A highly efficient lubricated piston-connecting rod assembly

Abstract

The present invention discloses a highly efficient lubricated piston-connecting rod assembly, comprising a piston, a piston pin, a bushing, and a connecting rod. The piston is provided with a piston cavity, in which the connecting rod is connected to the piston through a piston pin, and the outer wall of the connecting portion of the piston pin and the connecting rod is sleeved with a bushing. The piston is provided with an inner cooling oil passage, in which two oil drainage holes are provided and communicated with the inner cavity of the piston, and the oil drainage holes are provided at the diagonally opposite sides of the front and rear sides of the connecting rod, and are located in the middle of the gap between the piston and the side of the connecting rod; the inner surface of the bushing is provided with two oil grooves, the oil grooves are U-shaped, and the end faces of the oil grooves are oil inlets. The present invention aims to solve the existing problems of bushing wear caused by insufficient lubricating oil in the bushing of the connecting rod when the piston moves.

Description

Technical Field

[0001] The invention relates to the technical field of engines, and in particular to a piston-connecting rod assembly with high efficiency lubrication. Background Art

[0002] The piston is the heart of the automobile engine, bearing alternating mechanical and thermal loads. The piston-connecting rod assembly is an important transmission component of the engine, which transmits the pressure of the combustion gas to the crankshaft, causing the crankshaft to rotate and output power. The piston and the cylinder head form a combustion chamber, bearing the expansion pressure of the combustion gas, and transmitting the power to the crankshaft through the piston pin and connecting rod. Driven by the connecting rod, it completes the three auxiliary strokes of intake, compression, and exhaust. Since the piston bears the dual effects of mechanical and thermal loads, the working conditions are very harsh, and a good cooling and lubrication structure must be provided to reduce the temperature of the piston.

[0003] At present, the piston has two oil holes through the inner cavity, which are connected to the piston inner cooling oil channel. The angle between the two oil holes is about 90°, referred to as oil hole combination A, and is symmetrical about the center line of the piston. Two small holes are also opened on the upper part of the corresponding piston connecting rod head, which are connected to the inner surface of the connecting rod bushing. The angle of the oil inlet hole on the connecting rod is consistent with the angle of the oil hole mentioned above, and is symmetrical about the center line of the piston connecting rod, which is called oil hole combination B. When the piston runs to the top dead center or the bottom dead center, and the connecting rod is in the vertical direction, the center lines of oil hole combination A and oil hole combination B correspond to each other, and the lubrication effect of the connecting rod bushing is the best at this time. However, the above situation can only be achieved when the connecting rod is in a static state at the top dead center or the bottom dead center. During the movement of the connecting rod, it cannot always maintain a vertical position, that is, the center lines of oil hole combination A and oil hole combination B cannot always correspond when the piston moves. At the moment of non-correspondence, the connecting rod bushing receives relatively less lubricating oil from the piston oil channel, which is easy to cause bushing wear. Summary of the invention

[0004] In view of the above problems, the present invention provides a piston-connecting rod assembly with high efficiency lubrication, aiming to solve the problem that the existing piston-connecting rod cannot obtain engine oil for lubrication from the piston at any position during the entire movement process.

[0005] The present invention adopts the following technical solutions to achieve the above purpose:

[0006] A highly lubricated piston-connecting rod assembly comprises a piston, a piston pin, a bushing and a connecting rod, wherein a piston cavity is arranged in the piston, a connecting rod is connected to the piston via a piston pin in the piston cavity, a bushing is sleeved on the outer wall of the connecting portion between the piston pin and the connecting rod, an inner cooling oil passage is arranged in the piston, two oil drainage holes are provided in the inner cooling oil passage and are connected to the inner cavity of the piston, the oil drainage holes are arranged at oblique sides of the front and rear sides of the connecting rod and are located in the middle of the gap between the piston and the side faces of the connecting rod; two oil grooves are arranged on the inner surface of the bushing, the oil grooves are U-shaped, and the end faces of the oil grooves are oil inlets.

