Piston and combustion system
By setting ridges on the inner wall of the piston combustion pit to guide fuel flow, the problem of fuel collision in the combustion chamber is solved, achieving uniform mixing of fuel and air, improving in-cylinder air utilization and combustion speed, and reducing fuel consumption.
Patent Information
- Application Number
- CN202520317328.X
- 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 collision of fuel injected by the fuel injectors causes localized areas that are too rich or too lean, resulting in low in-cylinder air utilization and high fuel consumption.
The piston body is designed with symmetrically distributed combustion pits, and ridges are set on the inner wall of the pits. The ridges guide the fuel, promote fuel and air mixing, avoid fuel collision, and improve air utilization.
By setting ridges on the inner wall of the combustion pit, the uniform mixing of fuel and air is promoted, the in-cylinder air utilization rate is improved, the combustion speed is increased, and the fuel consumption is reduced.
Smart Images
Figure CN223578058U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to vehicle technical field especially, relates to a piston and combustion system. BACKGROUND
[0002] In order to alleviate energy crisis and environmental pollution, it is imperative to improve thermal efficiency and reduce emissions, for this, prior art proposes an opposed piston engine, specifically, the combustion chamber structure of opposed piston engine includes cylinder liner, and two pistons axially movably arranged in cylinder liner and axially distributed, the center of piston is equipped with center pit, two tapered pits are arranged on the opposite sides of center pit, two fuel injectors correspondingly spray fuel into center pit through two tapered pits, center pit is used as main combustion chamber for fuel diffusion and combustion.
[0003] Two fuel injectors are installed in cylinder liner with 180° apart, spray fuel into combustion chamber through fuel injector, the fuel of two fuel injectors is opposite, collides in combustion chamber and makes local over-concentration area and local over-dilution area appear in combustion chamber, fuel cannot fully diffuse in combustion chamber, part of air in combustion chamber center cannot be fully utilized, leading to low cylinder air utilization rate and high fuel consumption. CONTENT OF UTILITY MODEL
[0004] The utility model discloses a kind of piston and combustion system, can promote fuel and air mixing, accelerate combustion speed.
[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 symmetrically distributed about first preset plane, two the combustion pit is separately arranged on the two sides of the first preset plane, the central axis of the piston body is located on the first preset plane;
[0007] One end of the combustion pit extends to the outer peripheral wall of the piston body, the inner wall of the combustion pit is convexly provided with ridge, the ridge extends along the circumference of the combustion pit and the two ends of the ridge extend to the outer peripheral wall of the piston body, the ridge is located between the lowest point of the combustion pit and the intersection line between the combustion pit and the top surface.
[0008] As an implementable solution of the above piston, the combustion recess is formed by rotating a preset generatrix around a preset axis by a preset angle, the preset angle is greater than 180°, a second preset plane perpendicular to the first preset plane intersects with the outer peripheral wall of the piston body to form two preset axes, and the central axis of the piston body is located in the second preset plane; the two preset axes are arranged in one-to-one correspondence with the two combustion recesses, the combustion recess and the corresponding preset axis are located on the same side of the first preset plane; the preset generatrix has at least one arc ridge, so that the inner wall of the combustion recess forms the convex ridge.
[0009] As an implementable solution of the above piston, along the radial direction of the combustion recess, the minimum distance between the intersection point of the combustion recess and the top surface and the corresponding preset axis is c, and D / 3≤c≤D / 2, where D represents the cylinder diameter.
[0010] As an implementable solution of the above piston, the maximum depth of the combustion recess is f, and 0.2c≤f≤0.3c.
[0011] As an implementable solution of the above piston, for any preset generatrix, the arc ridge farthest from the corresponding preset axis is a first arc ridge;
[0012] Along the radial direction of the combustion recess, the minimum distance between the end of the first arc ridge close to the preset generatrix and the corresponding preset axis is b, and 0.2D<b<0.3D, where D represents the cylinder diameter.
[0013] As an implementable solution of the above piston, 1.1b≤c≤1.3b; and / or,
[0014] For any preset generatrix, the arc ridge closest to the corresponding preset axis is a second arc ridge, and along the axial direction of the combustion recess, the minimum distance between the end of the second arc ridge close to the top surface and the top surface is d, and 0.2b≤d≤0.4b.
[0015] As an implementable solution of the above piston, along the axial direction of the piston body, the minimum distance between the end of the second arc ridge close to the top surface and the top surface is e, and 0.4d≤e≤0.6d.
