A method and system for unmanned testing of wear resistance of excavator pins and bushings

Abstract

This invention relates to the field of intelligent control technology, and specifically to an unmanned testing method and system for the wear resistance of excavator pins and bushings. The method includes the following steps: determining the hydraulic pressure and position parameters corresponding to the boom, arm, and bucket during normal digging operations; acquiring the real-time hydraulic pressure and position parameters of the boom, arm, and bucket during the digging process; calculating the deviation between the real-time hydraulic pressure and position of the boom, arm, and bucket and the hydraulic pressure and position during normal digging operations; determining and recording the number of effective digging operations; and continuing until a certain pin and bushing wear out, effectively determining its service life. This method requires no manual operation and saves manpower.

Description

Technical Field

[0001] This invention belongs to the field of excavating machinery technology, and in particular relates to an unmanned testing method and system for the wear resistance of excavator pins and bushings. Background Technology

[0002] An excavator is a digging machine that uses a bucket to excavate materials and load them into transport vehicles or unload them into stockpiles. Its main applicable materials include soil, coal, silt, and pre-loosened soil and rock. In recent years, the development of excavators has been relatively rapid, and it has become one of the major types of construction machinery.

[0003] An excavator mainly consists of a base, boom, arm, and bucket. The boom and base, the arm and boom, the bucket and arm, and the hydraulic cylinders and boom, arm and bucket are all hinged together using pins and bushings. During operation, these pins and bushings experience wear. The degree of wear varies depending on the material being excavated and the excavator's load. While not the most visible parts, pins and bushings are crucial for efficient operation. Excavators are used in various environments, some of which are complex and harsh, leading to different levels of wear on the pins and bushings. To ensure optimal excavation performance, pins and bushings are typically replaced before complete damage, improving efficiency and operational safety.

[0004] Currently, there are industry standards for the pins and bushings of various excavators. However, due to different working environments, the service life of pins and bushings varies greatly. There is no technical solution in the existing technology to test the service life of excavator pins and bushings for specific working environments. Usually, they are inspected periodically. Sometimes, the working environment is harsh, making inspection difficult. Or, they are only discovered and replaced when the pins and bushings are worn out and affect normal operation. This will affect the quality, efficiency and safety of operation to some extent. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides an unmanned testing method and system for the wear resistance of excavator pins and bushings, aiming to solve the technical problem that the service life of excavator pins and bushings in different working environments cannot be effectively predetermined in the existing technology.

[0006] This invention provides an unmanned testing method for the wear resistance of excavator pins and bushings, comprising the following steps: Determine the hydraulic pressure and position parameters corresponding to the boom, arm, and bucket during normal digging operations; The real-time hydraulic pressure and position parameters of the boom, arm, and bucket during the excavation process are obtained, and the deviation between the real-time hydraulic pressure and position of the boom, arm, and bucket and the hydraulic pressure and position during normal excavation is calculated. If the real-time position deviation is less than or equal to the preset first position deviation value, and the real-time pressure value is greater than or equal to the normal pressure value or the real-time pressure deviation is less than or equal to the preset first pressure deviation value, the excavation action is determined to be normal. After the excavation action is completed, it is counted as valid excavation, and the next excavation action is continued. If the real-time position deviation is greater than the preset first position deviation value and less than or equal to the second position deviation value, the second position deviation value is greater than the first position deviation value, and the real-time pressure value is greater than or equal to the normal pressure value or the real-time pressure deviation is less than or equal to the preset first pressure deviation value, it is determined that the corresponding pin and bushing are worn and damaged, and the operation is stopped. The number of effective excavations recorded before this is the service life of the damaged pin and bushing. If the real-time position deviation is greater than or equal to the second position deviation value, or the real-time pressure value is less than the normal pressure value and the real-time pressure deviation is greater than the preset first pressure deviation value, the equipment is judged to be faulty, the test is stopped, and the previously recorded valid digging count is retained.

[0007] As a further improvement, the hydraulic pressure and position parameters corresponding to the boom, arm, and bucket during normal digging operations are determined as follows: Determine the hydraulic pressure of the boom, arm, and bucket when unloaded based on the equipment conditions, and determine the hydraulic pressure of the boom, arm, and bucket within the effective load range of the bucket based on the material conditions. The position changes of the boom, arm, and bucket directly driven by the hydraulic cylinder are determined based on the changes in oil volume, oil pressure, and stroke. Based on the initial positions of the boom, arm, and bucket, the positions corresponding to the boom, arm, and bucket after a certain oil pressure and oil volume output under normal working conditions are calculated. Alternatively, real-time position parameters of the boom, arm, and bucket during normal operation are collected by position sensors, and a functional model of real-time position parameters with real-time oil pressure and flow rate is established. The normal digging positions corresponding to the boom, arm, and bucket are determined based on the real-time digging oil pressure and flow rate.

[0008] As a further improvement, the real-time hydraulic pressure of the boom, arm and bucket during the excavation process is monitored and collected in real time by pressure sensors, and the real-time position parameters are collected by position sensors. The position parameters for normal excavation are calculated based on the real-time position parameters, real-time hydraulic pressure and flow rate. During the excavation process, the real-time pressure data of the corresponding hydraulic circuits of the boom, arm, and bucket, as well as the real-time position data of the boom, arm, and bucket, are compared with the pressure and position data of the corresponding normal excavation operation. The PID algorithm is then used to calculate the adjustment parameters of the hydraulic circuit pressure and flow rate.

