A process for improving the performance of an excavator

Abstract

The application discloses a process for improving the performance of a excavator and relates to the technical field of excavators. The process comprises the following steps: step S01, starting the engine and making it run at full throttle after preheating and performing digging, soil throwing, walking and lifting operations, detecting and recording the bucket digging force, bucket rod digging force, lifting force and traction force; and step S02, installing a hydraulic system tester on the high-pressure pipeline of the hydraulic pump of a new excavator by using a bypass method, making the pump run at a rated speed, and observing and recording the flow readings of the front and rear pumps of the tester when the hydraulic oil temperature is 50+ / -5 DEG C. The application is a process technology for adjusting the pressure of each working oil cylinder of the main control valve in the hydraulic system of a new or old excavator and the excellent matching of the pump and the engine, fully improves the fuel utilization rate of the engine and the working efficiency and benefit of the whole machine, saves energy and is economical, and can improve and repair the performance and quality of the new or old excavator, such as the digging, crushing, lifting moment and speed.

Description

Technical Field

[0001] This invention belongs to the field of excavators, and more specifically, relates to a process for improving the performance of excavators. Background Technology

[0002] The design of large, medium, and small tracked hydraulic excavators (hereinafter referred to as excavators) begins with calculations based on the actual load of the bucket and the commonly used pressure of the hydraulic system (selected based on design experience, generally 25-39 MPa). Then, the parameters of the bucket cylinder, boom cylinder, arm cylinder, and main control valve are calculated and selected. Next, the pressure of the hydraulic pump (hereinafter referred to as the pump) is calculated, with a 25-30% reserve capacity based on years of industry experience. Finally, the minimum required net power of the engine is calculated. Because the required net power in actual operation is generally only 60% of the engine's rated power, resulting in low actual utilization, the engines selected for excavators must have a 30-40% power reserve to ensure sufficient power under various complex working conditions. Therefore, the excavator's engine, pump, and load involve issues of balancing power performance, speed curve matching, and work efficiency with fuel economy, as well as control. Therefore, pump flow feedback or pump outlet pressure sensing technology is generally used to match and control the throttle position of the excavator when the hydraulic pump is unloaded (i.e., the pump outlet has no pressure). The throttle position is set for each gear (generally 10 gears and 3-4 working modes), and then digging tests are conducted. During the test, the pump power is adjusted by continuously supplying current to the pump's proportional pressure reducing valve to ensure the pump matches the engine's operation well. The pump and load are matched using load sensing or flow control technology, which involves two partial matching methods: pump and engine, and pump and load. Therefore, there is some incoordination between the engine, pump, and load, making it impossible to achieve excellent overall power matching.

[0003] Existing technologies struggle to precisely match the engine, pump, and load to the optimal levels of the engine's power performance and speed characteristics. Achieving this optimal match requires extensive experimentation and continuous adjustment of the current supply to the proportional solenoid valve. However, it's impossible to simulate every actual working condition in experiments, especially given the many complex and extreme conditions in real-world operations where current values ​​are precisely defined. Therefore, the overall matching is inevitably somewhat coarse and imperfect, particularly compared to this patent. The most obvious drawbacks of existing technologies are: lower digging force, breaking force, lifting force, and speed—key performance parameters for excavators—resulting in lower work efficiency and economic benefits. Users report that the excavators are weak, slow, and fuel-inefficient. This leads to poor excavator quality, resulting in weak competitiveness despite lower prices; and faster aging and wear, with million-yuan excavators aging rapidly within 2-3 years, becoming weak and slow. Essentially, wear on the valve stem and body of the main control valve, such as the bucket and boom, leads to oil leakage and a decrease in pressure in the working oil circuit. This naturally reduces digging force, resulting in weaker and slower digging, thus lowering the resale value of the excavator. Currently, the common repair method is to replace the pump or main control valve, or perform repairs, but this is costly, time-consuming, and ineffective. Especially when the main control valve wears down, the digging force drops significantly, requiring replacement with a new part, which is very expensive. Even after repair, the best result for a small number of excavators is only comparable to the performance and quality of a new machine. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a process for improving the performance of excavators.