[0016] In order to achieve the above-mentioned purpose, the utility model also provides a combustion system, including cylinder sleeve and the piston of any scheme, the piston hole is equipped in the cylinder sleeve, two the piston movable along the axial direction of the piston hole is equipped in the piston hole, the top surface of two the piston is opposite to be arranged along the axial direction of the piston, and the combustion chamber is surrounded between two the piston and the inner wall of the piston hole;
[0017] The combustion system further comprises two injectors arranged along the axial direction of the piston between the two pistons, and each of the two injectors is arranged corresponding to one of the two combustion pits of each piston, and the two injectors are used for injecting fuel into the combustion pit.
[0018] As an implementable solution of the combustion system, each of the two injectors is provided with two groups of injection holes, and each group of the injection holes comprises at least two injection holes, wherein the central axis of one group of the injection holes intersects with the inner wall of one of the corresponding combustion pits, and the central axis of the other group of the injection holes intersects with the inner wall of the other of the corresponding combustion pits.
[0019] The central axis of each of the injection holes of the two injectors intersects with the inner wall of one of the corresponding combustion pits.
[0020] As an implementable solution of the combustion system, for the generatrix of any of the combustion pits, the arc ridge closest to the corresponding generatrix is the second arc ridge, and the central axis of the injection hole intersects with the second arc ridge of the corresponding combustion pit.
[0021] The piston and the combustion system have the following beneficial effects:
[0022] The piston and the combustion system have the following beneficial effects: BRIEF DESCRIPTION OF DRAWINGS
[0023] Figure 1 is a fuel injection schematic diagram in the combustion system provided by the embodiment of the utility model;
[0024] Figure 2 is a sectional view of the combustion system provided by the embodiment of the utility model;
[0025] Figure 3 is a flow schematic diagram of the flame in the combustion pit provided by the embodiment of the utility model;
[0026] Figure 4 is a partial sectional view of the piston provided by the embodiment of the utility model;
[0027] Figure 5 is Figure 4 a local enlarged view at B in Fig.
[0028] in the figure:
[0029] 100, piston body; 110, combustion bowl; 120, ridge; 130, top surface;
[0030] 10, preset axis; 20, arc ridge; 30, first preset plane; 40, second preset plane. DETAILED DESCRIPTION
[0031] The utility model will be described in further detail below 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 are not limited to the utility model. In addition, it should be noted that only the parts related to the utility model are shown in the drawings for ease of description, not all the structures.
[0032] In the description of the utility model, unless otherwise explicitly specified and limited, the terms "connected", "connected", "fixed" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship of two elements. For ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.
[0033] In the utility model, unless otherwise explicitly specified and limited, the "upper" or "lower" of the first feature to 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 "upper", "upper" and "upper" of the first feature to the second feature include 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 "below", "below" and "below" of the first feature to the second feature include 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.
[0034] In the description of the embodiment, the terms "upper", "lower", "right", etc. orientation or position relationship is based on the orientation or position relationship shown in the drawings, only for the convenience of description and simplification of operation, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore cannot be understood as a limitation on the utility model. In addition, the terms "first", "second" are only used to distinguish in the description, and have no special meaning.
[0035] The embodiment of the utility model provides a kind of piston, the combustion system comprising the piston and the engine comprising the combustion system to promote fuel and air mixing, accelerate combustion speed.
[0036] Wherein, the combustion system further includes cylinder liner and injector, cylinder liner is equipped with piston hole, two pistons movable along its axial direction are arranged in piston hole, as Figures 1 to 3 As shown, the piston includes piston body 100, the piston body 100 has top surface 130, the top surface 130 of two pistons is oppositely arranged along the axial direction of piston, and the combustion chamber is surrounded by two pistons and the inner circumferential wall of piston hole between two pistons.
[0037] The top surface 130 is provided with two combustion pits 110, and the top surface 130 is provided with two combustion pits 110 symmetrically distributed about the first preset plane 30, the two combustion pits 110 are arranged on the two sides of the first preset plane 30 at intervals, and the central axis of the piston body 100 is located on the first preset plane 30.
[0038] The combustion system further includes two injectors, which are arranged between the two pistons along the axial direction of the piston, and the two injectors are arranged one by one corresponding to the two combustion pits 110 of each piston, and the injector is used for injecting fuel into the corresponding combustion pit 110. Exemplarily, the two injectors are symmetrically arranged about the first preset plane 30, the projection of the injection end of the injector on the plane where the top surface 130 is located is the injection projection, and the injection projection is located in the projection of the corresponding combustion pit 110 on the plane where the top surface 130 is located.