[0009] As a further improvement, the preset first position deviation value includes: determining the corresponding normal wear allowance value based on the assembly play, normal wear allowance and operation and load factors of different pins and bushings, calculating the deviation value between the position of the boom, arm and bucket corresponding to the maximum value of the normal wear allowance value and the real-time position in the normal digging state, which is the first position deviation value; when the real-time position deviation value is less than the preset first position deviation value, the pins and bushings are in the normal wear state. The preset second position deviation value includes: the limit value reached by the pin and bushing under severe wear under normal hydraulic pressure. The limit position of the boom, arm and bucket is calculated based on the limit value. The deviation value between the limit position and the normal digging position is the second position deviation value. Based on the material conditions, determine the real-time hydraulic pressure value corresponding to the bucket being unloaded or fully loaded. Calculate the deviation between the real-time hydraulic pressure value and the hydraulic pressure value corresponding to normal digging operation. The first pressure deviation value when unloaded is less than the first pressure deviation value when the bucket is loaded. The first pressure deviation value when the bucket is loaded is used to reflect the load condition of the bucket. If the deviation between the real-time hydraulic pressure value and the hydraulic pressure value during normal digging operation is greater than the first pressure deviation value, it is recorded as an invalid digging operation.

[0010] This invention also provides an unmanned testing system for the wear resistance of excavator pins and bushings, comprising: The hydraulic drive unit is used to drive the boom, arm, and bucket to perform digging operations. The information acquisition unit includes a pressure sensor for real-time acquisition of the hydraulic pressure of the boom, arm and bucket, and a position sensor for real-time measurement of the position of the boom, arm and bucket. The control unit includes an information sending module, an information receiving module, and an information processing module. The information sending module is used to send operation instructions to the hydraulic drive unit. The information receiving module is used to receive data collected by the information acquisition unit. The information processing module is used to process the data collected by the information receiving module, analyze the pressure data of the corresponding oil circuits of the boom, arm, and bucket, as well as the position data of the boom, arm, and bucket, and compare them with the oil circuit pressure data and position data corresponding to effective digging to determine the damage status and service life of the corresponding pins and bushings. The power supply unit is used to supply power to the hydraulic drive unit, information acquisition unit, and control unit.

[0011] As a further improvement, the control unit is equipped with a PID module, which is used to compare the real-time pressure data of the corresponding oil circuits of the boom, arm and bucket, as well as the real-time position data of the boom, arm and bucket, with the pressure data and position data of the corresponding normal digging action, and calculate the adjustment parameters of the oil circuit pressure and flow rate.

[0012] As a further improvement, the hydraulic drive unit includes a hydraulic pump station, the oil outlet of which is connected to the boom oil circuit, the arm oil circuit and the bucket oil circuit respectively. The boom hydraulic circuit includes a first proportional directional valve and a boom cylinder. The P port of the first proportional directional valve is connected to the outlet of the hydraulic pump station, the T port is connected to the oil tank, the A port is connected to the plug chamber of the boom cylinder, and the B port is connected to the rod chamber of the boom cylinder. A first check valve is provided on the hydraulic circuit between the A port and the boom cylinder to allow hydraulic oil to flow from the A port to the boom cylinder. The outlet of the first check valve is connected to the P port through a second check valve to allow hydraulic oil to flow to the P port. A damping orifice is connected between the inlet of the first check valve and the inlet of the second check valve. The inlet of the first check valve is connected to the T port through a relief valve and a third check valve arranged in parallel. The inlet of the third check valve is connected to the T port. The B port is connected to the T port through a relief valve and a fourth check valve arranged in parallel. The inlet of the fourth check valve is connected to the T port. The boom hydraulic circuit includes a second proportional directional valve and a boom cylinder. The P port of the second proportional directional valve is connected to the outlet of the hydraulic pump station, the T port is connected to the oil tank, the A port is connected to the plug chamber of the boom cylinder, and the B port is connected to the rod chamber of the boom cylinder. The A port is connected to the T port through a relief valve and a fifth check valve arranged in parallel. The inlet of the fifth check valve is connected to the T port. The B port is connected to the first solenoid ball valve. A damping orifice is connected between the inlet and outlet of the first solenoid ball valve. The outlet of the first solenoid ball valve is connected to the B port. The A port and the inlet of the first solenoid ball valve are connected to a second solenoid ball valve. The outlet of the second solenoid ball valve is connected to the A port. The inlet of the first solenoid ball valve is connected to the T port through a relief valve and a sixth check valve arranged in parallel. The inlet of the sixth check valve is connected to the T port. The bucket hydraulic circuit includes a third proportional directional valve and a bucket cylinder. The P port of the third proportional directional valve is connected to the outlet of the hydraulic pump station, the T port is connected to the oil tank, the A port is connected to the plug chamber of the bucket cylinder, and the B port is connected to the rod chamber of the bucket cylinder. The A port is connected to the T port through a relief valve and a seventh check valve arranged in parallel. The inlet of the seventh check valve is connected to the T port. The B port is connected to the bucket cylinder through a parallel eighth check valve and a damping orifice. The inlet of the eighth check valve is connected to the B port, and the outlet of the eighth check valve is connected to the P port through a ninth check valve. The outlet of the ninth check valve is connected to the P port. A relief valve and a tenth check valve are arranged in parallel between the inlet of the eighth check valve and the T port. The inlet of the tenth check valve is connected to the T port.

