensor of each plunger pump column in different hydraulic oil temperature ranges, the maximum value p in different hydraulic oil temperature ranges is obtained. max出口 , the minimum value p min出口 .

[0194] According to the maximum value p max出口 , the minimum value p min出口 , calculate the pressure threshold P for different hydraulic oil temperature ranges 出口阈值 , the pressure threshold P of different hydraulic oil temperature ranges 出口阈值 The expression is as follows:

[0195] P 出口阈值 =k4*k5*(p max出口 +p min出口 ) / 2

[0196] Among them, k4 represents the outlet pressure threshold coefficient, and k5 represents the temperature coefficient.

[0197] Furthermore, when the operator starts to manipulate the construction machinery by controlling the handle, the diagnostic program is terminated, or when the running time reaches a set value, the diagnostic program stops and outputs the plunger pump fault diagnosis result.

[0198] Embodiment 6:

[0199] This embodiment introduces a diagnostic method for an intelligent plunger pump fault diagnosis system in embodiment 2. The diagnostic method is the same as the diagnostic method for an intelligent plunger pump in embodiments 4 and 5, and will not be described in detail here.

[0200] Embodiment 7:

[0201] In order to achieve the purpose of accurately controlling the pump output flow rate by using its own control calculation unit, the intelligent plunger pump of the present invention adds a swing angle sensor to the variable swash plate, and the swing angle sensor is installed on the outside of the housing. When the control unit gives a signal to the plunger pump, the swing angle of the swash plate changes, and the swing angle sensor detects the signal change and accurately detects the swing angle of the swash plate. By installing pressure sensors at the pressure measuring points on the housing, the output pressure measuring points of the proportional pressure reducing valve, and the outlet pressure measuring points, the pressure and swing angle of the main pump are collected in real time, and real-time diagnosis and analysis are performed in conjunction with the speed, torque, and power signals sent by the engine through the CAN signal.

[0202] The engine starts and drives the plunger pump to rotate. The pilot gear pump supplies the guide oil to the proportional pressure reducing valve of the plunger pump. The proportional pressure reducing valve controls the current to control the output pressure of the proportional pressure reducing valve. The proportional pressure reducing valve pressure sensor can detect the output pressure of the proportional pressure reducing valve. The proportional pressure reducing valve outputs oil to push the swash plate of the plunger pump to change its swing angle. The swing angle sensor detects the pump swing angle value. The plunger pump sucks hydraulic oil from the oil tank, outputs hydraulic oil from the pump outlet, and then returns to the oil tank through the unloading valve of the opened multi-way reversing valve. The pressure generated by the unloading valve is detected by the outlet pressure sensor. The plunger pump oil drain port can return to the oil tank through the housing oil drain port, and its pressure value can be detected by the oil drain pressure sensor.

[0203] When the fault diagnosis module is running, when the operator controls the handle to start manipulating the construction machinery, the program operation is terminated, or after the running time is set, the program stops and outputs the plunger pump fault diagnosis result.

[0204] The present invention realizes accurate monitoring of the swash plate angle, and in combination with its own control calculation unit, can adjust and accurately control the output flow of the pump in real time. At the same time, in conjunction with the output pressure data of the proportional pressure reducing valve, by comparing with the threshold value in the first fault diagnosis module, it is determined whether the proportional pressure reducing valve and the variable regulating mechanism of the pump are abnormal; in conjunction with the housing pressure data, by comparing with the threshold value in the second fault diagnosis module, it is determined whether the leakage of the pump is abnormal, thereby effectively preventing faults caused by flow fluctuations or abnormalities.

[0205] In view of the influence of the consistency difference of unloading valves on the accuracy of flow calculation in the traditional algorithm, the present invention introduces the consistency avoidance mechanism of unloading valves in the volumetric efficiency diagnosis algorithm, which can accurately calculate and compensate for the differences between unloading valves of different batches, and judge whether the volumetric efficiency of the pump is too low by comparing with the threshold value in the third fault diagnosis module, thereby significantly improving the versatility and accuracy of the volumetric efficiency diagnosis algorithm. This improvement enables the algorithm to be more widely applied to plunger pumps of different models and batches, reducing the diagnosis cost and improving the diagnosis efficiency.

