A piston ring-cylinder liner friction test system

Abstract

This invention relates to a piston ring-cylinder liner friction testing system, comprising a piston ring, a cylinder liner, a piston ring-cylinder liner fixing assembly, a piston ring-cylinder liner heating assembly, a lubricating oil supply assembly, and a power assembly. The piston ring-cylinder liner fixing assembly includes a housing, an elastic thrust rod, steel balls, a tension / compression sensor, a bracket, and a piston ring clamp. The bracket is located on the single-cylinder engine of the power assembly, and the housing is located on the bracket. An annular oil groove is provided on the inner wall of the bottom of the housing, and an oil outlet communicating with the annular oil groove is provided at the bottom of the housing. The cylinder liner is located inside the housing, with its sidewall facing the annular oil groove. The lubricating oil supply assembly includes an oil supply passage and an oil supply cap. The cap is located inside the cylinder liner, with its perimeter edges close to the inner wall of the cylinder liner. The cap has an oil supply port, providing circumferential oil supply to the cylinder liner. The testing system is located outside the single-cylinder engine, eliminating the need to modify the internal structure of the engine, thus saving costs and simplifying experimental operation.

Description

Technical Field

[0001] This invention belongs to the field of engine energy-saving technology, specifically a piston ring-cylinder liner friction experimental system. This system can conduct frictional power consumption experiments on the piston ring-cylinder liner system based on thermal management, revealing the heat transfer characteristics of the piston ring-cylinder liner system. Background Technology

[0002] With rapid societal development, higher demands are being placed on energy and the environment, posing significant challenges to the traditional internal combustion engine industry. As a traditional energy source, in-depth research into energy conservation in internal combustion engines will generate substantial economic and social benefits. Low friction is one of the key technologies for energy conservation in internal combustion engines. Piston ring-cylinder liner friction losses account for approximately 20-30% of the mechanical losses in internal combustion engines, making it the most significant source of mechanical losses.

[0003] Currently, most researchers at home and abroad choose friction testing machines to cut cylinder liners and piston rings and take a section of the sample for friction power consumption experiments. However, since the section of cylinder liner and piston rings cut in the experiment is small, and the entire section sample needs to be immersed in lubricating oil or only a certain point needs to be supplied with oil to ensure lubrication, it cannot reflect the spatial distribution of temperature and material deformation of the cylinder liner as a whole during the experiment.

[0004] Chinese patent application No. 201710565266.4 discloses a low-friction piston ring-cylinder liner experimental system based on thermal management and its usage method. The system is installed in a single-cylinder engine, which requires modification of the single-cylinder engine and increases the experimental cost. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the technical problem this invention aims to solve is to provide a piston ring-cylinder liner friction test system.

[0006] The technical solution adopted by the present invention to solve the aforementioned technical problem is as follows:

[0007] A piston ring-cylinder liner friction testing system includes a piston ring, a cylinder liner, a piston ring-cylinder liner fixing assembly, a piston ring-cylinder liner heating assembly, a lubricating oil supply assembly, and a power assembly. The piston ring-cylinder liner fixing assembly comprises a housing, an elastic thrust rod, steel balls, a tension / compression sensor, a bracket, and a piston ring clamp. The bracket is located on a single-cylinder engine of the power assembly, the housing is located on the bracket, the inner wall of the bottom of the housing has an annular oil groove, and the bottom of the housing has an oil outlet communicating with the annular oil groove. The cylinder liner is located inside the housing. The sidewall of the cylinder liner faces the annular oil groove of the outer shell; the outer wall of the cylinder liner is provided with an upper boss and a lower boss, one end of the elastic thrust rod passes through the sidewall of the outer shell and is in close contact with the upper boss of the cylinder liner, and a steel ball is provided between the lower boss of the cylinder liner and the inner wall of the outer shell, and the bottom of the cylinder liner is connected to the bottom of the outer shell through a tension and compression sensor; the piston ring is fixed on the upper part of the piston ring clamp, the outer wall of the piston ring is in contact with the inner wall of the cylinder liner, and the lower part of the piston ring clamp passes through the bracket and is connected to the power assembly, which realizes the reciprocating motion of the piston ring in the cylinder liner;

[0008] The lubricating oil supply assembly includes an oil supply passage and an oil supply cap; the upper part of the oil supply cap is connected to the upper part of the outer shell, the cap body is located inside the cylinder liner, the four edges of the oil supply cap body are close to the inner wall of the cylinder liner, and the oil supply cap is provided with an oil supply port; one end of the oil supply passage is connected to the oil supply port, and the other end is connected to the oil outlet on the outer shell.

