CN115111086A

CN115111086A - Split type piston assembly of piston reciprocating engine

Info

Publication number: CN115111086A
Application number: CN202210741923.7A
Authority: CN
Inventors: 尹艳君; 刘玮; 刘金龙; 李耀宗; 樊巨廷; 于波; 孙勇
Original assignee: China North Engine Research Institute Tianjin
Current assignee: China North Engine Research Institute Tianjin
Priority date: 2022-06-28
Filing date: 2022-06-28
Publication date: 2022-09-27

Abstract

The invention provides a split type piston assembly of a piston reciprocating engine, which comprises a cylinder, a piston assembly and a connecting rod, wherein the periphery of the piston assembly is connected to the inner wall of the cylinder in a sliding manner, the lower end of the piston assembly is hinged to the upper end of the connecting rod, the piston assembly can be pushed to slide along the axial direction of the cylinder by combustion pressure generated in a combustion chamber, and a gap is formed between the outer edge of the upper end of the piston assembly and the inner wall of the cylinder. According to the split piston assembly of the piston reciprocating engine, the lateral thrust formed by the mechanism such as the connecting rod or the cam of the piston reciprocating engine in the conversion process of the rotary motion and the linear motion only acts on the skirt piston, and the skirt piston is far away from a high-temperature region, so that the thermal deformation is small, and the cylinder pulling phenomenon is not easy to occur; meanwhile, the friction fit pair design gap between the skirt piston and the inner wall of the cylinder can be reduced, so that the guidance performance is better, and the molded line design between the outer wall of the skirt piston and the inner wall of the cylinder can be simplified or even eliminated.

Description

Split type piston assembly of piston reciprocating engine

Technical Field

The invention belongs to the technical field of internal combustion engines, and particularly relates to a split type piston assembly of a piston reciprocating engine.

Background

In the working process of the piston reciprocating engine, high temperature in a combustion chamber is transferred to the inner wall of a cylinder through a piston and a piston ring, the performance requirements of the piston and the piston ring are different, the materials are often different, the deformation is different, and once the friction fit clearance between the piston and the piston ring is reduced, the cylinder pulling phenomenon is easy to occur under the action of lateral thrust formed in the conversion process of rotary motion and linear motion.

Disclosure of Invention

In view of this, the present invention provides a split piston assembly for a piston reciprocating engine, so as to solve the problem of cylinder scuffing caused by high temperature of the engine, knocking in the cylinder, and other factors, and improve the structural reliability and the possibility of improving the performance of the engine.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

the utility model provides a split type piston assembly of piston reciprocating engine, includes cylinder, piston assembly and connecting rod, and the peripheral sliding connection of piston assembly to cylinder inner wall, and the piston assembly lower extreme articulates to the connecting rod upper end, and the combustion pressure that produces in the combustion chamber can promote piston assembly along cylinder endwise slip, and is equipped with the clearance between piston assembly upper end outer fringe and the cylinder inner wall.

Furthermore, the piston assembly comprises a head piston and a skirt piston arranged at the lower end of the head piston, the lower end of the skirt piston is hinged to the upper end of the connecting rod, the outer diameter of the head piston is smaller than the inner diameter of the cylinder, and a friction matching pair is arranged between the periphery of the skirt piston and the inner wall of the cylinder.

Further, the periphery of the head piston is provided with a piston ring, and the periphery of the piston ring is in contact connection with the inner wall of the cylinder.

Furthermore, the lower end of the head piston and the upper end of the skirt piston are respectively provided with a first pin shaft, and the two ends of the first hinge are respectively rotatably sleeved on the periphery of one first pin shaft.

Furthermore, the lower end of the head piston and the lower end of the skirt piston are respectively provided with a second pin shaft, two ends of a second hinge element are respectively rotatably sleeved on the periphery of one second pin shaft, and the upper end of the connecting rod is rotatably sleeved on the periphery of the second pin shaft of the skirt piston.

