Variable-compression-ratio combined piston and air cylinder

Abstract

The invention discloses a variable-compression-ratio combined piston and an air cylinder, and relates to the technical field of engines, the variable-compression-ratio combined piston comprises a piston sleeve, a piston rotor and a driving mechanism, the piston rotor is slidably arranged in the piston sleeve in the axial direction of the piston sleeve, a combustion chamber is defined between one axial end of the piston sleeve and the piston rotor, and the other axial end of the piston sleeve is connected with the driving mechanism; the driving direction of the driving mechanism is the same as the sliding direction of the piston rotor; the piston is divided into the piston sleeve and the piston mover, the combustion chamber is defined by the inner wall of the piston sleeve and the end face of the piston mover, the position of the piston mover in the piston sleeve is adjusted through the driving mechanism, the variable compression ratio is achieved, and in the sliding adjustment process of the piston mover, the shape of the whole combustion chamber cannot be greatly changed; normal formation of mixed gas can be guaranteed, reliability is high, and the combustion effect and heat efficiency of the air cylinder can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of engines, and in particular to a variable compression ratio combined piston and cylinder. Background Art

[0002] Global warming, oil crisis and other issues are becoming increasingly serious. Energy transformation and energy conservation and emission reduction have become a consensus in various industries. At the same time, the scale of engine electric energy replacement is getting larger and larger. This puts forward requirements for traditional piston engines in terms of multi-fuel applicability, fuel economy and power stability. Among them, variable compression ratio technology is an important technology for engines to adapt to the needs of efficient combustion of multiple fuels, improve fuel economy and improve power stability.

[0003] The existing variable compression ratio technology is mainly achieved by changing the piston stroke through a telescopic piston rod and changing the combustion chamber volume through an external telescopic device. However, whether changing the piston stroke or changing the combustion chamber volume, the shape of the combustion chamber will change significantly, resulting in the formation of the mixture in the combustion chamber being hindered, resulting in low reliability of the variable compression ratio technology, poor cylinder combustion effect of the engine and reduced thermal efficiency.

[0004] Therefore, people are in urgent need of a variable compression ratio combined piston with high reliability and the ability to improve cylinder combustion effect and thermal efficiency. Summary of the Invention

[0005] The purpose of the present invention is to provide a variable compression ratio combined piston and cylinder to solve the problems existing in the above-mentioned prior art. The piston is disassembled, the piston sleeve and the sliding piston mover are designed, and the position of the piston mover in the piston sleeve is adjusted in conjunction with the driving mechanism to achieve a variable compression ratio. Moreover, during the sliding process of the piston mover, the shape of the combustion chamber does not change significantly, thereby improving reliability and further improving the cylinder combustion effect and thermal efficiency.

[0006] To achieve the above-mentioned purpose, the present invention provides the following solution: The present invention provides a variable compression ratio combined piston, comprising a piston sleeve, a piston mover and a driving mechanism, wherein the piston mover is arranged in the piston sleeve along the axial sliding direction of the piston sleeve, a combustion chamber is formed between one axial end of the piston mover and the piston sleeve, and the other axial end is connected to the driving mechanism, and the driving direction of the driving mechanism is the same as the sliding direction of the piston mover.

[0007] Preferably, the driving mechanism includes a hydraulic cylinder body and a hydraulic slider, the hydraulic cylinder body is fixedly connected to the piston sleeve, the hydraulic slider is slidably arranged in the hydraulic cylinder body, the sliding direction of the hydraulic slider is the same as the sliding direction of the piston mover, the hydraulic slider divides the inner cavity of the hydraulic cylinder body into a first cavity and a second cavity, the first cavity and the second cavity are respectively connected to the hydraulic system through hydraulic oil circuits, and the hydraulic slider is connected to the piston mover through a connecting member.

[0008] Preferably, the end surface of the hydraulic sliding block corresponding to the first cavity is provided with a first protrusion, and the end surface of the hydraulic sliding block corresponding to the second cavity is provided with a second protrusion.

[0009] Preferably, the second cavity is located on a side of the first cavity away from the piston mover, and an end surface area of the second protrusion away from the hydraulic slider is smaller than an end surface area of the first protrusion away from the hydraulic slider.

[0010] Preferably, the first protrusion and the second protrusion are both integrally provided with the hydraulic slider.

[0011] Preferably, the hydraulic cylinder body and the piston mover are spaced apart.

[0012] Preferably, the hydraulic cylinder body and the piston mover are coaxially arranged, the diameter of the hydraulic cylinder body is larger than the diameter of the piston mover, and the cavity between the hydraulic cylinder body and the piston mover is connected to the external environment through an exhaust hole.

[0013] Preferably, the connecting member passes through both ends of the hydraulic cylinder body along the axial direction of the hydraulic cylinder body, and the exhaust hole is arranged inside the connecting member.