[0039] It should be noted that, Figure 2 In the two black dashed boxes, the position of the two injectors is shown; Figure 3 The dashed arrow in the figure shows the flow direction of the fuel in the combustion pit 110.
[0040] One end of the combustion pit 110 extends to the outer circumferential wall of the piston body 100, the inner wall of the combustion pit 110 is convexly provided with a ridge 120, the ridge 120 extends along the circumferential direction of the combustion pit 110, and the two ends of the ridge 120 extend to the outer circumferential wall of the piston body 100, and the ridge 120 is located between the lowest point of the combustion pit 110 and the intersection line between the combustion pit 110 and the top surface 130.
[0041] Each combustion chamber is provided with a combustion pit 110, and the two combustion pits 110 are symmetrically and spacedly arranged about the first preset plane 30 to avoid the fuel injected into the corresponding combustion pit 110 from colliding, and to avoid the problems of local fuel over-concentration and local fuel over-dilution in the combustion chamber; by arranging a ridge 120 on the inner wall of the combustion pit 110, and arranging the ridge 120 between the lowest point of the combustion pit 110 and the intersection line between the combustion pit 110 and the top surface 130, the fuel injected into the corresponding combustion pit 110 by the injector is guided by the ridge 120 to promote the mixing of fuel and air, improve the air utilization rate in the cylinder, and accelerate the combustion speed.
[0042] In some embodiments, the combustion pit 110 is formed by rotating a preset generatrix about a preset axis 10 by a preset angle, the preset angle is greater than 180°, a second preset plane 40 perpendicular to the first preset plane 30 intersects with the outer peripheral wall of the piston body 100 to form two preset axes 10, and the central axis of the piston body 100 is located in the second preset plane 40; the two preset axes 10 are arranged one-to-one corresponding to the two combustion pits 110, and the combustion pit 110 and the corresponding preset axis 10 are located on the same side of the first preset plane 30; the preset generatrix has at least one arc ridge 20, so that the inner wall of the combustion pit 110 forms the above-mentioned ridge 120. By such arrangement, the structure of the combustion pit 110 can be simplified, the shape of the combustion pit 110 can be made to conform to the development trend of the flame, and the combustion effect can be improved.
[0043] In some embodiments, as shown in Figure 4 along the radial direction of the combustion pit 110, the minimum distance between the intersection point of the combustion pit 110 and the top surface 130 and the corresponding preset axis 10 is c, and D / 3≤c≤D / 2, where D represents the cylinder diameter. If c is greater than D / 2, the two combustion pits 110 will intersect, and the fuel in the two combustion pits 110 will collide. If c is less than D / 3, the development path of the flame in the combustion pit 110 will be too short, and the fuel cannot be fully burned. By limiting D / 3≤c≤D / 2, the two combustion pits 110 can be spacedly arranged on the basis of extending the development path of the flame in the combustion pit 110 as much as possible, and the two combustion pits 110 can be prevented from intersecting. It should be noted that c can be selected from any one of 8D / 24, 9D / 24, 10D / 24, 11D / 24 and 12D / 24.
[0044] In some embodiments, as shown in Figure 4As shown, the maximum depth of the combustion pit 110 is f, where 0.2c ≤ f ≤ 0.3c. If f is greater than 0.3c, the combustion pit 110 will be too deep, which is not conducive to the mixing of air and fuel near the top surface 130 of the piston body 100; if f is less than 0.2c, fuel may be ejected from the combustion pit 110. By limiting the value to 0.2c ≤ f ≤ 0.3c, the fuel can be made to burn within the combustion pit 110, preventing the flame from being ejected from the combustion pit 110; at the same time, the uniformity of air and fuel mixing is also taken into account. It should be noted that f can be selected from any one of 0.2c, 0.21c, 0.22c, 0.23c, 0.24c, 0.25c, 0.26c, 0.27c, 0.28c, 0.29c, and 0.3c. Preferably, f = 0.25c.