Compared with the prior art, the split piston assembly of the piston reciprocating engine has the following beneficial effects: the side thrust formed by the mechanism such as the connecting rod or the cam of the piston reciprocating engine in the conversion process of the rotary motion and the linear motion only acts on the skirt piston. The skirt piston is far away from a high-temperature area, so that the thermal deformation is small, and the cylinder pulling phenomenon is not easy to occur; meanwhile, the design clearance of the friction fit pair between the skirt piston and the inner wall of the cylinder can be reduced, so that the guidance quality is better, and the design of the molded line between the outer wall of the skirt piston and the inner wall of the cylinder can be simplified or even eliminated; the skirt piston is hinged with the head piston through the connecting piece and the pin shaft, and the head piston rotates along the pin shaft under the action of lateral thrust, so that the direct contact between the head piston and the inner wall of the cylinder, namely the cylinder pulling phenomenon, is avoided; the head piston and the skirt piston adopt split structures, different materials can be flexibly selected for the head piston according to requirements of temperature resistance, corrosion resistance and the like, the skirt piston only plays a role of guiding and the like, is far away from a high-temperature area, has small thermal deformation, and can be made of light materials, and the total weight of the piston assembly cannot be greatly increased; the structure of the invention is similar to the basic structure of the piston assembly of the traditional piston reciprocating engine, and relates to a solution for the cylinder pulling phenomenon caused by the factors such as high temperature of the piston reciprocating engine, knocking in the cylinder and the like, wherein the improved parts are less, and the improved cost is low.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention, illustrate embodiments of the invention and together with the description serve to explain the invention and do not constitute a limitation of the invention. In the drawings:

FIG. 1 is a schematic cross-sectional view of a split piston assembly of a reciprocating piston engine according to an embodiment of the present invention;

FIG. 2 is a force diagram of a split piston assembly of a piston reciprocating engine according to an embodiment of the present invention.

Description of reference numerals:

1-a cylinder; 2-a head piston; 3-a connecting rod; 4-a second pin shaft; 5-a first articulation; 6-a piston ring; 7-combustion pressure; 8-rotational moment of lateral thrust conversion; 9-lateral thrust; 10-reciprocating inertial force; 11-skirt piston.

Detailed Description

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used only for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention. Furthermore, the terms "first", "second", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first," "second," etc. may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless otherwise specified.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art through specific situations.

The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

As shown in fig. 1-2, a split piston assembly of a piston reciprocating engine comprises a cylinder 1, a piston assembly and a connecting rod 3, the periphery of the piston assembly is connected to the inner wall of the cylinder 1 in a sliding manner, the lower end of the piston assembly is hinged to the upper end of the connecting rod 3, the combustion pressure 7 generated in the combustion chamber can push the piston assembly to slide along the axial direction of the cylinder 1, a gap is arranged between the outer edge of the upper end of the piston assembly and the inner wall of the cylinder 1, the piston assembly comprises a head piston 2 and a skirt piston 11 arranged at the lower end of the head piston 2, the lower end of the skirt piston 11 is hinged to the upper end of the connecting rod 3, the outer diameter of the head piston 2 is smaller than the inner diameter of the cylinder 1, a friction matching pair is arranged between the periphery of the skirt piston 11 and the inner wall of the cylinder 1, a piston ring 6 is arranged on the periphery of the head piston 2, the periphery of the piston ring 6 is in contact connection with the inner wall of the cylinder 1, the head piston 2 is not in direct contact with the inner wall of the cylinder 1, and is suspended in the inner cavity of the cylinder 1 through the piston ring 6; the skirt piston 11 and the inner wall of the cylinder 1 are in friction fit, and the head piston 2 and the skirt piston 11 are hinged through a first hinge part 5 and a first pin shaft.