[0014] Preferably, a piston gas ring for sealing is provided between the outer peripheral wall of the piston mover and the inner peripheral wall of the piston sleeve.

[0015] The present invention also provides a cylinder using the variable compression ratio combined piston, comprising a cylinder body, wherein the piston in the cylinder body is the variable compression ratio combined piston.

[0016] Compared with the prior art, the present invention mainly achieves the following technical effects:

[0017] The piston is split into a piston sleeve and a piston mover. The inner wall of the piston sleeve and the end face of the piston mover are arranged to form a combustion chamber. The position of the piston mover in the piston sleeve is adjusted by a driving mechanism to achieve a variable compression ratio. During the sliding adjustment process of the piston mover, the shape of the end face used to form the combustion chamber will not change, that is, the shape of the end face corresponding to the cylinder valve timing and fuel injection will not change. The only change is that the overall combustion chamber is lengthened or shortened, so that the shape of the overall combustion chamber will not change significantly, which can ensure the normal formation of the mixture and high reliability, thereby helping to improve the cylinder combustion effect and thermal efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 A schematic cross-sectional view of a variable compression ratio combined piston according to an embodiment of the present invention;

[0020] Figure 2 Schematic diagram of the cross-sectional structure of the variable compression ratio combined piston when the combustion chamber volume is maximum in an embodiment of the present invention;

[0021] Figure 3 Schematic diagram of the cross-sectional structure of the variable compression ratio combined piston when the combustion chamber volume is minimum in the embodiment of the present invention;

[0022] Among them, 1. Piston sleeve; 2. Piston mover; 3. Sliding section; 4. Combustion chamber; 5. Blocking part; 6. Hydraulic cylinder body; 7. Hydraulic slider; 8. First cavity; 9. Second cavity; 10. First hydraulic oil circuit; 11. Second hydraulic oil circuit; 12. Connecting part; 13. Base; 14. Hydraulic cover; 15. First protrusion; 16. Second protrusion; 17. Exhaust hole; 18. Piston air ring. DETAILED DESCRIPTION

[0023] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0024] The purpose of the present invention is to provide a variable compression ratio combined piston and cylinder to solve the problems existing in the prior art. The piston is disassembled, and a piston sleeve and a sliding piston mover are designed. The position of the piston mover in the piston sleeve is adjusted in conjunction with a driving mechanism to achieve a variable compression ratio. Moreover, during the sliding process of the piston mover, the shape of the combustion chamber does not change significantly, thereby improving reliability and further improving the cylinder combustion effect and thermal efficiency.

[0025] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] Please refer to Figures 1 to 3 As shown, a variable compression ratio combined piston is provided, including a piston sleeve 1, a piston mover 2 and a driving mechanism. The piston mover 2 is cylindrical as a whole. A sliding section 3 with a diameter matching that of the piston mover 2 is provided in the piston sleeve 1. The piston mover 2 is arranged in the sliding section 3 of the piston sleeve 1 for axial sliding along the piston sleeve 1. A combustion chamber 4 is formed between one axial end of the piston mover 2 and the piston sleeve 1, and the other axial end is connected to the driving mechanism. The driving direction of the driving mechanism is the same as the sliding direction of the piston mover 2. This device splits a conventional piston into the piston sleeve 1 and the piston mover 2. The inner wall of the piston sleeve 1 and the end surface of the piston mover 2 are surrounded to form the combustion chamber 4. The position of the piston mover 2 in the piston sleeve 1 is adjusted by the driving mechanism. The volume of the combustion chamber 4 is changed to achieve a variable compression ratio, wherein when the volume of the combustion chamber 4 is minimum, the engine system operates at a maximum compression ratio, and when the volume of the combustion chamber 4 is maximum, the engine system operates at a minimum compression ratio. The limit value of the volume of the combustion chamber 4 can be limited by the stroke of the driving mechanism; during the sliding adjustment process of the piston mover 2, the shape of the end face used to enclose and form the combustion chamber 4 will not change, that is, the shape of the end face corresponding to the cylinder valve timing and fuel injection will not change, and the only change is that the entire combustion chamber 4 is lengthened or shortened, so that the shape of the entire combustion chamber 4 will not change significantly, which can ensure the normal formation of the mixture and high reliability, thereby helping to improve the cylinder combustion effect and thermal efficiency.

[0027] The end face shape of the piston mover 2 can be designed according to the actual required shape of the combustion chamber 4. In this embodiment, the end face of the piston mover 2 used to surround the combustion chamber 4 is designed to be high in the middle and low on all sides to cooperate with the piston sleeve 1 to form an ω-shaped combustion chamber. Under any compression ratio, the combustion chamber 4 always maintains the ω shape. When the entire piston moves to the top dead center, a squeeze flow can be formed to stabilize the mixed combustion gas.

