CN-122016635-A - Detection device for simulating service capability of small-end lubricating oil of piston connecting rod of internal combustion engine and working method

Abstract

The invention provides a detection device for simulating the service capability of small end lubricating oil of a piston connecting rod of an internal combustion engine and a working method thereof, and the detection device comprises a loading support, wherein the bottom end of the loading support is connected with the top end of the piston connecting rod through a locking pressing plate and a nut, a piston pin is sleeved in a round hole at the small end of the piston connecting rod, bearings are arranged at two ends of the piston pin, the bearings are fixed in a circular arc groove on an oil pan, the bearings are used for supporting the piston pin, a certain gap is formed between the small end of the piston connecting rod sleeved on the piston pin and the oil pan, the oil pan is fixed on a supporting base through an oil pan locking nut, two L-shaped driving pins are connected to the middle part of a square frame of the driving connecting rod, and the two driving pins are fixedly connected with the piston pin through a fastening nut. The invention simulates the motion form of a piston pin-connecting rod small-end bushing friction pair in a cylinder, and converts the planar reciprocating operation of a traditional testing machine into the motion of reciprocating rotation around an axis in a certain radian.

Inventors

• LOU WENJING
• YIN JUN
• JIANG CHENG
• Su Huaigang
• ZHAO QILONG
• YU HONGYUAN
• WANG YANAN
• ZONG XIDAN

Assignees

• 中国科学院兰州化学物理研究所

Dates

Publication Date

20260512

Application Date

20260204

Claims (8)

1. 1. The utility model provides a detection device of simulation internal-combustion engine piston connecting rod small end lubricating oil messenger ability, including the loading support, the loading support bottom is connected with the piston connecting rod top through locking clamp plate, the nut, the round hole cover of piston connecting rod small end is on the piston pin, the bearing is all installed to piston pin both ends, a serial communication port, the bearing is fixed in the circular arc inslot on the oil pan, the bearing is used for supporting the piston pin, make piston connecting rod small end and the oil pan that overlaps on the piston pin form certain space, the oil pan is fixed in on the support base through oil pan locking nut, two drive pins of L shape are connected at the back-form frame middle part of drive connecting rod, two drive pins pass through fastening nut and piston pin fixed connection.
2. 2. The device of claim 1, wherein the loading mount is connected to an external motorized loading device by a flange at the top.
3. 3. The apparatus of claim 1, wherein the load bracket has a bottom end with a groove for receiving the locking pressure plate and the nut.
4. 4. The apparatus of claim 1, wherein the support base is mounted at a lower end to a force sensor of a frictional wear testing machine.
5. 5. The device according to claim 1, wherein the drive link is connected to a device for horizontal displacement of the test site of the frictional wear testing machine, while a force sensor is connected thereto.
6. 6. The device of claim 1, wherein a temperature sensor is additionally arranged at a position 10mm away from the friction pair above the round hole of the small end of the piston connecting rod.
7. 7. The working method of the detection device for simulating the service capability of the small-end lubricating oil of the piston connecting rod of the internal combustion engine is characterized by comprising the following steps of: The method comprises the following steps that 1, a loading screw rod of a friction wear testing machine acts a load on a friction pair contact surface of a piston pin-connecting rod small end bushing along a loading bracket and a piston connecting rod, and the friction wear testing machine provides transverse reciprocating displacement and horizontal pulling force to convert the transverse reciprocating displacement into reciprocating rotation of a piston pin around a shaft; And 2, measuring the longitudinal load and the transverse tension acting on the piston pin-connecting rod small end bushing friction pair through a force sensor, calculating the friction coefficient of the piston pin-connecting rod small end bushing friction pair by utilizing the ratio of the longitudinal load and the transverse tension, and indirectly reflecting the service capacity of the lubricating oil of the piston connecting rod small end of the internal combustion engine by comparing the friction coefficient.
8. 8. The method of claim 7, further comprising pumping the small end of the piston rod during operation to drive the lubricant to circulate in the gap, wherein when the piston pin rotates periodically in the small end of the piston rod, the fit gap between the round hole of the small end of the piston rod and the piston pin becomes larger or smaller periodically due to transverse tension and thermal expansion, and when the gap increases, the lubricant is sucked from the oil sump, whereas the lubricant is discharged from the gap into the oil sump, and heat and abrasive dust are taken away.

