Piston, combustion system and engine
By designing a symmetrical arrangement and shape optimization of combustion pits and injectors in an opposed piston engine, the problem of poor combustion caused by uneven fuel injection was solved, achieving more efficient combustion and thermal energy utilization.
Patent Information
- Application Number
- CN202520316524.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-26
- Publication Date
- 2025-11-21
- Estimated Expiration
- 2035-02-26
AI Technical Summary
In the existing combustion chamber structure of opposed piston engines, the opposite injection of fuel by fuel injectors results in localized areas that are either too rich or too lean, leading to poor combustion and limited thermal efficiency.
The piston's combustion pits are arranged symmetrically around the central axis by 180° rotation and extend circumferentially. The injectors are set in correspondence with the combustion pits. The cross-sectional area of the combustion pits gradually increases, and the shape design conforms to the flame development pattern. The included angle of the injection port is controlled within 15°≤α≤45°.
It improves combustion efficiency and thermal efficiency, reduces areas of excessively rich or lean fuel, decreases the probability of flame collision, protects the piston top surface, and enhances air utilization.
Smart Images
Figure CN223578056U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the technical field of engine, especially a piston, combustion system and engine. BACKGROUND
[0002] In order to alleviate energy crisis and environmental pollution, it is imperative to improve thermal efficiency and reduce emissions, for this, the prior art proposes an opposed piston engine, specifically, the combustion chamber structure of the opposed piston engine includes a cylinder liner, and two pistons axially movably arranged in the cylinder liner and axially distributed, the center of the piston is provided with a central pit, two tapered pits are arranged on the opposite sides of the central pit, two fuel injectors correspondingly spray fuel into the central pit through the two tapered pits, and the central pit is used as a main combustion chamber for fuel diffusion and combustion.
[0003] The two fuel injectors are installed 180 degrees apart from the cylinder liner, and the sprayed fuel of the two fuel injectors moves towards each other, collides in the combustion chamber to form local over-concentration area and local over-dilution area, and the fuel cannot be fully diffused in the combustion chamber, so the combustion effect is poor and the thermal efficiency is limited. SUMMARY
[0004] The utility model discloses a kind of pistons, combustion system and engine, which can improve combustion effect and thermal efficiency of combustion system.
[0005] To achieve this purpose, the utility model adopts the following technical solutions:
[0006] Piston, including piston body, the piston body has top surface, the top surface is equipped with two combustion pits, two the combustion pit is arranged around the central axis of the piston body 180 ° rotation symmetry, two the combustion pit is spaced apart, and the combustion pit extends around the circumference of the piston body;
[0007] One end of the combustion pit extends to the outer peripheral wall of the piston body to form an incident port, and the central angle of each combustion pit corresponding to the two end edges along the circumferential direction of the piston body is greater than 180 °.
[0008] As one of the above-mentioned embodiments of the piston, the cross-sectional area of the combustion pit gradually increases along the circumferential direction of the piston body from one end of the incident port to the other end of the combustion pit.
[0009] As one of the above-mentioned embodiments of the piston, the projection of the extension axis of the combustion pit in the plane perpendicular to the axial direction of the piston body is a first projection, the first projection includes a first circular arc, a second circular arc and a third circular arc which are sequentially smooth and connected and have decreasing radii, and the first circular arc and the incident port are located at the same end of the combustion pit.
[0010] As an implementable solution of the above-mentioned piston, the radius of the first circular arc is r1, and r1≤D / 2, where D represents the diameter of the cylinder.
[0011] As an implementable solution of the above-mentioned piston, the intersection line of the combustion pit and the top surface comprises an inner curve, an outer curve and a fourth circular arc, the inner curve is closer to the central axis of the piston body than the outer curve, and the end of the inner curve away from the injection port is smoothly connected with the end of the outer curve away from the injection port through the fourth circular arc.
[0012] As an implementable solution of the above-mentioned piston, the maximum width of the combustion pit along the radial direction of the piston body is X, and d1X≤D / 2, where D represents the diameter of the cylinder, and d1 represents the radius of the injection end of the injector.
[0013] The maximum depth of the combustion pit along the axial direction of the piston body is Y, and Y≤X / 2.
