Automatic adjusting mechanism for gap between piston and cylinder wall of internal combustion engine

Abstract

The invention discloses an internal combustion engine piston and cylinder wall clearance automatic adjusting mechanism which comprises a wedge block containing cavity formed in a piston secondary thrust face and a triangular wedge block arranged in the wedge block containing cavity in a matched mode, the bottom edge of the triangular wedge block and the wedge block containing cavity are arranged in a clearance mode, and a spring hole is formed in the bottom of the triangular wedge block. A pre-tightening spring is arranged in the spring hole, the other end of the pre-tightening spring abuts against the inner wall of the wedge block containing cavity, and in the whole working stroke of the piston, the pre-tightening spring is in a compressed state all the time. The sliding fit clearance between the piston and the wall of the air cylinder is automatically adjusted through wedging force formed by mutual matching of the wedge block containing cavity located on the secondary thrust face of the piston, the triangular wedge block, the pre-tightening spring and the wall of the air cylinder, so that accurate vertical reciprocating motion of the piston in the working stroke is ensured; the problems that due to the fact that the gap between the piston of the internal combustion engine and the wall of the air cylinder is too large or too small, the piston swings laterally, the performance of the air cylinder is reduced, and oil consumption is increased are effectively solved.

Description

Technical Field

[0001] The invention relates to the technical field of internal combustion engines, and in particular to an automatic adjustment mechanism for the clearance between a piston and a cylinder wall of an internal combustion engine. Background Art

[0002] In order to ensure that the internal combustion engine can work normally under various working conditions and environments, the clearance between the piston and the cylinder wall of various types of internal combustion engines usually needs to be maintained in the range of 0.08 to 0.35 mm. This piston clearance is a key parameter to ensure the normal operation of the engine and extend its service life. The following is a detailed explanation of the piston clearance:

[0003] 1. Compensation for thermal expansion

[0004] When the internal combustion engine is working, the piston will absorb the heat of combustion and the friction with the gas, causing the temperature to rise, and then thermal expansion will occur. If there is no gap between the piston and the cylinder wall or the gap is too small, the piston may get stuck on the cylinder wall due to expansion in the hot state, causing the engine to malfunction or even damage.

[0005] 2. Ensure lubrication

[0006] Appropriate clearance allows the lubricating oil to form an oil film between the piston and the cylinder wall, which plays a lubricating role, reduces friction and wear between the two, reduces energy loss, and improves the efficiency and reliability of the engine. At the same time, the lubricating oil can also play a cooling and sealing role, helping the piston to dissipate heat and prevent the leakage of high-temperature and high-pressure gas in the combustion chamber.

[0007] 3. Assembly and manufacturing errors

[0008] During the manufacturing and assembly of the engine, it is difficult to ensure that the piston and the cylinder wall are perfectly matched due to the limitations of process and precision. Therefore, a certain gap must be reserved to compensate for these inevitable errors and ensure that the piston can move freely in the cylinder without abnormal resistance or wear due to local overtightening.

[0009] In summary, in actual operation of an internal combustion engine, there is inevitably a problem of too large or too small gap between the piston and the cylinder wall, which directly affects the improvement of the performance of the internal combustion engine. If the gap is too small, the piston will be stuck on the cylinder wall, causing the engine to fail to operate normally or even be damaged. If the gap is too large, the piston will swing sideways, causing the piston ring to deform, which will lead to poor fit between the piston ring and the cylinder wall and reduced sealing performance. The high-pressure gas in the combustion chamber will leak into the crankcase, reducing the compression ratio of the engine and the combustion efficiency. The internal combustion engine needs to consume more fuel to maintain the same power output. At the same time, the lateral swing of the piston will also increase the friction between the piston and the cylinder wall, and the internal combustion engine needs to consume more energy to overcome these additional frictions, resulting in additional fuel consumption.

[0010] The test results of numerous internal combustion engine designs in the industry show that due to the lateral swing of the piston in the internal combustion engine, multiple factors such as piston ring deformation and increased friction force are superimposed, resulting in an increase in fuel consumption of about 10% - 30%. After the piston and piston rings are worn, it may even be higher. Summary of the Invention

[0011] The purpose of the present invention is to propose an automatic clearance adjustment mechanism between the piston and the cylinder wall of an internal combustion engine to overcome the above-mentioned deficiencies in the prior art.