[0005] To solve the above-mentioned technical problems, the basic concept of the technical solution adopted by the present invention is as follows:

[0006] A process for improving the performance of an excavator includes the following steps:

[0007] Step S01: After starting and warming up, run the engine at full throttle and perform digging, soil throwing, walking, and lifting operations. Detect and record the bucket digging force, stick digging force, lifting force, and traction force.

[0008] Step S02: Install the hydraulic system tester on the high-pressure pipeline of the hydraulic pump of the new excavator using the bypass method, and run the pump at the rated speed. When the hydraulic oil temperature is 50±5℃, observe and record the flow readings of the front and rear pumps of the tester under no-load conditions.

[0009] Step S03: Use the loading valve to gradually increase the load pressure to the rated pressure of the pump system, and observe and record the flow readings of the front and rear pumps at this time.

[0010] Step S04: Extend and retract the bucket cylinder, stick cylinder, and lifting cylinder to their full extent to allow the system to overflow. Measure and record the pressure of the bucket, stick, and lifting overflow valves, as well as the safety valve pressure of the main valve.

[0011] Step S05: Adjust the pressure of the bucket overflow valve and the stick overflow valve in two steps, gradually increasing the pressure of the first-stage spring. Turn the adjusting screw in 5-45° to increase the pressure by 1-4MPa. After each adjustment, conduct a digging test for 40-50 minutes.

[0012] Step S06: Adjust the pressure of the crushing overflow valve by turning it in 5-30°. The working pressure of the crushing oil circuit is 20MPa and the flow rate is 160-180L / min.

[0013] Step S07: Detect and record the excavator's bucket digging force, stick digging force, hydraulic cylinder lifting force, and speed.

[0014] Optionally, after the excavator is adjusted in step S06, a test run should be conducted and the excavator's digging and breaking parts, pipes, joints, bucket cylinders, boom cylinders, and lifting cylinders should be carefully observed for oil leaks and vibrations, as well as abnormal wear or deformation of connecting rods and pin bushings.

[0015] Optionally, since hydraulic breakers are not very sensitive to pressure, adjustments should be made with caution and should not be increased. A flow rate of 160-180 L / min is recommended.

[0016] Optionally, the working cylinder pressure (i.e., the relief valve pressure) of the bucket, stick, lifting, etc. is a moderate pressure and safety value of 25-43MPa that takes into account the operation of the hydraulic circuit of the cylinder during the design.

[0017] Optionally, in step S02, if the measured pump flow reading before and after the test decreases by more than or equal to 15% compared to the no-load condition, or if the pressure gauge pointer of the pump deflects by more than ±150 kPa or swings very slowly, these are all abnormal situations, indicating that the pump has a fault and needs to be repaired or replaced.

[0018] Optionally, the hydraulic system tester consists of a pressure gauge, a flow meter, and a tachometer.

[0019] Optionally, the excavator of the above process includes a traveling mechanism, a cab is provided above the traveling mechanism, a hydraulic pump is provided on one side of the cab, an engine and a main control valve are provided above the cab, a lifting cylinder is provided above the cab, a boom is provided at the lifting cylinder, a forearm is hinged to one side of the boom, a stick cylinder is provided between the boom and the forearm, a connecting rod is provided on one side of the forearm, a bucket is provided on one side of the connecting rod, a bucket cylinder is provided between the connecting rod and the forearm, and an oil pipe is provided below the forearm.

[0020] Optionally, the traveling mechanism includes a lower frame, a traveling motor is installed below the lower frame, the output end of the traveling motor is connected to a support roller, and a track is fitted between the two support rollers.

