Air flow organization form variable opposed piston two-stroke engine cylinder sleeve

Abstract

The invention relates to the technical field of opposed two-stroke engines, and discloses an opposed piston two-stroke engine cylinder sleeve with a variable airflow organization form, which comprises a main cylinder sleeve and an air inlet end cylinder sleeve which are mutually sleeved and connected, the main cylinder sleeve comprises a near air inlet embedding end and a near air outlet fixing end, a plurality of inner air inlets are annularly formed in the side wall of the near air inlet embedding end, a plurality of air outlets are annularly formed in the side wall of the near air outlet fixing end, the air inlet end cylinder sleeve comprises an extended fixing end and an embedding end, n layers of outer air inlets of different configurations are distributed in the embedding end of the air inlet end cylinder sleeve in the axial direction, n is larger than or equal to 2, and n is larger than or equal to 2. The inner air inlets correspond to the outer air inlets of different configurations, so that the airflow organization form of the air cylinder sleeve is changed. The air inlet angle can be changed, and the problems that the air distribution form in the cylinder is single, and proper adjustment is difficult to make according to actual conditions are solved.

Description

Technical Field

[0001] The invention relates to the technical field of opposed two-stroke engines, and more specifically to an opposed piston two-stroke engine cylinder liner with a variable airflow organization form. Background Art

[0002] The cylinder of the opposed-piston two-stroke engine is formed by two opposed pistons, which has the advantages of small specific mass, simple structure, high power, and high torque. At the same time, due to the cylinder head-free design, heat loss and friction loss are reduced, making the opposed-piston two-stroke engine have a higher thermal efficiency. In addition, due to the opposed layout of the pistons, its vibration is relatively small. Among them, the spark ignition type has a smaller mass, lower cost, and gentler operation than the compression ignition type, and is particularly suitable for land transportation and other fields.

[0003] The opposed piston two-stroke engine does not have a separate ventilation stroke. It relies on the reciprocating motion of the piston to open or close the intake and exhaust ports to complete the ventilation process. Since the ventilation duration is very short and the intake and exhaust processes are carried out simultaneously, it will cause the mixing of fresh charge and exhaust gas, resulting in a large residual exhaust gas coefficient in the cylinder and poor scavenging quality. There are several scavenging ports and exhaust ports on both ends of the cylinder sleeve of the opposed piston two-stroke engine, and most of them adopt the direct current scavenging form. During the upward stroke of the intake piston and the downward stroke of the exhaust piston, the exhaust port is often opened first for natural exhaust. As the intake piston continues to move upward, the intake port opens. This moment is the scavenging timing moment, and fresh air enters the cylinder for scavenging and ventilation processes. The intake piston continues to move upward, and the area of ​​the scavenging port opening gradually increases until the piston fully opens the scavenging port and reaches the top dead center of the intake piston and moves downward, gradually closing the intake port.

[0004] Therefore, for opposed piston two-stroke engines, the ventilation process is a crucial part, which determines the quality of fresh gas that can enter the cylinder, and thus affects the entire cycle of the engine. The ventilation process is the focus and difficulty of two-stroke engine research. Well-organized in-cylinder gas flow plays an important role in driving away the exhaust gas in the cylinder and improving combustion efficiency. In traditional cylinder liners, the size parameters of the air intake port are fixed, so the intake angle is also immutable, and the in-cylinder airflow organization form is single, which makes it difficult to make appropriate adjustments according to actual conditions so that the engine can achieve the required power, economy and emissions. Summary of the invention

[0005] In view of this, the present invention provides an opposed-piston two-stroke engine cylinder liner with a variable airflow organization form, which can change the intake angle and solve the problem that the airflow organization form in the cylinder is single and difficult to make appropriate adjustments according to actual conditions.

[0006] To achieve the above-mentioned purpose, the present invention provides an opposed-piston two-stroke engine cylinder liner with a variable airflow organization form, comprising a main cylinder liner and an intake end cylinder liner which are sleeved and connected to each other, the main cylinder liner comprising a mating end near the inlet port and a fixed end near the exhaust port, a plurality of inner inlets are arranged on the side wall of the mating end near the inlet port, a plurality of exhaust ports are arranged on the side wall of the fixed end near the exhaust port, the intake end cylinder liner comprises an extended fixed end and a mating end, and n layers of external inlets of different configurations are distributed axially on the mating end of the inlet end cylinder liner, wherein n≥2, and the internal inlets correspond to the external inlets of different configurations respectively to change the airflow organization form in the cylinder liner.