[0007] Preferably, the oil inlet is trumpet-shaped with a large outside and a small inside, and the angle F is 70-80°, and the angle G between the lowest points of the two oil grooves and the line connecting the center point of the bushing is 80-90°. In this way, more engine oil can be captured, and the engine oil then penetrates into the piston pin hole along the piston pin, thereby improving the lubrication between the piston pin hole and the piston pin.

[0008] Preferably, the projection angle E between the axes of the two oil drain holes on the piston center plane is 80-100°. This arrangement makes it easier for the oil flowing out of the oil drain holes to lubricate the connecting rod bushing during the entire movement of the piston connecting rod.

[0009] The beneficial effects of the present invention are:

[0010] The present invention provides a piston-connecting rod assembly with high efficiency lubrication. Because the oil drain hole on the piston is located exactly between the piston pin seat and the bushing, the bushing can obtain engine oil from the piston for lubrication during the entire movement of the piston-connecting rod, no matter what position the connecting rod is in, and there is no situation where some positions cannot be lubricated. The bell mouth of the connecting rod bushing can capture more engine oil, and the engine oil then penetrates into the piston pin hole along the piston pin, thereby improving the lubrication between the piston pin hole and the piston pin, thereby allowing the piston-connecting rod to operate reliably for a long time. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 : A schematic structural diagram of a highly efficient lubricated piston-connecting rod assembly according to the present invention.

[0012] Figure 2 : A schematic top view of a piston of a piston-connecting rod assembly with high efficiency lubrication according to the present invention.

[0013] Figure 3 BB cross-sectional view of the piston of the efficient lubricating piston-connecting rod assembly described in the present invention.

[0014] Figure 4 Schematic diagram of a bushing of a piston-connecting rod assembly with high efficiency lubrication according to the present invention.

[0015] Figure 5: A schematic front view of a bushing of a piston-connecting rod assembly with high efficiency lubrication according to the present invention.

[0016] Figure 6 : A sectional view of a bushing AA of a piston-connecting rod assembly with high efficiency lubrication according to the present invention.

[0017] Figure 7 The oil temperature diagram is measured at different angles of the angle E of the piston connecting rod assembly with high efficiency lubrication described in the present invention.

[0018] In the figure: 1-piston; 2-piston pin; 3-bushing; 4-connecting rod; 5-oil drain hole; 6-internal cooling oil channel; 7-oil inlet; 8-lowest point of oil tank; 9-piston cavity; 10-oil tank. DETAILED DESCRIPTION

[0019] The following is combined with Figures 1 to 6 The present invention is described in detail with specific embodiments.

[0020] like Figure 1-6 As shown, it is an embodiment of the present invention, which provides a piston-connecting rod assembly with high efficiency lubrication, including a piston 1, a piston pin 2, a bushing 3, and a connecting rod 4. A piston cavity 9 is arranged in the piston 1, and the connecting rod 4 is connected to the piston 1 through the piston pin 2 in the piston cavity 9. The outer wall of the connecting part between the piston pin 2 and the connecting rod 4 is sleeved with a bushing 3. An internal cooling oil channel 6 is arranged in the piston 1, and two oil drainage holes 5 are provided in the internal cooling oil channel 6 and are connected to the piston cavity 9. The oil drainage holes 5 are arranged at an angle opposite to the front and rear sides of the connecting rod 4, and are located in the middle of the side gap between the piston 1 and the connecting rod 4. The projection angle E of the axes of the two oil drainage holes 5 on the central plane of the piston 1 is 80~100°; when the angle E is less than 80°, the engine oil cannot stay in the oil channel and absorb the heat generated by the piston; when the angle E is greater than 100°, the engine oil in the internal cooling oil channel is not easy to flow. Its experiment Figure 7 As shown:

[0021] like Figure 7 As shown,

[0022] The angle E is less than 80°, for example, when E=50°, the inner cooling oil outlet is almost vertically downward, and the oil in the inner cooling oil channel just enters the inner cooling oil channel and flows out before absorbing heat. Therefore, the oil temperature displayed at E=50° is much lower than the oil temperature at E=80~100°.