[0013] As a further improvement, the hydraulic pump station includes a double internal gear pump, which is connected to a servo motor. The servo motor is connected to a servo controller. One outlet of the double internal gear pump is connected to the boom oil circuit, the arm oil circuit, and the bucket oil circuit. The other outlet is connected to the oil tank through an eleventh check valve and a pilot-operated sequence valve arranged in parallel. The outlet of the eleventh check valve is connected to the other outlet of the double internal gear pump, an overflow valve, and a throttle valve. The overflow valve and the throttle valve are arranged in parallel and are both connected to the oil tank.

[0014] As a further improvement, pressure sensors are installed on the oil lines connecting the piston chamber and rod chamber of the boom cylinder, the oil lines connecting the piston chamber and rod chamber of the forearm cylinder, and the oil lines connecting the piston chamber and rod chamber of the bucket cylinder. The pressure sensors are connected to the control unit.

[0015] By adopting the above technical solution, the present invention has the following beneficial technical effects: Based on the working environment and material characteristics of the excavator, the hydraulic pressure of the boom, arm, and bucket when unloaded, as well as the hydraulic pressure and position parameters of the effective digging action, are set. The excavator is controlled by the control unit to dig. By monitoring, the hydraulic pressure is adjusted in real time to determine whether the digging action is effective and to record the number of effective digging actions. By performing a large number of effective digging actions in this way, the digging action in the actual working environment is simulated, and the wear of the corresponding pins and bushings is monitored. When the corresponding pins and bushings are worn out, the number of effective digging actions is recorded, thus obtaining the wear life of the bushing of a certain part of the excavator in a certain working environment. Similarly, the wear life of pins and bushings in different parts can be measured. The data is accurate and requires no manual operation, saving manpower. Attached Figure Description

[0016] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0017] Figure 1 This is a flowchart of a method according to an embodiment of the present invention; Figure 2 This is a structural block diagram of an embodiment of the present invention; Figure 3 This is a schematic diagram of the hydraulic circuit of the hydraulic pump station in an embodiment of the present invention; Figure 4 This is a schematic diagram of the hydraulic circuits of the boom, arm, and bucket in an embodiment of the present invention. Figure 5 This is a power supply schematic diagram of an embodiment of the present invention; Figure 6 This is an electrical schematic diagram of an embodiment of the present invention; Figure 7 This is a power supply schematic diagram of the expansion module of the control unit in an embodiment of the present invention; Figure 8 This is an electrical schematic diagram of the expansion module of the control unit in an embodiment of the present invention; Figure 9This is an electrical schematic diagram of the expansion module and the servo camera in an embodiment of the present invention; Figure 10 This is an electrical schematic diagram of the expansion module and the hydraulic valve in the oil circuit in an embodiment of the present invention. Detailed Implementation

[0018] The embodiments of the technical solution of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the present invention and are therefore intended to limit the scope of protection of the present invention.

[0019] like Figure 1 As shown, an unmanned testing method for the wear resistance of excavator pins and bushings includes the following steps: Determine the hydraulic pressure and position parameters corresponding to the boom, arm, and bucket during normal digging operations; The real-time hydraulic pressure and position parameters of the boom, arm, and bucket during the excavation process are obtained, and the deviation between the real-time hydraulic pressure and position of the boom, arm, and bucket and the hydraulic pressure and position during normal excavation is calculated. If the real-time position deviation is less than or equal to the preset first position deviation value, and the real-time pressure value is greater than or equal to the normal pressure value or the real-time pressure deviation is less than or equal to the preset first pressure deviation value, the excavation action is determined to be normal. After the excavation action is completed, it is counted as valid excavation, and the next excavation action is continued. If the real-time position deviation is greater than the preset first position deviation value and less than or equal to the second position deviation value, the second position deviation value is greater than the first position deviation value, and the real-time pressure value is greater than or equal to the normal pressure value or the real-time pressure deviation is less than or equal to the preset first pressure deviation value, it is determined that the corresponding pin and bushing are worn and damaged, and the operation is stopped. The number of effective excavations recorded before this is the service life of the damaged pin and bushing. If the real-time position deviation is greater than or equal to the second position deviation value, or the real-time pressure value is less than the normal pressure value and the real-time pressure deviation is greater than the preset first pressure deviation value, the equipment is judged to be faulty, the test is stopped, and the previously recorded valid digging count is retained.

[0020] In this embodiment, all deviations or deviation values ​​are absolute values.

[0021] In this embodiment, the effective digging actions of the excavator include boom extension and pitch swing, boom extension and pitch swing, and bucket pitch swing, including the complete material loading and unloading process. It does not include boom horizontal swing and boom horizontal swing because the horizontal swing action has minimal impact on the wear of the pins and bushings, so it is not calculated here. This also improves calculation efficiency and saves time. In this embodiment, the completion of the digging action means the bucket unloading is completed, or the bucket unloading is completed and returns to the initial position.