[0021] Optionally, the engine and hydraulic pump are connected by a drive shaft. The hydraulic pump converts the mechanical energy of the engine into hydraulic energy. The main control valve is connected to the hydraulic pump by an oil pipe. The main control valve mainly distributes the hydraulic energy to the lifting cylinder, stick cylinder, and bucket cylinder through the oil pipe, and operates and controls the action of each cylinder, thereby realizing functions such as digging, crushing, lifting, traveling, and rotating.

[0022] By adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art. Of course, any product implementing the present invention does not necessarily need to achieve all of the following advantages at the same time:

[0023] 1. This invention is a process technology that optimizes the matching of pressure in the main control valves of the hydraulic systems of new and old excavators with the pressure of each working cylinder (digging, boom, lifting, etc.) and the pump and engine. This significantly improves engine fuel efficiency and overall machine efficiency and effectiveness, resulting in energy savings and economy. It also enhances and repairs the digging, breaking, and lifting torque and speed performance of both new and old excavators. This invention is simple, convenient, fast, practical, and low-cost, with direct and significant effects, addressing user pain points and having a broad market application.

[0024] 2. This invention patent can solve the problem of power matching between the excavator's engine, pump, and load in a simple, convenient, fast, and economical way, making the excavator's digging force, breaking force, and lifting force greater, its speed faster, and the whole machine more energy-efficient and economical. Essentially, it uses reverse engineering on both new and old excavators, making multiple small adjustments to gradually increase the pressure of each working cylinder (bucket cylinder, boom cylinder, breaking cylinder, lifting cylinder, etc.) by 1-10% (because the design of different excavator models and the quality of their hydraulic components vary, the increased pressure they can withstand during normal operation will naturally differ). Then, by testing the excavator after each adjustment, it is determined whether the excavator can operate normally, thus fully allowing the load to absorb and utilize the actual power of the pump, especially the 25-30% reserve capacity added during pump design and selection due to actual needs. Because the pressure of the working cylinders such as the bucket, stick, and lifting cylinders (i.e., the pressure of each relief valve) is a moderate pressure and safety value considered during the design of the hydraulic circuit of the cylinder, generally 25-39MPa. These values ​​are selected based on individual design experience and vary from brand to brand and model to model. Therefore, this parameter has an appropriate selection range and can be adjusted appropriately according to actual conditions. Thus, in the actual work of improving the quality and efficiency of new excavators, this invention boldly breaks through the blind adherence to and constraints of design, adopting a method of gradually and appropriately increasing the hydraulic circuit pressure of the working cylinders such as the bucket, stick, and lifting cylinders by 1-10%, ensuring that the excavator can operate normally during test runs without black smoke, stalling, engine braking, or oil leaks.

[0025] 3. Maximize the actual working power of the pump and bring it close to the engine's output power, especially by fully absorbing and utilizing the 40% reserve power added to the engine during design and selection to meet actual needs. This allows the engine and pump to operate at their optimal points or operating ranges, ensuring that the engine's maximum output power is not wasted, improving fuel efficiency and overall machine efficiency. It also ensures that the power matching between the pump and engine is always approximately met, achieving optimal matching. This results in a 5-15% increase in key performance parameters of the excavator, such as digging force, breaking force, traction force, lifting force, and speed. In other words, digging force, breaking force, and lifting force are significantly increased, and the speed is faster, making the excavator more energy-efficient and economical. This simple, convenient, fast, and economical technical method easily and accurately solves the power matching problem between the excavator's engine, pump, and load. The resulting increased digging force, breaking force, and lifting force, faster speed, and greater overall energy efficiency and economy have yielded significant economic and social benefits. Its application is widespread, and its economic and social benefits are substantial.

[0026] The specific embodiments of the present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0027] The accompanying drawings described below are merely some embodiments. Those skilled in the art can obtain other drawings based on these drawings without any creative effort. In the drawings:

[0028] Figure 1 This is a schematic diagram of a structure according to an embodiment of the present invention;

[0029] Figure 2 This is a schematic diagram illustrating the matching relationship between the engine and the hydraulic system, including the pump and the main control valve, according to an embodiment of the present invention.