[0206] Considering the influence of ambient temperature changes on hydraulic oil viscosity and pump performance, the present invention incorporates a temperature correction model into the volumetric efficiency diagnosis algorithm. The model can obtain ambient temperature data in real time and adjust the algorithm parameters accordingly to accurately calculate the influence of hydraulic oil viscosity changes on pump flow at different temperatures. By comparing with the threshold in the third fault diagnosis module, it is determined whether the volumetric efficiency of the pump is too low. This innovation not only improves the accuracy of flow diagnosis, but also makes the diagnosis results more reliable and stable, providing a strong guarantee for the long-term stable operation of the pump.

[0207] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An intelligent plunger pump fault diagnosis system, characterized in that: include: Hydraulic system, control unit, controller, multi-way reversing valve; Wherein, the hydraulic system is used to connect the engine, plunger pump and pilot pump hydraulic circuits and control circuits; The control unit is used to input the plunger pump outlet pressure, housing pressure, proportional pressure reducing valve pressure and swash plate inclination sensor signal, the computing unit of the control unit outputs the corresponding control current PWM signal, and the fault diagnosis module of the control unit outputs the fault code and information by comparing the fault threshold; The controller is used to control the switch of the unloading valve in the multi-way reversing valve and store the fault information transmitted by the control unit; The multi-way reversing valve is used to control the flow direction and flow rate of the hydraulic oil by adjusting the unloading valve of the multi-way reversing valve.

2. The intelligent plunger pump fault diagnosis system according to claim 1, characterized in that: The hydraulic system comprises: a hydraulic oil tank, an engine, a plunger pump, and a pilot pump; Wherein, the swash plate on the plunger pump is provided with a plunger pump swing angle sensor, the oil drain port of the plunger pump is connected to the hydraulic oil tank, the oil drain port of the plunger pump is provided with an oil drain pressure sensor, the oil port of the swash plate of the plunger pump is connected to the P port of the plunger pump proportional pressure reducing valve, the A port of the plunger pump proportional pressure reducing valve is connected to the oil outlet of the pilot pump, and the oil port of the swash plate of the plunger pump is provided with a plunger pump proportional pressure reducing valve pressure sensor; the oil inlet of the plunger pump is connected to the hydraulic oil tank, the oil outlet of the plunger pump is connected to the oil inlet of the unloading valve of the multi-way reversing valve, the oil outlet of the unloading valve of the multi-way reversing valve is connected to the hydraulic oil tank, the oil outlet of the plunger pump is provided with a plunger pump outlet pressure sensor, the control port of the unloading valve of the multi-way reversing valve is connected to the P port of the unloading valve proportional pressure reducing valve, and the A port of the unloading valve proportional pressure reducing valve is connected to the oil outlet of the pilot pump; The engine is used to drive the plunger pump and the pilot pump.

3. The intelligent plunger pump fault diagnosis system according to claim 2, characterized in that: The plunger pump swing angle sensor, the oil leakage pressure sensor, the plunger pump proportional pressure reducing valve, the plunger pump proportional pressure reducing valve pressure sensor, and the plunger pump outlet pressure sensor are all arranged on the plunger pump body.

4. The intelligent plunger pump fault diagnosis system according to claim 2, characterized in that: The control unit is arranged on the body of the plunger pump.

5. An intelligent plunger pump fault diagnosis system, characterized in that: include: Hydraulic system, control unit, controller, multi-way reversing valve; Wherein, the hydraulic system is used to connect the engine, plunger pump and pilot pump hydraulic circuits and control circuits; The control unit is used to input the plunger pump outlet pressure, housing pressure, proportional pressure reducing valve pressure and swash plate inclination sensor signal, the computing unit of the control unit outputs the corresponding control current PWM signal, and the fault diagnosis module of the control unit outputs the fault code and information by comparing the fault threshold; The controller is used to control the switch of the unloading valve in the multi-way reversing valve and store the fault information transmitted by the control unit; The multi-way reversing valve is used to control the flow direction and flow rate of the hydraulic oil by adjusting the unloading valve of the multi-way reversing valve.