[0014] As an implementable solution of the above-mentioned piston, the cross section of the combustion pit is semi-elliptical.
[0015] In order to achieve the above-mentioned purpose, the utility model still provides a kind of combustion system, including cylinder sleeve and the piston as any of the above solutions, the piston hole is equipped in the cylinder sleeve, two the piston movable along its axial direction is equipped in the piston hole, the top surface of two the piston is oppositely arranged along the axial direction of the piston, and the inner peripheral wall of the piston hole between two the piston and two the piston is surrounded to form combustion chamber.
[0016] The combustion system further comprises two injectors, which are arranged between the two pistons along the axial direction of the pistons, and the two injectors are arranged one-to-one corresponding to the two combustion pits of each piston, and the injectors are used to inject fuel into the combustion chamber.
[0017] As an implementable solution of the above-mentioned combustion system, the projection of the extension axis of the combustion pit in the plane perpendicular to the axial direction of the piston body is a first projection, the first projection intersects with the outer peripheral wall of the piston body at point A, the included angle between the connecting line of the two A points and the extension axis of any first projection is α, and 15°≤α≤45°.
[0018] In order to achieve the above-mentioned purpose, the utility model further provides an engine comprising the combustion system according to any of the above solutions.
[0019] The utility model has the advantages of:
[0020] The piston, the combustion system and the engine provided by the utility model, two combustion pits are arranged in 180° rotation symmetry around the central axis of the piston body, and the combustion pits extend around the circumference of the piston body, and the central angle corresponding to the two end edges of each combustion pit along the circumference of the piston body is greater than 180°, so that the combustion pits are distributed on the whole circumferential direction of the piston body, the length of the single combustion pit extending around itself is prolonged, the path of fuel circulating in the single combustion pit is prolonged, fuel is fully diffused in the combustion pit, the area of fuel being too thick or too thin in the combustion pit is greatly reduced, the combustion of fuel is basically carried out in the combustion pit, and the two combustion pits are arranged at intervals, the probability of flame collision in the two combustion pits is greatly reduced, the top surface of the piston body is favorably protected, and the combustion efficiency is improved. BRIEF DESCRIPTION OF DRAWINGS
[0021] Figure 1 is the first schematic view of the piston provided by the utility model embodiment, viewed from the top surface of the piston body to the other end of the piston body;
[0022] Figure 2 is the second schematic view of the piston provided by the utility model embodiment, viewed from the top surface of the piston body to the other end of the piston body;
[0023] Figure 3 is the third schematic view of the piston provided by the utility model embodiment, viewed from the top surface of the piston body to the other end of the piston body;
[0024] Figure 4 is Figure 3 is the sectional view of B-B direction in the utility model embodiment;
[0025] Figure 5 is Figure 4 is the local enlarged schematic view of M in the utility model embodiment.
[0026] In the drawings:
[0027] 100, piston body; 110, top surface; 120, combustion pit; 121, incident port;
[0028] 10, first arc; 20, second arc; 30, third arc; 40, inner curve; 50, outer curve; 60, fourth arc. DETAILED DESCRIPTION
[0029] The utility model will be further described in detail in combination with the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the utility model, and not limit the utility model. In addition, it should be noted that, in order to facilitate the description, only the part related to the utility model is shown in the drawings, not all structures.
[0030] In the description of the utility model, unless another definite provision and limitation, the term "link", "connect", "fix" should do broad sense understanding, for example, can be fixed connection, also can be detachable connection, or be integrated;Can be mechanical connection, also can be electrical connection;Can be direct connection, also can through the indirect connection of intermediate medium, can be the communication of two elements or the interaction of two elements.For the ordinary skilled in the art, the specific meaning of the above-mentioned terms in the utility model can be understood according to the specific circumstances.
[0031] In the utility model, unless another definite provision and limitation, the first feature is "on" or "under" the second feature can include that the first and second features are in direct contact, or the first and second features are not in direct contact but are in contact through another feature between them.Moreover, the first feature "on", "above" and "above" the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature.The first feature "under", "below" and "below" the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.
[0032] In the description of the embodiment, the terms "up", "down", "right", etc.Orientations or positional relationships are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the utility model.In addition, the terms "first" and "second" are only used to distinguish in the description, and have no special meaning.