[0009] Furthermore, the oil supply cap is umbrella-shaped or conical, including an upper oil supply cap and a lower oil supply cap, with the upper oil supply cap covering the lower oil supply cap, forming a cavity between the two.

[0010] Furthermore, the piston ring clamp includes a connecting shaft, an upper clamping plate, and a lower clamping plate; the piston ring is located between the upper clamping plate and the lower clamping plate, the lower clamping plate is installed on the upper end of the connecting shaft, and the lower end of the connecting shaft is connected to the power assembly; the connecting shaft has a hollow structure.

[0011] Furthermore, the piston ring-cylinder liner heating assembly includes an annular electric heater, a temperature-sensing thermocouple, and electric heating rods; multiple annular electric heaters and multiple sets of electric heating rods are installed on the outer wall of the cylinder liner along the cylinder liner axial direction, and each set of electric heating rods includes electric heating rods distributed circumferentially on the outer wall of the cylinder liner; an annular electric heater is installed on the inner wall of the piston ring, and the temperature-sensing thermocouple is used to measure the temperature of the piston ring and the cylinder liner.

[0012] Compared with existing technologies, the beneficial effects of this invention are:

[0013] 1. Since the function of a single-cylinder engine is only to drive the piston rings to reciprocate within the cylinder liner, this invention sets the experimental system outside the single-cylinder engine, eliminating the need to modify the internal structure of the single-cylinder engine. This not only saves costs but also simplifies the experimental operation.

[0014] 2. This system features an independent lubricating oil supply circuit, separate from the single-cylinder engine's oil supply circuit, for better lubrication of the cylinder liners. The oil supply cap provides circumferential oil supply to the cylinder liners, thus lubricating the entire engine. An annular oil groove is located at the bottom of the outer casing, facilitating lubricating oil recovery and promoting its recycling.

[0015] 3. The hollow piston ring clamp facilitates the installation of annular electric heaters and temperature-sensing thermocouples, as well as convenient wiring, preventing wire breakage due to tension caused by the reciprocating motion of the piston ring clamp. The annular electric heaters and heating rods distributed on the outer wall of the cylinder liner facilitate temperature distribution control between the piston rings and the cylinder liner. Coordinated control of the annular electric heaters and heating rods can ensure both uniform temperature distribution within the cylinder liner and the creation of different temperature zones, enabling the study of the impact of thermal parameters on frictional power consumption and facilitating thermal management. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the arrangement structure of the present invention;

[0017] Figure 2 This is a distribution diagram of the annular electric heater and electric heating rod of the present invention on the cylinder liner;

[0018] Figure 3 This is a schematic diagram of the oil supply cap of the present invention;

[0019] Figure 4 This is an installation diagram of the piston ring and piston ring clamp of the present invention;

[0020] In the diagram, 1. Housing; 2. Cylinder liner; 3. Elastic thrust rod; 4. Annular electric heater; 5. Temperature measuring thermocouple; 6. Oil supply cap; 7. Steel ball; 8. Tension / compression sensor; 9. Bracket; 10. Connecting rod; 11. Crank-connecting rod mechanism; 12. Single-cylinder engine; 13. Flow meter; 14. Throttle valve; 15. Piston ring clamp; 16. Thermostatic oil bath; 17. Piston ring; 18. Lubricating oil cooler; 19. Coupling; 20. Speed ​​regulating motor; 22. Peristaltic pump; 23. Lubricating oil filter; 24. Electric heating rod;

[0021] 101. Annular oil groove; 102. Oil outlet; 201. Upper boss; 202. Lower boss; 601. Oil supply port; 602. Upper oil supply cover; 603. Lower oil supply cover; 1501. Connecting shaft; 1502. Upper clamping plate; 1503. Lower clamping plate; 1504. Partition plate; 1505. Lead wire hole. Detailed Implementation

[0022] The technical solution of the present invention will be further explained below with reference to the accompanying drawings and specific embodiments, but this does not limit the scope of protection of this application.