[0030] The attached diagram lists the components represented by each number as follows:

[0031] 1. Traveling mechanism; 2. Hydraulic pump; 3. Engine; 4. Cab; 5. Lifting cylinder; 6. Boom; 7. Stick cylinder; 8. Arm; 9. Bucket cylinder; 10. Connecting rod; 11. Main control valve; 12. Oil pipe; 13. Tracks; 14. Travel motor; 15. Track rollers; 16. Undercarriage; 17. Bucket.

[0032] It should be noted that these accompanying drawings and textual descriptions are not intended to limit the scope of the invention in any way, but rather to illustrate the concept of the invention to those skilled in the art by referring to specific embodiments. Detailed Implementation

[0033] The invention will now be described in further detail with reference to the accompanying drawings.

[0034] Please see Figure 1-2 As shown, this embodiment provides a process for improving the performance of an excavator, including the following steps:

[0035] Step S01: After starting and warming up, run the engine at full throttle and perform digging, soil throwing, walking, and lifting operations. Detect and record the bucket digging force, stick digging force, lifting force, and traction force.

[0036] Step S02: Install the hydraulic system tester on the high-pressure pipeline of the hydraulic pump of the new excavator using the bypass method, and run the pump at the rated speed. When the hydraulic oil temperature is 50±5℃, observe and record the flow readings of the front and rear pumps of the tester under no-load conditions.

[0037] Step S03: Use the loading valve to gradually increase the load pressure to the rated pressure of the pump system, and observe and record the flow readings of the front and rear pumps at this time.

[0038] Step S04: Extend and retract the bucket cylinder, stick cylinder, and lifting cylinder to their full extent to allow the system to overflow. Measure and record the pressure of the bucket, stick, and lifting overflow valves, as well as the safety valve pressure of the main valve.

[0039] Step S05: Adjust the pressure of the bucket overflow valve and the stick overflow valve in two steps, gradually increasing the pressure of the first-stage spring. Turn the adjusting screw in 5-45° to increase the pressure by 1-4MPa. After each adjustment, conduct a digging test for 40-50 minutes.

[0040] Step S06: Adjust the pressure of the crushing overflow valve by turning it in 5-30°. The working pressure of the crushing oil circuit is 20MPa and the flow rate is 160-180L / min.

[0041] Step S07: Detect and record the excavator's bucket digging force, stick digging force, hydraulic cylinder lifting force, and speed.

[0042] After the excavator is adjusted in step S06, a test run should be conducted and the excavator's digging and breaking parts, pipes, joints, bucket cylinders, boom cylinders, and lifting cylinders should be carefully observed for oil leaks and vibrations, as well as abnormal wear or deformation of connecting rods and pin bushings.

[0043] Hydraulic breakers are not very sensitive to pressure, so adjustments should be made carefully and never be too high. A flow rate of 160-180 L / min is ideal.

[0044] The pressure of the working cylinders for the bucket, boom, and lifting (i.e., the pressure of the relief valve) is a moderate pressure and safety value of 25-43 MPa, which is taken into account during the design of the hydraulic circuit of the cylinder.

[0045] In step S02, if the measured flow rate reading of the pump before and after the test drops by more than or equal to 15% compared to the no-load condition, or if the pressure gauge pointer of the pump deflects by more than ±150 kPa or swings very slowly, these are all abnormal situations, indicating that the pump has a fault and needs to be repaired or replaced.

[0046] The hydraulic system tester consists of a pressure gauge, a flow meter, and a tachometer.