[0007] Preferably, the outer wall of the mating end near the air inlet has a plurality of axial flat key grooves evenly distributed along the circumferential direction, and the inner wall of the mating end has a plurality of axial flat keys evenly distributed along the circumferential direction, and the flat keys are matched with the flat key grooves.

[0008] Preferably, the n layers of outer air inlets on the mating end are at least two of the following: a basic air inlet, a high swirl ratio air inlet and a high tumble ratio scavenging air inlet.

[0009] Preferably, it also includes an electric control device, which is connected to the extended fixed end of the cylinder liner at the intake end, and drives the cylinder liner at the intake end to move axially, so that the positions of external air inlets of different configurations correspond to the positions of the internal air inlets on the main cylinder liner.

[0010] Preferably, the power control device includes a linear stepper motor, a driver and a controller, the linear stepper motor is connected to the extended fixed end of the cylinder sleeve at the intake end, the controller is electrically connected to the driver to convert user instructions into pulse signals and transmit them to the driver, and the driver is electrically connected to the linear stepper motor to convert the pulse signals into angular displacements and transmit them to the linear stepper motor.

[0011] Preferably, there are two linear stepper motors, which are symmetrically placed and connected at the extended fixed end of the cylinder sleeve at the air intake end with the diameter as the symmetry axis.

[0012] Preferably, the two linear stepper motors are respectively connected to a first displacement sensor and a second displacement sensor, and the first displacement sensor and the second displacement sensor are used to respectively detect the displacement amounts of the two linear stepper motors so that the displacement amounts of the two linear stepper motors are the same.

[0013] Preferably, the linear stepper motor, driver and controller are all electrically connected to a DC power supply.

[0014] It can be seen from the above technical solutions that, compared with the prior art, the opposed piston two-stroke engine cylinder liner with a variable airflow organization provided by the present invention has the following beneficial effects: (1) The structure of the main cylinder liner and the intake end cylinder liner divides the cylinder liner of the opposed piston two-stroke engine into two parts. The interlocking structure can make the inner air inlet match different outer air inlets through the relative up and down movement of the main cylinder liner and the intake end cylinder liner, thereby changing the airflow organization form in the cylinder; (2) The flat key and flat keyway structure facilitates the engagement between the main cylinder liner and the intake end cylinder liner, limits the circumferential rotation of the intake end cylinder liner, and realizes relatively stable axial translation between the two parts of the cylinder liner; (3) The setting of the electric control device can drive the cylinder sleeve at the intake end to move up and down to adjust the matching of different external intake ports with the internal intake ports, thereby changing the intake angle, so that the air flow organization form in the cylinder can be appropriately adjusted according to the actual working conditions, so that the engine can achieve the required power, economy and emission performance; (4) Setting of displacement sensors, controlling the displacement of each linear stepper motor according to the displacement sensor, ensuring accurate matching of the inner and outer air inlets and ensuring synchronous operation of each linear stepper motor; (5) The controller and driver are configured to send control signals according to user instructions, convert and transmit signals, change the matching of internal and external air inlets according to requirements, and thus change the airflow organization form in the cylinder. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0016] Figure 1 It is a schematic diagram of the assembly structure of the cylinder liner of the opposed piston two-stroke engine with a variable airflow organization form of the present invention; Figure 2 It is a schematic diagram of the exploded structure of the cylinder liner of the opposed piston two-stroke engine with a variable airflow organization form of the present invention; Figure 3 A schematic diagram of the gas port coordination of the cylinder liner of an opposed piston two-stroke engine with a variable airflow organization form of the present invention; Figure 4 For the present invention Figure 3 Look at the structural diagram; Figure 5 For the present invention Figure 4 Schematic diagram of the cross-sectional structure of the EE section; Figure 6 For the present invention Figure 5 Schematic diagram of the cross-sectional structure of the cylinder liner at the intake end of the middle DD section; Figure 7 The figure is a schematic diagram of the working principle of the electric control device in the cylinder liner of an opposed-piston two-stroke engine with a variable airflow organization form of the present invention.