[0022] This embodiment determines an invalid digging action and also performs fault detection. If a fault is found, operation is stopped for repair; if no fault is found, the next digging operation continues. For example, if the oil pressure in a certain part is insufficient, and adjustment does not achieve the required level, and there is a significant difference compared to normal operating conditions (i.e., the difference exceeds the first pressure deviation value), then an oil circuit or mechanical fault is determined. This embodiment is used to determine the wear resistance of pins and bushings, but it does not rule out the possibility of damage to other components affecting the equipment's operation and testing. Based on the fault situation, an alarm signal can be issued, and related mechanisms can be controlled to stop operation or maintain a certain operating state. The associated moving mechanisms can be locked to prevent further damage or even safety accidents.

[0023] In this embodiment, the hydraulic pressure and position parameters corresponding to the normal digging operation of the boom, arm, and bucket include: Determine the hydraulic pressure of the boom, arm, and bucket when unloaded based on the equipment conditions, and determine the hydraulic pressure of the boom, arm, and bucket within the effective load range of the bucket based on the material conditions. The position changes of the boom, arm, and bucket directly driven by the cylinder are determined by the changes in oil volume, oil pressure, and stroke. Based on the initial positions of the boom, arm, and bucket, the positions of the boom, arm, and bucket after a certain oil pressure and oil volume output under normal working conditions are calculated. Since the hydraulic circuit is fixed and the hydraulic oil is not easily compressible, the position changes of the boom, arm, and bucket directly driven by the cylinder can be determined by the changes in the stroke. Based on their initial positions, the real-time positions of the boom, arm, and bucket after a certain oil pressure and oil volume output can be calculated. It can also collect real-time position parameters of the boom, arm, and bucket during normal operation through position sensors, establish a functional model of real-time position parameters and real-time oil pressure and flow rate, and determine the normal digging positions of the boom, arm, and bucket respectively based on the real-time digging oil pressure and flow rate.

[0024] Among them, the real-time oil pressure of the boom, arm and bucket during the excavation process is monitored and collected in real time by pressure sensors, and the real-time position parameters are collected by position sensors. The position parameters of normal excavation are calculated based on the real-time position parameters, real-time oil pressure and flow rate. During the excavation process, the real-time pressure data of the corresponding hydraulic circuits of the boom, arm, and bucket, as well as the real-time position data of the boom, arm, and bucket, are compared with the pressure and position data of the corresponding normal excavation action. The PID algorithm is used to calculate the adjustment parameters of the hydraulic circuit pressure and flow rate to achieve PID closed-loop control. The inventive point of this invention does not lie in the specific PID algorithm, which is not described in detail here. The existing PID closed-loop control technology for proportional valve control of hydraulic cylinder position can be used.

[0025] In this embodiment, the preset first position deviation value includes: determining the corresponding normal wear allowance value based on the assembly play, normal wear allowance, and operation and load factors of different pins and bushings; calculating the deviation value between the maximum value of the normal wear allowance value and the real-time position of the boom, arm, and bucket corresponding to the respective positions in the normal digging state, which is the first position deviation value; when the real-time position deviation value is less than the preset first position deviation value, the pins and bushings are in a normal wear state, and the excavator has good operational safety and effectiveness.

[0026] The preset second position deviation value includes: the limit value reached by the pin and bushing under severe wear under normal hydraulic pressure. The limit position of the boom, arm and bucket is calculated based on the limit value. The deviation value between the limit position and the normal digging position is the second position deviation value. When the real-time deviation exceeds the second position deviation value, it indicates that the problem is not with the pin and bushing, but with a fault in other parts of the equipment.

[0027] Based on the material conditions, determine the real-time hydraulic pressure value corresponding to the bucket being unloaded or fully loaded. Calculate the deviation between the real-time hydraulic pressure value and the hydraulic pressure value corresponding to normal digging operation. The first pressure deviation value when unloaded is less than the first pressure deviation value when the bucket is loaded. The first pressure deviation value when the bucket is loaded is used to reflect the load condition of the bucket. If the deviation between the real-time hydraulic pressure value and the hydraulic pressure value during normal digging operation is greater than the first pressure deviation value, it is recorded as an invalid digging operation.

[0028] Based on the equipment condition, determine the no-load oil pressure and position parameters of the equipment in advance. After excavating material, calculate the weight of the excavated goods based on the load change, and determine whether the excavation is at full load and meets the requirements for effective excavation based on the material of the goods.

[0029] like Figure 2 As shown, the present invention also provides an unmanned testing system for the wear resistance of excavator pins and bushings, comprising: The hydraulic drive unit is used to drive the boom, arm, and bucket to perform digging operations. The information acquisition unit includes a pressure sensor for real-time acquisition of the hydraulic pressure of the boom, arm and bucket, and a position sensor for real-time measurement of the position of the boom, arm and bucket. The control unit includes an information sending module, an information receiving module, and an information processing module. The information sending module sends operation instructions to the hydraulic drive unit. The information receiving module receives data collected by the information acquisition unit. The information processing module processes the data collected by the information receiving module, analyzes the pressure data of the corresponding hydraulic circuits of the boom, arm, and bucket, as well as the position parameters of the boom, arm, and bucket, and compares them with the hydraulic circuit pressure and position parameters corresponding to effective digging to determine the damage status and service life of the corresponding pins and bushings. If the difference between the effective digging position and pressure parameters is large and effective digging cannot be achieved after adjustment, a hydraulic circuit or mechanical fault is determined. The power supply unit is used to supply power to the hydraulic drive unit, information acquisition unit, and control unit.