[0028] The inner wall of the piston sleeve 1 corresponding to the combustion chamber 4 extends inward to form an annular blocking portion 5. The inner diameter of the blocking portion 5 is smaller than the diameter of the piston mover 2, thereby preventing the piston mover 2 from falling out. The annular blocking portion 5 can be used to cooperate with the end face of the piston mover 2 to form a combustion chamber with an ω-shaped cross-section.

[0029] In some embodiments, the driving mechanism includes a hydraulic cylinder body 6 and a hydraulic slider 7. The hydraulic cylinder body 6 is fixedly connected to the piston sleeve 1, and the hydraulic slider 7 is slidably arranged in the hydraulic cylinder body 6. The sliding direction of the hydraulic slider 7 is the same as the sliding direction of the piston mover 2. The hydraulic slider 7 divides the inner cavity of the hydraulic cylinder body 6 into a first cavity 8 and a second cavity 9. The first cavity 8 and the second cavity 9 are respectively connected to the hydraulic system through hydraulic oil circuits, wherein the first hydraulic oil circuit 10 corresponds to the first cavity 8, and the second hydraulic oil circuit 11 corresponds to the second cavity 9. The hydraulic slider 7 is connected to the piston mover 2 through a connecting member 12. The hydraulic cylinder body 6 and the hydraulic slider 7 actually form a hydraulic cylinder. The movement of the hydraulic slider 7 and the connecting member 12 is achieved by supplying oil to the first cavity 8 or the second cavity 9, thereby driving the piston mover 2 to move; in other embodiments, telescopic structures such as electric or pneumatic telescopic rods can also be selected as driving mechanisms to directly control the movement of the piston mover 2.

[0030] The connecting member 12 can be a round rod-shaped structure, and the end of the connecting member 12 close to the piston mover 2 is threaded or welded to the piston mover 2. The connecting member 12 can also be a square rod-shaped structure, and the end of the connecting member 12 close to the piston mover 2 is welded to the piston mover 2, so as to achieve sliding cooperation with the hydraulic cylinder body 6 and can be connected to the piston mover 2.

[0031] The hydraulic cylinder body 6 includes a base 13 and a hydraulic cover 14. The base 13 is opened at one end away from the piston mover 2. The hydraulic cover 14 is buckled into the opening of the base 13. Bolts pass through the hydraulic cover 14 and the base 13 in sequence and are threadedly connected to the piston sleeve 1.

[0032] In order to prevent the hydraulic slider 7 from moving to the extreme position and causing the first cavity 8 or the second cavity 9 to close, a first protrusion 15 is provided on the end surface of the hydraulic slider 7 corresponding to the first cavity 8, and a second protrusion 16 is provided on the end surface of the hydraulic slider 7 corresponding to the second cavity 9.

[0033] Among them, the second cavity 9 is set to be located on the side of the first cavity 8 away from the piston mover 2, and the end surface area of the second protrusion 16 away from the hydraulic slider 7 is smaller than the end surface area of the first protrusion 15 away from the hydraulic slider 7, ensuring that when the hydraulic slider 7 moves to the point where the second protrusion 16 contacts the wall of the hydraulic cylinder body 6, the second cavity 9 still has a larger hydraulic action area. The larger hydraulic action area can ensure that the pressure of the hydraulic oil can overcome the pressure of the combustion chamber 4 to realize the movement of the hydraulic slider 7; and when the first cavity 8 applies pressure to make the hydraulic slider 7 move in the direction away from the combustion chamber 4, there is no need to overcome the pressure of the combustion chamber 4, so the end surface area of the first protrusion 15 can be set to be larger than the end surface area of the second protrusion 16; in other embodiments, the end surface area of the first protrusion 15 can also be set to be equal to or smaller than the end surface area of the second protrusion 16, as long as it is ensured that the liquid pressure can overcome the pressure of the combustion chamber 4 to realize the movement of the hydraulic slider 7.

[0034] The first protrusion 15 and the second protrusion 16 are both integrally provided with the hydraulic slide 7 to improve the structural strength.

[0035] In some embodiments, at any point on the movement path of the piston mover 2, the hydraulic cylinder body 6 and the piston mover 2 are spaced apart to avoid large-area heat transfer between the hydraulic cylinder body 6 and the piston mover 2, effectively isolating the impact of high temperature on the hydraulic cylinder body 6 and improving its service life. In addition, during actual use, the oil splashing from below will also cool the bottom of the hydraulic cylinder body 6.