[0017] Description of reference numerals: 1-main cylinder sleeve; 11-fixed end near exhaust port; 12-fitting end near air inlet; 13-flat keyway; 14-inner air inlet; 15-exhaust port; 2-intake end cylinder sleeve; 21-extended fixed end; 22-fitting end; 23-flat key; 24-basic intake port; 25-high swirl ratio intake port; 26-high tumble ratio scavenging port; 3-power control device; 31-linear stepping motor; 32-DC power supply; 33-driver; 34-controller; 331-first displacement sensor; 332-second displacement sensor. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of an exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] Please see attached Figure 1-7 , is an opposed-piston two-stroke engine cylinder liner with a variable airflow organization form disclosed in the present invention.

[0020] As shown in the figure, the opposed-piston two-stroke engine cylinder liner with a variable airflow organization form provided by the present invention includes a main cylinder liner 1, an intake end cylinder liner 2 and an electric control device 3, and the main cylinder liner 1 and the intake end cylinder liner 2 are sleeved and connected with each other.

[0021] like Figure 2 As shown, the main cylinder sleeve 1 includes a fixed end 12 near the exhaust port and a mating end 11 near the air inlet port, a plurality of inner air inlets 14 are provided on the mating end 11 near the air inlet port, and the plurality of inner air inlets 14 are circumferentially arranged along the side wall of the mating end 11 near the air inlet port, a plurality of axial flat key grooves 13 are provided on the outer wall of the mating end 11 near the air inlet port, and the plurality of flat key grooves 13 are evenly distributed along the circumference of the mating end 11 near the air inlet port, and preferably 4 flat key grooves 13 are provided; a plurality of exhaust ports 15 are provided on the fixed end 12 near the exhaust port, and the plurality of exhaust ports 15 are circumferentially arranged along the side wall of the fixed end 12 near the exhaust port.

[0022] It should be noted that the air inlet height h, air inlet width w, air inlet inclination angle α and air inlet elevation angle β of the inner air inlet 14 are all basic design values, and the air inlet inclination angle α and air inlet elevation angle β can be set according to working conditions.

[0023] The intake end cylinder sleeve 2 includes an extended fixed end 21 and an engaging end 22. The inner wall of the engaging end 22 is provided with a plurality of axial flat keys 23. The plurality of flat keys 23 are evenly arranged along the circumference of the inner wall of the engaging end 22 and are adapted to the flat key grooves 13. Preferably, there are also four flat keys 23. The positions of the flat keys 23 and the flat key grooves 13 correspond for matching assembly. The cooperation between the flat keys 23 and the flat key grooves 13 facilitates the engagement of the main cylinder sleeve 1 and the intake end cylinder sleeve 2, limits the circumferential rotation between the two, and provides guidance for axial translation.

[0024] The mating end 22 of the cylinder sleeve 2 at the air intake end is distributed with n (n≥2) layers of external air intake ports of different configurations, and the n layers of external air intake ports of different configurations are arranged equidistantly along the axial direction of the mating end 22, such as Figure 2-3 As shown, the n layers of external air inlets of different configurations include but are not limited to basic air inlets 24 , high swirl ratio air inlets 25 and high tumble ratio scavenging air inlets 26 .

[0025] like Figure 4-6 As shown, the outer air inlets of different configurations correspond to the inner air inlet 14 respectively, so as to change the air flow organization form of the cylinder liner.

[0026] Specifically, when the basic air intake port 24 is matched with the inner air intake port 14, the air flow organization form in the cylinder can meet the emission and economy requirements under rated operating conditions; when the high swirl ratio air intake port 25 is matched with the inner air intake port 14, the swirl structure in the air flow organization form in the cylinder is enhanced, which can appropriately improve the thermal efficiency and further improve the economy; when the high tumble ratio air intake port 26 is matched with the inner air intake port 14, the tumble structure in the air flow organization form in the cylinder is enhanced, which promotes the mixing of fuel and fresh air, improves combustion efficiency, and improves working stability under low load conditions.

[0027] like Figure 7 As shown, the electric control device 3 is connected to the extended fixed end 21 of the intake end cylinder sleeve 2, driving the intake end cylinder sleeve 2 to move axially so that different external air ports can coincide with the internal air inlet 14 on the main cylinder sleeve 1.