[0030] In this embodiment, the control unit is equipped with a PID module, which is used to compare the real-time pressure data of the corresponding oil circuits of the boom, arm and bucket, as well as the real-time position data of the boom, arm and bucket, with the pressure data and position data of the corresponding normal digging action, and use the PID algorithm to calculate the adjustment parameters of oil circuit pressure and flow rate to realize PID closed-loop control.

[0031] In this embodiment, as Figure 3 and Figure 4 As shown, the hydraulic drive unit includes a hydraulic pump station, and the oil outlet of the hydraulic pump station is connected to the boom oil circuit, the forearm oil circuit and the bucket oil circuit respectively. The boom hydraulic circuit includes a first proportional directional valve 31.1 and a boom cylinder. The first proportional directional valve 31.1 controls the extension and retraction of the boom cylinder. The P port of the first proportional directional valve 31.1 is connected to the outlet of the hydraulic pump station, the T port is connected to the oil tank 1.1, the A port is connected to the plug chamber of the boom cylinder, and the B port is connected to the rod chamber of the boom cylinder. A first check valve 33.1 is installed on the hydraulic circuit between the A port and the boom cylinder, allowing hydraulic oil to flow from the A port to the boom cylinder. The outlet of the first check valve 33.1 is connected to the P port through a second check valve 32.3, allowing hydraulic oil to flow to the P port. A damping orifice is connected between the inlet of the first check valve 33.1 and the inlet of the second check valve 32.3. In this embodiment, the main... The hydraulic circuit uses DN32 pipes with a damping orifice specification of Rc1 / 8-∅1.0. The inlet of the first check valve 33.1 is connected to port T through a parallel-connected relief valve 34.2 and a third check valve 32.2. The inlet of the third check valve 32.2 is also connected to port T. Port B is connected to port T through a parallel-connected relief valve 34.1 and a fourth check valve 32.1. The inlet of the fourth check valve 32.1 is also connected to port T. Here, relief valves 34.2 and 34.1 are specifically cartridge-type relief valves with a pressure range of 55-315 bar. Relief valve 34.1 is used to set the maximum working pressure of the boom cylinder rod chamber, and relief valve 34.2 is used to set the maximum working pressure of the boom cylinder plug chamber. The boom hydraulic circuit includes a second proportional directional valve 31.2 and a boom cylinder. The second proportional directional valve 31.2 controls the extension and retraction of the boom cylinder. The P port of the second proportional directional valve 31.2 is connected to the outlet of the hydraulic pump station, the T port is connected to the oil tank 1.1, the A port is connected to the plug chamber of the boom cylinder, and the B port is connected to the rod chamber of the boom cylinder. The A port is connected to the T port through a parallel overflow valve 34.4 and a fifth check valve 32.4. The inlet of the fifth check valve 32.4 is connected to the T port, and the B port is connected to the first solenoid ball valve 36.1. The first solenoid ball valve 36.1 controls the speed of boom cylinder extension. A damping orifice is connected between the inlet and outlet of the first solenoid ball valve 36.1. The main hydraulic circuit specification is DN32, and the damping orifice specification is Rc1 / 8-∅1. 0. The oil outlet of the first solenoid ball valve 36.1 is connected to port B. The second solenoid ball valve 35.1 is connected between port A and the oil inlet of the first solenoid ball valve 36.1. The second solenoid ball valve 35.1 is used to control the differential extension of the boom cylinder. The oil outlet of the second solenoid ball valve 35.1 is connected to port A. The oil inlet of the first solenoid ball valve 36.1 is connected to port T through the parallel-connected relief valve 34.3 and the sixth check valve 32.5. The oil inlet of the sixth check valve 32.5 is connected to port T. Here, the relief valve 34.3 and the relief valve 34.4 are cartridge relief valves with a pressure range of 55-315 bar. The relief valve 34.3 is used to set the maximum working pressure of the boom cylinder rod chamber, and the relief valve 34.4 is used to set the maximum working pressure of the boom cylinder plug chamber. The bucket hydraulic circuit includes a third proportional directional valve 37.1 and a bucket cylinder. The third proportional directional valve 37.1 controls the extension and retraction of the bucket cylinder. The P port of the third proportional directional valve 37.1 is connected to the outlet of the hydraulic pump station, the T port is connected to the oil tank 1.1, the A port is connected to the plug chamber of the bucket cylinder, and the B port is connected to the rod chamber of the bucket cylinder. The A port is connected to the T port through a parallel overflow valve 40.2 and a seventh check valve 39.3. The inlet of the seventh check valve 39.3 is connected to the T port. The B port is connected to the bucket cylinder through a parallel eighth check valve 38.1 and a damping orifice. The main hydraulic circuit specification is DN25, and the damping orifice specification is... For Rc1 / 8-∅1.0, the inlet of the eighth check valve 38.1 is connected to port B, and the outlet of the eighth check valve 38.1 is connected to port P through the ninth check valve 39.1. The outlet of the ninth check valve 39.1 is also connected to port P. An overflow valve 40.1 and a tenth check valve 39.2 are connected in parallel between the inlet of the eighth check valve 38.1 and port T. The inlet of the tenth check valve 39.2 is connected to port T. The overflow valve 40.1 is a cartridge-type overflow valve used to set the maximum working pressure of the bucket cylinder rod chamber, and the overflow valve 40.2 is a cartridge-type overflow valve used to set the maximum working pressure of the bucket cylinder plug chamber.