[0033] The embodiment of the utility model provides a kind of piston, combustion system comprising the piston and engine comprising the combustion system to improve combustion effect and heat efficiency of combustion system.
[0034] Wherein, the combustion system further includes cylinder sleeve and injector, the cylinder sleeve is provided with piston hole, and two pistons movable along the axial direction are arranged in the piston hole, as shown in Figure 1 And Figure 2 As shown, the piston includes piston body 100, the piston body 100 has top surface 110, the top surface 110 of the two pistons is oppositely arranged along the axial direction of the piston, and the two pistons and the inner circumferential wall between the two pistons form a combustion chamber.
[0035] The top surface 110 is provided with two combustion pits 120, which are arranged in 180° rotational symmetry around the central axis of the piston body 100, are arranged at intervals, and extend around the circumference of the piston body 100. One end of the combustion pit 120 extends to the outer circumferential wall of the piston body 100 to form an incident port 121. The central angle of each combustion pit 120 corresponding to the two end edges in the circumferential direction of the piston body 100 is greater than 180°.
[0036] The combustion system further comprises two injectors arranged between the two pistons in the axial direction of the piston, and each of the two injectors is arranged corresponding to the two combustion pits 120 of each piston. The injectors are used to inject fuel into the combustion chamber. Exemplarily, the two injectors are arranged in 180° rotational symmetry around the central axis of the piston body 100, and the projections of the two combustion pits 120 corresponding to the same injector on a plane perpendicular to the axial direction of the piston body 100 completely coincide. The projection of the injection end of the injector on the plane where the top surface 110 is located is an injection projection, which is located within the projection of the corresponding combustion pit 120 on the plane where the top surface 110 is located.
[0037] Figure 2 The positions indicated by the two black squares are the mounting positions of the injectors, Figure 2 The two dashed arrows shown in the figure indicate the flow direction of the airflow in the combustion chamber.
[0038] The two combustion pits 120 are arranged in 180° rotational symmetry around the central axis of the piston body 100, extend around the circumference of the piston body 100, and the central angle of each combustion pit 120 corresponding to the two end edges in the circumferential direction of the piston body 100 is greater than 180°, so that the combustion pits 120 are distributed in the entire circumferential direction of the piston body 100, the length of the single combustion pit 120 extending in the direction thereof is elongated, the path of the fuel flowing in the single combustion pit 120 is elongated, the fuel is fully diffused in the combustion pit 120, the area where the fuel is too concentrated or too dilute in the combustion pit 120 is greatly reduced, the combustion of the fuel is basically carried out in the combustion pit 120, and the two combustion pits 120 are arranged at intervals, which greatly reduces the probability of flame collision in the two combustion pits 120, is beneficial to protect the top surface 110 of the piston body 100, and improves the combustion efficiency.
[0039] In some embodiments, as Figure 1As shown, the projection of the extension axis of the combustion pit 120 in the plane perpendicular to the axial direction of the piston body 100 is a first projection, and the first projection includes a first circular arc 10, a second circular arc 20 and a third circular arc 30 which are sequentially smoothly connected and have radii decreasing in turn, and the first circular arc 10 and the incident port 121 are located at the same end of the combustion pit 120. Specifically, the end of the first circular arc 10 away from the incident port 121 is tangent to one end of the second circular arc 20, and the other end of the second circular arc 20 is tangent to one end of the third circular arc 30.
[0040] In this way, on the basis of ensuring that the two combustion pits 120 are arranged at intervals, the central angle corresponding to the two end edges of each combustion pit 120 in the circumferential direction of the piston body 100 is greater than 180°, so that the combustion pits 120 are distributed in the entire circumferential direction of the piston body 100, thereby prolonging the length of the single combustion pit 120 in the extension direction thereof, prolonging the path of fuel flowing in the single combustion pit 120, and making the shape of the combustion pit 120 more consistent with the development of the flame, facilitating the fuel to fully diffuse in the combustion pit 120, improving the air utilization rate in the combustion chamber, and facilitating the fuel to burn substantially in the combustion pit 120, reducing the contact between the flame and the top surface 110 of the piston body 100, reducing heat transfer, and protecting the piston.