[0028] Specifically, the power control device 3 includes: a linear stepper motor 31, a DC power supply 32, a driver 33, a controller 34, a first displacement sensor 331 and a second displacement sensor 332. The linear stepper motor 31 is provided with m (m>1) linear stepper motors 31, and the m linear stepper motors 31 are fixedly connected to the extended fixed end 21 of the intake end cylinder sleeve 2. The extended fixed end 21 is extended on the length of the basic intake end cylinder sleeve 2 to connect the linear stepper motor 31. The m linear stepper motors 31 are evenly distributed in the circumferential direction of the intake end cylinder sleeve 2.

[0029] In this embodiment, there are two linear stepper motors 31, which are respectively connected to the extended fixed end 21 of the cylinder sleeve 2 at the air intake end, and the two linear stepper motors 31 are symmetrically placed and connected at the extended fixed end 21 of the cylinder sleeve 2 at the air intake end with the diameter as the symmetry axis; the linear stepper motor 31, the driver 33, and the controller 34 are all electrically connected to the DC power supply 32, and the DC power supply 32 provides energy for the power control device 3; the controller 33 is electrically connected to the driver 34, and converts the user's instructions into pulse signals and transmits them to the driver 34; the driver 34 is electrically connected to the linear stepper motor 31, and converts the pulse signals into angular displacement and transmits them to the linear stepper motor 31; the first displacement sensor 331 and the second displacement sensor 332 are connected to the linear stepper motor 31 to detect the displacement of each linear stepper motor 31 to ensure that the displacement of each linear stepper motor 31 is the same.

[0030] So far, the embodiments of the present disclosure have been described in detail in conjunction with the accompanying drawings. It should be noted that the implementation methods not shown or described in the drawings or the body of the specification are all forms known to ordinary technicians in the relevant technical field and are not described in detail. In addition, the above definitions of each element and method are not limited to the various specific structures, shapes or methods mentioned in the embodiments, and ordinary technicians in the field can simply change or replace them.

[0031] In summary, the opposed-piston two-stroke engine cylinder liner with a variable airflow organization form provided by the present invention divides the existing opposed-piston two-stroke engine cylinder liner at the intake end into two parts, namely the main cylinder liner 1 and the intake end cylinder liner 2, which are interlocked through the flat key 23 and the flat key groove 13 structure, and the intake end cylinder liner 2 is driven up and down by the electric control device 3, so that the selection of air ports with different structural designs can adapt to actual working conditions, so that the engine can achieve the required power, economy and emission.

[0032] It should also be noted that the directional terms mentioned in the embodiments, such as "upper", "lower", "front", "back", "left", "right", etc., are only reference directions of the drawings and are not intended to limit the scope of protection of the present disclosure. Throughout the drawings, the same elements are represented by the same or similar reference numerals. Conventional structures or configurations will be omitted when they may cause confusion in the understanding of the present disclosure.

[0033] Moreover, the shapes and sizes of the components in the figures do not reflect the real size and proportion, but only illustrate the contents of the embodiments of the present disclosure. In addition, in the claims, any reference symbols between brackets shall not be constructed as limiting the claims.

[0034] Unless otherwise indicated, the numerical parameters in this specification and the appended claims are approximate values ​​and can vary according to the desired properties obtained through the content of the present disclosure. Specifically, all numbers used in the specification and claims to express the content of the composition, reaction conditions, etc., should be understood to be modified by the term "about" in all cases. In general, the meaning of the expression is to include a variation of ±10% in some embodiments, ±5% in some embodiments, ±1% in some embodiments, and ±0.5% in some embodiments by a specific number.

[0035] Furthermore, the word "comprising" does not exclude the presence of elements or steps not listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.

[0036] The ordinal numbers used in the specification and claims, such as "first", "second", "third", etc., to modify the corresponding elements, do not themselves mean that the elements have any ordinal numbers, nor do they represent the order of one element and another element, or the order in the manufacturing method. The use of these ordinal numbers is only used to clearly distinguish a component with a certain name from another component with the same name.