Description

Detection device for simulating service capability of small-end lubricating oil of piston connecting rod of internal combustion engine and working method Technical Field The invention belongs to the technical field of machinery, and particularly relates to a detection device for simulating the service capacity of lubricating oil of a small end of a piston connecting rod of an internal combustion engine and a working method thereof. Background In recent years, with the upgrading and upgrading of oil products and engine technologies, the development and pushing out of long-life engine oil with a long oil-changing period as a key part of an engine for the research of the reliability of lubrication technology become common knowledge in industry. Engine manufacturers are continually proposing to extend the oil change cycle of engine oils from the standpoint of protecting the engine, reducing maintenance costs and facilitating the user. Therefore, in order to better meet the requirements of energy conservation and environmental protection, the upgrading and upgrading of the oil products must be quickened, the product performance is optimized, and the step of oil change period is prolonged. When the engine works normally, abrasion is inevitably generated between moving components, normal sound is smooth and rhythmically coordinated sound, the connecting rod is impacted by regular pulse force in the period running process of the piston in the cylinder body, the contact area of the small-end bushing and the piston pin is smaller than the contact area of the large end of the connecting rod and the crankshaft, and the abrasion of the small-end bushing is the most important concern relative to the abrasion of the large-end bushing of the connecting rod because the lubricating condition is worse. The small-end bushing of the connecting rod adopts a splash lubrication mode, and aims to form a lubrication film with normal bearing capacity and low tangential shear strength between friction surfaces, reduce friction resistance and reduce material abrasion. However, the splash lubrication mode and the swing characteristic lead to difficult establishment of a lubricating oil film, mixed lubrication and even dry friction states are extremely easy to occur, abnormal wear, high-temperature ablation, loosening of a bushing and other faults of a small-end bushing of a connecting rod are caused, abnormal noise of an engine is caused, even cracking of a piston, cylinder pulling and other conditions seriously affect the operation of the whole machine are caused, so that research on the friction performance of the small-end bushing of the connecting rod has important significance, and how to evaluate the friction performance of lubricating oil in a service state becomes an urgent problem to be solved. Aiming at the problem of friction and abrasion of friction pairs on the contact surface of a moving part, relatively mature technology for developing a friction and abrasion testing machine exists at home and abroad, but few special testing tables are used for friction pairs in a special movement form (such as a connecting rod small-end bushing-piston pin friction pair), students often adopt a general testing machine to conduct test research, and the method can analyze the friction and abrasion performance of materials, but ignores the actual movement of the friction pairs, and cannot obtain the lubrication and friction state of the actual operation of the friction pairs. When the engine works, the reciprocating motion of the piston pin relative to the small end bushing of the connecting rod accelerates lubricating oil to enter the small end bushing of the connecting rod through an oil way in the connecting rod, and pumping effect is generated. When the friction and wear test of the small end bushing-piston pin of the connecting rod is carried out, only the swinging motion is generally considered, the reciprocating motion of the piston pin in the small end bushing of the connecting rod caused by the bearing clearance is ignored, the pumping action cannot be reflected, and the research on the actual lubrication and friction and wear characteristics of the small end bushing-piston pin of the connecting rod is greatly influenced. Aiming at the friction and wear problem of the piston pin-connecting rod small end bushing, a plurality of students build a simple friction and wear testing machine and test and analyze the wear mechanism on the basis of the friction and wear testing machine, and theoretical basis is provided for the friction and wear control technology. However, most of the test machines are ring block test machines or pin-disc test machines, and the simulation of the piston pin-connecting rod small end bushing pair is not strong. Disclosure of Invention The invention designs a detection device and a working method for simulating the service capability of small end lubricating oil of a piston connecting rod of an internal combusti