6. The intelligent plunger pump fault diagnosis system according to claim 5, characterized in that: The hydraulic system comprises: a hydraulic oil tank, an engine, a first plunger pump, a second plunger pump, and a pilot pump; Wherein, the swash plate on the first plunger pump is provided with a first plunger pump swing angle sensor, the oil drain port of the first plunger pump is connected to the hydraulic oil tank, the oil drain port of the first plunger pump is provided with a first oil drain pressure sensor, the oil port of the swash plate of the first plunger pump is connected to the P port of the first plunger pump proportional pressure reducing valve, the A port of the first plunger pump proportional pressure reducing valve is connected to the oil outlet of the pilot pump, and the oil port of the swash plate of the first plunger pump is provided with a first plunger pump proportional pressure reducing valve pressure sensor; the oil inlet of the first plunger pump is connected to the hydraulic oil tank, the oil outlet of the first plunger pump is connected to the oil inlet of the unloading valve of the first multi-way reversing valve, the oil outlet of the unloading valve of the first multi-way reversing valve is connected to the hydraulic oil tank, the oil outlet of the first plunger pump is provided with a first plunger pump outlet pressure sensor, the control port of the unloading valve of the first multi-way reversing valve is connected to the P port of the first unloading valve proportional pressure reducing valve, and the A port of the first unloading valve proportional pressure reducing valve is connected to the oil outlet of the pilot pump; The swash plate on the second plunger pump is provided with a second plunger pump swing angle sensor, the oil drain port of the second plunger pump is connected to the hydraulic oil tank, the oil drain port of the second plunger pump is provided with a second oil drain pressure sensor, the oil port of the swash plate of the second plunger pump is connected to the P port of the second plunger pump proportional pressure reducing valve, the A port of the second plunger pump proportional pressure reducing valve is connected to the oil outlet of the pilot pump, and the oil port of the swash plate of the second plunger pump is provided with a second plunger pump proportional pressure reducing valve pressure sensor; the oil inlet of the second plunger pump is connected to the hydraulic oil tank, the oil outlet of the second plunger pump is connected to the oil inlet of the unloading valve of the second multi-way reversing valve, the oil outlet of the unloading valve of the second multi-way reversing valve is connected to the hydraulic oil tank, the oil outlet of the second plunger pump is provided with a second plunger pump outlet pressure sensor, the control port of the unloading valve of the second multi-way reversing valve is connected to the P port of the second unloading valve proportional pressure reducing valve, and the A port of the second unloading valve proportional pressure reducing valve is connected to the oil outlet of the pilot pump; The engine is used to drive the first plunger pump, the second plunger pump and the pilot pump.

7. The intelligent plunger pump fault diagnosis system according to claim 5, characterized in that: The first plunger pump swing angle sensor, the first oil leakage pressure sensor, the first plunger pump proportional pressure reducing valve, the first plunger pump proportional pressure reducing valve pressure sensor, and the first plunger pump outlet pressure sensor are all arranged on the body of the first plunger pump.

8. The intelligent plunger pump fault diagnosis system according to claim 5, characterized in that: The second plunger pump swing angle sensor, the second oil leakage pressure sensor, the second plunger pump proportional pressure reducing valve, the second plunger pump proportional pressure reducing valve pressure sensor, and the second plunger pump outlet pressure sensor are all arranged on the body of the second plunger pump.

9. The intelligent plunger pump fault diagnosis system according to claim 5, characterized in that: The control unit is arranged on the bodies of the first plunger pump and the second plunger pump.

10. The diagnostic method of an intelligent plunger pump fault diagnosis system according to any one of claims 1 to 4, characterized in that: Specifically include: During the time Δt2, the plunger pump control current PWM signal is maintained at the maximum value I max ; The pressure value p of the oil leakage pressure sensor is collected after Δt2 壳体 ; The pressure value p 壳体 With pressure threshold P 壳体阈值 For comparison, if the pressure value p 壳体 Greater than the pressure threshold P 壳体阈值 , then the plunger pump leakage is abnormal, otherwise, the plunger pump is normal.