[0023] This invention relates to a piston ring-cylinder liner friction test system, comprising a piston ring 17, a cylinder liner 2, a piston ring-cylinder liner fixing assembly, a piston ring-cylinder liner heating assembly, a lubricating oil supply assembly, and a power assembly;

[0024] The piston ring-cylinder liner fixing assembly includes a housing 1, an elastic thrust rod 3, steel balls 7, a tension / compression sensor 8, a bracket 9, and a piston ring clamp 15. The bracket 9 is fixed to the single-cylinder engine 12 of the power assembly, and the housing 1 is fixed to the bracket 9. An annular oil groove 101 is provided on the inner wall of the bottom of the housing 1, and an oil outlet 102 communicating with the annular oil groove 101 is provided at the bottom of the housing 1. The cylinder liner 2 is located inside the housing 1, and the side wall of the cylinder liner 2 is directly opposite the annular oil groove 101 of the housing 1. An upper boss 201 and a lower boss 202 are provided on the outer wall of the cylinder liner 2, and one end of the elastic thrust rod 3 passes through the housing 1. The side wall of the cylinder liner 2 is in close contact with the upper boss 201 of the cylinder liner 2. The lower boss 202 of the cylinder liner 2 is provided with steel balls 7 between it and the inner wall of the outer shell 1. The bottom of the lower boss 202 of the cylinder liner 2 is connected to the bottom of the outer shell 1 through the tension and compression sensor 8 to realize the floating fixation of the cylinder liner 2. The piston ring 17 is fixed on the upper part of the piston ring clamp 15. The outer wall of the piston ring 17 is in contact with the inner wall of the cylinder liner 2. The lower part of the piston ring clamp 15 passes through the bracket 9 and is connected to the power assembly. The power assembly drives the piston ring clamp 15 to reciprocate along the axial direction of the cylinder liner 2 to realize the reciprocating motion of the piston ring 17 in the cylinder liner 2.

[0025] The lubricating oil supply assembly includes an oil supply passage and an oil supply cap 6. The oil supply cap 6 is umbrella-shaped or conical. The upper part of the oil supply cap 6 is connected to the upper part of the outer shell 1 through a connecting rod 10. The cap body of the oil supply cap 6 is located inside the cylinder liner 2. The four edges of the cap body of the oil supply cap 6 are close to the inner wall of the cylinder liner 2. The oil supply cap 6 is provided with an oil supply port 601. One end of the oil supply passage passes through the outer shell 1 and is connected to the oil supply port 601. The other end is connected to the oil outlet 102 on the outer shell 1. The oil supply passage provides lubricating oil to the system. The lubricating oil enters from the oil supply port 601 and flows along the cap body of the oil supply cap 6 to the inner wall of the cylinder liner 2, realizing circumferential oil supply to the cylinder liner 2, thereby lubricating and cooling the cylinder liner 2. The lubricating oil flows down along the inner wall of the cylinder liner 2 and is collected into the annular oil groove 101 of the outer shell 1. Then, it enters the oil supply passage through the oil outlet 102 for cooling and filtration, and then enters the oil supply cap 6, realizing the recycling of lubricating oil.

[0026] The oil supply circuit includes a flow meter 13, a throttle valve 14, a constant temperature oil bath 16, a lubricating oil cooler 18, a peristaltic pump 22, and a lubricating oil filter 23. The recovered lubricating oil is first cooled by the lubricating oil cooler 18, and then filtered by the lubricating oil filter 23 through the peristaltic pump 22. The filtered lubricating oil then enters the constant temperature oil bath 16 for constant temperature treatment, and then enters the oil supply cap 6 through the lubricating oil filter 23, the peristaltic pump 22, the flow meter 13, and the throttle valve 14.