[0023] The angle E is greater than 100°. For example, when E=150°, the outlet angle is too large and the oil cannot flow out in time, which is equivalent to stopping the flow in the internal cooling oil channel. Without flow, there is no fresh, low-temperature oil to replenish. Although the oil temperature is high, it cannot be taken away in time, and thus cannot achieve the purpose of timely cooling of the piston.

[0024] like Figure 4 As shown in Fig. 6, two oil grooves 10 are arranged on the inner surface of the bushing 3. The oil grooves 10 are U-shaped. The end face of the oil grooves 10 is an oil inlet 7. The oil inlet 7 is a trumpet-shaped one with a large outside and a small inside. The included angle is F=70-80°. The upper edge of the trumpet-shaped oil inlet 7 should be arranged as close to the top of the bushing as possible, and the lower edge is close to the horizontal position. When the included angle F is less than 70°, the engine oil cannot smoothly enter the bushing for lubrication. If the included angle E is greater than 80°, the bushing will have insufficient pressure bearing capacity and cannot be well lubricated by the engine oil. Figure 6 As shown, the angle G between the lowest point 8 of the two oil grooves and the line connecting the center point of the bushing 3 is 80-90°. If the angle G is less than 80°, the bearing capacity of the bushing bottom is poor and the lubrication is insufficient. If the angle G is greater than 90°, the lowest point 8 of the oil groove is too shallow, resulting in a reduction in the connecting rod part lubricated by the oil groove, so that the connecting rod is not lubricated well and the wear is aggravated. The experimental data are as follows: The bearing capacity of the bushing bottom at different angles,

[0025] angle G＝60° G＝80～90° G＝110° Bushing bottom bearing pressure (Mpa) 80 70 90

[0026] As shown in the figure above, when the angle G is less than 80°, for example, when G=60°, the lowest point 8 of the oil groove is close to the bottom of the bushing, and the pressure on the bottom surface increases; on the contrary, when the angle G is greater than 90°, such as when G=110°, the lowest point 8 of the oil groove is farther away from the bottom of the bushing, and the bottom is a pressure-bearing surface, so the lubricating oil that the bottom surface can receive cannot be fully lubricated because it is too far away from the oil groove, which aggravates the wear between the bushing and the connecting rod.

[0027] The present invention provides a highly efficient lubricated piston-connecting rod assembly, which enables the bushing 3 to be lubricated with engine oil regardless of the position of the connecting rod 4 during the entire movement process. In addition, the bushing 3 is arranged in this way to capture more engine oil and improve the lubrication between the piston pin hole and the piston pin 2.

[0028] Although the present invention has been described in detail above with specific embodiments, it is obvious to those skilled in the art that some modifications or improvements can be made to the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all belong to the scope of protection claimed by the present invention.

Claims

1. A highly efficient lubricated piston-connecting rod assembly , comprising a piston (1), a piston pin (2), a bushing (3), and a connecting rod (4), wherein a piston cavity (9) is arranged in the piston (1), wherein the connecting rod (4) is connected to the piston (1) via the piston pin (2) in the piston cavity (9), and a bushing (3) is sleeved on the outer wall of the connecting portion between the piston pin (2) and the connecting rod (4), characterized in that: The piston (1) is provided with an inner cooling oil passage (6), and two oil drain holes (5) are provided in the inner cooling oil passage (6) and are connected to the piston inner cavity (9). The oil drain holes (5) are provided at obliquely opposite sides of the front and rear sides of the connecting rod (4) and are located in the middle of the side gap between the piston (1) and the connecting rod (4); the inner surface of the bushing (3) is provided with two oil grooves (10), and the oil grooves (10) are U-shaped, and the end faces of the oil grooves (10) are oil inlets (7); the projection angle E of the axes of the two oil drain holes (5) on the central plane of the piston (1) is 80 to 100 degrees; the oil inlet (7) is trumpet-shaped with a larger outer side and a smaller inner side, and its angle F is 70 to 80 degrees, and the angle G between the lowest points (8) of the two oil grooves and the line connecting the central points of the bushing (3) is 80 to 90 degrees.

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