[0045] In some embodiments, such as Figure 4 As shown, for any preset generatrix, the arc ridge 20 furthest from the corresponding preset axis 10 is the first arc ridge; along the radial direction of the combustion pit 110, the minimum distance between the end of the first arc ridge closest to the preset generatrix and the corresponding preset axis 10 is b, where 0.2D < b < 0.3D, and D represents the cylinder diameter. If b is less than or equal to 0.2D, it may cause the fuel jet injected into the combustion pit 110 by the injector to cross; if it is greater than or equal to 0.3D, it will reduce the guiding effect of the first ridge 120 on the fuel, which is not conducive to promoting fuel and air mixing. By limiting 0.2D < b < 0.3D, it is possible to avoid the crossover of the fuel jet injected into the combustion pit 110 by the injector while improving the guiding effect of the first ridge 120 on the fuel, thus promoting fuel and air mixing within the combustion pit 110. It should be noted that b can be any one of 0.21D, 0.22D, 0.23D, 0.24D, 0.25D, 0.26D, 0.27D, 0.28D, or 0.29D.
[0046] In some embodiments, such as Figure 4 As shown, 1.1b ≤ c ≤ 1.3b ensures a suitable distance between the bottom of the first arc ridge and the combustion pit 110, and between the piston top surface 130, guaranteeing the guiding effect of the first ridge 120 on the fuel. It should be noted that c can be any one of 1.1b, 1.15b, 1.2b, 1.25b, and 1.3b. Preferably, c = 1.2b.
[0047] In some embodiments, such as Figure 4 As shown, for any combustion pit 110, the arc ridge 20 closest to the corresponding preset axis 10 is the second arc ridge. Along the axial direction of the combustion pit 110, the minimum distance between the end of the second arc ridge near the top surface 130 and the top surface 130 is d, where 0.2b≤d≤0.4b. For example, each combustion pit 110 is provided with two arc ridges 20.
[0048] If d is less than 0.2b, the distance between the second arc ridge and the top surface 130 is too small, and the fuel flows out of the combustion pit 110 under the flow guiding effect of the second arc ridge; if d is greater than 0.4b, the distance between the second arc ridge and the top surface 130 is too large, and the fuel near the top surface 130 is poorly guided. By limiting 0.2b≤d≤0.4b, the flow guiding effect of the second arc ridge on the fuel can be effectively ensured, and the mixing effect between the fuel and the air near the top surface 130 can be improved. It should be noted that d can be selected as any one of 0.2b, 0.25b, 0.3b, 0.35b, and 0.4b. Preferably, d=b / 3.
[0049] As shown in FIG. 1, Figure 4 along the radial direction of the combustion pit 110, the distance between the highest point of the second arc ridge and the corresponding preset axis 10 is a, a<b<c, e<d<f, so that in the direction from the lowest point of the combustion pit 110 to the top surface 130, the combustion pit 110 has a substantially stepped structure.
[0050] In some embodiments, as shown in FIG. 1, Figure 4 and Figure 5 along the axial direction of the piston body 100, the minimum distance between the end of the second arc ridge near the top surface 130 and the top surface 130 is e, 0.4d≤e≤0.6d. In this way, the distance between the second arc ridge and the top surface 130 can be avoided to be too large or too small, and the flow guiding effect of the second arc ridge on the fuel can be effectively ensured, and the mixing effect between the fuel and the air near the top surface 130 can be improved. It should be noted that e can be selected as any one of 0.4d, 0.45d, 0.5d, 0.55d, and 0.6d. Preferably, e=0.5d.
[0051] In some embodiments, as shown in FIG. 1, Figure 1 each injector is provided with two groups of injection holes, each group of injection holes includes at least two injection holes, the center axis of one group of injection holes intersects with the inner wall of one of the combustion pits 110, and the center axis of the other group of injection holes intersects with the inner wall of the other combustion pit 110. In this way, the same injector can simultaneously inject fuel into the corresponding two combustion pits 110.
[0052] In some embodiments, as shown in FIG. 1, Figure 1 the center axis of the multiple injection holes of each injector projects a preset projection on a third preset plane, the multiple preset projections are distributed circumferentially around the preset axis 10 of the combustion pit 110, and the third preset plane is perpendicular to the axial direction of the piston. In this way, the projections of the multiple injection holes of the same injector on the third preset plane can be staggered, and the fuel in the two combustion pits 110 corresponding to the same injector can be avoided to cross. It should be noted that for the same injector, Figure 1The medium gray fuel jet is injected into one corresponding fuel pit, while the black jet represents fuel injected into another corresponding combustion pit 110.
[0053] For example, each set of injection holes has two injection holes, and the preset projections of the two sets of injection holes of the same injector are arranged alternately around the preset axis 10 in the circumferential direction to improve the uniformity of the fuel injected into each combustion pit 110.