[0047] The excavator described above includes a traveling mechanism 1, a cab 4 above the traveling mechanism 1, a hydraulic pump 2 on one side of the cab 4, an engine 3 and a main control valve 11 above the cab 4, a lifting cylinder 5 above the cab 4, a boom 6 at the lifting cylinder 5, a forearm 8 hinged to one side of the boom 6, a stick cylinder 7 between the boom 6 and the forearm 8, a connecting rod 10 on one side of the forearm 8, a bucket 18 on one side of the connecting rod 10, a bucket cylinder 9 between the connecting rod 10 and the forearm 8, and an oil pipe 12 below the forearm 8.

[0048] The traveling mechanism 1 includes a lower frame 16, a traveling motor 14 is arranged below the lower frame 16, the output end of the traveling motor 14 is connected to a support roller 15, and a track 13 is sleeved between the two support rollers 15.

[0049] The engine 3 and the hydraulic pump 2 are connected by a drive shaft. The hydraulic pump 2 converts the mechanical energy of the engine 3 into hydraulic energy. The main control valve 11 is connected to the hydraulic pump 2 by an oil pipe 12. The main control valve 11 mainly distributes the hydraulic energy to the lifting cylinder 5, the stick cylinder 7, and the bucket cylinder 9 through the oil pipe, and operates and controls the action of each cylinder, thereby realizing the functions of digging, crushing, lifting, traveling, and rotating.

[0050] This invention boldly breaks through the constraints of blindly following design conventions. It appropriately increases the hydraulic pressure of the bucket, boom, lifting, and crushing cylinders by 1-10%, ensuring the machine operates normally without emitting black smoke, stalling, or coming to a stop. It is crucial that the excavator maintains stability and avoids tipping over when fully loaded, ensuring its dynamic balance and safety. This allows the pump's actual power to be fully absorbed and utilized, especially the 25-30% reserve power added during pump design and selection to meet practical needs. The pump is then used for digging and unloading earth and rock under load, maximizing its actual working power and bringing it close to the engine's output power, particularly absorbing and utilizing the 40% reserve power added during engine design and selection to meet practical needs. This allows the engine and pump to operate at their optimal points or operating ranges, ensuring that the engine's maximum output power is not wasted, improving fuel efficiency and overall machine efficiency. It also ensures a near-optimal match between the pump and engine, resulting in energy savings, improved economic efficiency, and enhanced key performance characteristics and quality of the excavator, including digging force, breaking force, lifting force, and speed. Finally, the excavator's bucket and boom digging forces, hydraulic cylinder lifting force, and overall traction force were measured and recorded. Comparing this data with the data before the hydraulic system adjustment, it is clear that through this hydraulic system adjustment, without adding any parts or altering the excavator's shape, the excavator's main performance characteristics, including bucket and boom digging forces, breaking force, hydraulic cylinder lifting force, overall traction force, and speed, were improved by 5-15%. The overall performance and quality of the machine were significantly enhanced, resulting in substantial economic and social benefits.

[0051] Due to differences in excavator design and hydraulic system main accessories, the pressure adjustment varies. However, the cumulative pressure adjustment should not exceed 10% of the design pressure. (The actual pressure of the excavator is lower than the design pressure due to various reasons such as materials and manufacturing. Excavators can actually reach the design pressure requirements, and for large and medium-sized excavators, it is advisable not to exceed 40MPa. This is to prevent pipe bursts or damage to the hydraulic main accessories caused by excessive pressure, as well as stalling and engine shutdown.)