11. The diagnostic method according to claim 10, characterized in that: The pressure threshold P 壳体阈值 The acquisition method is as follows: By conducting pressure tests on different batches of plunger pumps, the plunger pump control current PWM signal is controlled to maintain the maximum value I max , taking time Δt2, collect the casing pressure of each plunger pump; From each piston pump case pressure, obtain the maximum value p max壳体 , the minimum value p min壳体 ; According to the maximum value p max壳体 , the minimum value p min壳体 , calculate the pressure threshold P 壳体阈值 , pressure threshold P 壳体阈值 The expression is as follows: P 壳体阈值 = k1*(p max壳体 +p min壳体 ) / 2; Wherein, k1 represents the shell pressure threshold coefficient.

12. The diagnostic method of an intelligent plunger pump fault diagnosis system according to any one of claims 1 to 4, characterized in that: Specifically include: During the time Δt3, the plunger pump control current PWM signal is maintained at the maximum value I max ; After Δt3, the pressure value p of the pressure sensor of the proportional pressure reducing valve of the piston pump is collected. 阀 , the swing angle value α of the plunger pump swing angle sensor, the pressure value p of the plunger pump outlet pressure sensor 出口 ; The pressure value p 阀 With pressure threshold P 阈值 For comparison, if the pressure value p 阀 Less than the pressure threshold P 阈值 , then the piston pump proportional pressure reducing valve is degraded abnormally; The swing angle value α and the swing angle threshold α 阈值 Compare, if the swing angle value α is less than the swing angle threshold α 阈值 , then the plunger pump variable adjustment block is degraded abnormally; The pressure value p 出口 Pressure threshold P in different hydraulic oil temperature ranges 出口阈值 For comparison, if the pressure value p 出口 Less than the pressure threshold P 出口阈值 , the output flow of the plunger pump will degrade abnormally and the volumetric efficiency will be low.

13. The diagnostic method according to claim 12, characterized in that: The pressure threshold P 阈值 The acquisition method is as follows: The plunger pump control current PWM signal of different batches of plunger pumps is kept at the maximum value I max , using time Δt3, collecting the pressure of the plunger pump proportional pressure reducing valve of each plunger pump; From the pressure of the piston pump proportional pressure reducing valve of each piston pump, obtain the maximum value P MAX阀 ; According to the maximum value P MAX阀 , calculate the pressure threshold P 阈值 , pressure threshold P 阈值 The expression is as follows: P 阈值 =k2*P MAX阀 ; Wherein, k2 represents the pressure threshold coefficient of the proportional pressure reducing valve.

14. The diagnostic method according to claim 12, characterized in that: The swing angle threshold α 阈值 The acquisition method is as follows: The plunger pump control current PWM signal of different batches of plunger pumps is kept at the maximum value I max , using time Δt3, collecting the swing angle value of the plunger pump swing angle sensor of each plunger pump column; From the swing angle value of the piston pump swing angle sensor of each piston pump, obtain the maximum value α MAX ; According to the maximum value P MAX阀 , calculate the swing angle threshold α 阈值 , swing angle threshold α 阈值 The expression is as follows: α 1阈值 =k3*α MAX ； Wherein, k3 represents the swing angle threshold coefficient.

15. The diagnostic method according to claim 12, characterized in that: The pressure threshold value P of different hydraulic oil temperature intervals 出口阈值 The acquisition method is as follows: The plunger pump control current PWM signal of different batches of plunger pumps is kept at the maximum value I under different hydraulic oil temperature ranges. max , using time Δt3, collecting the pressure value of the plunger pump outlet pressure sensor of each plunger pump column in different hydraulic oil temperature ranges; From the pressure value of the plunger pump outlet pressure sensor of each plunger pump column in different hydraulic oil temperature ranges, the maximum value p in different hydraulic oil temperature ranges is obtained. max出口 , the minimum value p min出口 ; According to the maximum value p max出口 , the minimum value p min出口 , calculate the pressure threshold P for different hydraulic oil temperature ranges 出口阈值 , the pressure threshold P of different hydraulic oil temperature ranges 出口阈值 The expression is as follows: P 出口阈值 =k4*k5*(p max出口 +p min出口 ) / 2; Among them, k4 represents the outlet pressure threshold coefficient, and k5 represents the temperature coefficient.