[0027] The piston ring-cylinder liner heating assembly includes an annular electric heater 4, a temperature measuring thermocouple 5, and an electric heating rod 24. Multiple annular electric heaters 4 and multiple sets of electric heating rods are installed on the outer wall of the cylinder liner 2 along the axial direction of the cylinder liner 2. Each set of electric heating rods includes electric heating rods 24 distributed circumferentially on the outer wall of the cylinder liner 2. The cylinder liner 2 is heated by the annular electric heaters 4 and the electric heating rods 24. An annular electric heater 4 is installed on the inner wall of the piston ring 17. The temperature measuring thermocouple 5 is used to measure the temperature of the cylinder liner 2 and the piston ring 24.

[0028] The power assembly includes a single-cylinder engine 12, a crank-connecting rod mechanism 11, and a speed-regulating motor 20. The speed-regulating motor 20 is connected to the crank-connecting rod mechanism 11 via a coupling 19. The crank-connecting rod mechanism 11 is connected to the piston of the single-cylinder engine 12, and the piston of the single-cylinder engine 12 is simultaneously connected to the lower part of the piston ring clamp 15. The speed-regulating motor 20 drives the crank-connecting rod mechanism 11 to move, which in turn drives the piston of the single-cylinder engine 12 to reciprocate, thereby driving the piston ring clamp 15 connected to the piston of the single-cylinder engine 12 to reciprocate within the cylinder liner 2, thus realizing the reciprocating motion of the piston ring 17 within the cylinder liner 2.

[0029] The oil supply cap 6 is divided into an upper oil supply cap 602 and a lower oil supply cap 603. The upper oil supply cap 602 covers the lower oil supply cap 603, and a cavity is formed between the two. Lubricating oil enters the cavity from the oil supply port 601 and flows to the inner wall of the cylinder liner 2.

[0030] The piston ring clamp 15 is T-shaped and includes a connecting shaft 1501, an upper clamping plate 1502, a lower clamping plate 1503, and a partition plate 1504. Piston rings 17 are located between the upper clamping plate 1502 and the lower clamping plate 1503. When multiple piston rings 17 are installed, they are separated by the partition plate 1504. The lower clamping plate 1503 is installed at the upper end of the connecting shaft 1501, and the lower end of the connecting shaft 1501 is connected to the piston of the single-cylinder engine 12. The connecting shaft 1501 has a hollow structure and a lead hole 1505, facilitating the installation of a temperature-measuring thermocouple 5 and an annular electric heater 4 for heating the piston rings 17.

[0031] The working principle and workflow of this invention are as follows:

[0032] (1) The cylinder liner 2 is fixed to the outer shell 1 by the elastic thrust rod 3, the steel ball 7 and the tension and compression sensor 8. The outer shell 1 is fixed to the single cylinder engine 12 by the bracket 9, so as to realize the "floating cylinder liner method" to measure friction.

[0033] (2) Check whether each component and pipeline is normal and leaking oil. Then control the speed of the speed regulating motor 20 to drive the crank connecting rod mechanism 11 to drive the piston ring 17 on the piston ring clamp 15 to reciprocate in the cylinder liner 2.

[0034] (3) Add an appropriate amount of lubricating oil to the constant temperature oil bath 26, turn on the switch of the constant temperature oil bath 16 to heat the lubricating oil, and after the temperature is constant, filter it and deliver it to the oil supply cover 6 through the peristaltic pump 22. The lubricating oil flows evenly along the four edges of the oil supply cover 6 to the inner wall of the cylinder liner 2, and finally flows into the annular oil groove 101 at the bottom of the outer shell 1. The lubricating oil then returns to the constant temperature oil bath 16 through the oil outlet 102, the lubricating oil cooler 18, and the peristaltic pump 22.

[0035] (4) The heating temperature of the annular electric heater 4 and the electric heating rod 24 is controlled by the external temperature control device, and the temperature of the cylinder liner 2 and the piston ring 17 is controlled. The temperature data of the piston ring 17 and the cylinder liner 2 are transmitted to the host computer by the temperature measuring thermocouple 5. The friction force is measured by the tension and compression sensor 8, and the friction power consumption is calculated by combining the movement speed of the piston ring 17. The heating temperature of the annular electric heater 4 and the electric heating rod 24 is changed to change the temperature of the cylinder liner and the piston ring, and the friction force is measured, the friction power consumption is calculated, the minimum friction power consumption is found, and the temperature of the lubricating oil, cylinder liner and piston ring corresponding to the minimum friction power consumption is recorded.