[0052] Case Study 1: The excavator has been increasingly weak at digging recently, even at maximum throttle, it can't dig anymore. We rushed to the owner's site and, after a test run, found the situation to be as the owner described: the engine wasn't emitting black smoke, the smoke was normal, and it accelerated without any oil leaks or power loss issues; the oil pump had just been calibrated, the boom lifting and traveling functions were normal, and the stick could throw soil, but digging was weak; the bucket cylinder wasn't leaking oil or slipping. This indicated the engine was fine, and the traveling, lifting, and swinging functions were normal, indicating the main pump was working properly. Based on this, our initial assessment was that the problem lay with the bucket valve in the main control valve, most likely due to severe wear and tear on the valve stem causing internal leakage; insufficient pressure was thus preventing effective digging. First, run the engine at full throttle and perform digging, dumping, traveling, and lifting operations. Test and record the bucket digging force as 70.5KN (83.4KN for a new machine), the boom digging force as 65KN (66.5KN for a new machine), and the traction force as 110KN (114KN for a new machine). Install a hydraulic system tester (consisting of a pressure gauge, flow meter, tachometer, etc.) on the high-pressure line of the old excavator's hydraulic pump using a bypass method. Run the pump at its rated speed of 2200rpm. When the hydraulic oil temperature is 50±5℃, observe and record the pressure gauge pointer deflection range of the front and rear pumps under no-load conditions. A range of ±130KPa or ±150KPa indicates that the pump has aged and worn, but can still be used for a period after adjustment without immediate repair or replacement. Then disassemble the pump power controller to check for jamming or excessive wear. If there is minor wear but it is still usable, clean and blow it clean, then replace all the O-rings and seals. After installation, start the engine and run it at full throttle. Check and record the pressure of the safety valve of the main valve, the overflow valve of the bucket and the stick. Check the pressure of each hydraulic system: (1) Stop the excavator on a flat surface and turn off the engine; (2) Release the pressure of the hydraulic system; (3) Install a 50MPa pressure gauge on the pressure test connector of the safety valve of the main control valve; (4) Install a 490kPa pressure gauge on the power conversion connector; (5) Start the engine and operate the stick control lever at full stroke, repeatedly swinging the bucket and stick cylinders inward and outward until the hydraulic oil temperature reaches 55℃. (6) The power mode selection switch is in position III, the engine throttle knob is in position 10, and the AEC switch is in the OFF position. Under no-load conditions, the engine speed is the rated speed. The rated engine speed of 2200 rpm and the safety valve pressure of 28 MPa are detected and recorded. The pressure is within the standard system pressure range of (28400±490) KPa. The normal pressure indicates that the safety valve is intact. (7) Then adjust the overflow valve pressure of the bucket cylinder of 27.8 MPa and the overflow valve pressure of the boom cylinder of 28 MPa to their standard pressure of 31.4 MPa by looking at the pressure gauge. After repeated test runs, the digging force is significantly greater than before and the speed is faster.Then, for the first adjustment, turn the adjusting screw of the first-stage spring (i.e., the inner spring) of the bucket and stick overflow valve inward by about 30°, increasing the pressure by about 2.1 MPa. Conduct a digging test for 40-50 minutes. During the test run, carefully observe the excavator's digging components, including pipes, joints, bucket cylinders, and stick cylinders. There should be no oil leakage or vibration, and the connecting rods and pins should show no abnormal wear or deformation. The machine should function normally. Next, turn the adjusting screw inward by about 15°, increasing the pressure by about 1 MPa, and conduct another digging test for 40-50 minutes. The excavator should function normally again. Then, adjust the pressure of the breaker valve inward by 25° and continue the test run. There should be no pipe bursting, stalling, or engine failure. Finally, test the machine using actual working conditions to verify and ensure that it can operate normally under this increased pressure. This compensates for the pressure leakage caused by aging and wear of the bucket and stick valves, naturally restoring and improving digging force. The excavator remained stable during loading and movement without any tendency to tip over, ensuring its dynamic balance and safety performance. Finally, the excavator's bucket digging force was tested and recorded as 85 kN, an increase of 1.9% compared to the new machine standard of 83.4 kN and 20.56% compared to before repair; the boom digging force was 68 kN, an increase of 2.3% compared to the new machine standard of 66.5 kN and 4.6% compared to before repair of 65 kN; and the overall traction force was 115 kN, an increase of 1% compared to the standard of 114 kN and 4.5% compared to before repair of 110 kN. The cylinder lifting force, walking force, and speed also showed significant improvements. Therefore, the hydraulic system adjustment technology of this invention can achieve excellent economic and social benefits in practice.