[0054] In some embodiments, such as Figure 3 As shown, when the piston is at top dead center, the central axis of the injection hole intersects with the second arc ridge of the corresponding combustion pit 110, so that the second arc ridge achieves a better flow splitting effect.
[0055] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make various obvious changes, readjustments, and substitutions without departing from the protection scope of this utility model. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.
Claims
1. A piston characterized by, The piston body (100) has a top surface (130) provided with two combustion pits (110) symmetrically distributed about a first preset plane (30), the two combustion pits (110) are arranged on both sides of the first preset plane (30) at intervals, and the central axis of the piston body (100) is located on the first preset plane (30); One end of the combustion pit (110) extends to the outer peripheral wall of the piston body (100), the inner wall of the combustion pit (110) is provided with a ridge (120), the ridge (120) extends along the circumference of the combustion pit (110), and both ends of the ridge (120) extend to the outer peripheral wall of the piston body (100), and the ridge (120) is located between the lowest point of the combustion pit (110) and the intersection line of the combustion pit (110) and the top surface (130).
2. The piston of claim 1 wherein, The combustion pit (110) is formed by rotating a preset generatrix about a preset axis (10) by a preset angle, the preset angle is greater than 180°, a second preset plane (40) perpendicular to the first preset plane (30) intersects with the outer peripheral wall of the piston body (100) to form two preset axes (10), and the central axis of the piston body (100) is located in the second preset plane (40); the two preset axes (10) are arranged one by one corresponding to the two combustion pits (110), the combustion pit (110) and the corresponding preset axis (10) are located on the same side of the first preset plane (30); the preset generatrix has at least one arc ridge (20), so that the inner wall of the combustion pit (110) forms the ridge (120).
3. The piston of claim 2 wherein, Along the radial direction of the combustion pit (110), the minimum distance between the intersection point of the combustion pit (110) and the top surface (130) and the corresponding preset axis (10) is c, and D / 3≤c≤D / 2, where D represents the cylinder diameter.
4. The piston of claim 3 wherein, The maximum depth of the combustion pit (110) is f, and 0.2c≤f≤0.3c.
5. The piston of claim 3 wherein, For any preset generatrix, the arc ridge (20) farthest from the corresponding preset axis (10) is the first arc ridge; Along the radial direction of the combustion pit (110), the minimum distance between one end of the first arc ridge close to the preset generatrix and the corresponding preset axis (10) is b, and 0.2D<b<0.3D, where D represents the cylinder diameter.
6. The piston of claim 5 wherein, 1.1b≤c≤1.3b; and / or, For any preset generatrix, the arc ridge (20) closest to the corresponding preset axis (10) is the second arc ridge, and along the axial direction of the combustion pit (110), the minimum distance between one end of the second arc ridge close to the top surface (130) and the top surface (130) is d, and 0.2b≤d≤0.4b.
7. The piston of claim 6 wherein, Along the axial direction of the piston body (100), the minimum distance between one end of the second arc ridge close to the top surface (130) and the top surface (130) is e, and 0.4d≤e≤0.6d.
8. A combustion system characterized by, The cylinder liner is provided with a piston hole, and the piston hole is provided with two pistons movable along the axial direction of the piston hole, and the top surfaces (130) of the two pistons are oppositely arranged along the axial direction of the piston, and a combustion chamber is formed between the two pistons and the inner wall of the piston hole. The combustion system further comprises two injectors arranged between the two pistons along the axial direction of the piston, and the two injectors are arranged one-to-one with the two combustion pits (110) of each piston, and the injectors are used to inject fuel into the combustion pits (110).
9. The combustion system of claim 8, wherein, Each of the injectors is provided with two groups of injection holes, and each group of the injection holes comprises at least two injection holes, wherein the central axis of one group of the injection holes intersects with the inner wall of one of the corresponding combustion pits (110), and the central axis of the other group of the injection holes intersects with the inner wall of the other of the corresponding combustion pits (110). The central axes of the injection holes of each of the injectors are projected on a third preset plane to form a preset projection, and a plurality of the preset projections are circumferentially distributed around a preset axis (10) of the combustion pit (110), and the third preset plane is perpendicular to the axial direction of the piston.
10. The combustion system of claim 9, wherein, For a preset generatrix of any of the combustion pits (110), the arc ridge (20) closest to the corresponding preset axis (10) is a second arc ridge, and when the piston is at the top dead center, the central axis of the injection hole intersects with the second arc ridge of the corresponding combustion pit (110).