16. A diagnostic method for an intelligent plunger pump fault diagnosis system according to any one of claims 5 to 9, characterized in that: Specifically include: Within the time Δt1, the first plunger pump control current PWM signal and the second plunger pump control current PWM signal are respectively changed from the minimum value I min Gradually increase to the maximum value I max ; At several time points within the time Δt1, the pressure value p of the pressure sensor of the proportional pressure reducing valve of the first plunger pump is collected respectively. 1阀 , the pressure value p of the pressure sensor of the proportional pressure reducing valve of the second piston pump 2阀 , the swing angle value α1 of the first plunger pump swing angle sensor, the swing angle value α2 of the second plunger pump swing angle sensor; Compare the pressure value p at each time point 1阀 With pressure value p 2阀 Is it consistent? If the pressure value p 1阀 With pressure value p 2阀 Inconsistent, and the pressure value p 1阀 With pressure value p 2阀 The difference is greater than the pressure threshold p 阀阈值 When , the first plunger pump and the second plunger pump are abnormal; Compare the swing angle values ​​α1 and α2 at each time point to see if they are consistent. If the swing angle values ​​α1 and α2 are inconsistent, and the difference between the swing angle values ​​α1 and α2 is greater than the angle threshold α 阈值 When the first plunger pump and the second plunger pump are abnormal.

17. A diagnostic method for an intelligent plunger pump fault diagnosis system according to any one of claims 5 to 9, characterized in that: Specifically include: During the time Δt2, the first plunger pump control current PWM signal and the second plunger pump control current PWM signal are respectively maintained at the maximum value I max ; After Δt2, the pressure value p of the first oil leakage pressure sensor is collected respectively. 1壳体 and the pressure value p of the second oil leakage pressure sensor 2壳体 ; The pressure value p 1壳体 , pressure value p 2壳体 With pressure threshold P 壳体阈值 For comparison, if the pressure value p 1壳体 Greater than the pressure threshold P 壳体阈值 , then the first plunger pump has leakage abnormality, otherwise, the first plunger pump has no abnormality; if the pressure value p 2壳体 Greater than the pressure threshold P 壳体阈值 , then the second plunger pump has leakage abnormality, otherwise, the second plunger pump has no abnormality.

18. The diagnostic method according to claim 17, characterized in that: The pressure threshold P 壳体阈值 The acquisition method is as follows: By conducting pressure tests on different batches of plunger pumps, the plunger pump control current PWM signal is controlled to maintain the maximum value I max , taking time Δt2, collect the casing pressure of each plunger pump; From each piston pump case pressure, obtain the maximum value p max壳体 , the minimum value p min壳体 ; According to the maximum value p max壳体 , the minimum value p min壳体 , calculate the pressure threshold P 壳体阈值 , pressure threshold P 壳体阈值 The expression is as follows: P 壳体阈值 = k1*(p max壳体 +p min壳体 ) / 2; Wherein, k1 represents the shell pressure threshold coefficient.