[0053] Implementation Case 2:

[0054] First, after starting and warming up, run the engine at full throttle and perform digging, soil-throwing, walking, and lifting operations. When the hydraulic oil temperature reaches 50±5℃, measure and record the performance parameters: bucket digging force 210KN, stick digging force 170KN, and traction force 243KN. Install a hydraulic system tester (consisting of a pressure gauge, flow meter, tachometer, etc.) on the high-pressure line of the new excavator's hydraulic pump using a bypass method. Run the pump at its rated speed and observe and record the flow readings of the front and rear pumps under no-load conditions. Then, apply load using the loading valve, gradually increasing the load pressure to the pump system's rated pressure, and observe and record the flow readings of the front and rear pumps at this point. Next, extend and retract the bucket cylinder and stick cylinder to their full extent to allow the system to overflow. Measure and record the pressure of the bucket and stick overflow valves and the safety valve pressure of the main valve. The safety valve pressure reaches the system pressure standard of 34.3MPa and requires no adjustment; the bucket and stick overflow valve pressures are both 37.3MPa. Next, the bucket overflow valve pressure and stick overflow valve pressure were adjusted by 30° to the first-stage spring (i.e., the inner spring), increasing the pressure by approximately 1.6 MPa. A digging test was then conducted for 40-50 minutes; the excavator operated normally. Then, the bucket overflow valve pressure and stick overflow valve pressure were adjusted by 15° to the first-stage spring (i.e., the inner spring), increasing the pressure by 0.8 MPa. Another digging test was conducted for 40-50 minutes. There were no oil leaks or vibrations in the excavator's digging and breaking parts' pipelines, joints, bucket cylinders, and stick cylinders. There were no abnormal wear or deformation of the connecting rods or pin sleeves. However, some pipe joints in the bucket cylinder pipeline showed oil leakage, and the total pressure reached 39.8 MPa, very close to the maximum limit of 40 MPa. Therefore, the bucket overflow valve pressure was adjusted too high. The pressure gauge was adjusted back slightly by 5°, and the pressure was 39.6 MPa, at which point the oil leakage disappeared. Then, turn the pressure adjustment valve of the crusher 20° to increase the working pressure of the crushing oil circuit slightly, and adjust the flow rate to the maximum of 180L / min. Test run: digging force is normal, the machine does not stall or stall, and the increased pressure is within the permissible range. Note that when the excavator is fully loaded, the entire machine must be stable and not tilted; dynamic balance and safety performance of the excavator must be ensured! Finally, the adjusted bucket digging force is measured and recorded as 255KN, and the stick digging force as 218KN. Comparing this with the data measured before the hydraulic system adjustment, it is clear that through this hydraulic system adjustment, without adding any parts or changing the excavator's shape, the excavator's main quality performance, such as bucket digging force, stick digging force, cylinder lifting force, overall traction force, and speed, has been improved by 5-15%. The overall performance quality of the machine has been significantly enhanced, resulting in significant economic and social benefits.

[0055] This invention is not limited to the embodiments described above. Anyone should understand that structural changes made under the guidance of this invention, and any technical solutions that are the same as or similar to this invention, fall within the protection scope of this invention. Technical aspects, shapes, and structures not described in detail in this invention are all publicly known technologies.