[0012] To achieve the above technical objectives, the technical solution of the present invention is realized as follows:

[0013] An automatic clearance adjustment mechanism between the piston and the cylinder wall of an internal combustion engine includes a wedge block accommodation cavity opened on the secondary thrust surface of the piston and a triangular wedge block adaptively arranged in the wedge block accommodation cavity. The bottom edge of the triangular wedge block is arranged with a clearance from the wedge block accommodation cavity. A spring hole is opened at the bottom of the triangular wedge block, and a pre-tightening spring is arranged in the spring hole. The other end of the pre-tightening spring abuts against the inner wall of the wedge block accommodation cavity. During the entire working stroke of the piston, the pre-tightening spring is always in a compressed state.

[0014] The beneficial effects of the present invention: The present invention automatically adjusts the sliding fit clearance between the piston and the cylinder wall through the wedging force formed by the mutual cooperation between the wedge block accommodation cavity, the triangular wedge block, the pre-tightening spring and the cylinder wall on the secondary thrust surface of the piston, ensuring the accurate vertical reciprocating movement of the piston during the working stroke, effectively solving the problems such as excessive or too small clearance between the piston and the cylinder wall of the internal combustion engine, resulting in piston lateral swing, and then the decline of cylinder sealing performance, power reduction, fuel consumption increase, accelerated wear of the piston and cylinder, cylinder pulling, seizure, and increased working noise of the internal combustion engine, which are difficult to solve by traditional technologies. Brief Description of the Drawings

[0015] Figure 1 is the overall structural schematic diagram of the mechanism described in the embodiment of the present invention applied to the piston;

[0016] Figure 2 is the unfolded structural schematic diagram of the mechanism described in the embodiment of the present invention applied to the piston;

[0017] Figure 3 is Figure 1 the cross-sectional view of;

[0018] Figure 4 is the overall structural schematic diagram of the mechanism described in the embodiment of the present invention applied to the internal combustion cylinder;

[0019] Figure 5 is the working structural schematic diagram during the piston intake stroke;

[0020] Figure 6It is a schematic diagram of the working structure of the piston during the compression stroke;

[0021] Figure 7 It is a schematic diagram of the working structure of the piston during the power stroke;

[0022] Figure 8 It is a schematic diagram of the working structure during the piston exhaust stroke.

[0023] As shown in the figure:

[0024] 1-piston; 2-triangular wedge; 3-preload spring; 4-wedge accommodating chamber; 5-spring hole; 6-secondary thrust surface; 7-internal combustion engine connecting rod; 8-crankshaft; 9-cylinder body; 10-main thrust surface; 11-inclined surface 1; 12-inclined surface 2; 13-outer cylindrical surface; 14-piston ring. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present invention are described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0026] First of all, it should be explained that in the technology of this field, the secondary thrust surface of the piston refers to the side that bears the piston side pressure during the intake, compression and exhaust strokes in the four working strokes of the internal combustion engine, and the main thrust surface refers to the side that bears the piston side pressure during the power stroke in the four working strokes of the internal combustion engine.

[0027] Based on the above description, if Figure 1-4 As shown, an automatic adjustment mechanism for the gap between the piston and the cylinder wall of an internal combustion engine according to an embodiment of the present invention comprises a wedge block accommodating chamber 4 opened on a secondary thrust surface 6 of a piston 1 and a triangular wedge block 2 adapted to be arranged in the wedge block accommodating chamber 4, a gap is arranged between the bottom edge of the triangular wedge block 2 and the wedge block accommodating chamber 4, a spring hole 5 is opened at the bottom of the triangular wedge block 2, a preload spring 3 is arranged in the spring hole 5, the other end of the preload spring 3 abuts against the inner wall of the wedge block accommodating chamber 4, and the preload spring 3 is always in a compressed state during the entire working stroke of the piston 1.

[0028] Specifically, the wedge block accommodating chamber 4 is arranged on one side of the secondary thrust surface 6, the triangular wedge block 2 is installed in the wedge block accommodating chamber 4, and the inclined surface 11 of the wedge block accommodating chamber 4 and the inclined surface 2 12 of the triangular wedge block 2 are closely matched with each other. When the triangular wedge block 2 slides upward, the height of its outer cylindrical surface 13 will be equal to the secondary thrust surface 6 of the piston 1 under the action of the inclined surface. When the triangular wedge block 2 slides downward, the height of its outer cylindrical surface 13 will be higher than the secondary thrust surface 6 of the piston 1 under the action of the inclined surface. One end of the preload spring 3 is installed in the spring hole 5 of the triangular wedge block 2, and the other end contacts the top plane of the wedge block accommodating chamber 4.