[0041] In some embodiments, as shown, Figure 1 As shown, from the direction in which the incident port 121 of the combustion pit 120 is arranged from one end to the other end, the cross-sectional area of the combustion pit 120 gradually increases in the circumferential direction of the piston body 100.
[0042] In this way, not only can the central angle corresponding to the two end edges of each combustion pit 120 in the circumferential direction of the piston body 100 be greater than 180° on the basis of ensuring that the two combustion pits 120 are arranged at intervals, so that the combustion pits 120 are distributed in the entire circumferential direction of the piston body 100, but also the shape of the combustion pit 120 is more consistent with the development of the flame under the action of the vortex, facilitating the fuel to fully diffuse in the combustion pit 120, improving the air utilization rate in the combustion chamber. Exemplarily, the projection of the combustion pit 120 perpendicular to the axial direction of the piston body 100 is roughly horn-shaped.
[0043] Specifically, from the direction in which the incident port 121 of the combustion pit 120 is arranged from one end to the other end, the width of the combustion pit 120 gradually increases, and the depth of the combustion pit 120 gradually increases.
[0044] This configuration ensures that the cross-sectional area of the combustion pit 120 gradually increases circumferentially along the piston body 100 from one end of the combustion pit 120 to the other, making the shape of the combustion pit 120 more consistent with the development of the flame under the action of vortex. This facilitates the full diffusion of fuel during its flow within the combustion pit 120. Furthermore, the flame stops moving forward after hitting the inner wall at the end of the combustion pit 120, resulting in the maximum depth at the end of the combustion pit 120. This design also helps reduce the probability of the flame being rolled out of the combustion pit 120 by the action of the inner wall.
[0045] For example, the cross-section of the combustion pit 120 is semi-elliptical. Specifically, the major axis of the ellipse is in the direction of the width of the groove in the combustion pit 120, and the minor axis of the ellipse is in the direction of the depth of the combustion pit 120. In other embodiments, the cross-section of the combustion pit 120 may also be semi-circular.
[0046] In some embodiments, such as Figure 1 As shown, the radius of the first arc 10 is r1, r1≤D / 2, where D represents the diameter of the cylinder.
[0047] This configuration allows the end of the combustion pit 120 that is away from the injection port 121 to be closer to the injection port 121 of the other combustion pit 120, and it does not connect with the injection port 121 of the other combustion pit 120, thus avoiding the problem of flame collision when the two combustion pits 120 connect.
[0048] In some embodiments, the intersection line between the combustion pit 120 and the top surface 110 includes an inner curve 40, an outer curve 50 and a fourth arc 60. The inner curve 40 is closer to the central axis of the piston body 100 than the outer curve 50. The end of the inner curve 40 away from the injection port 121 is smoothly connected to the end of the outer curve 50 away from the injection port 121 through the fourth arc 60.
[0049] This design helps to make the end of the combustion pit 120 that is far away from the injection port 121 more in line with the development pattern of the flame under the action of vortex, which is conducive to the full diffusion of fuel in the combustion pit 120 and improves the air utilization rate in the combustion chamber.
[0050] In some embodiments, such as Figures 3 to 5 As shown, the maximum width of the combustion recess 120 along the radial direction of the piston body 100 is X, d1 < X ≤ D / 2, where D represents the diameter of the cylinder and d1 represents the radius of the injector's injection end; the maximum depth of the combustion recess 120 along the axial direction of the piston body 100 is Y, Y ≤ X / 2. This design helps ensure the installability of the injector's injection end.
[0051] It should be noted that the width of the entry port 121 and the depth of the entry port 121 along the axial direction of the piston body 100 are related to the size of the injection end of the injector, and are not specifically defined here.
[0052] In some embodiments, as shown in Figure 3 and Figure 4 The projection of the extension axis of the combustion pit 120 in the plane perpendicular to the axial direction of the piston body 100 is a first projection, the first projection intersects the outer peripheral wall of the piston body 100 at point A, and the angle between the line connecting the two A points and the extension axis of any first projection is α, 15°≤α≤45°.