19. The diagnostic method of an intelligent plunger pump fault diagnosis system according to any one of claims 5 to 9, characterized in that: Specifically include: During the time Δt3, the first plunger pump control current PWM signal and the second plunger pump control current PWM signal are respectively maintained at the maximum value I max ; After Δt3, the pressure value p of the pressure sensor of the proportional pressure reducing valve of the first plunger pump is collected respectively. 1阀 , the pressure value p of the pressure sensor of the proportional pressure reducing valve of the second piston pump 2阀 , the swing angle value α1 of the first plunger pump swing angle sensor, the swing angle value α2 of the second plunger pump swing angle sensor, the pressure value p of the first plunger pump outlet pressure sensor 1出口 and the pressure value p of the second plunger pump outlet pressure sensor 2出口 ; The pressure value p 1阀 With pressure threshold P 阈值 Or the pressure value p 2阀 With pressure threshold P 阈值 For comparison, if the pressure value p 1阀 Less than the pressure threshold P 阈值 , then the proportional pressure reducing valve of the first plunger pump is degraded abnormally. If the pressure value p 2阀 Less than the pressure threshold P 阈值 , then the proportional pressure reducing valve of the second plunger pump is degraded abnormally; The swing angle value α1 and the swing angle threshold α 阈值 Or the swing angle value α2 and the swing angle threshold α 阈值 Compare, if the swing angle value α1 is less than the swing angle threshold α 阈值 , then the first plunger pump variable adjustment block is degraded abnormally. If the swing angle value α2 is less than the swing angle threshold α 阈值 , then the second piston pump variable regulating block degrades abnormally; The pressure value p 1出口 Pressure threshold P in different hydraulic oil temperature ranges 出口阈值 Or the pressure value p 2出口 Pressure threshold P in different hydraulic oil temperature ranges 出口阈值 For comparison, if the pressure value p 1出口 Less than the pressure threshold P 出口阈值 , the output flow of the first plunger pump degrades abnormally and the volumetric efficiency is low. If the pressure value p 2出口 Less than the pressure threshold P 出口阈值 , the output flow of the second plunger pump degrades abnormally and the volumetric efficiency is low.

20. The diagnostic method according to claim 19, characterized in that: The pressure threshold P 阈值 The acquisition method is as follows: The plunger pump control current PWM signal of different batches of plunger pumps is kept at the maximum value I max , using time Δt3, collecting the pressure of the plunger pump proportional pressure reducing valve of each plunger pump; From the pressure of the piston pump proportional pressure reducing valve of each piston pump, obtain the maximum value P MAX阀 ; According to the maximum value P MAX阀 , calculate the pressure threshold P 阈值 , pressure threshold P 阈值 The expression is as follows: P 阈值 =k2*P MAX阀 ; Wherein, k2 represents the pressure threshold coefficient of the proportional pressure reducing valve.

21. The diagnostic method according to claim 19, characterized in that: The swing angle threshold α 阈值 The acquisition method is as follows: The plunger pump control current PWM signal of different batches of plunger pumps is kept at the maximum value I max , using time Δt3, collecting the swing angle value of the plunger pump swing angle sensor of each plunger pump column; From the swing angle value of the piston pump swing angle sensor of each piston pump, obtain the maximum value α MAX ; According to the maximum value P MAX阀 , calculate the swing angle threshold α 阈值 , swing angle threshold α 阈值 The expression is as follows: α 1阈值 =k3*α MAX ； Wherein, k3 represents the swing angle threshold coefficient.

22. The diagnostic method according to claim 19, characterized in that: The pressure threshold value P of different hydraulic oil temperature intervals 出口阈值 The acquisition method is as follows: The plunger pump control current PWM signal of different batches of plunger pumps is kept at the maximum value I under different hydraulic oil temperature ranges. max , using time Δt3, collecting the pressure value of the plunger pump outlet pressure sensor of each plunger pump column in different hydraulic oil temperature ranges; From the pressure value of the plunger pump outlet pressure sensor of each plunger pump column in different hydraulic oil temperature ranges, the maximum value p in different hydraulic oil temperature ranges is obtained. max出口 , the minimum value p min出口 ; According to the maximum value p max出口 , the minimum value p min出口 , calculate the pressure threshold P for different hydraulic oil temperature ranges 出口阈值 , the pressure threshold P of different hydraulic oil temperature ranges 出口阈值 The expression is as follows: P 出口阈值 =k4*k5*(p max出口 +p min出口 ) / 2; Among them, k4 represents the outlet pressure threshold coefficient, and k5 represents the temperature coefficient.

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