[0037] Similarly, it should be understood that in order to streamline the present disclosure and aid in understanding one or more of the various disclosed aspects, in the above description of the exemplary embodiments of the present disclosure, the various features of the present disclosure are sometimes grouped together into a single embodiment, figure, or description thereof. However, this disclosed method should not be interpreted as reflecting the following intention: the claimed disclosure requires more features than the features explicitly recited in each claim. More specifically, as reflected in the claims below, the disclosed aspects are less than all the features of the single embodiment disclosed above. Therefore, the claims that follow the specific embodiment are hereby expressly incorporated into the specific embodiment, with each claim itself serving as a separate embodiment of the present disclosure.

[0038] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present disclosure. It should be understood that the above description is only a specific embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure should be included in the protection scope of the present disclosure.

Claims

1. An opposed piston two-stroke engine cylinder liner with a variable airflow organization, characterized in that: The invention comprises a main cylinder sleeve (1) and an intake end cylinder sleeve (2) which are sleeved and connected to each other, wherein the main cylinder sleeve (1) comprises a mating end (11) near the intake port and a fixed end (12) near the exhaust port, a plurality of inner intake ports (14) are arranged on the side wall of the mating end (11) near the intake port, and a plurality of exhaust ports (15) are arranged on the side wall of the fixed end (12) near the exhaust port, and the intake end cylinder sleeve (2) comprises an extended fixed end (21) and a mating end (22), and n layers of outer intake ports of different configurations are distributed axially on the mating end (22) of the intake end cylinder sleeve (2), wherein n≥2, and the inner intake ports (14) correspond to the outer intake ports of different configurations respectively, so as to change the airflow organization form of the cylinder sleeve.

2. The opposed piston two-stroke engine cylinder liner with variable airflow organization according to claim 1, characterized in that: The outer wall of the mating end (11) near the air inlet is uniformly provided with a plurality of axial flat key grooves (12) along the circumferential direction, and the inner wall of the mating end (22) is uniformly provided with a plurality of axial flat keys (23) along the circumferential direction, wherein the flat keys (23) are adapted to the flat key grooves (12).

3. The opposed-piston two-stroke engine cylinder liner with a variable airflow organization according to claim 1, characterized in that: The n layers of outer air inlets on the mating end (22) are at least two of a basic air inlet (24), a high swirl ratio air inlet (25) and a high tumble ratio scavenging air inlet (26).

4. The opposed-piston two-stroke engine cylinder liner with a variable airflow organization according to claim 1, characterized in that: It also includes an electric control device (3), the electric control device (3) being connected to the extended fixed end (21) of the intake end cylinder sleeve (2), the electric control device (3) driving the intake end cylinder sleeve (2) to move axially, so that the positions of the external intake ports of different configurations correspond to the internal intake ports (14) on the main cylinder sleeve (1).

5. The opposed-piston two-stroke engine cylinder liner with a variable airflow organization according to claim 4, characterized in that: The power control device (3) comprises a linear stepping motor (31), a driver (33) and a controller (34); the linear stepping motor (31) is connected to the extended fixed end (21) of the cylinder sleeve (2) at the air intake end; the controller (33) is electrically connected to the driver (34) to convert a user instruction into a pulse signal and transmit it to the driver (34); the driver (34) is electrically connected to the linear stepping motor (31) to convert the pulse signal into an angular displacement and transmit it to the linear stepping motor (31).

6. The opposed-piston two-stroke engine cylinder liner with a variable airflow organization according to claim 5, characterized in that: There are two linear stepper motors (31), and the two linear stepper motors (31) are symmetrically placed and connected at the extended fixed end (21) of the cylinder sleeve (2) at the air intake end, with the diameter as the symmetry axis.

7. The opposed-piston two-stroke engine cylinder liner with a variable airflow organization according to claim 6, characterized in that: The two linear stepper motors (31) are respectively connected to a first displacement sensor (331) and a second displacement sensor (332); the first displacement sensor (331) and the second displacement sensor (332) are used to respectively detect the displacement amounts of the two linear stepper motors (31) so that the displacement amounts of the two linear stepper motors (31) are the same.

8. The opposed-piston two-stroke engine cylinder liner with a variable airflow organization according to claim 5, characterized in that: The linear stepping motor (31), the driver (33), and the controller (34) are all electrically connected to the direct current power supply (32).

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