[0036] The hydraulic cylinder body 6 is coaxially arranged with the piston mover 2. The diameter of the hydraulic cylinder body 6 is larger than the diameter of the piston mover 2 so as to maximize the hydraulic action area in the second cavity 9. The cavity between the hydraulic cylinder body 6 and the piston mover 2 is connected to the external environment through the exhaust hole 17. While the cavity between the hydraulic cylinder body 6 and the piston mover 2 is connected to the external environment, heat can be dissipated to the outside world.

[0037] The connecting piece 12 may be provided to pass through both ends of the hydraulic cylinder body 6 along the axial direction of the hydraulic cylinder body 6 , and the exhaust hole 17 may be provided inside the connecting piece 12 , or the exhaust hole 17 may be directly provided on the hydraulic cylinder body 6 .

[0038] The connecting piece 12 needs to be slidably connected to the hydraulic cylinder body 6, and a sealing ring is provided at the sliding opening of the hydraulic cylinder body 6 for the connecting piece 12 to prevent oil leakage.

[0039] A piston gas ring 18 for sealing is provided between the outer peripheral wall of the piston mover 2 and the inner peripheral wall of the piston sleeve 1. Specifically, an annular groove can be opened on the outer peripheral wall of the piston mover 2 or the inner peripheral wall of the piston sleeve 1, and the piston gas ring 18 can be embedded in the annular groove.

[0040] During actual use, hydraulic oil is supplied to the first cavity 8 or the second cavity 9 through the hydraulic system, so that the hydraulic slider 7 slides in the hydraulic cylinder body 6, and then drives the piston mover 2 to slide axially in the piston sleeve 1 through the connecting piece 12, so as to change the volume of the combustion chamber 4 and realize a variable compression ratio.

[0041] The present invention also provides a cylinder using the variable compression ratio combined piston, comprising a cylinder body, wherein the piston in the cylinder body is a variable compression ratio combined piston.

[0042] Adaptive changes based on actual needs are all within the scope of protection of the present invention.

[0043] It should be noted that it will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the present invention is defined by the appended claims, not the foregoing description, and it is intended that all variations within the meaning and range of equivalents of the claims be encompassed within the present invention. Any reference signs in the claims should not be construed as limiting the claim to which they relate.

[0044] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A variable compression ratio combined piston, characterized in that: It includes a piston sleeve, a piston mover and a driving mechanism. The piston mover is arranged in the piston sleeve along the axial sliding direction of the piston sleeve. A combustion chamber is formed between one axial end of the piston mover and the piston sleeve, and the other axial end is connected to the driving mechanism. The driving direction of the driving mechanism is the same as the sliding direction of the piston mover.

2. The variable compression ratio combined piston according to claim 1, characterized in that: The driving mechanism includes a hydraulic cylinder body and a hydraulic slider. The hydraulic cylinder body is fixedly connected to the piston sleeve. The hydraulic slider is slidably arranged in the hydraulic cylinder body. The sliding direction of the hydraulic slider is the same as the sliding direction of the piston mover. The hydraulic slider divides the inner cavity of the hydraulic cylinder body into a first cavity and a second cavity. The first cavity and the second cavity are respectively connected to the hydraulic system through hydraulic oil circuits. The hydraulic slider is connected to the piston mover through a connecting piece.

3. The variable compression ratio combined piston according to claim 2, characterized in that: The end surface of the hydraulic sliding block corresponding to the first cavity is provided with a first protrusion, and the end surface of the hydraulic sliding block corresponding to the second cavity is provided with a second protrusion.

4. The variable compression ratio combined piston according to claim 3, characterized in that: The second cavity is located on a side of the first cavity away from the piston mover, and an end surface area of the second protrusion away from the hydraulic slider is smaller than an end surface area of the first protrusion away from the hydraulic slider.

5. The variable compression ratio combined piston according to claim 3, characterized in that: The first protrusion and the second protrusion are both integrally provided with the hydraulic slide.

6. The variable compression ratio combined piston according to claim 2, characterized in that: The hydraulic cylinder body and the piston mover are spaced apart.

7. The variable compression ratio combined piston according to claim 2, characterized in that: The hydraulic cylinder body and the piston mover are coaxially arranged, the diameter of the hydraulic cylinder body is larger than the diameter of the piston mover, and the cavity between the hydraulic cylinder body and the piston mover is connected to the external environment through an exhaust hole.

8. The variable compression ratio combined piston according to claim 7, characterized in that: The connecting member passes through both ends of the hydraulic cylinder body along the axial direction of the hydraulic cylinder body, and the exhaust hole is arranged inside the connecting member.

9. The variable compression ratio combined piston according to claim 1, characterized in that: A piston gas ring having a sealing function is arranged between the outer peripheral wall of the piston mover and the inner peripheral wall of the piston sleeve.

10. A cylinder, characterized in that: The variable compression ratio combined piston according to any one of claims 1 to 9 includes a cylinder body, and the piston in the cylinder body is the variable compression ratio combined piston.

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