The traditional piston is designed into a structure that the head piston 2 and the skirt piston 11 are separated according to different functions. The head piston 2 is not directly contacted with the inner wall of the cylinder 1, but is suspended in the inner cavity of the cylinder 1 through a piston ring 6, the combustion pressure 7 generated in a combustion chamber at the top of the head piston generates downward thrust along the axial direction to do work, and the deformation of the head piston 2 caused by high temperature is not enough to contact with the inner wall of the cylinder 1 due to large clearance between the head piston and the cylinder, so that the cylinder pulling phenomenon is avoided; the piston skirt part and the inner wall of the cylinder 1 are in friction fit design, the clearance is reduced, the guidance performance is better, and the piston skirt part simultaneously bears the reciprocating inertia force 10 of mechanisms such as a connecting rod 3 and a cam in the piston reciprocating engine in the process of converting the rotary motion into a linear motion conversion mechanism to form a side thrust 9 and a combustion pressure 7 transmitted by the piston head part. On one hand, the skirt piston 11 is far away from a high-temperature area, the thermal deformation is small, the cylinder pulling phenomenon is not easy to occur, and the design of the molded line of the outer wall of the skirt piston 11 and the inner wall of the cylinder 1 can be simplified or even eliminated; on the other hand, the head piston 2 is hinged with the skirt piston 11 through the connecting piece and the pin shaft, when the lateral thrust 9 transmitted by the piston skirt acts on the head piston 2, the head piston 2 swings along the pin shaft, and therefore the head piston 2 is prevented from contacting with the inner wall of the cylinder, and the cylinder pulling phenomenon is not easy to occur.

Meanwhile, the head piston 2 and the skirt piston 11 adopt split structures, different materials can be flexibly selected for the head piston 2 according to requirements of temperature resistance, corrosion resistance and the like, the skirt piston 11 only has guiding and other effects, is far away from a high-temperature area, has small thermal deformation, and can be made of light materials, the total weight of the piston assembly cannot be greatly increased, in order to further reduce the axial length of the piston assembly, the lower end of the head piston 2 and the lower end of the skirt piston 11 can be respectively provided with a second pin shaft 4, two ends of a second hinge part are respectively rotatably sleeved on the periphery of the second pin shaft 4, and the upper end of a connecting rod 3 is rotatably sleeved on the periphery of the second pin shaft 4 of the skirt piston 11.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims

1. A split piston assembly of a piston reciprocating engine is characterized in that: including cylinder (1), piston assembly and connecting rod (3), and the peripheral sliding connection of piston assembly to cylinder (1) inner wall, the piston assembly lower extreme articulates to connecting rod (3) upper end, and combustion pressure (7) that produce in the combustion chamber can promote piston assembly along cylinder (1) endwise slip, and is equipped with the clearance between piston assembly upper end outer fringe and cylinder (1) inner wall.

2. The split piston assembly of claim 1, wherein: piston assembly includes skirt portion piston (11) of head piston (2) and lower extreme installation, and skirt portion piston (11) lower extreme articulates to connecting rod (3) upper end, and the external diameter of head piston (2) is less than the internal diameter of cylinder (1), sets up friction between the periphery of skirt portion piston (11) and cylinder (1) inner wall and joins in marriage vice.

3. The split piston assembly of claim 2, wherein: the periphery of the head piston (2) is provided with a piston ring (6), and the periphery of the piston ring (6) is in contact connection with the inner wall of the cylinder (1).

4. The split piston assembly of claim 2, wherein: the lower end of the head piston (2) and the upper end of the skirt piston (11) are respectively provided with a first pin shaft, and the two ends of the first articulated element (5) are respectively rotatably sleeved to the periphery of one first pin shaft.

5. The split piston assembly of claim 2, wherein: the lower end of the head piston (2) and the lower end of the skirt piston (11) are respectively provided with a second pin shaft (4), the two ends of a second articulated element are respectively rotatably sleeved on the periphery of one second pin shaft (4), and the upper end of the connecting rod (3) is rotatably sleeved on the periphery of the second pin shaft (4) of the skirt piston (11).