[0032] In this embodiment, the hydraulic pump station includes a double internal gear pump 8.1, which is connected to a servo motor M1. Specifically, a coupling 9.1 and a bell-shaped housing 10.1 are provided. The servo motor M1 is connected to a servo controller 12.1. One outlet of the double internal gear pump 8.1 is connected to the boom oil circuit, the forearm oil circuit, and the bucket oil circuit. A pressure sensor 13.1 is installed at this outlet to monitor the pressure at the pump outlet. This pressure sensor 13.1 is connected to the servo controller 12.1. The other outlet is connected to... The eleventh check valve 15.1 and the pilot-operated sequence valve 14.1 are connected to the oil tank 1.1. The oil outlet of the eleventh check valve 15.1 is connected to the other oil outlet of the double internal gear pump 8.1, the cartridge relief valve 16.1 and the cartridge throttle valve 17.1. The cartridge relief valve 16.1 and the cartridge throttle valve 17.1 are connected in parallel and are both connected to the oil tank 1.1. The pilot-operated sequence valve 14.1 is used to control the unloading pressure of the large displacement pump of the servo pump group, and the cartridge relief valve 16.1 is used to set the maximum working pressure of the system.

[0033] In this embodiment, pressure testing connectors 41.1 and 41.2 are respectively installed on the oil lines connecting the plug cavity and rod cavity of the boom cylinder, for installing pressure sensors or pressure gauges to monitor the pressure in the plug cavity and rod cavity of the boom cylinder, respectively. Pressure sensors 42.1 and 42.2 are respectively installed on the oil lines connecting the plug cavity and rod cavity of the boom cylinder, for monitoring the pressure in the plug cavity and rod cavity of the boom cylinder, respectively. Pressure sensors 42.3 and 42.4 are respectively installed on the oil lines connecting the plug cavity and rod cavity of the bucket cylinder, for monitoring the pressure in the plug cavity and rod cavity of the bucket cylinder, respectively. Each pressure sensor is communicatively connected to the control unit.

[0034] In this embodiment, the oil inlet of the oil circuit between the T-port of the first proportional directional valve 31.1, the second proportional directional valve 31.2, and the third proportional directional valve 37.1 and the oil tank 1.1 is connected to the return oil line. A twelfth check valve 20.1 is provided on the return oil line. The outlet of the twelfth check valve 20.1 is connected to the oil tank 1.1. The return oil port of the oil tank 1.1 is provided with a return oil filter 21.1. The outlet of the twelfth check valve 20.1 is connected to the third solenoid ball valve 19.1. The third solenoid ball valve 19.1 is connected to the high-pressure filter 18.1. The high-pressure filter 18.1 is connected to the outlet of the double internal gear pump 8.1 and the outlet of the eleventh check valve 15.1. The third solenoid ball valve 19.1 is used to control the unloading and pressurization of the system.

[0035] The oil tank 1.1 is also equipped with a liquid level and temperature gauge 3.1, a cartridge-type check valve 33.1, a liquid level and temperature sensor 4.1, an air filter 2.1, a pressure test connector 41.1, an electric heater 6.1, a magnet 7.1, and a magnet 7.2. The bottom of the oil tank 1.1 is equipped with a low-pressure ball valve 5.1. The oil tank 1.1 is also connected to a vane pump 25.1. The vane pump 25.1 is connected to a motor 28.1 through a coupling 26.1 and a bell-shaped cover 27.1. The oil outlet of the vane pump 25.1 is connected in sequence to an air cooler 29.1 and a return oil filter 30.1. The return oil filter 30.1 is connected to the oil tank 1.1.

[0036] In this embodiment, based on the working environment and material characteristics of the excavator, the driving hydraulic pressure of the boom, arm, and bucket when unloaded, as well as the hydraulic pressure and position parameters for effective digging actions, are set. The excavator is controlled by the control unit to dig. Through monitoring, the hydraulic pressure is adjusted in real time to determine whether the digging action is effective and to record the number of effective digging actions. By performing a large number of effective digging actions in this way, the digging actions in the actual working environment are simulated, and the wear of the corresponding pins and bushings is monitored. When the corresponding pins and bushings are worn out, the number of effective digging actions is recorded, thus obtaining the wear life of the bushing of a certain part of the excavation in a certain working environment. Similarly, the wear life of pins and bushings in different parts can be measured. The data is accurate and requires no manual operation, saving manpower.