[0053] If the angle α is too small, such as less than 15°, the fuel will be injected onto the center boss between the two combustion pits 120, and if the angle α is too large, such as greater than 45°, the fuel will be injected to the side of the combustion pit 120 away from the center axis of the piston body 100, resulting in wet wall of the cylinder liner.
[0054] For different types of engines, the angle α can be determined according to the intensity of the in-cylinder vortex and the simulation results, and the specific value of the angle α is not specifically defined here.
[0055] Obviously, the above embodiments of the present application are only examples for clearly illustrating the present application, and are not a limitation on the embodiments of the present application. For those skilled in the art, various obvious changes, re-adjustments and substitutions can be made without departing from the scope of the present application. Here, it is not necessary and impossible to exhaust all the embodiments. Any modification, equivalent substitution and improvement made within the spirit and principle of the present application shall be included in the protection scope of the claims of the present application.
Claims
1. A piston, characterized in that, The piston body (100) includes a piston body (100) having a top surface (110) and two combustion pits (120) provided on the top surface (110). The two combustion pits (120) are arranged symmetrically about the central axis of the piston body (100) at 180°, and the two combustion pits (120) are spaced apart. The combustion pits (120) extend circumferentially around the piston body (100). One end of the combustion pit (120) extends to the outer peripheral wall of the piston body (100) to form an injection port (121), and the central angle corresponding to the two ends of each combustion pit (120) along the circumference of the piston body (100) is greater than 180°.
2. The piston according to claim 1, characterized in that, The combustion pit (120) forms the direction from one end of the injection port (121) to the other end, and the cross-sectional area of the combustion pit (120) gradually increases along the circumference of the piston body (100).
3. The piston according to claim 1, characterized in that, The projection of the extension axis of the combustion pit (120) onto a plane perpendicular to the axial direction of the piston body (100) is the first projection. The first projection includes a first arc (10), a second arc (20), and a third arc (30) that are smoothly connected in sequence and whose radii decrease in sequence. The first arc (10) and the injection port (121) are located at the same end of the combustion pit (120).
4. The piston according to claim 3, characterized in that, The radius of the first arc (10) is r1, r1≤D / 2, where D represents the diameter of the cylinder.
5. The piston according to claim 1, characterized in that, The intersection line between the combustion pit (120) and the top surface (110) includes an inner curve (40), an outer curve (50) and a fourth arc (60). The inner curve (40) is closer to the central axis of the piston body (100) than the outer curve (50). The end of the inner curve (40) away from the injection port (121) is smoothly connected to the end of the outer curve (50) away from the injection port (121) through the fourth arc (60).
6. The piston according to any one of claims 1 to 5, characterized in that, The maximum width of the combustion pit (120) along the radial direction of the piston body (100) is X, d1 < X ≤ D / 2, where D represents the diameter of the cylinder and d1 represents the radius of the injection end of the injector; the maximum depth of the combustion pit (120) along the axial direction of the piston body (100) is Y, where Y ≤ X / 2.
7. The piston according to any one of claims 1 to 5, characterized in that, The cross-section of the combustion pit (120) is semi-elliptical.
8. A combustion system, characterized in that, Includes a cylinder liner and a piston as described in any one of claims 1 to 7, wherein the cylinder liner is provided with a piston bore, and two pistons are provided in the piston bore that are movable along its axial direction, the top surfaces (110) of the two pistons are arranged opposite each other along the axial direction of the pistons, and the inner peripheral wall of the piston bore between the two pistons and the piston bore between the two pistons forms a combustion chamber; The combustion system also includes two injectors, which are disposed between the two pistons along the axial direction of the pistons. The two injectors are configured to correspond one-to-one with the two combustion pits (120) of each piston. The injectors are used to inject fuel into the combustion chamber.
9. The combustion system according to claim 8, characterized in that, The projection of the extension axis of the combustion pit (120) onto a plane perpendicular to the axial direction of the piston body (100) is the first projection. The first projection intersects the outer peripheral wall of the piston body (100) at point A. The angle between the line connecting the two points A and the extension axis of any of the first projections is α, where 15°≤α≤45°.
10. An engine, characterized in that, Includes the combustion system as described in claim 8 or 9.