[0029] Except for the wedge accommodating cavity 4, the triangular wedge 2 and the preload spring 3, the rest of the structure of the present invention is a traditional structure of an internal combustion engine piston.

[0030] Working principle of the present invention:

[0031] 1. Inhalation stroke; see Figure 5 , the crankshaft 8 rotates clockwise, the intake valve opens, and the piston 1 moves to the bottom dead center through the connecting rod 7, and fresh air (compression ignition internal combustion engine) or combustible gas (ignition internal combustion engine) is sucked into the cylinder. In the process of the piston 1 moving downward from the top dead center to the bottom dead center, the triangular wedge 2 and the inner wall of the cylinder body 9 generate friction, thereby compressing the preload spring 3. The triangular wedge 2 moves upward and loses the wedge force. The side pressure of the piston 1 in the intake stroke is mainly borne by the piston secondary thrust surface 6. The triangular wedge 2 only bears part of the side pressure under the action of the preload spring 3. After the piston 1 moves to the bottom dead center, the intake valve closes and the intake stroke ends.

[0032] 2. Compression stroke; see Figure 6 , the crankshaft 8 continues to rotate clockwise, driving the piston 1 to move the compressed air or combustible gas from the bottom dead center to the top dead center through the connecting rod 7. In the process of the piston 1 moving upward from the bottom dead center to the top dead center, the friction between the triangular wedge block 2 and the inner wall of the cylinder body 9 causes the triangular wedge block 2 to move downward. Therefore, the triangular wedge block 2 forms a wedging force under the mutual compression of the wedge block accommodating chamber 4 and the inner wall of the cylinder body 9, forcing the main thrust surface 10 of the piston 1 to be close to the inner wall of the cylinder body 9. The piston 1 achieves gapless vertical movement throughout the compression stroke, making preliminary preparations for the internal combustion engine's fuel injection combustion or ignition work.

[0033] 3. Power stroke; see Figure 7 , the crankshaft 8 continues to rotate clockwise, driving the piston to the top dead center through the connecting rod 7. After the compression stroke is completed, the spark plug ignites the combustible gas or the fuel injector sprays fuel to burn and expand, pushing the piston 1 to do work. As mentioned above, since the compression stroke begins, the main thrust surface 10 of the piston 1 has been moving closely against the inner wall of the cylinder body 9 under the action of the wedging force of the triangular wedge 2. Therefore, during the alternation between the compression stroke and the power stroke, the piston 1 will not swing sideways, and will always move vertically to the bottom dead center during the power stroke. During this process, the piston ring 14 installed on the piston 1 can always slide closely against the inner wall of the cylinder body 9, ensuring good sealing performance during the operation of the internal combustion engine, eliminating all the disadvantages caused by the lateral swing of the piston in the alternation between the compression stroke and the power stroke of the traditional internal combustion engine, reducing the energy loss of the internal combustion engine and extending its service life.

[0034] 4. Exhaust stroke; see Figure 8, the crankshaft 8 continues to rotate clockwise, the exhaust valve opens, and the piston 1 is driven to move from the bottom dead center to the top dead center through the connecting rod 7, and the exhaust gas in the cylinder of the internal combustion engine is expelled from the cylinder by the piston 1. During the exhaust stroke, the movement law between the piston 1 and the triangular wedge block 2 is basically the same as that of the compression stroke, so it will not be repeated.

[0035] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An automatic adjustment mechanism for the clearance between a piston and a cylinder wall of an internal combustion engine, characterized in that: The invention comprises a wedge block accommodating chamber (4) provided on the secondary thrust surface (6) of the piston (1) and a triangular wedge block (2) adapted to be arranged in the wedge block accommodating chamber (4); a gap is arranged between the bottom edge of the triangular wedge block (2) and the wedge block accommodating chamber (4); a spring hole (5) is provided at the bottom of the triangular wedge block (2); a preload spring (3) is arranged in the spring hole (5); the other end of the preload spring (3) abuts against the inner wall of the wedge block accommodating chamber (4); and the preload spring (3) is always in a compressed state during the entire working stroke of the piston (1).

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