[0037] This embodiment includes a power supply unit for powering the hydraulic drive unit, information acquisition unit, control unit, cooling, and heating structures. See the detailed electrical schematic diagram below. Figures 5 to 10 In this embodiment, the control unit is a PLC, model Siemens SIMATIC S7-1200 series 6ES7 214-1BG40-0XB0, and its I / O expansion module model is 6ES7 223-1PL32-0XB0. In this embodiment, UK3N terminal blocks can be selected to match a suitable terminal box.

[0038] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A method for unmanned testing of the wear resistance of excavator pins and bushings, characterized in that, Includes the following steps: Determine the hydraulic pressure and position parameters corresponding to the boom, arm, and bucket during normal digging operations; The real-time hydraulic pressure and position parameters of the boom, arm, and bucket during the excavation process are obtained, and the deviation between the real-time hydraulic pressure and position of the boom, arm, and bucket and the hydraulic pressure and position during normal excavation is calculated. If the real-time position deviation is less than or equal to the preset first position deviation value, and the real-time pressure value is greater than or equal to the normal pressure value or the real-time pressure deviation is less than or equal to the preset first pressure deviation value, the excavation action is determined to be normal. After the excavation action is completed, it is counted as valid excavation, and the next excavation action is continued. If the real-time position deviation is greater than the preset first position deviation value and less than or equal to the second position deviation value, the second position deviation value is greater than the first position deviation value, and the real-time pressure value is greater than or equal to the normal pressure value or the real-time pressure deviation is less than or equal to the preset first pressure deviation value, it is determined that the corresponding pin and bushing are worn and damaged, and the operation is stopped. The number of effective excavations recorded before this is the service life of the damaged pin and bushing. If the real-time position deviation is greater than or equal to the second position deviation value, or the real-time pressure value is less than the normal pressure value and the real-time pressure deviation is greater than the preset first pressure deviation value, the equipment is judged to be faulty, the test is stopped, and the previously recorded valid digging count is retained. All deviations and deviation values ​​mentioned above are absolute values.

2. The unmanned testing method for the wear resistance of excavator pins and bushings according to claim 1, characterized in that, The hydraulic pressure and position parameters for the boom, arm, and bucket during normal digging operations include: Determine the hydraulic pressure of the boom, arm, and bucket when unloaded based on the equipment conditions, and determine the hydraulic pressure of the boom, arm, and bucket within the effective load range of the bucket based on the material conditions. The position changes of the boom, arm, and bucket directly driven by the hydraulic cylinder are determined based on the changes in oil volume, oil pressure, and stroke. Based on the initial positions of the boom, arm, and bucket, the positions corresponding to the boom, arm, and bucket after a certain oil pressure and oil volume output under normal working conditions are calculated. Alternatively, real-time position parameters of the boom, arm, and bucket during normal operation are collected by position sensors, and a functional model of real-time position parameters with real-time oil pressure and flow rate is established. The normal digging positions corresponding to the boom, arm, and bucket are determined based on the real-time digging oil pressure and flow rate.

3. The unmanned testing method for the wear resistance of excavator pins and bushings according to claim 2, characterized in that, During the excavation process, the real-time hydraulic pressure of the boom, arm, and bucket is monitored and collected in real time by pressure sensors, and the real-time position parameters are collected by position sensors. The position parameters for normal excavation are calculated based on the real-time position parameters, real-time hydraulic pressure, and flow rate. During the excavation process, the real-time pressure data of the corresponding hydraulic circuits of the boom, arm, and bucket, as well as the real-time position data of the boom, arm, and bucket, are compared with the pressure and position data of the corresponding normal excavation operation. The PID algorithm is then used to calculate the adjustment parameters of the hydraulic circuit pressure and flow rate.

4. The unmanned test method for the wear resistance of excavator pins and bushings according to claim 2 or 3, characterized in that, The preset first position deviation value includes: determining the corresponding normal wear allowance value based on the assembly play, normal wear allowance, and operation and load factors of different pins and bushings; calculating the deviation value between the maximum value of the normal wear allowance value and the real-time position of the boom, arm, and bucket corresponding to the corresponding position of the boom, arm, and bucket in normal digging state, which is the first position deviation value; when the real-time position deviation value is less than the preset first position deviation value, the pins and bushings are in normal wear state. The preset second position deviation value includes: the limit value reached by the pin and bushing under severe wear under normal hydraulic pressure. The limit position of the boom, arm and bucket is calculated based on the limit value. The deviation value between the limit position and the normal digging position is the second position deviation value. Based on the material conditions, determine the real-time hydraulic pressure value corresponding to the bucket being unloaded or fully loaded. Calculate the deviation between the real-time hydraulic pressure value and the hydraulic pressure value corresponding to normal digging operation. The first pressure deviation value when unloaded is less than the first pressure deviation value when the bucket is loaded. The first pressure deviation value when the bucket is loaded is used to reflect the load condition of the bucket. If the deviation between the real-time hydraulic pressure value and the hydraulic pressure value during normal digging operation is greater than the first pressure deviation value, it is recorded as an invalid digging operation.