Claims

1. A process for improving the performance of an excavator, characterized in that, Includes the following steps: Step S01: After starting and warming up, run the engine at full throttle and perform digging, throwing, walking, and lifting operations. Detect and record the bucket digging force, stick digging force, lifting force, and traction force. Step S02: Install the hydraulic system tester on the high-pressure pipeline of the hydraulic pump of the new excavator using the bypass method, and run the pump at the rated speed. When the hydraulic oil temperature is 50±5℃, observe and record the flow readings of the front and rear pumps of the tester under no-load conditions. Step S03: Use the loading valve to gradually increase the load pressure to the rated pressure of the pump system, and observe and record the flow readings of the front and rear pumps at this time. Step S04: Extend and retract the bucket cylinder, stick cylinder, and lifting cylinder to their full extent to allow the system to overflow. Measure and record the pressure of the bucket, stick, and lifting overflow valves, as well as the safety valve pressure of the main valve. Step S05: Gradually adjust the pressure of the bucket overflow valve and the stick overflow valve by turning the first-stage spring to increase the pressure. Turn the adjusting screw in 5-45° to increase the pressure by 1-4MPa. After each adjustment, conduct a digging test for 40-50 minutes. Step S06: Adjust the pressure of the crushing overflow valve by turning it in by 5-30°. The working pressure of the crushing oil circuit is 20MPa, and the flow rate is 160-180L / min. Step S07: Detect and record the excavator's bucket digging force, stick digging force, hydraulic cylinder lifting force, and speed.

2. The process for improving the performance of an excavator according to claim 1, characterized in that, After adjusting the excavator in step S06, a test run must be performed. The driver carefully inspected the excavator's digging and crushing parts, including pipes, joints, bucket cylinders, boom cylinders, and lifting cylinders, for oil leaks and vibrations, as well as the connecting rods and pin bushings for abnormal wear or deformation.

3. The process for improving the performance of an excavator according to claim 1, characterized in that, The flow rate of the hydraulic breaker is 160-180 L / min, which is sensitive to pressure.

4. The process for improving the performance of an excavator according to claim 1, characterized in that, The relief valve pressure of the bucket cylinder, boom cylinder, and lifting cylinder is 25-43 MPa. This pressure is the working pressure of the hydraulic circuit and the safety design value.

5. The process for improving the performance of an excavator according to claim 1, characterized in that, If, in step S02, the measured flow rate readings of the pump before and after the test decrease by more than or equal to 15% compared to the no-load condition, or if the pressure gauge pointer of the pump deflects by more than ±150 kPa or swings very slowly, these are all abnormal situations, indicating that the pump has a fault and needs to be repaired or replaced.

6. The process for improving the performance of an excavator according to claim 1, characterized in that, The hydraulic system tester includes a pressure gauge, a flow meter, and a tachometer.

7. The process for improving the performance of an excavator according to claim 1, characterized in that, The excavator includes a traveling mechanism (1), a cab (4) is provided above the traveling mechanism (1), a hydraulic pump (2) is provided on one side of the cab (4), an engine (3) and a main control valve (11) are provided above the cab (4), a lifting cylinder (5) is provided above the cab (4), a boom (6) is provided at the lifting cylinder (5), a forearm (8) is hinged to one side of the boom (6), a stick cylinder (7) is provided between the boom (6) and the forearm (8), a connecting rod (10) is provided on one side of the forearm (8), a bucket (18) is provided on one side of the connecting rod (10), a bucket cylinder (9) is provided between the connecting rod (10) and the forearm (8), and an oil pipe (12) is provided below the forearm (8).

8. The process for improving the performance of an excavator according to claim 7, characterized in that, The traveling mechanism (1) includes a lower frame (16), a traveling motor (14) is provided below the lower frame (16), the output end of the traveling motor (14) is connected to a support roller (15), and a track (13) is fitted between the two support rollers (15).

9. The process for improving the performance of an excavator according to claim 8, characterized in that, Engine (3) and liquid The hydraulic pumps (2) are connected by a drive shaft. The hydraulic pump (2) converts the mechanical energy of the engine (3) into hydraulic energy. The main control valve (11) The hydraulic pump (2) is connected by an oil pipe (12). The main control valve (11) mainly distributes the hydraulic energy to the lifting cylinder (5), the boom cylinder (7), and the bucket cylinder (9) through the oil pipe, and operates and controls the action of each cylinder, thereby realizing digging, crushing, lifting, walking, and turning.

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