[0036] This invention utilizes a crank-connecting rod mechanism to drive a single-cylinder engine using a speed-regulating motor. This mechanism converts the rotational motion of the speed-regulating motor into the reciprocating motion of the piston ring clamps. Simultaneously, to ensure smooth start-up and stable operation of the entire system, the rated power and maximum torque of the starter motor must meet certain conditions: the rated power P of the speed-regulating motor must be P ≥ 2 × (0.15~0.3) × the rated power of the engine, and the maximum torque T must be T ≥ 2 × (0.15~0.3) × the maximum torque of the engine. This selection of conditions takes into account the mechanical losses of the diesel engine, the effects of cold-start operation and heat dissipation, and variations in the number of piston rings. The number of piston rings in this experimental system ranges from 1 to 4; during the experiment, the number of piston rings can be increased or decreased as needed.

[0037] Any aspects not covered in this invention are applicable to existing technologies.

Claims

1. A piston ring-cylinder liner friction testing system, comprising a piston ring, a cylinder liner, a piston ring-cylinder liner fixing assembly, a piston ring-cylinder liner heating assembly, a lubricating oil supply assembly, and a power assembly; characterized in that, The piston ring-cylinder liner fixing assembly includes a housing, an elastic thrust rod, steel balls, a tension / compression sensor, a bracket, and a piston ring clamp. The bracket is located on the single-cylinder engine of the power assembly, and the housing is located on the bracket. The inner wall of the bottom of the housing has an annular oil groove, and the bottom of the housing has an oil outlet communicating with the annular oil groove. The cylinder liner is located inside the housing, and the side wall of the cylinder liner faces the annular oil groove of the housing. The outer wall of the cylinder liner has an upper boss and a lower boss. One end of the elastic thrust rod passes through the side wall of the housing and is in close contact with the upper boss of the cylinder liner. A steel ball is placed between the lower boss of the cylinder liner and the inner wall of the housing. The bottom of the cylinder liner is connected to the bottom of the housing through the tension / compression sensor. The piston ring is fixed to the upper part of the piston ring clamp, and the outer wall of the piston ring contacts the inner wall of the cylinder liner. The lower part of the piston ring clamp passes through the bracket and is connected to the power assembly. The power assembly realizes the reciprocating motion of the piston ring within the cylinder liner. The lubricating oil supply assembly includes an oil supply passage and an oil supply cap; the upper part of the oil supply cap is connected to the upper part of the outer shell, the cap body is located inside the cylinder liner, the four edges of the oil supply cap body are close to the inner wall of the cylinder liner, and the oil supply cap is provided with an oil supply port; one end of the oil supply passage is connected to the oil supply port, and the other end is connected to the oil outlet on the outer shell. The oil supply cap is umbrella-shaped or conical, including an upper oil supply cap and a lower oil supply cap, with the upper oil supply cap covering the lower oil supply cap, forming a cavity between the two; The piston ring-cylinder liner heating assembly includes an annular electric heater, a temperature-sensing thermocouple, and electric heating rods. Multiple annular electric heaters and multiple sets of electric heating rods are installed on the outer wall of the cylinder liner along the cylinder liner axial direction. Each set of electric heating rods includes electric heating rods distributed circumferentially on the outer wall of the cylinder liner. The annular electric heaters and electric heating rods control the temperature distribution of the cylinder liner. An annular electric heater is installed on the inner wall of the piston ring, and the temperature-sensing thermocouple is used to measure the temperature of the piston ring and the cylinder liner.

2. The piston ring-cylinder liner friction test system according to claim 1, characterized in that, The piston ring clamp includes a connecting shaft, an upper clamping plate, and a lower clamping plate; the piston ring is located between the upper clamping plate and the lower clamping plate, the lower clamping plate is installed on the upper end of the connecting shaft, and the lower end of the connecting shaft is connected to the power assembly; the connecting shaft has a hollow structure.

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