5. An unmanned testing system for the wear resistance of excavator pins and bushings, characterized in that, include: The hydraulic drive unit is used to drive the boom, arm, and bucket to perform digging operations. The information acquisition unit includes a pressure sensor for real-time acquisition of the hydraulic pressure of the boom, arm and bucket, and a position sensor for real-time measurement of the position of the boom, arm and bucket. The control unit includes an information sending module, an information receiving module, and an information processing module. The information sending module is used to send operation instructions to the hydraulic drive unit. The information receiving module is used to receive data collected by the information acquisition unit. The information processing module is used to process the data collected by the information receiving module, analyze the pressure data of the corresponding oil circuits of the boom, arm, and bucket, as well as the position data of the boom, arm, and bucket, and compare them with the oil circuit pressure data and position data corresponding to effective digging to determine the damage status and service life of the corresponding pins and bushings. The power supply unit is used to supply power to the hydraulic drive unit, information acquisition unit, and control unit.

6. The unmanned testing system for the wear resistance of excavator pins and bushings according to claim 5, characterized in that, The control unit is equipped with a PID module, which compares the real-time pressure data of the corresponding oil circuits of the boom, arm, and bucket, as well as the real-time position data of the boom, arm, and bucket, with the pressure data and position data of the corresponding normal digging action, and calculates the adjustment parameters of the oil circuit pressure and flow rate.

7. The unmanned testing system for the wear resistance of excavator pins and bushings according to claim 5, characterized in that, The hydraulic drive unit includes a hydraulic pump station, and the oil outlet of the hydraulic pump station is connected to the boom oil circuit, the arm oil circuit and the bucket oil circuit respectively. The boom hydraulic circuit includes a first proportional directional valve and a boom cylinder. The P port of the first proportional directional valve is connected to the outlet of the hydraulic pump station, the T port is connected to the oil tank, the A port is connected to the plug chamber of the boom cylinder, and the B port is connected to the rod chamber of the boom cylinder. A first check valve is provided on the hydraulic circuit between the A port and the boom cylinder to allow hydraulic oil to flow from the A port to the boom cylinder. The outlet of the first check valve is connected to the P port through a second check valve to allow hydraulic oil to flow to the P port. A damping orifice is connected between the inlet of the first check valve and the inlet of the second check valve. The inlet of the first check valve is connected to the T port through a relief valve and a third check valve arranged in parallel. The inlet of the third check valve is connected to the T port. The B port is connected to the T port through a relief valve and a fourth check valve arranged in parallel. The inlet of the fourth check valve is connected to the T port. The boom hydraulic circuit includes a second proportional directional valve and a boom cylinder. The P port of the second proportional directional valve is connected to the outlet of the hydraulic pump station, the T port is connected to the oil tank, the A port is connected to the plug chamber of the boom cylinder, and the B port is connected to the rod chamber of the boom cylinder. The A port is connected to the T port through a relief valve and a fifth check valve arranged in parallel. The inlet of the fifth check valve is connected to the T port. The B port is connected to the first solenoid ball valve. A damping orifice is connected between the inlet and outlet of the first solenoid ball valve. The outlet of the first solenoid ball valve is connected to the B port. The A port and the inlet of the first solenoid ball valve are connected to a second solenoid ball valve. The outlet of the second solenoid ball valve is connected to the A port. The inlet of the first solenoid ball valve is connected to the T port through a relief valve and a sixth check valve arranged in parallel. The inlet of the sixth check valve is connected to the T port. The bucket hydraulic circuit includes a third proportional directional valve and a bucket cylinder. The P port of the third proportional directional valve is connected to the outlet of the hydraulic pump station, the T port is connected to the oil tank, the A port is connected to the plug chamber of the bucket cylinder, and the B port is connected to the rod chamber of the bucket cylinder. The A port is connected to the T port through a relief valve and a seventh check valve arranged in parallel. The inlet of the seventh check valve is connected to the T port. The B port is connected to the bucket cylinder through a parallel eighth check valve and a damping orifice. The inlet of the eighth check valve is connected to the B port, and the outlet of the eighth check valve is connected to the P port through a ninth check valve. The outlet of the ninth check valve is connected to the P port. A relief valve and a tenth check valve are arranged in parallel between the inlet of the eighth check valve and the T port. The inlet of the tenth check valve is connected to the T port.

8. The unmanned testing system for the wear resistance of excavator pins and bushings according to claim 7, characterized in that, The hydraulic pump station includes a double internal gear pump, which is connected to a servo motor. The servo motor is connected to a servo controller. One outlet of the double internal gear pump is connected to the boom oil circuit, the arm oil circuit, and the bucket oil circuit. The other outlet is connected to the oil tank through an eleventh check valve and a pilot-operated sequence valve arranged in parallel. The outlet of the eleventh check valve is connected to the other outlet of the double internal gear pump, an overflow valve, and a throttle valve. The overflow valve and the throttle valve are arranged in parallel and are both connected to the oil tank.

9. The unmanned testing system for the wear resistance of excavator pins and bushings according to claim 7, characterized in that, Pressure sensors are installed on the oil lines connecting the piston chamber and rod chamber of the boom cylinder, the oil lines connecting the piston chamber and rod chamber of the forearm cylinder, and the oil lines connecting the piston chamber and rod chamber of the bucket cylinder. The pressure sensors are connected to the control unit.

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